Target sources of polyphenols in different food products and their processing by-products

Target sources of polyphenols in different food products and their processing by-products

5

Urszula Tylewicz1, Małgorzata Nowacka2, Beatriz Martín-García3, Artur Wiktor2, Ana Maria Gómez Caravaca3 1Alma Mater Studiorum-Università di Bologna, Cesena (FC), Italy; 2Warsaw University of Life Sciences (WULS-SGGW), Warsaw, Poland; 3University of Granada, Granada, Spain  

1.  Introduction Polyphenols are the most abundant antioxidants in the human diet, and the largest and best studied class of polyphenols are phenolic acids, flavonoids, and tannins. They can exert a protective action on human health thanks to their antioxidant, immunomodulatory actions and anticancer and antibacterial activity. However, in some cases, polyphenols are considered to decrease the nutritional value since tannins for instance can reduce the digestibility of food. Raw fruit and vegetables are a good source of polyphenols. However, due to their seasonal nature they are often industrially processed. Consequently, a significant amount of by-products (peel, pulp, seeds, stones, stem) are produced, which contain valuable bioactive compounds, such as flavonols, flavanols, anthocyanins, and phenolic acids (ferulic acid, vanillic acid, caffeic acid, etc.). Cereals (maize, wheat, rice, and also barley, sorghum, oat, and rye) and their by-products (e.g., bran) are rich in a variety of phytochemical compounds, such as phenolic compounds, carotenoids, vitamin E, γ-oryzanols, dietary fibers, and β-glucans. The phenolic compounds in legumes (chickpeas, beans, lentils, and peas) and their by-products (e.g., seed coat) are mainly represented by tannins, phenolic acids, and flavonoids. Another good source of polyphenols is present in beverages such as coffee, tea, wine, and beer and also in their by-products created during their production (e.g., coffee silverskin, spent coffee grains, grape pomace, brewers’ spent grain). Olive oil and by-products (olive leaves, olive mill waste water (OMWW), and pomace) generated during the olive oil industrial processing are rich in secoiridoids, phenyl alcohols, flavonoids, lignans, and phenolic acids. Cocoa and cocoa-derived products contain mainly flavanols such as epicatechin (EC), catechin, and procyanidins. Finally, herbs and spices (e.g., coriander, thyme, sage, rosmarin, etc.) and waste extracts obtained from the essential oil production are also a good source of polyphenols, mainly phenolic acids. This chapter provides a description of the main natural sources of polyphenols, with particular attention focused on the new trend of food processing by-products and plant waste extracts. Polyphenols: Properties, Recovery, and Applications. https://doi.org/10.1016/B978-0-12-813572-3.00005-1 Copyright © 2018 Elsevier Inc. All rights reserved.

136

Polyphenols: Properties, Recovery, and Applications

1.1  Fruits Fruits are a rich source of polyphenols, which are natural antioxidant compounds with multiple biological effects. They are present in the fruits, seeds, and leaves and their amount depends on the cultivar, condition of cultivation, maturity of the fruit, type and variety and part of the plant (Kondo et al., 2002; Kalinowska et al., 2014; Díazde-Cerio et al., 2017). Polyphenols are the most abundant antioxidants in the human diet and the lack of these compounds leads to health problems. Biochemical studies indicate that free radicals and their reactive products are responsible for the formation of civilization diseases, such as atherosclerosis, Alzheimer disease, Parkinson disease, cancer, faster aging, heart attacks, cardiovascular disease, etc. (Madsen et al., 2000; Heinonen and Meyer, 2002; Sluis et al., 2002; Schirrmacher and Schempp, 2003; Wolfe et al., 2003; Lima et al., 2014; Gowe, 2015; Skrovankova et al., 2015; Helkar et al., 2016; Bondonno et al., 2017). A very important role in preventing the effects of free radicals is played by the polyphenols provided by food. The best sources of polyphenols are raw fruits and vegetables. However, due to their seasonal nature they are often processed in the industries. Consequently, a significant amount of by-products (peel, pulp, seeds, stones, stem) are produced. It is estimated that from 30% to even 75% of processed fruits and vegetable are wasted. Food production generates a large amount of waste that is used in small quantities as animal feed and the rest cause a growing environmental problem (Dhillon et al., 2013; Kammerer et al., 2014; Lima et al., 2014; Gowe, 2015; Helkar et al., 2016). However, by-products contain valuable components such as bioactive compounds, phytochemicals, flavor compounds, carbohydrates, polysaccharides, proteins, vitamins, minerals, etc., which can be considered as cheap sources of natural food additives and nutraceutical ingredients to produce innovative food products, enriched food, or supplements (Gowe, 2015; Varzakas et al., 2016; Kowalska et al., 2017).

1.1.1  Apple and apple pomace The world production of apples is the third largest production, just after the bananas and watermelons. In 2014, the apple harvest was more than 84 million tons (FAOSTAT, 2017). Apple is a fruit containing about 85% of water, 14% of carbohydrates, including fiber and sugars, vitamins, minerals, and polyphenols (Bondonno et al., 2017). Apple contains phenolic compounds in a quantity of 296.3 mg GAE/100g FW, which are present mainly in soluble-free form, while only small amounts are represented by bound phenolics (Sun et al., 2002). The major apple polyphenols are flavonoids such as procyanidins, catechins, ECs, quercetin glycosides, dihydrochalcones (phlorizin), hydroxybenzoic acids (phydroxybenzoic acid, protocatechuic acid, gallic acid, syringic acid, gentisic acid), and hydroxycinnamic acids and their derivatives (p-coumaric acid, caffeic acid, ferulic acid, chlorogenic acid [CGA]) (Kalinowska et al., 2014; Bondonno et al., 2017). The content of bioactive compounds is higher in epidermis and in tissue located just below the skin than in the middle part of the fruits (Kondo et al., 2002; Schirrmacher and Schempp, 2003; Wolfe et al., 2003; Kalinowska et al., 2014; Bondonno et al., 2017).

Target sources of polyphenols in different food products and their processing by-products

137

The antioxidant capacity of apples with peel is nearly 100% higher than that of peeled fruit. Wolfe et al. (2003) reported that the phenolic content in peeled fruits and with skin was 219.8 and 290.2 mg/100 g apples, respectively. It is estimated that 70%–75% of the apple is freshly consumed, while the rest 25%– 30% of the production is converted into products such as concentrated apple juice, fermented apple cider, vinegar, jam, and sweets. After production, by-products (skin, apple pulp, and seed core) in an amount around 11% of total fruit mass are produced, what gives almost 3 million tons of waste annually (Goñi and Hervert-Hernández, 2011; Dhillon et al., 2013; Kammerer et al., 2014; Rana et al., 2015; FAOSTAT, 2017; Bondonno et al., 2017). Often, only 20% of apple waste is used as animal feed and 80% goes to the landfill, causing serious environmental problems (Dhillon et al., 2013; Kammerer et al., 2014). During the processing of apple, most of the peels are removed; thereby main products lose valuable sources of polyphenol compounds. After apple juice production, more antioxidant compounds remain in the pomace than in the juice (Sluis et al., 2002) so this by-product represents a rich source of polyphenols, carbohydrate, fiber, pectin, minerals, aroma compounds, and organic acids (Gowe, 2015; Rana et al., 2015; Varzakas et al., 2016; Kowalska et al., 2017). Apple by-products contain polysaccharides (pectin, cellulose, hemicellulose, lignin, and gums) and phenolic compounds such as CGA and phlorizin, which are concentrated in seeds and peel (Varzakas et al., 2016). For example, phlorizin could be used as a potential therapeutic compound in obesity and as an antihyperglycemic and antihyperlipidemic agent in diabetes. Moreover, the apple pomace includes flavanols such as EC and catechin and anthocyanins such as cyanidin-3-galactosides. Furthermore, apple seeds may be used to produce oil; however, they can contain toxic substances (amygdalin), which have to be separated from the final product (Najafian et al., 2012; Kammerer et al., 2014; Kowalska et al., 2017).

1.1.2  Berries and their processing by-products Berry fruits, especially black chokeberry, black elderberry, black currant, blueberry, blackberry, cranberry, strawberry, raspberry, black grapes, and others, are good sources of a wide variety of phenolics (Skrovankova et al., 2015). Berries can be consumed in fresh form, but due to their seasonal nature the products such as juices, jams, jellies, purees, and ice creams are produced. Some berry fruits, such as black chokeberry or cranberries, require special treatment to obtain an acceptable taste (Nowacka et al., 2017). Berries are used in nutraceuticals and novel functional food production and due to the presence of anthocyanins they are used as raw materials for the production of food dyes (Skrovankova et al., 2015; Kowalska et al., 2017). Berries contain phytochemicals, such as phenolic acids (hydroxybenzoic and hydroxycinnamic acid), flavonoids such as flavonols (quercetin, kaempferol, myricetin), flavanols (catechins and EC), anthocyanins (cyanidin glucosides and pelargonidin glucosides), and tannins (proanthocyanidins, ellagitannins). The anthocyanins are responsible for the fruits color and they are mainly found in the fruits’ skin (Grace et al., 2014; Skrovankova et al., 2015). Fig. 5.1 presents the total polyphenol content in some selected berries (Pérez-Jiménez et al., 2010; Grace et al., 2014).

138

Polyphenols: Properties, Recovery, and Applications 

7RWDOSRO\SKHQROVFRQWHQWPJJ

         

U\

HU

KR

F

FN

D %O

E NH

OG

H

FN

D %O

U\

HU

E HU

Z

/R

EO



VK

EX

U\

HU

E XH

QW

%O

D

FN

U\

HU

UD

U FX

E DQ

&

U

LJ

+

EO



VK

X KE

U\

U\

HU

HU

E XH

%O

D

E FN

UU\

6

Z WUD

E VS

UD

HG

5

U\

HU

EH

D

%O

H

DS

JU

 FN

Figure 5.1  The total polyphenol content in different type of berries (self-developed).

Chokeberry fruit is characterized by the highest quantity of polyphenols. It is used mainly to produce juice and only 10% is added to fruit teas, diet supplements, and cosmetic products. Black chokeberry fruit is primarily a rich source of proanthocyanidins and anthocyanins (cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, cyanidin-3-O-arabinoside, cyanidin-3-O-xyloside). Moreover, it contains flavonols (quercetin glycosides), flavanols (EC), and hydroxycinnamic acids (CGA, neochlorogenic acid). During the manufacturing of chokeberry juice, a significant quantity of pomace is produced, which contains a lot of valuable components that are not transferred into the juice. Indeed, amygdalin within the range of 7–185 mg/100 g has been found in the seed fraction of chokeberry pomace (Sójka et al., 2013). The second fruit with high polyphenol content is black elderberry, which contains large amounts of anthocyanins (813 ± 156 mg/100g), flavonols, and cinnamic acid derivatives. However, not only berry fruits are rich in polyphenols but also the elderberry branches contain high concentrations of cinnamic acids and flavonols. The total phenol content is 1191 and 708 mg/100g fresh weight for berries and branches, respectively. This by-product represents a good source of a low-cost alternative source of natural antioxidants (Silva et al., 2017). Another source of polyphenols is blueberry fruits, containing proanthocyanidins, anthocyanins, and flavonols. However, their total phenolic compound content depends on fruit types, e.g., lowbush blueberries contain more phenolic compounds than highbush blueberries (Pérez-Jiménez et al., 2010; Skrovankova et al., 2015). Similarly, black currants and cranberries have comparable amounts of phenolic compounds to blueberries. However, in cranberries, flavonoids such as quercetin and ellagic acid are

Target sources of polyphenols in different food products and their processing by-products

139

found in abundance. For example, ellagic acid represents 51% of the total phenolic compounds in cranberry fruits (Grace et al., 2014; Skrovankova et al., 2015). Blackberries, raspberries, and strawberries contain a similar amount of total phenolic compounds (215–260 mg/100g) (Pérez-Jiménez et al., 2010) like hydrolyzable tannins including ellagitannins, which is what makes them a good dietary source. However, the strawberries contain a much lower content of anthocyanin in comparison to blueberries, blackberries, and raspberries (Skrovankova et al., 2015).

1.1.3   Tropical fruits Oranges are another group of fruits with a huge world production, which is more than 72 million tons (FAOSTAT, 2017). Oranges are characterized by high content in vitamin C, A, and B minerals such as calcium, phosphorus, potassium, dietary fiber, phytochemicals, pectin, and low fat content (Rezzadori et al., 2012; Helkar et al., 2016). Among the phytochemicals present in orange flavonoids, amino acids, triterpenes, phenolic acids (ferulic acid, vanillic acid, caffeic acid), and carotenoids can be found (Rafiq et al., 2016; Banerjee et al., 2017). The total phenol content in orange fruits ranged from 31.0 to 217 mg GAE/100 g FW (Sun et al., 2002; Faller and Fialho, 2009). The citrus flavonoids include a class of glycosides (hesperidin and naringin) and a class of O-methylated aglycones of flavones (nobiletin and tangeritin) (Rafiq et al., 2016). Orange fruits are mainly consumed in raw and peeled forms or as a juice. Juice manufacturing leads to the production of different residue as peel, pulp, seeds, orange leaves, and whole orange fruits that do not reach the quality requirements (Rezzadori et al., 2012). Phenolics are present both in edible and nonedible parts of plants, therefore by-products might be used to produce food supplements, which provide dietary fiber and polyphenols (Rafiq et al., 2016). The most valuable citrus by-product is the essential oil obtained from the orange peel, which is widely used as an ingredient in foods and beverages, and also in cosmetic factories (Rezzadori et al., 2012; Rafiq et al., 2016). Another fruit of high world production is mango, whose harvest was more than 45 million tons in 2014 (FAOSTAT, 2017). Mango by-products, especially seeds and peels, are considered to be a good source of phenolic compounds (ferulic acid, vanillic acid, caffeic acid, gallic acid, protocatechuic acid, syringic acid, kaempferol, quercetin), carotenoids, vitamin C, and dietary fiber (Dorta et al., 2012; Gowe, 2015; Jahurul et al., 2015). The total phenolics in mango peel and seed are 5.9 and 37.3 mg GAE/g FW, respectively (Gowe, 2015). Mango peels are used to produce flour, which can be added to noodles, biscuits, sponge cakes, bread, and other bakery products. Besides, mango bio-wastes in dried form are used as a substrate for the production of pectinase from microorganisms due to its high content of protein, pectin and other carbohydrates, and low fat content (Dorta et al., 2012; Taboada and Siacor, 2013; Jahurul et al., 2015; Banerjee et al., 2017; Kowalska et al., 2017). Pomegranate contains phenolic compounds such as hydrolyzable tannins (ellagitannins), flavonoids (anthocyanins), and condensed tannins (proanthocyanidins). Some of the main polyphenol constituents found in pomegranate include phenolic

140

Polyphenols: Properties, Recovery, and Applications

acids, gallic acid, ellagic acid, and punicalagin A and B composition of this fruit is specific and has a beneficial effect on the human body and high antioxidant properties (Qu et al., 2012; Varzakas et al., 2016). After production, pomegranate juice and its concentrate, peels, and seeds are left as by-products, which contain high levels of polyphenols and this material is a potential source of antioxidants. Pomegranate biowastes are used as an ingredient, preservative, or component preventing instability in food products such as meat products, bread, edible oils, probiotic ice creams, jams, jellies, juices, and wines (Qu et al., 2012; Helkar et al., 2016). Guava (Psidium guajava L.) belongs to the Myrtaceae family and is a highly consumed fruit in tropical countries. Guava fruits are rich in anthocyanins, flavonoids, proanthocyanidins, nonflavonoids such as phenolic acid derivatives, stilbenes, acetophenones, and benzophenones (Flores et al., 2015; Rojas-Garbanzo et al., 2017). Particular attention should be paid also to the guava leaves, whose extracts have been shown to possess antispasmodic and antimicrobial properties, antioxidant, anticough, and antidiabetic activities among others due to the presence of phenolic compounds (Liu et al., 2015). Díaz-de-Ceiro et al. (2017) reported the results of phenolic compound quantification in two different varieties of P. guajava L. leaves, showing that the higher concentration of total phenolic compounds has been found in the pyrifera variety than in the pomifera one (P < .05), 49.7 and 46.2 mg/g leaf DM, respectively. Moreover, the pyrifera variety also showed a higher amount of flavonols and flavan3-ols and the highest amounts of ellagic acid derivatives.

1.2  Vegetables Vegetables are edible parts of cultivated or wild-growing plants. In general, the following parts of vegetables are consumed as raw or cooked: stems, stalks, roots, tubers, bulbs, leaves, fruits, seeds, flowers, or leaves. In some regions, mushrooms and seaweeds are considered as vegetables even if botanically they should not be regarded as vegetables (Vainio and Bianchini, 2003). Global production of vegetables is estimated to be more than 1 billion tons annually (FAO, 2013; Diop and Jaffee, 2004), and it increased between 2006 and 2014 by 27% as measured together with harvested fruits (FAO, 2015). Table 5.1 presents the total polyphenol content of selected vegetables, whose production was higher than 50 million tons in 2014. According to these data, potatoes are characterized as the world’s largest production, estimated at 0.382 billion tones in 2014 (FAO, 2015). Potatoes could be considered as the second biggest gross source of polyphenols among all vegetables, overtaken only by sweat potatoes and followed by onions. Thus it can be stated that the global gross supply of polyphenols that could be obtained from vegetables produced in amounts bigger than 50 million tons ranges between 0.5 and 1.9 million tons (Fig. 5.2). However, it needs to be emphasized that this estimation does not take into account the production of each particular variety of vegetable. Phenolic compounds in vegetable tissue are present in bound and free form. A vast majority of different vegetables can be characterized by a higher content of free form of polyphenols, which exceeds 50% of total phenolic compounds. Cabbages, carrots, and potatoes contain more than 30% of bound polyphenols, which increases their

Target sources of polyphenols in different food products and their processing by-products

141

Table 5.1 

Production and total polyphenol content of selected vegetables (self-developed)

Vegetable

Production in 2014 (FAO, 2015) [million tons]

Total polyphenol content

Source

Potatoes

382

18.2–25.9 mg GAE/100 g FW

268

26.85–64.32 mg GAE/100 g FW (white and yellow flesh) 69.54–86.72 mg GAE/100 g FW (purple flesh) 1.2–120 mg/100 g DW

Zarzecka et al. (2013) Murniece et al. (2014)

107

192.7–1159.08 mg GAE/100 g DW

171

9.8–23.0 mg GAE/100 g FW

Cassava and cassava leaves Sweet potatoes Tomatoes

16.0–17.8 mg GAE/100 g FW Onions

93

606–2232 mg/100 g DW (yellow onions) 571–1858 mg/100 g DW (red onions) 150 mg/100 g FW

Brassicas

71

393.1 mg/100 g FW (red cabbage) 531 mg/100 g DW (white cabbage) 1285 mg/100 g DW (broccoli)

Montagnac et al. (2009) Rumbaoa et al. (2009) Hernandez et al. (2007) George et al. (2011) Cheng et al. (2013) Cieślik et al. (2006) Chun et al. (2004) Heimler et al. (2006)

bioactive, nutritional value (Shahidi and Ambigaipalan, 2015). Nevertheless, because of the huge production, vegetables, their by-products, and wastes should be considered as a good source of polyphenols both for extraction and nutritional purposes. Potatoes are the fifth largest harvested crop in the world and because of that their importance to human civilization is of paramount importance (FAO, 2015). They are widely processed by the industry that uses them to produce fries, chips, mashed potatoes, or other types of meals. Because of high intake of potatoes, they are an important source of many nutrients; for instance, ascorbic acid, potassium, or fiber (Akyol et al., 2016). Besides the abovementioned ingredients, this vegetable is a good source of polyphenols. Polyphenols are present in potato flesh or skin. It should be emphasized that the skin contains more than 50% of all polyphenols present in a tuber (Friedman, 1997; Ezekiel et al., 2013), which makes this by-product very interesting concerning its further processing and application. Polyphenol content of potatoes depends on many factors. First, it is strongly related to the variety of the plant. It was reported that

142

Polyphenols: Properties, Recovery, and Applications

*OREDOJURVVVXSSO\RISRO\SKHQROV0W





0D[LPDOHVWLPDWHGJOREDO JURVVVXSSO\RISRO\SKHQROV 0LQLPDOHVWLPDWHGJOREDO JURVVVXSSO\RISRO\SKHQROV











3RWDWRHV &DVVDYD 6ZHDW 7RPDWRHV 2QLRQV &DEEDJHV 7RWDO SRWDWRHV DQG EUDVVLFDV

Figure 5.2  Estimated global gross supply of polyphenols of vegetables, whose production in higher than 50 million tons (own elaboration based on data presented in Table 5.1).

varieties with purple flesh contain more phenolic compounds than tubers with white or yellow flesh (Murniece et al., 2014). Furthermore, polyphenol content in potatoes depends on weather conditions or storage (Hamouz et al., 2006). It depends also on the agrotechnical treatment of the potato plantation. For instance, a significant correlation between the type of insecticides used for fighting the Colorado potato beetle was found by Zarzecka et al. (2013). According to literature, most of the polyphenols present in potato can be included into phenolic acids. Among this group of polyphenols, CGAs are the most abundant and its quantity equals to 170–190 mg/kg FW (Manach et al., 2004; Dao and Friedman, 1992). The highest quantity of CGA was found in the potato peel (Friedman, 1997). Most of the phenolic acids are lost during the processing of potatoes (Perla et al., 2012). Apart from CGA, potatoes are reported to contain a noticeable quantity of caffeic acids (25–72 mg/kg) and smaller amounts of gallic acid, ferulic acid, p-coumaric acid, vanillic acid, sinapic acid, salicylic acid, and syringic acid (Akyol et al., 2016). Flavonoids are the second most important group of polyphenols present in potatoes. According to Lewis et al. (1998), this plant contains 200–300 μg/g FW. As in the case of phenolic acids, potato peel contains more flavonoids than its flesh. It is worth emphasizing anthocyanins’ impact on this value in the highest extent, especially in the case of colored flesh varieties, which contain for instance peonidin or pelargonidin. Catechin also belongs to one of the predominant flavonoids in potatoes and it is followed by EC, kaempferol, naringenin, and rutin (Lewis et al., 1998; Akyol et al., 2016).

Target sources of polyphenols in different food products and their processing by-products

143

Because of both the high production quantity of potatoes and distribution of phenolic compounds in tubers, much attention is paid to the potato peel as a source of natural antioxidants. In literature, there are a number of publications concerning extraction and further application of the potato peel extract. Kanatt et al. (2005) investigated the effectiveness of the potato peel extract for retarding lipid oxidation of radiated lamb meat. The potato peel extract that they have obtained contained 70.82 mg of catechin equivalent/100g FW of polyphenols with CGA as the most abundant polyphenol (27.56 mg/100g FW). The authors have found that the antioxidant activity of potato peel extract was similar to butylated hydroxytoluene (BHT). In this experiment, it was added to meat before radiation in a concentration of 0.04% (total mass) and it delayed lipid peroxidation of irradiated lamb meat. Similar results were obtained by Farvin et al. (2012), who checked the antioxidant effect of potato peel extract using minced horse mackerel meat. Potato peel extract was also examined as antioxidant agents preventing oil oxidation (Rehman et al., 2004; Franco et al., 2016). Cassava is one of the most important crops for Africans since it is tolerant of drought and its roots can be stored for a long time without significant loss of nutritional quality. The presence of polyphenols in cassava is mainly considered to play an antinutritional role since they can inhibit nonheme-Fe absorption, reduce digestibility of protein or starch (Montagnac et al., 2009). The number of publications concerning the polyphenol content of cassava is limited. Total polyphenol content of cassava ranges from 1.2 to 120 mg GAE/100g DW (Montagnac et al., 2009), which considering dry matter content to 40% gives 0.48–48 mg GAE/100g FW and stays in accordance with other publications (de Lima et al., 2017). Different flavonoids were identified in cassava roots: catechins (catechin, catechin gallate, gallocatechin) and flavone 3-glycosides (rutin, kaempferol 3-rutinoside). In turn, in cassava leaves mainly the presence of anthocyanidins (cyanidin, delphinidin) was stated (Montagnac et al., 2009; Latif and Müller, 2015). Because of the high production quantity of cassava and due to the fact that leaves are considered as a by-product, they exhibit a very high potential regarding polyphenolic extraction. However, the presence of other compounds that exhibit toxic activity (Latif and Müller, 2015) needs to be considered before its final utilization. More than 95% of the world’s supply of sweet potatoes is produced in developing countries (Rumbaoa et al., 2009). Sweet potato is not a demanding plant since it adapts very easily to different agroecological conditions (Musilová et al., 2017). Considering phenolic compounds, a lot of attention is attracted to purple flesh varieties of sweet potatoes since they can be used to produce natural colorants with antioxidant potential (Lebot et al., 2016). Major phenolic compounds of sweet potatoes are hydroxycinnamic acid, CGAs, in which white-fleshed tubers are richer than purple-fleshed varieties (Padda and Picha, 2008), isochlorogenic, neochlorogenic, and 4-O-caffeoylquinic acids (Shahidi and Ambigaipalan, 2015). Musilová et al. (2017) found that the raw flesh of the O’Henry variety contained 1.726 mg of chlorogenic acid equivalent (CAE)/kg DW, whereas the Beauregard variety contained 12.41 mg CEA/ kg DW of caffeic acid. In the same study, it was reported that the peel of raw sweet potatoes contains from 4263 to 13998 mg GAE/kg DW of total phenolics and from 272.3 to 320.7 mg CAE/kg DW of caffeic acid. Thus it can be stated that distribution of phenolic acids in sweet potato is similar to the distribution found in potatoes.

144

Polyphenols: Properties, Recovery, and Applications

Anthocyanins are characteristic polyphenols for purple-fleshed tubers. The quantity of these compounds ranges from 32 to 1390 mg/100 g DW and it depends on the variety of plant (Wang et al., 2016). Currently, 39 anthocyanins have been found and identified in sweet potatoes. These anthocyanins are dominated by acylated glucosides of cyanidin and peonidin (Gras et al., 2017). Leaves of sweet potatoes are considered as wastes and they are discarded in amounts higher than 95% (Xi et al., 2015), but their total polyphenol content ranges from 6.3 to 27.33 mg CAE/g DW (Gras et al., 2017). They exhibit very high potential regarding extraction of polyphenols since they can be harvested several times per year (Xi et al., 2015). According to literature, the major phenolic acids identified in sweet potato leaves were hydroxycinnamic acid, sinapic acid, and hydroxybenzoic acid (Gras et al., 2017). Extracts of sweat potato leaves exhibit high antioxidant activity, but they need to be purified before final application (Shahidi and Chandrasekara, 2015; Xi et al., 2015). Tomatoes are appreciated not only because of their high carotenoid content but also because of their polyphenol content (Table 5.1). Green tomatoes contain quite a high amount of CGA; however, its concentration decreases during ripening (Shahidi and Ambigaipalan, 2015). However, according to Anton et al. (2017) and Helyes and Lugasi (2006), total polyphenol content increases during maturation and the increment depends on the variety of the plant. Polyphenols that tomatoes are most abundant in are naringenin chalcone, rutin, quercetin, CGA, and naringenin. The concentration of these compounds varies from 0.1 to 18.2 mg/100g FW. In turn, the main anthocyanidins identified in tomatoes are delphinidin, malvidin, and petunidin (Martí et al., 2016). Some researchers report that cherry tomatoes contain quercetin, kaempferol, and myricetin (Manach et al., 2004). Accumulation of many polyphenols occurs mainly in the peel. Because of that fact, cherry tomatoes contain higher quantities of polyphenols that regular tomatoes, in fact they exhibit higher skin-to-flesh ratio (Martí et al., 2016). Since during tomato processing peel and seeds are generally removed, they are assumed to be an interesting source of polyphenols. Extracts of freeze-dried tomato peel exhibited the yield of total polyphenols of 38.67 mg tannic acid equivalent/100 g peel. What is worth emphasizing is that the utilization of convective drying gave similar results, hence it can be stated that the method of drying had a negligible effect on polyphenol retention in tomato peel (Sarkar and Kaul, 2014). Literature shows that extracts made of tomato peel exhibit higher antioxidant activity than BHT, which makes them interesting as they can add value to food stuffs (Elbadrawy and Sello, 2016). Polyphenols can be accumulated also in the stem or leaves of tomatoes. However, the literature in this field is very limited (Martí et al., 2016). Consumption of onions has a beneficial impact on human health. Quercetin is the main polyphenol compound that can be found in onions. Besides quercetin, these plants contain kaempferol, myricetin, and catechin; together with quercetin, these flavonoids shape the antioxidant activity of onions (Cheng et al., 2013). Some phenolic acids are present in onions as a part of the cell wall (Shahidi and Ambigaipalan, 2015). It is worth mentioning that the highest concentration of flavonoids, especially quercetin, was stated in the outer layers of the bulb, including peel (Lee et al., 2014). Moreover, it is estimated that 500,000 tons of onion waste is disposed of every year in the European Union. The abovementioned information indicates that wastes and

Target sources of polyphenols in different food products and their processing by-products

145

by-products of onion exhibit an extremely high potential considering polyphenolic extraction. Onion peel extract can be further used in a number of food/medical applications since they can enhance the immune system (Lee et al., 2014). From onion and onion wastes, the following by-products can be obtained: juice (a liquid fraction), paste (a solid–liquid mixture), and bagasse (a solid fraction). These by-products can be further utilized as natural antioxidant ingredients for food applications. Among them, bagasse is characterized by the highest total quercetin quantity, which ranges from 600.72 to 2230.89 mg/100g DW depending on the onion variety (Roldan et al., 2008). Flavonoids are the most abundant group of polyphenols present in Brassicas. Only in the case of broccoli, phenolic acids surpass their quantity of flavonoids. According to literature, kaempferol derivatives and hydroxycinnamic derivatives were identified in broccoli, Brussels sprout, and Italian kale (Heimler et al., 2006). Some Brassicas, for instance red cabbage, contain also bigger quantities of anthocyanins among which cyanidin derivatives are the most frequent form (Shahidi and Ambigaipalan, 2015). Polyphenols can be extracted from Brussels sprouts, stalks, and red cabbage wastes. What is interesting is a proper selection of processing conditions allows extraction of even these polyphenols from Brassicas by-products that are considered nonextractable. For instance, nonextractable polyphenol content of Brussels stalks were higher than the total polyphenol content of the so-called extractable fraction (Gonzales et al., 2015).

1.3  Cereals and legumes 1.3.1  Phenolic compounds in cereals Cereals are fundamental components in a varied diet, which are consumed in large quantities. The most important cereals based on annual production are maize, wheat, and rice, and also barley, sorghum, oat, and rye (Kaur et al., 2014; Gani et al., 2012). Whole grains are rich in a variety of phytochemical compounds, such as phenolic compounds, carotenoids, vitamin E, γ-oryzanols, dietary fibers, and β-glucans (Okarter and Liu, 2010). All of these compounds have demonstrated beneficial effects in human health. Specifically, phenolic compounds in cereals present antioxidant activities (Žilić et al., 2012; Liu et al., 2016; Mazzoncini et al., 2015; Bian et al., 2015; Mateo et al., 2010; Zhao and Moghadasian, 2008; Guo et al., 2015; Inglett and Chen, 2011; Alrahmany and Tsopmo, 2012; Jian Guo et al., 2009; Bijalwan et al., 2016) and help in the prevention of different chronic diseases (Pandey and Rizvi, 2009; Hossain and Alam, 2015; Gani et al., 2012). However, phenolic compounds are not equally distributed in the cereal grains. Total phenolic concentration is higher in their outer layers (husk, pericarp, testa, and aleurone that constitute the bran) than in the endosperm layer, which is usually used to obtain refined flours (Kaur et al., 2014; Verardo et al., 2008b). Bran is the major by-product generated by debranning grains before milling to obtain refined flour (Jäger et al., 2009; Zanoletti et al., 2017). Moreover, phenolic compounds of cereals are generally in higher quantities in their free form. However, phenolic acids are usually found in higher concentrations in their bound form (Vaher et al., 2010; Verardo et al., 2011a; Irakli et al., 2012).

146

Polyphenols: Properties, Recovery, and Applications

Wheat grains mainly contain phenolic acids such as p-hydroxybenzoic acid, vanillic acid, ferulic acid, syringic acid, or p-coumaric acid. Ferulic acid is the main phenolic acid present in this cereal grain, with concentrations around 1000 μg/g DW (Hernández et al., 2011). These compounds are present in the free and in the bound fractions, but their concentration is higher in the bound fraction (Nicoletti et al., 2013). Flavonoids are also present in wheat represented by apigenin and luteolin, and like phenolic acids, they mainly occur in the bound form, attached to the cell wall of wheat. Lignans such as 7-hydroxymatairesinol, secoisolariciresinol, lariciresinol, pinoresinol, medioresinol, and syringaresinol are also present in wheat and their concentration vary depending on the variety (3.4–22.7 μg/g) (Smeds et al., 2009). Colored grains also contain anthocyanins, whose compounds are principally located in the aleurone layer or pericarp and gives wheat a blue or purple color. The main anthocyanins in purple wheat are peonidin and cyanidin glycosides, whereas the main anthocyanins detected in the blue variety are delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside. The differences in color can be attributed to the different compounds present in each variety and also due to the higher concentration of anthocyanins present in purple wheat (Giordano et al., 2017). Barley phenolic compounds differ considerably between the free and bound fraction. On the one hand, the free phenolic fraction of barley contains a high concentration of flavan-3-ols, especially proanthocyanidin trimers, such as C-GC-C, prodelphinidin B3, and procyanidin B2. On the other hand, the main phenolic family in the bound phenolic fraction is phenolic acids and the major compound, as occurs in wheat, is ferulic acid (250–550 μg/g flour DW) (Verardo et al., 2008a). The bran fraction contains higher concentrations of these compounds than the inner part of the grain; in fact, different experiments have been carried out using air classification to obtain enriched flour fractions (coarse fraction) in phenolic compounds. The coarse fractions have presented concentrations of free and bound phenolic compounds that were 1.2–1.3 times higher than whole meal (Gómez-Caravaca et al., 2014, 2015). Anthocyanins also appear in colored varieties such as purple, blue, or black barley. They exist mostly as glycoside derivatives, including cyanidin-3-glucoside, peonidin-3-glucoside, and delphinidin-3-glucoside (Abdel-Aal et al., 2006, 2012; Lee et al., 2013). Corn phenolic fraction is mainly constituted by phenolic acids, and the highest concentration of them appears linked to the cell walls in the bound fraction. The concentration of phenolic compounds in the free fraction ranged between 1 and 5 mg/100g DW, whereas in the bound fraction it ranged between 150 and 300 mg/100g DW (GonzálezMuñoz et al., 2013). Among the phenolic acids contained in corn can be found gallic acid, 4-hydroxybenzoic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, transferulic acid, sinapic acid, and transcinnamic acid. Ferulic and p-coumaric acid are the major constituents of the phenolic fraction (Montilla et al., 2011; Chiremba et al., 2012a). Regarding phenolic acids, corn bran contains around 20-fold more concentration of these compounds than corn flour (Chiremba et al., 2012a). Furthermore, some flavonoids have also been reported in corn. Recently, derivatives of quercetin, kaempferol, and isorhamnetin have been described in purple corn (Paucar-Menacho et al., 2017). Anthocyanins such as pelargonidin, cyanidin, and peonidin derivatives have been found in colored corn cultivars (Montilla et al., 2011; Paucar-Menacho et al., 2017).

Target sources of polyphenols in different food products and their processing by-products

147

Oat grains present three important families of phenolic compounds: phenolic acids, flavonoids, and avenanthramides. Avenanthramides are phenolic alkaloids and they are mainly present in oat. The most common and abundant avenanthramides found in oat are avenanthramides 2c, 2p, and 2f, but also bisavananthramide B1 is present in the free phenolic fraction of oat (Hitayezu et al., 2015; Verardo et al., 2011b). Phenolic acids have been found in the free and bound phenolic fractions of oat, and they are represented by gallic, p-hydroxybenzoic, benzoic, vanillic, caffeic, ferulic, p-coumaric, and sinapic acid. The concentration of phenolic acids is much higher in the bound fraction and ferulic acid is the major phenolic acid in both oat fractions. Finally, flavonoids are also present in oat: catechin, rutin, quercetin, and tricin have been described in the free fraction, whereas kaempferol has been determined in the bound fraction (Hitayezu et al., 2015; Verardo et al., 2011b; Bei et al., 2017; Irakli et al., 2012). Phenolic compounds of rice belong to two different families, phenolic acids and flavonoids. Among phenolic acids, the major compound is ferulic acid that accounts for more than 70% of total phenolic acids (Goufo et al., 2015; Liu et al., 2017). Other phenolic acids such as gallic, protocatechuic, p-hydroxybenzoic, vanillic, syringic, chlorogenic, caffeic, p-coumaric, and sinapic acids have also been found in the free and bound phenolic fractions. Nevertheless, phenolic acid dehydrodimers and trimers only appear in the bound fraction, i.e., diferulic, disinapic and dehydrotriferulic acid (Qiu et al., 2010; Verardo et al., 2016). Different glycosylated forms of flavonoids have also been described in the free phenolic fraction of rice, such as apigenin-6,8-di-Cglycoside, 6-C-arabinosyl-8-C-glucosyl apigenin, C-dipentosyl apigenin, and tricin (Verardo et al., 2016). Furthermore, several anthocyanins have been determined in colored rice grains. Cyanidin-3-glucoside is the major anthocyanin present in colored rice; although, red and black rice also shows peonidin-3-glucoside, and evidences of the presence of cyanidin-3-glucoside have been found for black rice (Kapcum et al., 2016; Hang et al., 2010). However, the concentration of anthocyanins is much higher in black rice than in the red one (Kapcum et al., 2016; Laokuldilok et al., 2011). Pelargonidin-3-glucoside has been found in Japanese black–purple rice seed (Pereiracaro et al., 2013) and traces of delphinidin and petunidin have also been described in literature (Kim et al., 2008; Yao et al., 2010). It is also important to highlight that rice bran contains around 10-fold more concentration of phenolic compounds than whole rice grain (Goufo et al., 2015). Regarding millets, it is important to highlight that there are different kinds that differ in the profile and content in phenolic compounds. The main phenolic families that are contained in millet are phenolic acids and flavonoids. The major phenolic acid depends on the kind of millet, i.e., in finger millet they are salicylic, protocatechuic, p-hydroxybenzoic, ferulic, and cinnamic acids (Udeh et al., 2017), whereas CGA is one of the highest concentrated phenolic acids in proso millet (Zhang et al., 2014). Indeed, as it has been determined by some authors, total bound phenolic compounds are around twofold more than total free phenolic compounds in proso and kodo millets (Zhang et al., 2014; Sharma et al., 2017). On the contrary, flavonoids are mainly in their free form. Different flavones have been described in finger millet, namely orientin, isoorientin, vitexin, isovitexin, saponarin, violanthin, lucenin-1, and tricin (Dykes and Rooney, 2006). However, other flavonoids such as quercetin, catechin,

148

Polyphenols: Properties, Recovery, and Applications

gallocatechin, EC, epigallocatechin (EGC), and proanthocyanidins have also been found in millets (Shahidi and Ambigaipalan, 2015). Rye grain differs from the rest of the cereals because it contains the highest concentration of alkylresorcinols. Total concentration of alkylresorcinols in rye ranges between 800 and 1300 μg/g rye. Alkylresorcinols from C15:0 to C25:0 and also alkenylresorcinols with one unsaturated bond have been determined in rye, being C19:0, the highest concentrated compound found in this sample (around 24%) (Landberg et al., 2009; Hietaniemi et al., 2015). These compounds are principally located in the bran of the rye grains with concentrations that reach more than 1400 μg/g rye (Hietaniemi et al., 2015). Indeed, phenolic acids, flavonoids, and lignans have also been described in rye grains. Phenolic acids are present in the free and bound phenolic fractions of rye; however, the free phenolic fraction shows very low concentrations of these compounds (10–35 μg/g rye) (Belobrajdic and Bird, 2013; Nyström et al., 2008) compared to the bound phenolic fraction (300–1000 μg/g rye) (Hietaniemi et al., 2015; Irakli et al., 2012). The major phenolic acid contained in rye is ferulic acid, followed by sinapic acid, 2,4-dihydroxybenzoic acid, and p-coumaric acid. Regarding flavonoids, flavones such as vitexin and luteolin have been described in rye (Hietaniemi et al., 2015) and also proanthocyanidins have demonstrated to be present in rye bran (212 mg/100g) (Hosseinian and Mazza, 2009). Indeed, lignans such as secoisolariciresinol, matairesinol, isolariciresinol, OH-matairesinol, lariciresinol, pinoresinol, and syringaresinol have been found in rye (Hosseinian and Mazza, 2009). Sorghum is a matrix that shows a wide variety of phenolic compounds. Recently, nearly 70 phenolic compounds have been identified in the hydromethanolic extracts of brown, red, and white sorghum whole grains. Most of them are phenolic acids such as ferulic acid, diferulic acid, p-coumaric acid, caffeic acid, and their derivatives (Stanisavljević et al., 2016; Chiremba et al., 2012b). The other main family present in sorghum is flavonoids: luteolin, apigenin, catechin, kaempferol taxifolin, quercetin, and their derivatives. Condensed tannins (8.69 mg catechin equivalent/g) and anthocyanins (11.49 mg/100g) have also been determined in sorghum (Moraesa et al., 2015). As it has been observed in most cereals, the outer layers of the grain are richer in phenolic compounds than the inner part (Moraesa et al., 2015).

1.3.2  Phenolic compounds in legumes Legumes are an important component of the human diet. Legumes for human consumption include chickpeas, beans, lentils, and peas, and they are rich in proteins, carbohydrates, dietary fiber, vitamins, and minerals (Campos-Vega et al., 2010). Legumes are a rich source of natural antioxidant, which have shown beneficial effects in maintenance of health (Ladjal Ettoumi and Chibane, 2015). The most abundant phenolic compounds in legumes are mainly tannins, phenolic acids, and flavonoids (Campos-Vega et al., 2010). Legumes are processed by dehulling or milling, the processing of these legumes results in the production of various types of by-products such as seed coat, embryonic axe fraction, and cotyledon. Seed coat of legumes contains high concentration of phenolic compounds; this by-product has the potential to be used as an ingredient in the preparation of specialty products for human consumption (Sreerama et al., 2010a).

Target sources of polyphenols in different food products and their processing by-products

149

The content of phenolic compounds in legumes depends, among other factors, on the variety. Regarding chickpeas, the highest content of phenolic compounds has been found in the dark variety on chickpeas (Giusti et al., 2017; Segev et al., 2010). Therefore colored chickpeas possess stronger antioxidant activity (Segev et al., 2010). The phenolic compounds identified in chickpeas were mainly flavonoids and phenolic acids. The phenolic acids identified in chickpea can be classified in compound derivatives of hydroxybenzoic acids (dihydroxybenzoic, trihydroxybenzoic like gallic acid, o-methylated like vanillic acid, protocatechuic, p-hydroxybenzoic, and syringic) as well as conjugated acids with sugars (hexose, pentose), malonic acid, and hydroxycinnamic acid derivatives such as caffeic, chlorogenic, ferulic, sinapic, and p-coumaric acids (Mekky et al., 2015). The flavanones and flavonols detected in chickpea have been luteolin, myricetin, pinocembrin, kaempferol, and quercetin, and their derivatives such as pinocembrin malonylhexoside, kaempferol 3-O-β-d-glucopyranoside, kaempferol 3-O-rutinoside, kaempferide, quercetin 3-O-β-d-glucopyranoside, and quercetin O-rutinoside (Aguilera et al., 2011; Magalhães et al., 2017; Mekky et al., 2015). Additionally, isoflavones such as genistein hexoside, biochanin A and biochanin B and their derivatives (Aguilera et al., 2011), and isoflavonoids like orobol, and two isomers of dalpanin (Mekky et al., 2015) have been detected in chickpea. The highest content of phenolic compounds in chickpea has been found in the seed coat, followed by embryonic axe and cotyledon (Sreerama et al., 2010b). However, the families of phenolic compounds are distributed differently; Sreerama et al. (2010b) carried out the quantification of phenolic compounds in chickpeas’ milled fractions, and the major concentration of phenolic acids were located in the cotyledon (590.2 μg/g), followed by embryonic axe (292.9 μg/g) and seed coat (191.3 μg/g). The major phenolic acids were ferulic, caffeic, and p-coumaric acid. On the contrary, the highest concentration of flavonoids was located in the seed coat (231.96 μg/g), followed by embryonic axe (164.8 μg/g) and cotyledon (23.51 μg/g) of chickpea, quercetin and kaempferol being the major flavonoids. Concerning chickpea anthocyanins, they were found in high concentrations in the seed coat (513.3 μg/g), whereas the embryonic axe presented a low anthocyanin content (25.6 μg/g) and cyanidin was the major anthocyanin (Sreerama et al., 2010b). The phenolic compounds present in beans are mainly classified as phenolic acids and flavonoids. The highest content of phenolic compounds was located in the seed coat of bean, followed by the whole bean and cotyledon (Boudjou et al., 2013). The phenolic compounds identified in mung beans and faba beans were hydroxybenzoic acid derivatives such as gallic, protocatechuic, vanillic, and CGA and also, hydroxycinnamic acid derivatives like caffeic, p-coumaric, ferulic, and sinapic acid. Regarding flavonoids, mung beans have shown compounds such as quercetin, catechin, and luteolin; indeed, they have presented stilbenes such as resveratrol and trans-stilbene (Singh et al., 2017). The main phenolic family of faba beans is flavonoids, and among them flavanols (gallocatechin, catechin, EC), proanthocyanidins type-B (prodelphinidins and procyanidins), flavonols and flavanonols (mainly derivatives of myricetin, quercetin, and kaempferol), flavones (derivatives of apigenin, luteolin, and chrysin), and flavanones (such as derivatives of naringenin and pinocembrin) (Singh et al., 2017; El-Mergawi and Taie, 2014; Abu-Reidah et al., 2014; Baginsky et al., 2013; Magalhães et al., 2017). In addition, polymers of polyhydroxyflavan-3-ol monomers

150

Polyphenols: Properties, Recovery, and Applications

(condensed tannins) were found in high levels in V. faba seeds, being considered major compounds in Vicia genus (Gulewicz et al., 2014; Abu-Reidah et al., 2014; Magalhães et al., 2017). The phenolic compounds present in lentils belong to two principal families: flavonoids and phenolic acids. The major content of phenolic compounds was found in the hull of lentils, followed by the whole lentil and cotyledon (Boudjou et al., 2013). In colored lentils, the highest phenolic content was observed in black lentils (Giusti et al., 2017). The phenolic acids detected in lentils were hydroxybenzoic acids and its derivatives, such as protocatechuic acid, 2,3,4-trihydroxybenzoic, p-hydroxybenzoic acid, protocatechualdehyde and gallic acid; and hydroxycinnamic acids (CGA, caffeic acid, p-coumaric acid, m-coumaric acid, and sinapic acid). The main flavonoids detected were catechin and EC, rutin, quercetin, luteolin, and naringenin. The most abundant of these phenolic compound in lentil were CGA and caffeic acid (Fratianni et al., 2014; Xu and Chang, 2010; Troszyńska et al., 2011). Phenolic compounds of peas can also be classified in phenolic compounds and flavonoids. In yellow peas, the major content of phenolic compounds was located in the seed coat followed by the whole pea (Oomah et al., 2011). Fratianni et al. (2014) determined the content of phenolic compounds present in two different varieties of grass pea and observed that it varied between 194 and 221 μg/g. The main phenolic acids identified were gallic, chlorogenic, caffeic, and coumaric acids and the flavonoids detected were EC, rutin, quercetin, luteolin, and naringenin. The major phenolic compounds were gallic acid, CGA, and EC (Fratianni et al., 2014). Furthermore, phenolic compounds of pea seed coat extracts have been studied due to their antioxidant and anticancer activities. The highest antioxidant activities could be attributed to the presence of gallic acid, EGC, naringenin, and apigenin; whereas the cytotoxic effects against the malignant cell lines are strongly correlated with contents of EGC and luteolin (Stanisavljević et al., 2016). Recently, the content of phenolic compounds has also been studied in different varieties of seeds of field peas ranging between 96.6 and 254.6 μg/g and protocatechuic acid and p-hydroxybenzoic acids were the major phenolic compounds (57.5–248.2 μg/g) (Magalhães et al., 2017).

1.4  Beverages 1.4.1  Coffee Coffee beverage is the end product obtained from roasted and ground Coffea plant seeds and, together with tea, is one of the most consumed beverages every day (Esquivel and Jiménez, 2012). Apart from the stimulant properties of caffeine, coffee is very rich in functional ingredients, such as flavonoids (catechins and anthocyanins), acids (chlorogenic, caffeic, ferulic, gallic, protocatechuic), and rutin (Meletis, 2006; Chu et al., 2008). Caffeoylquinic acid, often referred to as CGA, is an ester of caffeic acid with quinic acid, and it is one of the major coffee polyphenols known for its antioxidant, anticarcinogenic, and antiinflammatory properties (Tajik et al., 2017). The term CGAs,

Target sources of polyphenols in different food products and their processing by-products

151

however, denote the complete set of hydroxycinnamic esters with quinic acid, including caffeoyl-, feruloyl-, dicaffeoyl-, and coumaroylquinic acids. Moreover, different isomeric forms of CGA are present in different coffee extracts, but the most common isomer is 5-caffeoylquinic acid (5-CQA) (Perrone et al., 2010). Additionally, by-products of the coffee industry are a potential source of compounds with functional properties (Esquivel and Jiménez, 2012). Coffee pulp contains flavonols, anthocyanidins, flavan-3-ols, and hydroxycinnamic acids (Ramírez-Coronel et al., 2004), with the highest concentration for 5-CQA, followed by EC and 3,5-dicaffeoylquinic acid (Ramírez-Martínez, 1988). Bresciani et al. (2014) identified the following phenolic compounds in coffee silverskin: 3-, 4- and 5-CQA, 4- and 5-feruloylquinic acid, caffeoylquinic acid lactone, and 3-, 5- coumaroylquinic acids. Moreover, low-grade green and spent coffee exert a strong antioxidant and antitumor activity due to the presence of caffeine, trigonelline, and CGAs (Ramalakshmi et al., 2009).

1.4.2  Green, black, and oolong teas Hot water infusion of dried tea leaves, produced from the tea plant (Camellia sinensis), is characterized by a high content in polyphenols, which are responsible for its antioxidant activity and therefore its benefit on human health. The most common polyphenols in tea leaves are flavan-3-ols, typically referred to as catechins (Coe et al., 2013). The polyphenol profile of teas depends on many factors, the most important is the processing method; however, it could be influenced also by varieties, brands, area, and season of harvest. Green tea is a gently processed tea; the leaves immediately after harvest are fried or steamed followed by rolling and drying. In this way the polyphenol oxidase is rapidly inactivated, thus preserving the freshness and polyphenol profile (Bruno et al., 2014). In fact, the catechin profile in green teas represents up to 85% of the total polyphenols originally present in the leaves at harvest (Ferruzzi, 2010). In general, the total concentrations of catechins in the green tea ranged from 12.3 to 136.3 mg/g (Friedman et al., 2010). The catechins present at the highest concentrations are epigallocatechin gallate (about 50% of the total catechin) followed by EGC, epicatechin gallate, EC (Bruno et al., 2014), and gallocatechin gallate (Bae et al., 2015). Oolong tea, a partially fermented product, contains a mixture of catechins, theaflavins, and thearubigins (Liang et al., 2017). Green tea polyphenols have been successfully used to increase the stability of vacuum impregnated apples during the storage (Tappi et al., 2017). Black tea instead is a more processed product. Fresh tea leaves are fully fermented before final drying and they are characterized by a high level of theaflavins and thearubigins, which provide the characteristic orange-brown color and flavor of fermented black teas (Ferruzzi, 2010). The total concentration of four theaflavins found in black tea (theaflavin-TF, theaflavin-3-gallate-TF3G, theaflavin-3′-gallate-TF3′G, theaflavin-3,3′-digallate-TF33′G) ranged from 3.7 to 20.7 (mg/g) (Friedman et al., 2010). Black tea also contains catechins in the quantity of 9.6–111.0 mg/g; moreover, it has been found that it presents gallic acid and rutin at higher concentrations in comparison to green and oolong teas (Bae et al., 2015).

152

Polyphenols: Properties, Recovery, and Applications

Concerning the tea by-products, a very fine dust powder could be obtained during the decaffeination of black tea, which contains the same quantity of bioactive compound as decaffeinated tea: the polyphenols and theanine (Culetu et al., 2015).

1.4.3  Wine Wines are characterized by high levels of polyphenols, responsible for wine quality and its positive effects on human health, when consumed with moderation (Shahidi and Ambigaipalan, 2015). Grapes contain a large number of different phenolic compounds in skins, pulp, and seeds that are molecules partially extracted during the wine-making process; however, the phenolic profile in wine depends on many factors, including grape variety, climatic condition, vineyard location, and vinification technology process, and wine storage (Lachman et al., 2009). Red wines, made from darkskinned grape varieties, generally contain up to 3500 mg/L of phenolic compounds, of which 1000–1800 mg/L are classified as flavonoids (Di Lorenzo et al., 2016). The most common flavonoids in wine are flavonols (quercetin, kaempferol, and myricetin), flavan-3-ols (catechin and EC), tannins, and anthocyanins (cyanin), and proanthocyanidins (Shahidi and Ambigaipalan, 2015). Phenolic compounds in red wine are derived from the grape’s skin, seeds, stems, or grape pulp, which are very rich in flavanols that are transferred to the wine during fermentation. On the contrary, white wines are usually made from the free-running juice, without the grape mash having any contact with the grape skins. This is thought to be the main reason for the relatively low polyphenol content and for the lower antioxidant activity of white wines in comparison to red ones (Fuhrman et al., 2001). Wine production generates huge amounts of by-products mainly represented by organic wastes, wastewater, emission of greenhouse gases, and inorganic residues (Teixeira et al., 2014). The valorization of organic by-products (grape pomace, containing seeds, pulp and skins, grape stems, and grape leaves) is of great importance, since they are a rich source of bioactive compounds, mainly polyphenols. Grape pomace is generated during the must production (grape juice) by pressing whole grapes. Grape pomace is an important source of polyphenols due to incomplete extraction during the wine- and juice-making process. Grape pomace contains condensed tannins, phenolic acids, the flavanols, which include catechin, EC, proanthocyanidins (B1 and B2), and anthocyanins. Moreover, in grape skin there are proanthocyanidins, prodelphinidins, ellagic acid, myricetin, quercetin, kaempferol, transresveratrol, and in seeds—gallic acid, catechin, EC, dimeric procyanidin, and proanthocyanidins (Brenesa et al., 2016). Grape pomace is a cheap source of phytochemicals that can be used in food industries, pharmaceuticals, and cosmetics (Varzakas et al., 2016). It is used for xylanase and pectinase enzyme production (Kowalska et al., 2017), food dyes production, as natural antioxidants (Kammerer et al., 2014; Banerjee et al., 2017), and is directly added to meat products to improve food quality (Brenesa et al., 2016). Moreover, due to enormous volumes of grape wastes generated during harvest season, the grape marc is dried and in this form used for livestock feed production (Celma et al., 2009). Medouni-Adrar et al. (2015) studied the total phenolic content (TPC) in Vitis vinifera L. cv. Ahmar Bou-Amar seeds and skin showing TPC content of 73.15–96.56 mg GAE/g and 39.57–54.84 mg GAE/g

Target sources of polyphenols in different food products and their processing by-products

153

in seeds and skin, respectively. Additionally, Rockenbach et al. (2011) showed a higher concentration of phenolic compounds in seeds; in particular, skin was very rich in anthocyanins, ranging from 289 to 935 mg/100g DW, while seeds presented a high content of catechin (24–117 mg/100g DW). Concerning the phenolic composition of grape stems, they contain mainly flavanols (catechin, EC), flavonols (quercetin 3-O-glucuronide and quercetin 3-O-rutinoside-rutin), dihydroflavonols (astribin), and phenolic acids such as caftaric acid (Karvela et al., 2009). The grape leaves V. vinifera L. are the less studied and valorized by-products from the wine industry. However, they contain phenolic acids, flavonols, tannins, procyanidins, and anthocyanins (Teixeira et al., 2014). The wine lees, which are the residues generated during the fermentation and aging processes of industrial wine production, could present the total phenolics of 36,4 mg of gallic acid/100 mg of lees extract; in particular, anthocyans (Mv3G, Cm-Mv3G), myricetin, quercetin, quercetin-3-β-glucoside, caffeic acid, and p-coumaric acid were found in wine lees (PérezSerradilla and Luque de Castro, 2011). Finally, transresveratrol, its dimer k–viniferin, and vineatrol could be a fraction isolated from vine-shots extracts (Billard et al., 2002).

1.4.4   Beer Beer is a good source of phenolic compounds, which contributes to its colloidal, foam, flavor, color, and sensory properties. The total polyphenol content in lager beers ranged from 74 to 339 mg/L (Zhao et al., 2010; Oladokun et al., 2016). The phenolic compounds in beer are mainly phenolic acids, flavonoids, proanthocyanidins, tannins, and amino phenolic compounds (Shahidi and Ambigaipalan, 2015). Oladokun et al. (2016) identified the following phenolic compounds: gallic acid, hydroquinone, protocatechuic acid, catechin, EC, 4-hydroxybenzoic acid, 4-hydroxyphenylacetic acid, caffeic acid, vanillic acid, sinapic acid, syringic acid, p-coumaric acid, ferulic acid, and cinnamic acid. Ferulic acid was the most abundant phenolic acid present in the beers, with a concentration ranging from 0.98 mg/L to 7.61 mg/L (Oladokun et al., 2016), followed by sinapic, vanillic, caffeic, p-coumaric, and 4-hydroxyphenylacetic acid (Piazzon et al., 2010). Moreover, Callemien et al. (2008) showed that the most beer dimers are procyanidins B3 while most trimers are prodelphinidins. Waste materials from beer production such as brewery waste streams or vegetative waste material of hop pellets are rich sources of phenolic compounds. A huge amount of waste stream, which contains large amounts of polyphenols, is produced during the procedures to prevent haze formation and thus extend the shelf life of beer, which are the reduction of the concentration of haze-active proteins and/or reduction of the concentration of haze-active polyphenols (Callemien and Collin, 2010). Barbosa-Pereira et al. (2014) studied the selective recovery of polyphenols from the waste stream generated during regeneration of polyvinylpolypyrrolidone used for polyphenol adsorption during the haze reduction process. They found that catechin and ferulic acid are the main compounds present in the crude extract followed by caffeic acid, p-coumaric acid, and protocatechuic acid. Brewers’ spent grain is another by-product of the brewing industry produced in large quantities annually. It has been found that brewers’ spent grain contains mainly hydroxycinnamic acids including ferulic acid, p-coumaric acid, and caffeic acid (McCarthy et al., 2013).

154

Polyphenols: Properties, Recovery, and Applications

1.5  Olive oil and its by-products The olive tree (Olea europaea L.) is one of the oldest known cultivated trees in the world and; therefore, olive oil is the main edible oil of the Mediterranean diet. In fact, it has been used by humans since antiquity (Boskou et al., 2006). Despite this, the interest in olive oil is now higher than ever, mainly due to the scientific evidences that demonstrate that olive oil can act as a prevention and treatment against several diseases such as cancer, atherosclerosis, obesity, diabetes, endothelial dysfunction, etc. (Martín-Peláez et al., 2013; Visioli and Bernardini, 2011). These health benefits are attributed to its special composition in fatty acids and also because of some minor components such as phenolic compounds. In fact, there is an approved regulation established by the Commission Regulation about olives with the following health claim: “olive oil polyphenols contribute to the protection of blood lipids from oxidative stress” (Commission Regulation (EU) 432/2012 Off, 2012)”. Because of the importance of the phenolic fraction of the olive oil, it has widely been studied in the last years by different analytical techniques such as CE, GC, and HPLC coupled to different detection systems (Carrasco-Pancorbo et al., 2009). These studies have helped to determine the phenolic families that constitute the polar fraction of olive oil, mainly secoiridoids, phenyl alcohols, flavonoids, lignans, and phenolic acids (Bendini et al., 2007; Pérez-Trujillo et al., 2010). However, the phenolic profile of olive oil depends on different factors that affect olive fruits such as agronomical and environmental factors (cultivar, season, geographic area, irrigation, temperature, etc.). Secoiridoids are compounds produced from the secondary metabolism of terpenes, their carbon skeleton is derived from mevalonic acid. The main structure of secoiridoids is formed by a phenyl ethyl alcohol (hydroxytyrosol or tyrosol), elenolic acid (EA), and, eventually, a glucosidic residue (Goulas et al., 2012). The two major secoiridoids of olive oil are oleuropein and ligstroside. Oleuropein is an ester of hydroxytyrosol (3,4-DHPEA) and EA glucoside, whereas ligstroside is an ester of tyrosol (p-HPEA) and EA glucoside. However, in olive oil, secoiridoids appear in their aglycone form. Besides oleuropein aglycone, ligstroside aglycone, and their derivatives, other major secoiridoids in olive oil are the dialdehydic forms of EA linked to hydroxytyrosol or tyrosol (3,4-DHPEA-EDA and p-HPEA-EDA) (Ricciutelli et al., 2017). Phenyl alcohols contained in olive oil are tyrosol and hydroxytyrosol, and their concentration increases during the hydrolytic processes suffered during olive oil oxidation (Tsimidou, 1998). Phenolic acids are secondary aromatic plant metabolites that also occur in olive oil. They present two different structures derived from hydroxycinnamic and hydroxybenzoic acids. However, they are found in very low concentrations in olive oil (<1 mg/ kg olive oil). Phenolic acids that are usually present in olive oil are: protocatechuic, gallic, vanillic, caffeic, p-hydroxybenzoic, syringic, p- and o-coumaric, ferulic, and cinnamic acid (Gómez-Caravaca et al., 2006; Franco et al., 2014). Lignans are phytoestrogens that are required in a healthy diet. The natural lignans found in olive oil are (+)-pinoresinol and 1-acetoxypinoresinol. Although (+)-pinoresinol has been identified in other plants, 1-acetoxypinoresinol is specifically found in olives (López-Biedma et al., 2016). They are present in olive oils in concentrations

Target sources of polyphenols in different food products and their processing by-products

155

up to 100 mg/kg (Owen et al., 2000). Moreover, some authors have described the possibility to use these compounds as varietal markers of olive oil (Brenes et al., 2002). Flavonoids are widespread secondary plant metabolites and their precursors are phenylalanine, obtained via the shikimate and arogenate pathways, and malonyl-CoA, derived from citrate produced by the tricarboxylic acid cycle (Andersen and Markham, 2006). Flavonoids are subdivided into flavones, flavonols, flavanones, and flavanols, and their structural variation are in part due to modifications produced by hydroxylation, methoxylation, prenylation, or glycosylation. The flavonoids that are usually present in olive oil are luteolin and apigenin and their concentration ranged between 0.2 and 10 mg/kg (Kelebek et al., 2017). During olive oil processing by the industry a huge amount of wastes are generated. The main olive oil by-products are olive leaves, olive mill waste water, and pomace. These residues can suppose a problem due to the high quantity generated by the olive oil industry. On the one hand, treatment of OMWW and pomace is difficult due to the high concentration of organic matter and also due to their potential phytotoxicity caused by the high concentration of phenolic compounds (Giovanni et al., 2002; Gómez-Caravaca et al., 2011). On the other hand, olive leaves are usually used as animal food (Molina-Alcaide and Yáñez-Ruiz, 2008) or biomasses (D’Andria et al., 2013). Because of that, there is a great interest in the reutilization of these by-products to obtain extracts enriched in bioactive compounds that can be used in food, pharmaceutical, or medical formulations. Olive leaves contain different phenolic families represented by simple phenols, secoiridoids, and flavonoids. The principal difference with the composition of olive oil is the presence of oleuropein and ligstroside and several flavonoids in their glycosylated form (luteolin-7-O-rutinoside, luteolin-7-O-glucoside, luteolin-5-O-glucoside, quercetin-7-O-rutinoside, etc.) (Talhaoui et al., 2015). Secoiridoids are the principal phenolic family present in olive leaves, and oleuropein the major component of the phenolic fraction with a concentration ranged between 24.7 and 143.2 × 103 mg/kg dry leaf (Talhaoui et al., 2014). The total concentration of phenolic compounds in olive leaves is much higher than the one found in olive oil, 10000–82000 mg/kg in olive leaves (Talhaoui et al., 2015b) versus 40–1000 mg/kg olive oil (Bajoub et al., 2017; Loubiri et al., 2017). OMWW contains high concentrations of phenolic compounds. Nevertheless, the study of the composition of OMWW is not easy due to the processes of oxidation, hydrolysis, polymerization, etc. that occur and that continually change its phenolic fraction (Obied et al., 2005). The most representative components of the phenolic profile of OMWW are benzoic acid derivatives (4-hydroxybenzoic, protocatechuic, vanillic acids), hydroxycinnamic acid derivatives (ferulic, caffeic acids), and secoiridoid derivatives (particularly tyrosol and hydroxytyrosol). The concentration of hydroxytyrosol in OMWW is higher in comparison to olive oil and other by-products, because it is formed during olive oil extraction as a result of hydrolysis by esterase action. This compound is of special interest due to its high antioxidant activity and demonstrated health benefits. Olive pomace is a solid by-product produced in the three-phase centrifugation systems. However, the by-product generated by the two-phase centrifugation systems

156

Polyphenols: Properties, Recovery, and Applications

is a semisolid waste also called pomace or “alperujo”. These by-products can reach concentrations of phenolic compounds 100 times higher than olive oil (Sánchez de Medina et al., 2012), and similar to OMWW, due to oxidation, hydrolysis, etc., the presence of oleuropein and its derivatives is very low. In fact, the most concentrated compounds are hydroxytyrosol, tyrosol, EA, and its derivatives (Rubio-Senent et al. 2012, 2013). The extraction of phenolic compounds from pomace by using different thermal treatments has allowed the recovery of high concentrations of phenolic compounds: 1850 mg/kg phenyl alcohols, 990 mg/kg EA derivatives and 300 mg/kg other phenolic compounds.

1.6  Cocoa products Cocoa and cocoa-derived products are commonly consumed food all over the world due to their highly attractive sensory properties. Cocoa is obtained from cocoa beans, the seeds of the Theobroma cacao tree (Natsume et al., 2000; Wollgast, 2004; Hii et al., 2009; Beg et al., 2017). In cocoa, about 380 known chemicals have been identified and 10 of them are psychoactive compounds (Andújar et al., 2012). The main ingredients in cocoa beans are fatty acids, representing 50%–57% of dry matter, nutritional compounds such as carbohydrates, proteins, and dietary fiber. Moreover, cocoa also contains micronutrients such as copper, which could contribute significantly toward human dietary intake (Jalil and Ismail, 2008). However, cacao seeds are appreciated for their biologically active compounds (Natsume et al., 2000; Wollgast, 2004; Hii et al., 2009; Schinella et al., 2010; Andújar et al., 2012; Alean et al., 2016; Giacometti et al., 2016; Beg et al., 2017). Cocoa beans are rich sources of polyphenols and their content is about 6%–8% of total dry matter of cocoa seeds (Wollgast, 2004; Ferrazzano et al., 2009; Żyżelewicz et al., 2016). The main polyphenol groups found in cacao beans are flavanols such as EC (0.12–2.83 mg/g), catechin (0.040–0.90 mg/g), and procyanidins (B1, B2, B3, B4, B5, C1, and D). In cocoa, there are high quantities of EC, up to 35% of the total polyphenol content, whereas catechin, gallocatechin, and EGC are present in smaller quantities. The procyanidins constitute about 60% of the total polyphenol content. Moreover, the cocoa beans contain quercetin (0.00021–0.00325 mg/g), isoquercitrin (quercetin 3-O-glucoside) (0.0040–0.043 mg/g), hyperoside (quercetin 3-O-galactoside), and quercetin 3-O-arabinose (0.0021–0.040 mg/g). Other phenolic compounds present in the beans include anthocyanidins, apigenin, luteolin, naringenin, phenolic acids (vanillic, syringic, chlorogenic, phloretic, coumaric, caffeic, ferulic, and phenylacetic acid), and others identified at minor amounts (Natsume et al., 2000; Ferrazzano et al., 2009; Hii et al., 2009; Andújar et al., 2012; Bernaert et al., 2012; Martí et al., 2016; Żyżelewicz et al., 2016). The total polyphenol content in cocoa beans ranges from 40.0 to 84.2 mg GAE/g, depending on varieties of cocoa beans, geographical origins, and running processes on plantations (Hii et al., 2009; Żyżelewicz et al., 2016). The cocoa polyphenols have been studied extensively in recent years and their use in human diet gives favorable results to human health (Ferrazzano et al., 2009;

Target sources of polyphenols in different food products and their processing by-products

157

Hii et al., 2009; Schinella et al., 2010). The phenolics from cocoa have antioxidant properties, which give beneficial effects on several pathological disorders, including cardiovascular disease, metabolic and endocrine disorders, inflammatory processes, problems with immune system, allergies, and cancer. Moreover, polyphenols in cocoa modify the glycemic response and the lipid profile, increase resistance to oxidative stress, and prevent or delay insulin resistance (Natsume et al., 2000; Ferrazzano et al., 2009; Hii et al., 2009; Rimbach et al., 2011; Andújar et al., 2012; Bernaert et al., 2012; Martín et al., 2013; Martí et al., 2016). Furthermore, polyphenols from cocoa are effective against the adhesion of bacteria on the surface of teeth (Ferrazzano et al., 2009; Andújar et al., 2012) and the cocoa flavanols have health characteristics for skin (Bernaert et al., 2012). Similarly, cocoa-derived products have good influence on health; for instance, chocolate can lower blood pressure (Hii et al., 2009). Cocoa and chocolate production is an extremely complex and complicated technological process, during which the polyphenol content is significantly reduced. However, this high amount of polyphenols has an impact on the bitter taste of cocoa, which have to be masked by adding sugar (Bernaert et al., 2012). The cocoa beans are subjected to fermentation, drying, alkalization, roasting, and grinding processes to obtain cocoa and chocolate products (Wollgast, 2004; Hii et al., 2009; Żyżelewicz et al., 2016). These processes are crucial for the aroma, color, and flavor of cocoa products and are carried out in elevated temperatures for a long time, which affects the biologically active compounds and consequently loss of polyphenols is even up to 90% in the cocoa products in comparison to the raw material (Andújar et al., 2012; Alean et al., 2016; Żyżelewicz et al., 2016; Beg et al., 2017; Okiyama et al., 2017). Cocoa-derived products such as cocoa liquor, cocoa powder, and milk and dark chocolates with different cocoa content and cocoa butter may contain varied polyphenol contents and have different levels of antioxidant capacity (Jalil and Ismail, 2008; Hii et al., 2009). During each production process, some waste is generated. During cocoa processing, the cocoa shell is left and is an industrial by-product of cocoa production, which is treated as a waste or is utilized in a wrong way. The cocoa shell contains an interesting amount and profile of phenolic compounds, which could be used in the food industry as partially purified pectin, fiber-rich product, fiber concentrates with antioxidant properties, soluble cocoa fiber, extract, chocolate flavors, and others (Okiyama et al., 2017). Cocoa products are called as “food of the gods” according to their high phenolic compounds, which have a beneficial effect on the human body (Wollgast, 2004). Nevertheless, in many cocoa products as in chocolate, there is a relatively high content of sugars and saturated fatty acids, which are known as unhealthy components (Rimbach et al., 2011). Moreover, cocoa and its products contain methylxanthines (caffeine, theobromine, and theophylline), which have both positive and negative health effects (Jalil and Ismail, 2008). Due to this fact and the global problems with overweight and obesity, especially for developing countries, people should use the benefits and abundance of cocoa products wisely (Lima et al., 2014).

158

Polyphenols: Properties, Recovery, and Applications

1.7  Herbs and spices Herbs and spices have been used for a long time to improve the flavor of food due to their sensory properties and to increase the shelf life since they also can act as preservation agents (Vallverdu-Queralt et al., 2014). Moreover, they are also a very good source of phenolic compounds that may exert beneficial effects on human health (Table 5.2).

1.7.1  Coriander Coriander (Coriandrum sativum L.) is a medicinal and aromatic plant belonging to the Apiaceae family. Its nutritional as well as medicinal properties have been widely revised by Laribi et al. (2015). Coriander seeds are a good source of secondary plant metabolites such as polyphenols, particularly phenolic acids and flavonoids. TPC of coriander seeds has been found in the range of 0.5119–2.6297 g GAE/100g and total flavonoids content (TFC) ranged between 0.2315 and 0.6280 g catechin equivalent/100g (Zeković et al., 2014). The following polyphenol compounds have been identified in coriander seeds: catechin, 3,4-dimethoxycinnamic acid, coumaric acid, Table 5.2 

Total polyphenol content of selected herbs and spices (self-developed)

Coriander seeds Rosemary Thyme

Sage

Basil Parsley Oregano Turmeric Ginger

amg

GAE/g seeds. GAE, gallic acid equivalents.

Total polyphenol content (mg GAE/g DW)

Source

0.94–1.09 5.12–26.29a 5.02 ± 0.43 35.29–55.5 3.36 ± 0.14 4.75–8.10 23.12–38.28 4.25–5.95 62.2–102.83 (sage by-products) 90.20–290.28 (sage by-products) 29.74 ± 6.37 about 2.5 23.88 ± 2.63 2.23 ± 0.18 146.70 ± 5.63 0.43 ± 0.04 182 ± 0.6 11.27–11.62 16 ± 0.15

Msaada et al. (2017) Zeković et al. (2014) Vallverdu-Queralt et al. (2014) Calinescu et al. (2017) Vallverdu-Queralt et al. (2014) Roby et al. (2013) Calinescu et al. (2017) Roby et al. (2013) Zeković et al. (2017) Pavlić et al. (2017) Śledź et al. (2013) Fratianni et al. (2017) Śledź et al. (2013) Vallverdu-Queralt et al. (2014) Śledź et al. (2013) Vallverdú-Queralt et al. (2015) Danciu et al. (2015) Ghasemzadeh et al. (2016) Danciu et al. (2015)

Target sources of polyphenols in different food products and their processing by-products

159

daidzein, ferulic acid, sinapic acid, and transferulic acid depending on the extraction conditions (Zeković et al., 2016). Concerning the vegetative part of coriander, Barros et al. (2012) showed that quercetin derivatives were the main flavonoids and quercetin-3-O-rutinoside (3296 mg/kg DW) was the main polyphenol found in this part of coriander.

1.7.2  Rosemary, thyme, and sage Rosemary (Rosmarinus officinalis L.) contains 5–55  mg  GAE/g  DW of TPC (Vallverdu-Queralt et al., 2014; Calinescu et al., 2017). The predominant phenolic compound is carnosic acid, followed by carnosol, rosmanol, methyl carnosate, and flavonoids, such as cirsimaritin and genkwanin (Ibañez et al., 2003; Mena et al., 2016). Thyme (Thymus vulgaris L.) and sage (Salvia officinalis L.) are popular herbal and spice plants of the mint family. Sadowska et al. (2017) reported that they have commonly been applied in traditional medicine, against respiratory congestion, and digestive disorders (thyme), and as an antiinflammatory agent (sage). In thyme, the TPC content was found to vary from 3 to 38 mg GAE/g DW (Vallverdu-Queralt et al., 2014; Calinescu et al., 2017), and the highest content of polyphenolic compounds was found in whole fresh thyme as compared to the fresh leaves with flowers (Sadowska et al., 2017). Sage is a good source of polyphenols, particularly phenolic acid derivatives, such as rosmarinic, carnosic, caffeic, ferulic, cinnamic, and CGA (Roby et al., 2013) and some flavonoids, with the highest concentration of luteolin-7-O-glucoside (37.9–166 mg/L) (Zimmermann et al., 2011). During the production of filter tea, plant material is subjected to various unit operations, such as drying, cutting, grinding, fractionation, etc., which could lead to the production of a certain amount of fine powder (∼20%), which has been recognized as herbal dust and has been considered as a by-product (Pavlić et al., 2017). TPC of sage dust (by-product) varied between 6.22 and 10.283 g GAE/100 g DW and total flavonoid content varied from 5.027 to 7.803 g CE/100g DW, depending on the type of extraction used (Zeković et al., 2017). In particular, sage by-products are rich in caffeic acid (18.07–33.69 mg/100g DW), p-coumaric acid (5.03-5-53 mg/100g DW), ferulic acid (4.72–14.08 mg/100g DW), and rosmarinic acid (840.43–1724.81 mg/100g DW) (Zeković et al., 2017). A huge amount of by-products are generated during the production of essential oil by steam distillation of rosemary, thyme, and sage. During this process, two aqueous extracts as by-products are generated, a water fraction of the distillate (hydrolate) and a decoction, which are a powerful antioxidant resource due to the high content of polyphenols (Mielnik et al., 2008). For example, polyphenolic from distillate rosemary leaves (mainly phenolic acids such as carnosic, rosmarinic, caffeic, ferulic, and coumaric, together with carnosol, hesperidin, naringin, luteolin, apigenin, and genkwanin) has successfully been used as a diet supplement for ewes during gestation and lactation to transfer these polyphenols in lamb muscle (Moñino et al., 2008).

1.7.3  Basil, parsley, and oregano Basil (Ocimum basilicum L.) contains 29.74 ± 6.37 mg of GAE/g DW of total polyphenols (Śledź et al., 2013). In particular, caffeic acid was found in the highest

160

Polyphenols: Properties, Recovery, and Applications

concentration, followed by chlorogenic and gallic acid. Moreover, quercetin, rutin, rosmarinic acid, kaempferol, caftaric acid, catechin, and apigenin were identified (Güez et al., 2017; Fratianni et al., 2017). Lee and Scagel (2009) proved also for the first time the presence of cichoric acid (51.8–88.5 mg/100g f.w.) in basil leaves. Parsley (Petroselinum crispum) contains 23.88 ± 2.63 mg of GAE/g DW of total polyphenols (Śledź et al., 2013). Concerning the individual phenolic compounds, the highest concentration of apigenin-7-apiosylglucoside (apiin) (1240 mg/kg DW), isorhamnetin-3-O-galactoside (1240  mg/kg  DW), and diosmetin-apiosylglucoside (123  mg/ kg DW) have been found in parsley. Moreover, for the first time p-coumaroyl-hexoside has been identified by El-Zaeddi et al. (2017). In oregano (Origanum vulgare L.), the total polyphenol content ranged from 2.23 to 146.70 mg of gallic acid/g DW of total polyphenols (Vallverdu-Queralt et al., 2014; Śledź et al., 2013). The main compounds found in oregano are rosmarinic acid and carvacrol (Pizzale et al., 2002).

1.7.4  Turmeric and ginger Turmeric (Curcuma longa L.) and ginger (Zingiber officinale R.) are two main representatives of the Zingiberaceae family studied because of their therapeutic properties. Turmeric is an aromatic, nutraceutical plant, where the polyphenolic curcuminoid (curcumin) is the major active compound responsible for the antioxidant, antiinflammatory, anticancer effects (Kocaadam and Şanlier, 2017). The total polyphenol content has been found in the range of 0.43–182 mg GAE/g DW (Danciu et al., 2015; Vallverdú-Queralt et al., 2015). In addition to curcuminoids, other compounds possessing antioxidant capabilities that are present in turmeric include ferulic acid, CGA, p-coumaric acid, p-hydroxybenzoic acid, protocatechuic acid, rosmarinic acid, syringic acid, and quercetin (Vallverdú-Queralt et al., 2015). Ginger contains a variety of pungent and biologically active compounds such as phenolics, flavonoids, gingerol, shogaol, and zingerone responsible for their therapeutic action. In general, TPC content on fresh ginger varied from 11 to 16 mg GAE/g DW, while TFC varied from 3.79 to 4.38 mg quercetin E/g DW, depending on the ginger variety (Danciu et al., 2015; Ghasemzadeh et al., 2016). Major phenolic acids present in ginger were identified as gallic acid, ferulic acid, cinnamic acid, and tannic acid, while major flavonoids as quercetin, rutin, catechin, EC, and kaempferol (Ghasemzadeh et al., 2016).

2.  Conclusion Polyphenols are compounds that have health beneficial properties, since they can protect the human body against civilization diseases, such as atherosclerosis, Alzheimer and Parkinson disease, faster aging, heart attacks, cardiovascular disease, and cancer. Rich sources of polyphenols are the raw fruit and vegetables, cereals, legumes, oilseeds, olive oil, cocoa products, herbs and spices, among others. However, these substrates are often processed in the food industries with a subsequent and annual generation of a huge amount of by-products (e.g., peel, pulp, seeds, stones, stem etc.).

Target sources of polyphenols in different food products and their processing by-products

161

By-products contain valuable components, namely bioactives, vitamins, flavor compounds, phytochemicals, carbohydrates, polysaccharides, proteins, minerals, etc. Besides, these by-products contain in many cases a higher quantity of bioactive compounds compared to the initial source, allowing their reutilization as a cheap source of phenolic compounds. To this line, phenolic compounds, natural food additives, and nutraceutical ingredients obtained from by-products are nowadays used to produce innovative food products, enriched food, or supplements.

References Abdel-Aal, E.-S.M., Young, J.C., Rabalski, I., 2006. Anthocyanin composition in black, blue, pink, purple, and red cereal grains. Journal of Agricultural and Food Chemistry 54, 4696–4704. Abdel-Aal, E.-S.M., et al., 2012. Free and bound phenolic acids and total phenolics in black, blue, and yellow barley and their contribution to free radical scavenging capacity. Cereal Chemistry Journal 89, 198–204. Abu-Reidah, I.M., et al., 2014. UHPLC-ESI-QTOF-MS-based metabolic profiling of Vicia faba L. (Fabaceae) seeds as a key strategy for characterization in foodomics. Electrophoresis 35, 1571–1581. Aguilera, Y., et al., 2011. Phenolic profile and antioxidant capacity of chickpeas (Cicer arietinum L.) as affected by a dehydration process. Plant Foods for Human Nutrition 66, 187–195. Akyol, H., et al., 2016. Phenolic compounds in the potato and its byproducts: an overview. International Journal of Molecular Sciences 835, 1–19. Alean, J., Chejne, F., Rojano, B., 2016. Degradation of polyphenols during the cocoa drying proces. Journal of Food Engineering 189, 99–105. Alrahmany, R., Tsopmo, A., 2012. Role of carbohydrases on the release of reducing sugar, total phenolics and on antioxidant properties of oat bran. Food Chemistry 132 (1), 413–418. Andersen, O.M., Markham, K.R. (Eds.), 2006. Flavonoids: Chemistry, Biochemistry and Applications. CRC Press Taylor & Francis Group. Andújar, I., et al., 2012. Cocoa polyphenols and their potential benefits for human health. Oxidative Medicine and Cellular Longevity 1–23 Article ID: 906252. Anton, D., et al., 2017. Changes in polyphenols contents and antioxidant capacities of organically and conventionally cultivated tomato (Solanum lycopersicum L.) fruits during ripening. International Journal of Analytical Chemistry 1–10. Bae, I.K., et al., 2015. Simultaneous determination of 15 phenolic compounds and caffeine in teas and mate using RP-HPLC/UV detection: method development and optimization of extraction process. Food Chemistry 172, 469–475. Baginsky, C., et al., 2013. Phenolic compound composition in immature seeds of fava bean (Vicia faba L.) varieties cultivated in Chile. Journal of Food Composition and Analysis 31, 1–6. Bajoub, A., et al., 2017. In-depth two-year study of phenolic profile variability among olive oils from autochthonous and mediterranean varieties in Morocco, as revealed by a LC-MS chemometric profiling approach. International Journal of Molecular Sciences 18, 52. Banerjee, J., et al., 2017. Bioactives from fruit processing wastes: green approaches to valuable chemicals. Food Chemistry 225, 10–22.

162

Polyphenols: Properties, Recovery, and Applications

Barbosa-Pereira, L., et al., 2014. Brewery waste as a potential source of phenolic compounds: optimisation of the extraction process and evaluation of antioxidant and antimicrobial activities. Food Chemistry 145, 191–197. Barros, L., et al., 2012. Phenolic profiles of in vivo and in vitro grown Coriandrum sativum L. Food Chemistry 132, 841–848. Beg, M.S., et al., 2017. Status, supply chain and processing of cocoa - a review. Trends in Food Science & Technology 66, 108–116. Bei, Q., et al., 2017. Improving free, conjugated, and bound phenolic fractions in fermented oats (Avena sativa L.) with Monascus anka and their antioxidant activity. Journal of Functional Foods 32, 185–194. Belobrajdic, D.P., Bird, A.R., 2013. The potential role of phytochemicals in wholegrain cereals for the prevention of type-2 diabetes. Belobrajdic and Bird Nutrition Journal 12, 62. Bendini, A., et al., 2007. Phenolic molecules in virgin olive oils: a survey of their sensory properties, health effects, antioxidant activity and analytical methods. An overview of the last decade. Molecules 12, 1679–1719. Bernaert, H., et al., 2012. Industrial treatment of cocoa in chocolate production: health implications. In: Paoletti, R., et al. (Ed.), Chocolate and Health. Springer-Verlag, Italia, pp. 17–31. Bian, Y.-Y., et al., 2015. Macroporous adsorbent resin-based wheat bran polyphenol extracts inhibition effects on H2O2-induced oxidative damage in HEK293 cells. Royal Society of Chemistry Advances 5, 20931–20938. Bijalwan, V., et al., 2016. Hydroxycinnamic acid bound arabinoxylans from millet brans-structural features and antioxidant activity. International Journal of Biological Macromolecules 88, 296–305. Billard, C., et al., 2002. Comparative antiproliferative and apoptotic effects of resveratrol, ε-viniferin and vine-shots derived polyphenols (vineatrols) on chronic B lymphocytic leukemia cells and normal human lymphocytes. Leukemia & Lymphoma 43 (10), 1991–2002. Bondonno, N.P., et al., 2017. The cardiovascular health benefits of apples: whole fruit vs. isolated compounds. Trends in Food Science & Technology. (in press) https://doi.org/ 10.1016/j.tifs.2017.04.012. Boskou, D., Tsimidou, M., Blekas, G., 2006. Polar phenolic compounds. In: Olive Oil Chemistry and Technology, second ed. Dimitrios Boskou, AOCS, pp. 73–92. Boudjou, S., et al., 2013. Phenolics content and antioxidant and anti-inflammatory activities of legume fractions. Food Chemistry 138 (2–3), 1543–1550. Brenes, M., et al., 2002. Use of 1-acetoxypinoresinol to authenticate Picual olive oils. International Journal of Food Science and Technology 37, 615–625. Brenesa, A., et al., 2016. Use of polyphenol-rich grape by-products in monogastric nutrition. A review. Animal Feed Science and Technology 211, 1–17. Bresciani, L., et al., 2014. Phenolic composition, caffeine content and antioxidant capacity of coffee silverskin. Food Research International 61, 196–201. Bruno, R.S., Bomser, J.A., Ferruzzi, M.G., 2014. Antioxidant capacity of green tea (Camellia sinensis). In: PREEDY, V.R. (Ed.), Processing and Impact on Antioxidants in Beverages. Academic Press, Waltham (MA,USA) (Chapter 4). Calinescu, I., et al., 2017. Integrating microwave-assisted extraction of essential oils and polyphenols from rosemary and thyme leaves. Chemical Engineering Communications 1–9. http://dx.doi.org/10.1080/00986445.2017.1328678. (in press). Callemien, D., Collin, S., 2010. Structure, organoleptic properties, quantification methods, and stability of phenolic compounds in beer–a review. Food Reviews International 26, 1–84.

Target sources of polyphenols in different food products and their processing by-products

163

Callemien, D., Guyot, S., Collin, S., 2008. Use of thiolysis hyphenated to RP-HPLC-ESI(-)-MS/ MS for the analysis of flavanoids in fresh lager beers. Food Chemistry 110, 1012–1018. Campos-Vega, R., Loarca-Piña, G., Oomah, B.D., 2010. Minor components of pulses and their potential impact on human health. Food Research International 43 (2), 461–482. Carrasco-Pancorbo, A., et al., 2009. Use of capillary electrophoresis with UV detection to compare the phenolic profiles of extra-virgin olive oils belonging to Spanish and Italian PDOs and their relation to sensorial properties. Journal of the Science of Food and Agriculture 89, 2144–2155. Celma, A.R., López-Rodríguez, F., Cuadros Blázquez, F., 2009. Experimental modelling of infrared drying of industrial grape by-products. Food and Bioproducts Processing 87, 247–253. Cheng, A., et al., 2013. Comparison of phenolic content and antioxidant capacity of red and yellow onions. Czech Journal of Food Science 31, 501–508. Chiremba, C., et al., 2012a. Phenolic acid content of sorghum and maize cultivars varying in hardness. Food Chemistry 134 (1), 81–88. Chiremba, C., Rooney, L.W., Beta, T., 2012b. Microwave-assisted extraction of bound phenolic acids in bran and flour fractions from sorghum and maize cultivars varying in hardness. Journal of Agricultural and Food Chemistry 60, 4735–4742. Chu, Q., et al., 2008. Study on extraction efficiency of natural antioxidant in coffee by capillary electrophoresis with amperometric detection. European Food Research and Technology 226, 1373–1378. Chun, O., et al., 2004. Antioxidant properties of raw and processed cabbages. International Journal of Food Sciences and Nutrition 55, 191–199. Cieślik, E., Gręda, A., Adamus, W., 2006. Contents of polyphenols in fruit and vegetables. Food Chemistry 94 (1), 135–142. Coe, S., Fraser, A., Ryan, L., 2013. Polyphenol bioaccessibility and sugar reducing capacity of black, green, and white teas. International Journal of Food Science 1–6 Article ID: 238216. Commission Regulation (EU) 432/2012 Off, 2012. EU, Establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children’s development and health. Official Journal of the European Union 136, 1–40. Culetu, A., Héritier, J., Andlauer, W., 2015. Valorisation of theanine from decaffeinated tea dust in bakery functional food. International Journal of Food Science and Technology 50, 413–420. Danciu, C., et al., 2015. Evaluation of phenolic profile, antioxidant and anticancer potential of two main representants of Zingiberaceae family against B164A5 murine melanoma cells. Biological Research 48 (1), 1–9. Dao, L., Friedman, M., 1992. Chlorogenic acid content of fresh and processed potatoes determined by ultraviolet spectrophotometry. Journal of Agricultural and Food Chemistry 40, 2152–2156. de Lima, A., et al., 2017. Processing of three different cooking methods of cassava: effects on in vitro bioaccessibility of phenolic compounds and antioxidant activity. LWT-Food Science and Technology 76, 253–258. Dhillon, G.S., Kaur, S., Brar, S.K., 2013. Perspective of apple processing wastes as low-cost substrates for bioproduction of high value products: a review. Renewable and Sustainable Energy Reviews 27, 789–805. Di Lorenzo, A., et al., 2016. Effect of winemaking on the composition of red wine as a source of polyphenols for anti-infective biomaterials. Materials 9, 316.

164

Polyphenols: Properties, Recovery, and Applications

Díaz-de-Cerio, E., et al., 2017. Design of sonotrode ultrasound-assisted extraction of phenolic compounds from Psidium guajava L. Leaves. Food Analytical Methods 10 (8), 2781–2791. Diop, N., Jaffee, S., 2004. Fruits and vegetables: global trade and competition in fresh and processed product markets. In: Beghin, W.J., Aksoy, i M. (Eds.), Global Agricultural Trade and Developing Countries. World Bank Publications, Wasgington, D.C, pp. 237–257. Dorta, E., Lobo, M.G., Gonzalez, M., 2012. Reutilization of mango byproducts: study of the effect of extraction solvent and temperature on their antioxidant properties. Journal of Food Science 71 (1), C80–C88. Dykes, L., Rooney, L.W., 2006. Sorghum and millet phenols and antioxidants. Journal of Cereal Science 44, 236–251. D’Andria, R., et al., 2013. Nutraceutical, cosmetic, health products derived from olive: present and future of the Mediterranean olive sector. Options Méditerranéennes: Série A 106, 153–161. El-Mergawi, R., Taie, H.A.A., 2014. Phenolic composition and antioxidant activity of raw seeds, green seeds and sprouts of ten faba bean (Vicia faba) cultivars consumed in Egypt. International Journal of Pharma and Bio Sciences 5 (2), 609–617. El-Zaeddi, H., et al., 2017. Preharvest treatments with malic, oxalic, and acetylsalicylic acids affect the phenolic composition and antioxidant capacity of coriander, dill and parsley. Food Chemistry 226, 179–186. Elbadrawy, E., Sello, A., 2016. Evaluation of nutritional value and antioxidant activity of tomato peel extracts. Arabian Journal of Chemistry 9, 1010–1018. Esquivel, P., Jiménez, V.M., 2012. Functional properties of coffee and coffee by-products. Food Research International 46, 488–495. Ezekiel, R., et al., 2013. Beneficial phytochemicals in potato - a review. Food Research International 50, 487–496. Faller, A.L.K., Fialho, E., 2009. Polyphenol availability in fruits and vegetables consumed in Brazil. Revista de Saúde Pública 43 (2), 1–8. FAO, 2013. Statistical Yearbook 2013, World Food and Agriculture. FAO, UN, Rome. FAO, 2015. Statistical Pocketbook, World Food and Agriculture. FAO, UN, Rome. FAOSTAT, 2017. http://www.fao.org/. Farvin, K., Grejsen, H., Jacobsen, C., 2012. Potato peel extract as a natural antioxidant in chilled storage of minced horse mackerel (Trachurus trachurus): effect on lipid and protein oxidation. Food Chemistry 131, 843–851. Ferrazzano, G.F., et al., 2009. Anti-cariogenic effects of polyphenols from plant stimulant beverages (cocoa, coffee, tea). Fitoterapia 80, 255–262. Ferruzzi, M.G., 2010. The influence of beverage composition on delivery of phenolic compounds from coffee and tea. Physiology & Behavior 100, 33–41. Flores, G., et al., 2015. Chemical composition and antioxidant activity of seven cultivars of guava (Psidium guajava) fruits. Food Chemistry 170, 327–335. Franco, M.N., et al., 2014. Phenolic compounds and antioxidant capacity of virgin olive oil. Food Chemistry 163, 289–298. Franco, D., et al., 2016. Antioxidant ability of potato (Solanum tuberosum) peel extracts to inhibit soybean oil oxidation. European Journal of Lipid Science and Technology 118, 1891–1902. Fratianni, F., et al., 2014. Polyphenol composition and antioxidant activity of different grass pea (Lathyrus sativus), lentils (Lens culinaris), and chickpea (Cicer arietinum) ecotypes of the Campania region (Southern Italy). Journal of Functional Foods 7, 551–557.

Target sources of polyphenols in different food products and their processing by-products

165

Fratianni, F., et al., 2017. Changes in visual quality, physiological and biochemical parameters assessed during the postharvest storage at chilling or non-chilling temperatures of three sweet basil (Ocimum basilicum L.) cultivars. Food Chemistry 229, 752–760. Friedman, M., 1997. Chemistry, biochemistry, and dietary role of potato polyphenols. Journal of Agricultural and Food Chemistry 45, 1523–1540. Friedman, M., et al., 2010. HPLC analysis of catechins, theaflavins, and alkaloids in commercial teas and green tea dietary supplements: comparison of water and 80% ethanol/water extracts. Journal of Food Science 71 (6), C328–C337. Fuhrman, B., et al., 2001. White wine with red wine-like properties: increased extraction of grape skin polyphenols improves the antioxidant capacity of the derived white wine. Journal of Agricultural and Food Chemistry 49, 3164–3168. Gani, A., et al., 2012. Whole-grain cereal bioactive compounds and their health benefits: a review. Food Processing & Technology 3 (3), 1–10. George, S., et al., 2011. Changes in the contents of carotenoids, phenolic compounds and vitamin C. Food Chemistry 124, 1603–1611. Ghasemzadeh, A., Jaafar, H.Z.E., Rahmat, A., 2016. Changes in antioxidant and antibacterial activities as well as phytochemical constituents associated with ginger storage and polyphenol oxidase activity. BMC Complementary and Alternative Medicine 16 (382), 1–11. Giacometti, J., et al., 2016. Cocoa polyphenols exhibit antioxidant, anti-inflammatory, anticancerogenic, and anti-necrotic activity in carbon tetrachloride-intoxicated mice. Journal of Functional Foods 23, 177–187. Giordano, D., et al., 2017. Bioactive compound and antioxidant activity distribution in roller-milled and pearled fractions of conventional and pigmented wheat varieties. Food Chemistry 233, 483–491. Giovanni, A., et al., 2002. Olive oil mill wastewater: isolation of polyphenols and their phytotoxicity in vitro. Allelopathy Journal 9 (1), 9–17. Giusti, F., et al., 2017. Determination of fourteen polyphenols in pulses by high performance liquid chromatography-diode array detection (HPLC-DAD) and correlation study with antioxidant activity and colour. Food Chemistry 221, 689–697. Gómez-Caravaca, A.M., et al., 2006. A simple and rapid electrophoretic method to characterize simple phenols, lignans, complex phenols, phenolic acids, and flavonoids in extra-virgin olive oil. Journal of Separation Science 29, 2221–2233. Gómez-Caravaca, A.M., Cerretani, L., Segura-Carretero, A., 2011. Qualitative phenolic profile (HPLC-DAD- MS) from olive oil mill waste waters at different states of storage and evaluation of hydrolysis process as a pretreatment to recover their antioxidants. Progress in Nutrition 13 (1), 22–30. Gómez-Caravaca, A.M., et al., 2014. A chemometric approach to determine the phenolic compounds in different barley samples by two different stationary phases: a comparison between C18 and pentafluorophenyl core shell columns. Journal of Chromatography A 1355, 134–142. Gómez-Caravaca, A.M., et al., 2015. Use of air classification technology as green process to produce functional barley flours naturally enriched of alkylresorcinols, β-glucans and phenolic compounds. Food Research International 73, 88–96. Goñi, I., Hervert-Hernández, D., 2011. By-products from plant foods are sources of dietary fibre and antioxidants. In: Rasooli, I. (Ed.), Phytochemicals - Bioactivities and Impact on Health. INTECH Publisher, Rijeta, Croatia, pp. 95–116. www.intechopen.com.

166

Polyphenols: Properties, Recovery, and Applications

Gonzales, G., et al., 2015. Liquid chromatography–mass spectrometry coupled with multivariate analysis for the characterization and discrimination of extractable and nonextractable polyphenols and glucosinolates from red cabbage and Brussels sprout waste streams. Journal of Chromatography A 1402, 60–70. González-Muñoz, A., et al., 2013. Potential of chilean native corn (Zea mays L.) accessions as natural sources of phenolic antioxidants and in vitro bioactivity for hyperglycemia and hypertension management. Journal of Agricultural and Food Chemistry 61, 10995–11007. Goufo, P., et al., 2015. Distribution of antioxidant compounds in the grain of the Mediterranean rice variety “Ariete”. CyTA-Journal of Food 13 (1), 140–150. Goulas, V., et al., 2012. Classification, biotransformation and antioxidant activity of olive fruit biophenols: a review. Current Bioative Compounds 8, 232–239. Gowe, C., 2015. Review on potential use of fruit and vegatable by-products as a valuable source of natural food additives. Food Science and Quality Management 45. Grace, M.H., et al., 2014. Comparative analysis of phenolic content and profile, antioxidant capacity and anti-inflammatory bioactivity in wild Alaskan and commercial Vaccinium berries. Journal of Agricultural and Food Chemistry 62 (18), 4007–4017. Gras, C., et al., 2017. Anthocyanins from purple sweet potato (Ipomoea batatas (L.) Lam.) and their color modulation by the addition of phenolic acids and food-grade phenolic plant extracts. Food Chemistry 235, 265–274. Güez, C.M., et al., 2017. Evaluation of basil extract (Ocimum basilicum L.) on oxidative, anti-genotoxic and anti-inflammatory effects in human leukocytes cell cultures exposed to challenging agents. Brazilian Journal of Pharmaceutical Sciences 53 (1), 15098. Gulewicz, P., et al., 2014. Non-nutritive compounds in Fabaceae family seeds and the improvement of their nutritional quality by traditional processing – a review. Polish Journal of Food and Nutrition Sciences 64 (2), 75–89. Guo, J., et al., 2015. Isolation and identification of bound compounds from corn bran and their antioxidant and angiotensin I-converting enzyme inhibitory activities. European Food Research and Technology 100, 37–47. Hamouz, K., et al., 2006. Influence of site conditions and cultivars on the contents of antioxidants in potato tubers. Zeszyty Problemowe Postępów Nauk Rolniczych 511, 245–254. Hang, M.W., et al., 2010. Phenolic profiles and antioxidant activity of lack rice bran of different commercially available varieties. Journal of Agricultural and Food Chemistry 58, 7580–7587. Heimler, D., et al., 2006. Antiradical activity and polyphenol composition of local Brassicaceae edible. Food Chemistry 99, 464–469. Heinonen, I.M., Meyer, A.S., 2002. Antioxidants in fruits, berries and vegetables. In: Jongen, W. (Ed.), Fruit and Vegetable Processing - Improving Quality. Woodhead Publishing Ltd. and CRC Press, LLC, Cambridge (chapter 3) http://www.foodnetbase.com. Helkar, P.B., Sahoo, A.K., Patil, N.J., 2016. Review: food industry by-products used as functional food ingredients. International Journal of Waste Resources 6 (3), 1–6 248. Helyes, L., Lugasi, A., 2006. Formation of certain compounds having technological and nutritional importance in tomato fruits during maturation. Acta Alimentaria 35, 183–193. Hernandez, M., Rodriguez, E., Diaz, C., 2007. Free hydroxycinnamic acids, lycopene, and color parameters in tomato cultivars. Food Chemistry 55, 8604–8615. Hernández, L., Afonso, D., Rodríguez, E.M., 2011. Phenolic compounds in wheat grain cultivars. Plant Foods for Human Nutrition 66, 408–415. Hietaniemi, V., Lehtinen, P., Poutanen, K., 2015. Phenolic compounds in wholegrain rye and its fractions. Journal of Food Composition and Analysis 38, 89–97.

Target sources of polyphenols in different food products and their processing by-products

167

Hii, C.L., et al., 2009. Polyphenols in cocoa (Theobroma cacao L.). Asian Journal of Food and Agro-Industry 2 (4), 702–722. Hitayezu, R., et al., 2015. Antioxidant activity, avenanthramide and phenolic acid contents of oat milling fractions. Journal of Cereal Science 63, 35–40. Hossain, H., Alam, A., 2015. HPLC-DAD system-based phenolic content analysis and in vitro antioxidant activities of rice bran obtained from aush dhan (Oryza sativa) of Bangladesh. Journal of Food Biochemistry 39, 462–470. Hosseinian, F.S., Mazza, G., 2009. Triticale bran and straw: potential new sources of phenolic acids, proanthocyanidins, and lignans. Journal of Functional Foods 1, 57–64. Ibañez, E., et al., 2003. Subcritical water extraction of antioxidant compounds from rosemary plants. Journal of Agricultural and Food Chemistry 51, 375–382. Inglett, G.E., Chen, D., 2011. Antioxidant activity and phenolic content of air-classified corn bran. Cereal Chemistry Journal 1, 36–40. Irakli, M.N., et al., 2012. Development and validation of an HPLC-method for determination of free and bound phenolic acids in cereals after solid-phase extraction. Food Chemistry 134 (3), 1624–1632. Jäger, S., et al., 2009. Pentacyclic triterpene distribution in various plants – rich sources for a new group of multi-potent plant extracts. Molecules 14, 2016–2031. Jahurul, M.H.A., et al., 2015. Mango (Mangifera indica L.) by-products and their valuable components: a review,. Food Chemistry 183, 173–180. Jalil, A.M.M., Ismail, A., 2008. Polyphenols in cocoa and cocoa products: is there a link between antioxidant properties and health? Molecules 13, 2190–2219. Jian Guo, X., et al., 2009. Dynamic changes in phenolic compounds and antioxidant activity in oats (Avena nuda L.) during steeping and germination. Agricultural and Food Chemistry 57, 10392–10398. Kalinowska, M., et al., 2014. Apples: content of phenolic compounds vs. variety, part of apple and cultivation model, extraction of phenolic compounds, biological properties. Plant Physiology and Biochemistry 84, 169–188. Kammerer, D.R., et al., 2014. Recovery of polyphenols from the by-products of plant food processing and application as valuable food ingredients. Food Research International 65, 2–12. Kanatt, S., et al., 2005. Potato peel extract-a natural antioxidant for retarding lipid peroxidation in radiation processed lamb meat. Journal of Agricultural and Food Chemistry 53, 1499–1504. Kapcum, N., et al., 2016. Anthocyanins, phenolic compounds and antioxidant activities in colored corn cob and colored rice bran. International Food Research Journal 23, 2347–2356. Karvela, E., et al., 2009. Deployment of response surface methodology to optimise recovery of grape (Vitis vinifera) stem polyphenols. Talanta 79, 1311–1321. Kaur, K.D., Jha, A., Sabikhi, L., 2014. Significance of coarse cereals in health and nutrition: a review. Journal of Food Science and Technology 51 (8), 1429–1441. Kelebek, H., Selli, S., Kola, O., 2017. Quantitative determination of phenolic compounds using LC-DAD-ESI-MS/MS in cv. Ayvalik olive oils as affected by harvest time. Journal of Food Measurement and Characterization 11 (1), 226–235. Kim, M., et al., 2008. Identification and quantification of anthocyanin pigments in colored rice. Nutrition Research and Practice 2, 46–49. Kocaadam, B., Şanlier, N., 2017. Curcumin, an active component of turmeric (Curcuma longa), and its effects on health. Critical Reviews in Food Science and Nutrition 57 (13), 2889–2895.

168

Polyphenols: Properties, Recovery, and Applications

Kondo, S., et al., 2002. Antioxidative activity of apple skin or flesh extracts associated with fruit development on selected apple cultivars. Scientia Horticulturae 96 (1–4), 177–185. Kowalska, H., et al., 2017. What’s new in biopotential of fruit and vegetable by-products applied in the food processing industry. Trends in Food Science & Technology 67, 150–159. Lachman, J., et al., 2009. Major factors influencing antioxidant contents and antioxidant activity in grapes and wines. International Journal of Wine Research 1, 101–121. Ladjal Ettoumi, Y., Chibane, M., 2015. Some physicochemical and functional properties of pea, chickpea and lentil whole flours. International Food Research Journal 22, 987–996. Landberg, R., et al., 2009. Comparison of GC and colorimetry for the determination of alkylresorcinol homologues in cereal grains and products. Food Chemistry 113 (4), 1363–1369. Laokuldilok, T., et al., 2011. Antioxidants and antioxidant activity of several pigmented rice brans. Journal of Agricultural and Food Chemistry 59, 193–199. Laribi, B., et al., 2015. Coriander (Coriandrum sativum L.) and its bioactive constituents. Fitoterapia 103, 9–26. Latif, S., Müller, J., 2015. Potential of cassava leaves in human nutrition: a review. Trends in Food Science & Technology 44 (2), 147–158. Lebot, V., Michalet, S., Legendre, L., 2016. Identification and quantification of phenolic compounds responsible for the antioxidant activity of sweet potatoes with different flesh colours using high performance thin layer chromatography (HPTLC). Journal of Food Composition and Analysis 49, 94–101. Lee, J., Scagel, C.F., 2009. Chicoric acid found in basil (Ocimum basilicum L.) leaves. Food Chemistry 115, 650–656. Lee, C., et al., 2013. Antioxidant and anti-hypertensive activity of anthocyanin-rich extracts from hulless pigmented barley cultivars. Food Science & Technology 48, 984–991. Lee, H.-A., et al., 2014. Onion peel water extracts enhance immune status in forced swimming rat model. Laboratory Animal Research 30, 161–168. Lewis, C., et al., 1998. Determination of anthocyanins, flavonoids and phenolic acids in potatoes. I: coloured cultivars of Solanum tuberosum. Journal of the Science of Food and Agriculture 77, 45–57. Liang, J., et al., 2017. Applications of chitosan nanoparticles to enhance absorption and bioavailability of tea polyphenols: a review. Food Hydrocolloids 69, 286–292. Lima, G.P.P., et al., 2014. Polyphenols in fruits and vegetables and its effect on human health. Food and Nutrition Sciences 5, 1065–1082. Liu, C.-W., et al., 2015. Guava (Psidium guajava Linn.) leaf extract promotes glucose uptake and glycogen accumulation by modulating the insulin signaling pathway in high-glucose-induced insulin-resistant mouse FL83B cells. Process Biochemistry 50, 1128–1135. Liu, L., et al., 2016. Effect of steam explosion-assisted extraction on phenolic acid profiles and antioxidant properties of wheat bran. Society of Chemical Industry 96, 3484–3491. Liu, L., et al., 2017. Complex enzyme hydrolysis releases antioxidative phenolics from rice bran. Food Chemistry 214, 1–8. López-Biedma, A., et al., 2016. The biological activities of natural lignans from olives and virgin olive oils: a review. Journal of Functional Foods 26, 36–47. Loubiri, A., et al., 2017. Usefulness of phenolic profile in the classification of extra virgin olive oils from autochthonous and introduced cultivars in Tunisia. European Food Research and Technology 243 (3), 467–479. Madsen, H.L., et al., 2000. Radical scavenging by dietary flavonoids. A kinetic study of antioxidant efficiencies. European Food Research and Technology 211, 240–246.

Target sources of polyphenols in different food products and their processing by-products

169

Magalhães, S.C.Q., et al., 2017. European marketable grain legume seeds: further insight into phenolic compounds profiles. Food Chemistry 215, 177–184. Manach, C., et al., 2004. Polyphenols: food sources and bioavailability. The American Journal of Clinical Nutrition 79, 727–747. Martí, R., Rosello, S., Cebolla-Cornejo, J., 2016. Tomato as a source of carotenoids and polyphenols targeted to cancer prevention. Cancers 58, 1–28. Martin, M.A., Goya, L., Ramos, S., 2013. Potential for preventive effects of cocoa and cocoa polyphenols in cancer. Food and Chemical Toxicology 56, 336–351. Martín-Peláez, S., et al., 2013. Health effects of olive oil polyphenols: recent advances and possibilities for the use of health claims. Molecular Nutrition & Food Research 1–12. Mateo, N., et al., 2010. Antioxidant and anti-inflammatory capacity of bioaccessible compounds from wheat fractions after gastrointestinal digestion. Journal of Cereal Science 51 (1), 110–114. Mazzoncini, M., et al., 2015. Organically vs conventionally grown winter wheat: effects on grain yield, technological quality, and on phenolic composition and antioxidant properties of bran and refined flour. Food Chemistry 175, 445–451. McCarthy, A.L., et al., 2013. Brewers’ spent grain; bioactivity of phenolic component, its role in animal nutrition and potential for incorporation in functional foods: a review. Proceedings of the Nutrition Society 72, 117–125. Medouni-Adrar, S., et al., 2015. Optimization of the recovery of phenolic compounds from Algerian grape by-products. Industrial Crops and Products 77, 123–132. Mekky, R.H., et al., 2015. Profiling of phenolic and other compounds from Egyptian cultivars of chickpea (Cicer arietinum L.) and antioxidant activity: a comparative study. Royal Society of Chemistry 5, 17751–17767. Meletis, C.D., 2006. Coffee—functional food and medicinal herb. Alternative and Complementary Therapies 12, 7–13. Mena, P., et al., 2016. Phytochemical profiling of flavonoids, phenolic acids, terpenoids, and volatile fraction of a rosemary (Rosmarinus officinalis L.). Extract Molecules 21, 1576. Mielnik, M.B., et al., 2008. By-products from herbs essential oil production as ingredient in marinade for Turkey thighs. LWT 41, 93–100. Molina-Alcaide, E., Yáñez-Ruiz, D.R., 2008. Potential use of olive by-products in ruminant feeding: a review. Animal Feed Science and Technology 147, 247–264. Moñino, I., et al., 2008. Polyphenolic transmission to Segureno lamb meat from ewes’ diet supplemented with the distillate from rosemary (Rosmarinus officinalis) leaves. Journal of Agricultural and Food Chemistry 56 (9), 3363–3367. Montagnac, J., Davis, C., Tanumihardjo, S., et al., 2009. Nutritional value of cassava for use as a staple food and recent advances for improvement. Comprehensive Reviews in Food Science and Food Safety 8, 181–194. Montilla, E.C., et al., 2011. Soluble and bound phenolic compounds in different bolivian purple corn (Zea mays L.) cultivars. Journal of Agricultural and Food Chemistry 59, 7068–7074. Moraesa, É.A., et al., 2015. Sorghum flour fractions: correlations among polysaccharides, phenolic compounds, antioxidant activity and glycemic index. Food Chemistry 180, 116–123. Msaada, K., et al., 2017. Antioxidant activity of methanolic extracts from three coriander (Coriandrum sativum L.) fruit varieties. Arabian Journal of Chemistry 10 (2), S3176–S3183. Murniece, I., et al., 2014. Carotenoids and Total Phenolic Content in Potatoes With Different Flesh Colour. FoodBalt (206–211). Latvia University of Agriculture, Jelgava.

170

Polyphenols: Properties, Recovery, and Applications

Musilová, J., et al., 2017. Polyphenols and phenolic acids in sweet potato (Ipomoea batatas L.) roots. Slovak Journal of Food Sciences 11, 82–87. Najafian, M., et al., 2012. Phloridzin reduces blood glucose levels and improves lipids metabolism in streptozotocin-induced diabetic rats. Molecular Biology Reports 39 (5), 5299–5306. Natsume, M., et al., 2000. Analyses of polyphenols in cacao liquor, cocoa, and chocolate by normal-phase and reversed-phase HPLC. Bioscience, Biotechnology, and Biochemistry 64 (12), 2581–2587. Nicoletti, I., et al., 2013. Identification and quantification of soluble Free, soluble conjugated, and insoluble bound phenolic acids in durum wheat (Triticum turgidum L. var. durum) and derived products by RP-HPLC on a semimicro separation scale. Journal Agricultural and Food Chemistry 61, 11800–11807. Nowacka, M., et al., 2017. Effect of ultrasound treatment during osmotic dehydration on bioactive compounds of cranberries. Ultrasonics. (in press) https://doi.org/ 10.1016/j.ultras.2017.06.022. Nyström, L., et al., 2008. Phytochemicals and dietary fiber components in rye varieties in the HEALTHGRAIN diversity screen. Journal of Agricultural and Food Chemistry 56, 9758–9766. Obied, H.K., et al., 2005. Bioactivity and analysis of biophenols recovered from olive mill waste. Journal of Agricultural and Food Chemistry 53, 823–837. Okarter, N., Liu, R.H., 2010. Health benefits of whole grain phytochemicals. Food Science and Nutrition 50, 193–208. Okiyama, D.C.G., Navarro, S.L.B., Rodrigues, C.E.C., 2017. Cocoa shell and its compounds: applications in the food industry. Trends in Food Science & Technology 63, 103–112. Oladokun, O., et al., 2016. The impact of hop bitter acid and polyphenol profiles on the perceived bitterness of beer. Food Chemistry 205, 212–220. Oomah, B.D., et al., 2011. Phenolics and antioxidant activity of lentil and pea hulls. Food Research International 44 (1), 436–441. Owen, R.W., et al., 2000. Identification of lignans as major components in the phenolic fraction of olive oil. Clinical Chemistry 46 (7), 976–988. Padda, M., Picha, D., 2008. Quantification of phenolic acids and antioxidant activity in sweetpotato genotypes. Scientia Horticulturae 119, 17–20. Pandey, K.B., Rizvi, S.I., 2009. Plant polyphenols as dietary antioxidants in human health and disease. Oxidative Medicine and Cellular Longevity 2 (5), 270–278. Paucar-Menacho, L.M., et al., 2017. Optimization of germination time and temperature to maximize the content of bioactive compounds and the antioxidant activity of purple corn (Zea mays L.) by response surface methodology. Food Science and Technology 76, 236–244. Pavlić, B., et al., 2017. Sage processing from by-product to high quality powder: I. Bioactive potential. Industrial Crops & Products 107, 81–89. Pereira-Caro, G., et al., 2013. Phytochemical profile of a Japanese black – purple rice. Food Chemistry 141 (3), 2821–2827. Pérez-Jiménez, J., et al., 2010. Identification of the 100 richest dietary sources of polyphenols: an application of the Phenol-Explorer database. European Journal of Clinical Nutrition 64, S112–S120. Pérez-Serradilla, J.A., Luque de Castro, M.D., 2011. Microwave-assisted extraction of phenolic compounds from wine lees and spray-drying of the extract. Food Chemistry 124, 1652–1659.

Target sources of polyphenols in different food products and their processing by-products

171

Pérez-Trujillo, M., et al., 2010. Separation and identification of phenolic compounds of extra virgin olive oil from Olea europaea L. by HPLC-DAD-SPE-NMR/MS. Identification of a new diastereoisomer of the aldehydic form of oleuropein aglycone. Journal Agricultural and Food Chemistry 58, 9129–9136. Perla, V., Holm, D., Jayanty, S., 2012. Effects of cooking methods on polyphenols, pigments and antioxidant activity in potato tubers. LWT - Food Science and Technology 45, 161–171. Perrone, D., et al., 2010. Modeling weight loss and chlorogenic acids content in coffee during roasting. Journal of Agriculture and Food Chemistry 58 (23), 12238–12243. Piazzon, A., Forte, M., Nardini, M., 2010. Characterization of phenolics content and antioxidant activity of different beer types. Journal of Agriculture and Food Chemistry 58 (19), 10677–10683. Pizzale, L., et al., 2002. Antioxidant activity of sage and oregano extracts related to their phenolic compound content. Journal of the Science of Food and Agriculture 82, 1645–1651. Qiu, Y., Liu, Q., Beta, T., 2010. Antioxidant properties of commercial wild rice and analysis of soluble and insoluble phenolic acids. Food Chemistry 121 (1), 140–147. Qu, W., et al., 2012. Quantitative determination of major polyphenol constituents in pomegranate products. Food Chemistry 132 (3), 1585–1591. Rafiq, S., et al., 2016. Citrus peel as a source of functional ingredient: a review. Journal of the Saudi Society of Agricultural Sciences. (in press) https://doi.org/10.1016/j.jssas.2016.07.006. Ramalakshmi, K., et al., 2009. Bioactives of low-grade green coffee and spent coffee in different in vitro model systems. Food Chemistry 115, 79–85. Ramírez-Coronel, M.A., et al., 2004. Characterization and estimation of proanthocyanidins and other phenolics in coffee pulp (Coffea arabica) by thiolysis-high-performance liquid chromatography. Journal of Agricultural and Food Chemistry 52, 1344–1349. Ramírez-Martínez, J.R., 1988. Phenolic compounds in coffee pulp: quantitative determination by HPLC. Journal of the Science of Food and Agriculture 43, 135–144. Rana, S., et al., 2015. Functional properties, phenolic constituents and antioxidant potential of industrial apple pomace for utilization as active food ingredient. Food Science and Human Wellness 4, 180–187. Rehman, Z-u., Habib, F., Shah, W., 2004. Utilization of potato peels extract as a natural antioxidant in soy bean oil. Food Chemistry 85, 215–220. Rezzadori, K., Benedetti, S., Amante, E.R., 2012. Proposals for the residues recovery: orange waste as raw material for new products. Food and Bioproducts Processing 90, 606–614. Ricciutelli, M., et al., 2017. Olive oil polyphenols: a quantitative method by high-performance liquid-chromatography-diode-array detection for their determination and the assessment of the related health claim. Journal of Chromatography A 1481, 53–63. Rimbach, G., Egert, S., de Pascual-Teresa, S., 2011. Chocolate: (un)healthy source of polyphenols? Genes and Nutrition 6, 1–3. Roby, M.H.H., et al., 2013. Evaluation of antioxidant activity, total phenols and phenolic compounds in thyme (Thymus vulgaris L.), sage (Salvia officinalis L.), and marjoram (Origanum majorana L.) extracts. Industrial Crops and Products 43, 827–831. Rockenbach, I.I., et al., 2011. Phenolic compounds and antioxidant activity of seed and skin extracts of red grape (Vitis vinifera and Vitis labrusca) pomace from Brazilian winemaking. Food Research International 44, 897–901. Rojas-Garbanzo, C., et al., 2017. Characterization of phenolic and other polar compounds in peel and flesh of pink guava (Psidium guajava L. cv. ‘Criolla’) by ultra-high performance liquid chromatography with diode array and mass spectrometric detection. Food Research International 100 (3), 445–453.

172

Polyphenols: Properties, Recovery, and Applications

Roldan, E., et al., 2008. Characterisation of onion (Allium cepa L.) by-products as food ingredients with antioxidant and antibrowning properties. Food Chemistry 108, 907–916. Rubio-Senent, F., et al., 2012. New phenolic compounds hydrothermally extracted from the olive oil byproduct alperujo and their antioxidative activities. Journal of Agricultural and Food Chemistry 60, 1175–1186. Rubio-Senent, F., et al., 2013. Phenolic extract obtained from steam-treated olive oil waste: characterization and antioxidant activity. LWT - Food Science and Technology 54 (1), 114–124. Rumbaoa, R., Cornago, D., Geronimo, I., 2009. Phenolic content and antioxidant capacity of Philippine sweet potato (Ipomoea batatas) varieties. Food Chemistry 113, 1133–1138. Sadowska, U., et al., 2017. The effect of drying methods on the concentration of compounds in sage and thyme. Journal of Food Process and Preservation. http://dx.doi.org/10.1111/jfpp.13286. Sánchez de Medina, V., Priego-Capote, F., Luque de Castro, M.D., 2012. Characterization of refined edible oils enriched with phenolic extracts from olive leaves and pomace. Journal of Agricultural and Food Chemistry 60, 5866–5873. Sarkar, A., Kaul, P., 2014. Evaluation of tomato processing by-products: a comparative study in a pilot scale setup. Journal of Food Process Engineering 37, 299–307. Schinella, G., et al., 2010. Antioxidant properties of polyphenol-rich cocoa products industrially processed. Food Research International 43, 1614–1623. Schirrmacher, G., Schempp, H., 2003. Antioxidative potential of flavonoid-rich extracts as new quality marker for different apple varieties. Journal of Applied Botany and Food Quality/ Angewandte Botanik 77 (5–6), 163–167. Segev, A., et al., 2010. Determination of polyphenols, flavonoids, and antioxidant capacity in colored chickpea (Cicer arietinum L.). Journal of Food Science 75 (2), 2–6. Shahidi, F., Ambigaipalan, P., 2015. Phenolics and polyphenolics in foods, beverages and spices: antioxidant activity and health effects – a review. Journal of Functional Foods 18, 820–897. Shahidi, F., Chandrasekara, A., 2015. Processing of millet grains and effects on non-nutrient antioxidant compounds. In: Preedy, V. (Ed.), Processing and Impact on Active Components in Food. Elsevier, San Diego. Sharma, S., Saxena, D.C., Riar, C.S., 2017. Using combined optimization, GC–MS and analytical technique to analyze the germination effect on phenolics, dietary fibers, minerals and GABA contents of Kodo millet (Paspalum scrobiculatum). Food Chemistry 233, 20–28. Silva, P., Ferreira, S., Nunes, F.M., 2017. Elderberry (Sambucus nigra L.) by-products a source of anthocyanins and antioxidant polyphenols. Industrial Crops and Products 95, 227–234. Singh, B., et al., 2017. Ultrasound assisted extraction of polyphenols and their distribution in whole mung bean, hull and cotyledon. Journal of Food Science and Technology 54 (4), 921–932. Skrovankova, S., et al., 2015. Bioactive compounds and antioxidant activity in different types of berries. International Journal of Molecular Sciences 16, 24673–24706. Śledź, M., et al., 2013. Selected chemical and physico-chemical properties of microwave-convective dried herbs. Journal of Food and Bioproducts Processing 91, 421–428. Sluis, A., et al., 2002. Activity and concentration of polyphenolic anti-oxidants in apple juice. Effect of existing production methods. Journal of Agricultural and Food Chemistry 50 (25), 7211–7214. Smeds, A.I., et al., 2009. Characterization of variation in the lignan content and composition of winter rye, spring wheat, and spring oat. Journal Agricultural and Food Chemistry 57, 5837–5842.

Target sources of polyphenols in different food products and their processing by-products

173

Sójka, M., Kołodziejczyk, K., Milala, J., 2013. Polyphenolic and basic chemical composition of black chokeberry industrial by-products. Industrial Crops and Products 51, 77–86. Sreerama, Y.N., et al., 2010a. Distribution of nutrients and antinutrients in milled fractions of chickpea and horse Gram: seed coat phenolics and their distinct modes of enzyme inhibition. Journal Agricultural and Food Chemistry 58, 4322–4330. Sreerama, Y.N., Sashikala, B.V., M.Pratape, V., 2010b. Variability in the distribution of phenolic compounds in milled fractions of chickpea and horse gram: evaluation of their antioxidant properties. Journal Agricultural and Food Chemistry 58, 8322–8330. Stanisavljević, N.S., et al., 2016. Identification of phenolic compounds from seed coats of differently colored european varieties of pea (Pisum sativum L.) and characterization of their antioxidant and in vitro anticancer activities. Nutrition and Cancer 68, 988–1000. Sun, J., et al., 2002. Antioxidant and antiproliferative activities of common fruits. Journal of Agricultural and Food Chemistry 50 (25), 7449–7454. Taboada, E., Siacor, F.D., 2013. Preparation of Pectin and Polyphenolic Compositions from Mango Peels. Patent WO2013141723 A1. Tajik, N., et al., 2017. The potential effects of chlorogenic acid, the main phenolic components in coffee, on health: a comprehensive review of the literature. European Journal of Nutrition. http://dx.doi.org/10.1007/s00394-017-1379-1. Talhaoui, N., et al., 2014. Determination of phenolic compounds of “Sikitita” olive leaves by HPLC-DAD-TOF-MS. Comparison with its parents “Arbequina” and “Picual” olive leaves. LWT - Food Science and Technology 58 (1), 28–34. Talhaoui, N., et al., 2015. Chemometric analysis for the evaluation of phenolic patterns in olive leaves from six cultivars at different growth stages. Journal of Agricultural and Food Chemistry 63 (6), 1722–1729. Talhaoui, N., et al., 2015. Phenolic compounds in olive leaves: analytical determination, biotic and abiotic influence, and health benefits. Food Research International 77, 92–108. Tappi, S., et al., 2017. Study on the quality and stability of minimally processed apples impregnated with green tea polyphenols during storage. Innovative Food Science & Emerging Technologies 39, 148–155. Teixeira, A., et al., 2014. Natural bioactive compounds from winery by-products as health promoters: a review. International Journal of Molecular Science 15 (9), 15638–15678. Troszyńska, A., et al., 2011. Relationship between the sensory quality of lentil (Lens culinaris) sprouts and their phenolic constituents. Food Research International 44, 3195–3201. Tsimidou, M., 1998. Polyphenols and quality of virgin olive oil in retrospect. Italian Journal of Food Science 99–116. Udeh, H.O., et al., 2017. Finger millet bioactive compounds, bioaccessibility, and potential health effects – a review. Czech Journal of Food Sciences 35 (1), 7–17. Vaher, M., et al., 2010. Phenolic compounds and the antioxidant activity of the bran, flour and whole grain of different wheat varieties. Procedia Chemistry 2 (1), 76–82. Vainio, H., Bianchini, F., 2003. IARC Handbooks of Cancer Prevention, Vol. 8 – Fruit and Vegetables. IARC Press, Lyon. Vallverdu-Queralt, A., et al., 2014. A comprehensive study on the phenolic profile of widely used culinary herbs and spices: rosemary, thyme, oregano, cinnamon, cumin and bay. Food Chemistry 154, 299–307. Vallverdú-Queralt, A., et al., 2015. Characterization of the phenolic and antioxidant profiles of selected culinary herbs and spices: caraway, turmeric, dill, marjoram and nutmeg. Food Science and Technology 35 (1), 189–195.

174

Polyphenols: Properties, Recovery, and Applications

Varzakas, T., Zakynthinos, G., Verpoort, F., 2016. Plant food residues as a source of nutraceuticals and functional foods. Foods 5, 88. http://dx.doi.org/10.3390/foods5040088. Verardo, V., et al., 2008a. Determination of free flavan-3-ol content in barley (Hordeum vulgare L.) air-classified flours: comparative study of HPLC-DAD/MS and spectrophotometric determinations. Journal Agricultural and Food Chemistry 56, 6944–6948. Verardo, V., et al., 2008b. Distribution of bound hydroxycinnamic acids and their glycosyl esters in barley (Hordeum vulgare L.) air-classified flour: comparative study between reversed phase-high performance chromatography-mass spectrometry (RP-HPLC/MS) spectrophotometric analysis. Journal of Agricultural and Food Chemistry 56, 11900–11905. Verardo, V., et al., 2011a. Air classification of barley flours to produce phenolic enriched ingredients: comparative study among MEKC-UV, RP-HPLC-DAD-MS and spectrophotometric determinations. LWT - Food Science and Technology 44 (7), 1555–1561. Verardo, V., et al., 2011b. Free and bound minor polar compounds in oats: different extraction methods and analytical determinations. Journal of Cereal Science 54 (2), 211–217. Verardo, V., et al., 2016. Determination of lipophilic and hydrophilic bioactive compounds in raw and parboiled rice bran. Royal Society of Chemistry 6, 50786–50796. Visioli, F., Bernardini, E., 2011. Extra virgin olive oil’s polyphenols: biological activities. Current Pharmaceutical Design 17 (8), 786–804. Wang, S., Nie, S., Zhu, F., 2016. Chemical constituents and health effects of sweet potato. Food Research International 89, 90–116. Wolfe, K., Wu, X., Liu, R.H., 2003. Antioxidant activity of apple peels. Journal of Agricultural and Food Chemistry 51 (3), 609–614. Wollgast, J., 2004. The Contents and Effects of Polyphenols in Chocolate Qualitative and Quantitative Analyses of Polyphenols in Chocolate and Chocolate Raw Products as Well as Evaluation of Potential Implications of Chocolate Consumption in Human Health Ph.D. thesis. (Gießen). Xi, L., Mu, T., Sun, H., 2015. Preparative purification of polyphenols from sweet potato (Ipomoea batatas L.) leaves by AB-8 macroporous resins. Food Chemistry 172, 166–174. Xu, B., Chang, S.K., 2010. Phenolic substance characterization and chemical and cell-based antioxidant activities of 11 lentils grown in the northern United States. Journal Agricultural and Food Chemistry 58, 1509–1517. Yao, Y., Zhou, M., Ren, G., 2010. Antioxidant and α-glucosidase inhibitory activity of colored grains in China. Journal of Agricultural and Food Chemistry 58 (2), 770–774. Zanoletti, M., et al., 2017. Debranning of purple wheat: recovery of anthocyanin-rich fractions and their use in pasta production. LWT - Food Science and Technology 75, 663–669. Zarzecka, K., et al., 2013. Polyphenols content in potato tubers. Progress in Plant Protection 53, 202–206 (in Polish, English abstract). Zeković, Z., et al., 2014. Optimization of subcritical water extraction of antioxidants from Coriandrum sativum seeds by response surface methodology. The Journal of Supercritical Fluids 95, 560–566. Zeković, Z., et al., 2016. Chemical characterization of polyphenols and volatile fraction of coriander (Coriandrum sativum L.) extracts obtained by subcritical water extraction. Industrial Crops and Products 87, 54–63. Zeković, Z., et al., 2017. Utilization of sage by-products as raw material for antioxidants recovery—ultrasound versus microwave-assisted extraction. Industrial Crops and Products 99, 49–59. Zhang, L., Liu, R., Niu, W., 2014. Phytochemical and antiproliferative activity of proso millet. PLoS One 9 (8).

Target sources of polyphenols in different food products and their processing by-products

175

Zhao, Z., Moghadasian, M.H., 2008. Chemistry, natural sources, dietary intake and pharmacokinetic properties of ferulic acid: a review. Food Chemistry 109, 691–702. Zhao, H., et al., 2010. Phenolic profiles and antioxidant activities of commercial beers. Food Chemistry 119, 1150–1158. Žilić, S., et al., 2012. Distributions of phenolic compounds, yellow pigments and oxidative enzymes in wheat grains and their relation to antioxidant capacity of bran and debranes flour. Journal of Cereal Science 56, 652–658. Zimmermann, B.F., et al., 2011. Rapid UHPLC determination of polyphenols in aqueous infusions of Salvia officinalis L. (sage tea). Journal of Chromatography B 879, 2459–2464. Żyżelewicz, D., et al., 2016. The influence of the roasting process conditions on the polyphenol content in cocoa beans, nibs and chocolates. Food Research International 89, 918–929.