Avocado by-products: Nutritional and functional properties

Trends in Food Science & Technology 80 (2018) 51–60

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Trends in Food Science & Technology journal homepage: www.elsevier.com/locate/tifs

Review

Avocado by-products: Nutritional and functional properties a

a

a

T b

Rafael G. Araújo , Rosa M. Rodriguez-Jasso , Héctor A. Ruiz , Maria Manuela E. Pintado , Cristóbal Noé Aguilara,∗ a b

Food Research Department, School of Chemistry, Universidad Autónoma de Coahuila, 25280, Saltillo, Coahuila, Mexico CBQF – Centro de Biotecnologia e Química Fina, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Porto, 4202-401, Portugal

A R T I C LE I N FO

A B S T R A C T

Keywords: Persea americana Mill. Nutritional value Functional properties By-products

Background: Avocado (Persea americana Mill.) is a tropical and subtropical fruit that is native to Mexico and Central America; avocado is gaining increasing worldwide acceptance and has received extensive marketing and a wide distribution due to its relevant nutritional benefits for human health. Mexico harvests more than 30% of avocados worldwide, representing the main producer and exporter of avocado, which has become a crop of high interest and has great economic impact on Mexico. Scope and approach: In this paper, we describe relevant information on the production, composition and application of avocado, with an emphasis on its by-products, focusing on the proper use of waste and the possibility of monetizing waste for nutritional and environmental purposes. The entire avocado is rich in biocompounds (pulp, seed and peel) and has many health benefits, such as antimicrobial, antioxidant and anticancer activities, as well as dermatological uses and others. In this paper, we demonstrate the current panorama of production, exportation and uses of avocado in Mexico. Key findings and conclusions: Several food grade ingredients can be obtained from avocado wastes, particularly premium-grade fats or extracts with a high functional power. Studies should continue to identify the profiles and phytochemicals available to the business sector, which can also be implemented to valorize the nutritional and functional potential of avocado seeds and peels.

1. Introduction The word “avocado” derives from the Aztec word “ahuacatl”, which after modifications by the Spanish language, resulted in the word “ahuacate” or “aguacate” (Cowan & Wolstenholme, 2016). Avocado is native to Mexico and Central America, and there is evidence of its consumption in Mexico for the last 10000 years (Gutiérrez-Contreras, Lara-Chávez, Guillén-Andrade, & Chávez-Bárcenas, 2010). The first evidence of the existence of avocado dates to the presence of avocado seeds in the Coxcatlan Cave, Tahuacan Valley Puebla, Mexico (Zafar & Sidhu, 2011). Usually, avocado is referred to as butter pear due its shape and the smooth texture of its pulp. Avocado belongs to the kingdom Plantae, family Lauraceae, order Laurales, genus Persea, and species P. americana (Zafar & Sidhu, 2011). Avocado is the most important and only edible fruit of the family Lauraceae and has a high commercial value. The genus Persea has more than 150 species, of which 70 species grow in warm regions of America (Ding, Chin, Kinghorn, & D'Ambrosio, 2007; Ranade & Thiagarajan, 2015). Botanically, the name of the avocado is Persea americana Mill., which contains

∗

three ecological races that, in some sources, are incorrectly labelled as botanical varieties or subspecies. However, the validity of these “botanical variants" has been questioned by researchers and requires further studies (Cowan & Wolstenholme, 2016). The main purpose of this review article is to generate interest in the research and development of new technologies and methodologies to valorize avocado residues and elucidate the importance and characteristics of bioactive compounds and added value compounds of avocado to propose these residues as a source of ingredients or additives in the food industry. 1.1. Avocado tree The avocado tree is leafy, evergreen and tall and can reach heights of up to 20 m (Litz, Raharjo, & Lim, 2007). Each tree can produce up to one million flowers, although only one in a thousand flowers transforms into a fruit, and a single tree can generate up to a thousand avocados in a year. The flowers appear in clusters and have the peculiarity of opening at two different times: first as a feminine flower and later as a male, thus avoiding self-fertilization (Litz et al., 2007; SIAP, 2015). It is

Corresponding author. E-mail address: [email protected] (C.N. Aguilar).

https://doi.org/10.1016/j.tifs.2018.07.027 Received 7 October 2017; Received in revised form 27 July 2018; Accepted 28 July 2018 Available online 01 August 2018 0924-2244/ © 2018 Elsevier Ltd. All rights reserved.

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Table 1 Characteristics of principal varieties of avocado. Variety

Parentage

Seed size

Skin texture

Blossom Type

Fruit Shape

Skin Colour Unripe

Skin colour ripe

Skin Thickness

Average Fruit weight (oz)

Origin

Hass

Hybrid

Medium

Pebbly

A

Green

Black

Medium

140–340

California

Bacon Ettinger Pinkerton

Mexican Mexican Hybrid

Large Large Small

B B A

Green Green Green

Green Green Green

Thin Thin Medium

170–510 255–570 255–510

California Israel California

Reed Fuerte Lam Hass Williams Zutanno Stewart McDonald Lula

Guatemalan Hybrid Hybrid Guatemalan Mexican Mexican Guatemalan Hybrid

Large Large Medium Medium Medium Small Medium Large

A B A A B A B B

Spheroid Obovate Obovate High spheroid Obovate Obovate Spheroid Pyriform

Green Green Black Green Green Black Green/Black Green

Green Green Black Black Green Black Black Green

Medium Medium Medium Medium Thin Thin Thick N/A

480–680 255–455 280–510 225 310–400 170–370 340–450 450–680

California Puebla, Mexico California California California California Hawaii Florida

Gwen Nabal Mexicola Mexicola grande Dickinson General Bureau Gil Dickey Lewis Puebla

Hybrid Guatemalan Mexican Mexican

Medium Large Large Large

Smooth Smooth Roughpebbly Medium Medium Pebbly Medium Smooth Smooth Rough Almost smooth Pebbly Smooth Smooth Smooth

Narrowly obovate to obovate Obovate Narrowly obovate Pyriform

A B A A

Obovate Spheroid Obovate Obovate

Green Green Black Black

Green Green Black Black

Medium Medium Thin Thin

170–425 450–850 110–185 170–200

California Guatemala California California

Guatemalan West India

Small Large

A A

Narrowly obovate Pyriform

Black Light green

Black Light green

Thick Medium

170–340 200–510

California Morocco

Hybrid Guatemalan West India Mexican

Large Small Medium Large

Pebbly Mostly smooth Pebbly Rough Smooth Smooth

A A N/A A

Narrowly obovate Pyriform Pyriform Obovate

Green/Black Green Green Black

Black Green Black Black

Thick N/A N/A Thick

255–400 340–680 595 170–450

Israel Mexico Hawaii Mexico

usually necessary to wait five years to obtain the first harvest from avocado trees that have grown from seeds, and approximately 50 fruits are obtained during this cycle; production continues to increase with time. Maximum production is usually achieved after 10 years, with each tree being able to supply more than 1000 fruits (SIAP, 2015). By contrast, with grafted trees, the production of fruits takes place in the first 2 years and reproducibility and fruit quality are totally ensured (Zafar & Sidhu, 2011). The avocado tree can grow in areas with different conditions, depending on the variety; with mild-winter conditions; dry subtropical and Mediterranean climates; and cool and high altitude tropical areas, but not under desert conditions (Zafar & Sidhu, 2011).

& Sidhu, 2011). Avocado fruit is dispersed worldwide in tropical and subtropical regions. There are numerous varieties of avocado around the world, according to the climate in which they grow, with different shapes, flavours, textures, colours and smells. The most well-known and marketed types are the Hass and Fuerte varieties (Litz et al., 2007; SIAP, 2015). 1.3. Avocado varieties Avocado fruit is variable size, shape and weight, depending on the variety, climatic conditions and agricultural practices used during cultivation (Arriola, Menchú, & Rolz, 1979). Currently, more than 500 varieties of avocado have been identified, but most of them are not commercially produced due to diverse problems, such as production time, quality in terms of protein and fat contents, resistance problems and damage during transportation. There are many differences between the varieties of avocado, namely, form, weight, size, and flavour, but the most prominent difference is the colour of the bark during ripening (Yahia & Woolf, 2011). Avocado is botanically classified into three groups, which have been termed the Mexican (Persea americana var. drymifolia), Guatemalan (Persea nubigena var. guatemalensis) and West Indian (Persea americana var. americana) types or races. The names are based on the respective origins and differences in growing conditions and characteristics of the fruit (Bergh & Ellstrand, 1986; Morton, 2004; Zafar & Sidhu, 2011). Currently, commercial varieties are mainly based on the Guatemalan and Guatemalan-Mexican hybrid cultivars, for example, the Hass variety is a Guatemalan-Mexican hybrid race (Cowan & Wolstenholme, 2016). Other varieties, such as Bacon, Ettinger, Pinkerton, Reed, Fuerte and Lam Hass, are currently commercialized, as shown in Table 1 (Cowan & Wolstenholme, 2016; Dabas, Shegog, Ziegler, & Lambert, 2013).

1.2. Avocado fruit Avocado is known as alligator pear, vegetable butter or sometimes as butter pear and is called aguacate, cura, cupandra, or palta by Spanish-speaking people; abacate in by Portuguese-speaking people; and avocatier by French-speaking people (Morton, 2004). Avocado can be as small as 120 g and as large as 2.5 kg; can have a smooth or rough surface; thin or thick skin; and pyriform, obovate or globose berry; avocado may have a single seed depending on the variety (Morton, 2004). Avocado is very heterogenous and has a long juvenile period due to the low occurrence of self-pollination. The varieties are classified as type A or B based on the flowering pattern, and the flowers are functionally female or male. However, type A is functionally a female flower in the morning, while type B is female in the afternoon, with two days of pollination (Litz et al., 2007). Avocado ripening is completely different from that of most other fruits because ripening does not happen in the tree, but only after harvest. Avocados present in trees achieve physiological ripening and can remain on the tree for many months until harvest (Blakey, Bower, & Bertling, 2009; Yahia & Woolf, 2011). Maturation in the tree is determined by the percentage of dry matter, which is reciprocal to the percentage of moisture and has been shown to correlate very well with the post-harvest ripening ability of avocado. This procedure has become standard for determining avocado maturity and is currently used worldwide (Cowan & Wolstenholme, 2016; Zafar

1.4. Nutritional composition of avocado Avocado is known for its high nutritional content (Table 2) and health benefits, which are essentially due to the source of fat-soluble 52

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Kylli, & Estévez, 2011). The composition of avocado or any other fruit is dependent on the variety, grade of ripening, climate, composition of soil and fertilizers (Alvarez et al., 2012). The lipid content is one of the most important factors in avocado since it contains a large amount of oil in comparison to other fruits (Ranade & Thiagarajan, 2015) and is rich in polar lipids, such as glycolipids and phospholipids, which are important in various cellular processes in cell membranes (Zafar & Sidhu, 2011) as well as in monounsaturated fatty acids, which are effective in reducing the blood levels of undesirable low-density lipoprotein (LDL) and increasing the levels of the beneficial high-density lipoprotein (HDL) (Alvarez et al., 2012; Cowan & Wolstenholme, 2016). Compared to other vegetable oils, avocado oil is known to contain high levels of monounsaturated fatty acids (oleic and palmitoleic acids), low quantities of polyunsaturated fatty acids (linoleic acid) and a significant quantity of saturated fatty acids (palmitic and stearic acids) (Duarte et al., 2016). Other fatty acids are found in avocado oils in a small proportion, such as myristic, linolenic, and eicosenoic acids (Carvalho, Bernal, Velásquez, & Cartagena, 2015). The composition of these fatty acids vary depending on the cultivars, maturity stage, anatomical region of the fruit and geographic location of plant growth (Lacerda et al., 2015; Tango, Carvalho, & Soares, 2004). The mineral content of avocado includes an abundant quantity of potassium, phosphorus, magnesium, calcium and sodium, and other minerals, including iron and zinc, which appear at amounts of less than 1 mg per gram of fresh weight of avocado. The high content of potassium and low content of sodium are beneficial for persons with lowsodium diets and protect against cardiovascular diseases (Alvarez et al., 2012; Cowan & Wolstenholme, 2016; Zafar & Sidhu, 2011). Another relevant advantage of avocado is the presence of vitamins, such as β-carotene, vitamin E, retinol, ascorbic acid, thiamine, riboflavin, niacin, pyridoxine and folic acid, which are of great importance for overall health and wellbeing (Alvarez et al., 2012; Duarte et al., 2016).

Table 2 Avocado pulp composition (USDA, 2011). Nutrient/phytochemical

Unity

Value per 100 g

1 fruit 136 g

1 serving 30 g

Proximate Water Energy Energy (insoluble fiber adjusted) Protein Total lipid (fat) Ash Carbohydrate Fiber Sugars Starch Minerals

(g) (kcal) (kcal) (g) (g) (g) (g) (g) (g) (g)

72.3 167 148 1.96 15.4 1.66 8.64 6.8 0.3 0.11

98.4 227 201 2.67 21 2.26 11.8 9.2 0.41 0.15

21.7 50 44 0.59 4.62 0.5 2.59 2 0.09 0.03

Calcium Iron Magnesium Phosphorus Potassium Sodium Zinc Copper Manganese Selenium Vitamins and Phytochemicals

(mg) (mg) (mg) (mg) (mg) (mg) (mg) (mg) (mg) (ug)

13 0.61 29 54 507 8 0.68 0.17 0.15 0.4

18 0.83 39 73 690 11 0.92 0.23 0.2 0.5

4 0.18 9 16 152 2 0.2 0.05 0.05 0.1

Vitamin C Thiamine Riboflavin Niacin Pantothenic acid Vitamin B-6 Folate food Choline total Betaine Vitamin B-12 Vitamin A Carotene beta Carotene alpha Cryptoxanthin beta Lutein + zeaxanthin Vitamin E (alpha-tocopherol) Tocopherol beta Tocopherol gamma Tocopherol delta Vitamin k1 (phylloquinone) Lipids

(mg) (mg) (mg) (mg) (mg) (mg) (μg) (mg) (mg) (μg) (μg) (μg) (μg) (μg) (μg) (mg) (mg) (mg) (mg) (μg)

8.8 0.08 0.14 1.91 1.46 0.29 89 14.2 0.7 0 7 63 24 27 271 1.97 0.04 0.32 0.02 21

12 0.1 0.19 2.6 2 0.39 121 19.3 1 0 10 86 33 37 369 2.68 0.05 0.44 0.03 28.6

2.6 0.02 0.04 0.57 0.44 0.09 27 4.3 0.2 0 2 19 7 8 81 0.59 0.01 0.1 0.01 6.3

Fatty acids, total monounsaturated Fatty acids, total saturated Fatty acids, total polyunsaturated Cholesterol Stigmasterol Campesterol Beta-sitosterol

(g)

9.8

13.3

2.94

(g) (g) (mg) (mg) (mg) (mg)

2.13 1.82 0 2 5 76

2.9 2.47 0 3 7 103

0.64 0.55 0 1 2 23

2. Worldwide production Avocado has a high nutritional content that has recently aroused increasing global interest. Global avocado production in 2014 was more than 5 million tons, with 547849 ha dedicated to avocado production. Mexico accounts for almost 30% of total avocados produced and is considered to be the largest worldwide avocado producer, producing 1.52 million tons (FAOSTAT, 2014). In recent years, avocado production and exportation has been increasing due to increasing demand for this fruit for food and medicinal purposes due to its aforementioned properties (Chel-Guerrero, Barbosa-Martín, Martínez-Antonio, González-Mondragón, & Betancur-Ancona, 2016; López-Cobo et al., 2016). Avocado production is adaptable to different tropical regions, and for this reason, avocado is produced in more than 60 countries, mainly Mexico, Israel, the United States of America, Colombia and the Dominican Republic (Chel-Guerrero et al., 2016; FAOSTAT, 2014). It is important to note that avocados are available throughout the year and that the Hass variety is the most produced and dominates the international market due its quality, productivity, resistance to commercial management and constant availability (Cowan & Wolstenholme, 2016; Rodríguez-Carpena et al., 2011).

nutrients or phytochemicals (Alvarez, Moreno, & Ochoa, 2012). Avocado pulp contains higher quantities of insoluble and soluble fibres (70 and 30%, respectively) and proteins than many other fruits (Cowan & Wolstenholme, 2016; Dreher & Davenport, 2013) as well as sugar, including sucrose and 7-carbon carbohydrates, such as d-mannoheptulose, pigments, tannins, polyphenols, phytoestrogens and perseitol (Cowan & Wolstenholme, 2016; Zafar & Sidhu, 2011). The nutritional composition of avocado pulp has been reported to have a moisture content ranging from 67 to 78%, lipid content ranging from 12 to 24%, carbohydrate content ranging from 0.8 to 4.8%, protein content ranging from 1.0 to 3.0%, ash content ranging from 0.8 to 1.5%, fibre content ranging from 1.4 to 3.0%, and energy between 140 and 228 kcal per avocado (Cowan & Wolstenholme, 2016; Duarte, Chaves, Borges, & Mendonça, 2016; Rodríguez-Carpena, Morcuende, Andrade,

2.1. Avocado in Mexico In 2015, avocado production in Mexico was 1.6 million tons and had a value of more than 1 billion dollars. Production was 6.6% more than in previous years, with a harvest area of 166944 ha. Michoacán is the Mexican state with the largest area dedicated to avocado plantation and provides more than 80% of national production. Michoacán is considered to be the most important avocado producing area in the world due to its microclimate, which is favourable for the production of 53

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for quality preservation of avocado fruits using biodegradable, natural and bioactive compounds of plants, such as moringa, aloe mucilage, purified polyphenols from Larrea tridentata, chitosan, carboxymethyl cellulose, candelilla wax, pectin and ellagic acid (Aguirre-Joya et al., 2017; Saucedo-Pompa et al., 2009; Tesfay & Magwaza, 2017). With these strategies, avocado shelf life can increase up to 2 weeks, which is of great importance in avocado exportation, mainly during exportation of Mexican avocados to Europe or Occidental countries, such as Japan, due to the extensive transportation time, which can be up to 17 days (Alvarez et al., 2012).

avocado (“SIAP,” 2015). Mexico contains for more than 20,000 producers and more than 48 exporting and packing companies certified for international export to 16 international markets. In 2015, Mexico reported values avocado exportation of 989718 tons valued at 1.9 million dollars, which represents an increase of 32% compared to the previous year. The United States of America is the main importer of Mexican avocados, followed by France, Japan and Canada (SIAP, 2015). The Association of Producers and Packers Exporters of Avocados of Michoacán, A.C., (APEAM), reported that 95,000 tons of avocados was sent to the United States, placing this fruit as one of the food protagonists of the Super Bowl 50.

3. Avocado residues

2.2. Conservation and uses

Avocado fruit is pear-shaped, often more or less necked, oval or nearly round, may be 7.5–33 cm long and up to 15 cm wide. The skin or peel may be yellow-green, deep-green or a very dark-green, reddishpurple, or such a dark a purple as to appear almost black and is sometimes speckled with tiny yellow dots. The skin or peel may be smooth or pebbled, glossy or dull, thin or leathery, up to 1/4 in (6 mm) thick, pliable or granular and brittle. In some fruits, immediately beneath the skin there is a thin layer of soft, bright-green flesh, but generally, the flesh is entirely pale to rich-yellow, buttery and bland or nutlike in colour. The only seed present is typically oblate, round, conical or ovoid, 2 to 2 1\2 in (5–6.4 cm) long, hard and heavy, ivory in colour but enclosed in two brown, thin, papery seed coats often adhering to the flesh cavity, while the seed slips out readily. Some avocado fruits are seedless because of a lack of pollination or other factors (Morton, 2004). As shown in Fig. 1, the seed is composed of a very thin shell (endocarp) that encloses the kernel (seed proper). The avocado processing industry produces essential oils, and once pulp is processed, seeds, peels and exhausted pulp are discarded as waste, which results in a large amount of solid residues that represent 21–30% of the fruit, with some exceptions in some varieties (López-Cobo et al., 2016). Another residue that is generated in large quantities is the residual pulp from the extraction of avocado oils (Dalle et al., 2016). Table 3 summarizes the chemical composition of seeds and peels of different cultivars of avocado. The composition of avocado residues varies between cultivars and sometimes varies between the same cultivar. This phenomenon is normal because each cultivar is different and there are many factors that influence the composition of the fruit during its development, including the region of avocado production, climate, altitude, precipitation, genetics and others. The predominant constituents of these residues are carbohydrates, such as fibres, hemicellulose and starch (seed), which can be a potential source of energy (bioethanol) and produce other added value compounds (Ruiz, Rodríguez-Jasso,

The resistance to ripening of avocado is lost after one to two days following harvesting (Alvarez et al., 2012; Yahia & Woolf, 2011) and requires 5–7 days to achieve this level of ripening at room temperature, leading to an increase in ethylene production and respiration rate (Wang, Bostic, & Gu, 2010). In the avocado industry, fruits are homogenously ripened in the presence of ethylene and at a controlled temperature before processing. Different biotechnological processes have been used to ripen avocados, while preserving its sensory and nutritional properties, to obtain avocado pulp, guacamole, avocado sauce and oils for food, cosmetic and pharmaceutical purposes (Cowan & Wolstenholme, 2016). Industrially, the main processing technologies are lyophilization, freezing, microwaving and high pressure; these technologies are used to preserve the qualities of the fruit and prevent enzymatic browning, which is the main conservation problem of avocado pulp (Alvarez et al., 2012; Zafar & Sidhu, 2011). Colour is the most important characteristic in judging the quality of a food since sight is the first sense employed for the selection and acceptance of any commercial product (Souza, Marques, Gomes, & Narain, 2015). Lyophilization is a post-freezing process and a potential avocado conservation method, but currently, no promising results have been obtained because studies have shown (Souza et al., 2015) that freezing, lyophilization pressure and rehydration induce darkening of avocado pulp. Microwave treatment by microwave radiation inactivates the enzymes polyphenol oxidase (PPO) and pectinmethylesterase in 80% of cases and prevents the reactivation of PPO during storage. These effects occur due to changes in temperature over short exposure times (80 s with 11 W/g sample) and an increasing the phenolic content up to 29%; however, no significant changes in colour, chlorophyll content or rheological behaviour have been observed (Zhou, Tey, Bingol, & Bi, 2016). Processed avocado products benefit from the use of high-pressure technologies, which allow the maintenance of the original freshness of the fruit, extension of the shelf-life of the product and, perhaps most importantly, increase its commercial life. The effect of high pressures on the enzyme polyphenol oxidase prevents browning and oxidation of the product (Toledo & Aguirre, 2016; Zafar & Sidhu, 2011). Other approaches used to inhibit the PPO enzyme include the use of natural extracts in avocado purees, such as aqueous extracts of Allium and Brassica, which are effective at preventing the natural darkening of avocado pulp for 30 days (Bustos, Mazzobre, & Buera, 2015). Additionally, avocados are used as fresh fruits to prepare different foods or sauces and can also be used as a dessert. In this case, the objective is to delay ripening to extend the avocado shelf life, which consists of reducing ethylene production and the respiration rate to decrease the responses that lead to ripening, such as tissue softening, cell wall disintegration, and pigment degradation (Alvarez et al., 2012). Some strategies are used to improve the avocado shelf life and preserve its quality, such as conservation at low temperatures (2–7 °C) (Yahia & Woolf, 2011); controlling atmospheric pressure with 1-methylcyclopropene, which prevents ethylene binding and consequent ripening; decreasing internal chilling injuries (Pereira, Sargent, & Huber, 2015; Zhang, Huber, & Rao, 2013); or using a formulation of edible coatings

Fig. 1. Pericarp composition of avocado fruit. 54

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Table 3 Chemical composition of avocado seed and peel of different cultivars (dry basis, % w/w).

Seed Peel Seed

Peel

Seed Peel

Seed Peel a

Cultivar

Moisture

Minerals

Lipids

Fibres

Proteins

Carbohydrates

Reference

Hass

14.55 9.87 7.66 9.44 1.78 5.83 8.04 14.5 12.18 6.65 10.26 6.86 54.45a 69.13a

2.81 2.15 3.85 2.79 3.48 2.73 4.3 6.05 2.34 3.82 3.82 4.9 1.29 1.5

3.32 2.18 5.52 6.32 6.7 6 4.05 9.14 5.47 5.62 5 4.31 14.7 2.2

3.97 1.29 3.98 4.24 4.06 2.67 2.19 50.65 53.35 54.63 48.3 34.56 – –

0.14 0.17 3.44 3.09 4.9 3.86 9.63 8.28 2.88 3.34 4.39 5.75 2.19 1.91

– – 79.54 78.37 72.14 81.58 42.45 62.03 77.14 80.57 76.53 43.62 – –

(Daiuto, Tremocoldi, Alencar, & Vieites, 2014)

Moisture

Minerals

Extractives

Cellulose

Hemicellulose

Lignin

7.02 7.33

0.87 1.04

35.95 34.38

6.48 27.58

47.88 25.3

1.79 4.37

Hass Utz Booth 8 Panchoy Shupte Hass Utz Booth 8 Panchoy Shupte Hass

Hass

(Bressani, Rodas, & Ruiz, 2009)

(Vinha, Moreira, & Barreira, 2013)

(Dávila et al., 2017)

Data reported in wet basis.

Avocado residues have been shown to contain phenolic compounds, such as quercetin glycosides, procyanidin dimers of type A and B, procyanidin trimers of type A, catechin, caffeoylquinic acid, coumaroylquinic acid (Agnieszka et al., 2012; López-Cobo et al., 2016).

Fernandes, Vicente, & Teixeira, 2013). Normally, avocado residues are not utilized and are discarded as waste, representing a severe environmental problem (Camberos, Velázquez, Fernández, & Rodríguez, 2013). Avocado residues represent a prospective source of bioactive compounds containing more phenolic compounds and several-fold greater antioxidant capacity than blueberries, which are known for their high antioxidant capacity (Agnieszka et al., 2012; Ayala-Zavala et al., 2011; Gómez, Sánchez, Iradi, Azman, & Almajano, 2014; LópezCobo et al., 2016). Another application of avocado residues is the extraction of oils, essential oils and fibres, which are currently highly sought-after ingredients for producing foods and other products.

3.2. Bioactivity of avocado residue extracts Extracts of avocado residues have long been used in traditional medicine to treat many diseases. Currently it is known that avocado extract has many interesting properties and many potential applications. Larvicidal, antifungal, antimicrobial, antioxidant, antiprotozoal, antidiabetic, antihypertensive, hypocholesterolemic, and antimycobacterial activities as well as inhibition of lipid and protein oxidation are the numerous biological activities reported to be related to extracts of avocado residues (Dabas et al., 2013; Jiménez-Arellanes et al., 2013; Leite et al., 2009; Yasir, Das, & Kharya, 2010). These reported activities indicate that avocado residues contain important bioactive compounds that can be recovered and applied for different treatments. Some studies report anticancer properties of avocado extracts (Lee, Yu, Lee, & Lee, 2008). Previous studies have also reported

3.1. Avocado residue phytochemical profile The bioactive compounds produced from a plant mainly derive from secondary metabolic processes (Guzmán-Rodríguez et al., 2013). Avocado residues are rich in a complex mixture of polyphenolic compounds, such as catechin, as well as high polymeric compounds, such as proanthocyanidins (Soong & Barlow, 2004). Tables 4 and 5 show the polyphenolic compounds found in avocado peel and seed, respectively.

Table 4 Polyphenol compounds proposed by Agnieszka et al. (2012) in avocado seed and peel. Peak

Proposed compound

Avocado peel 1 5-O-caffeoylquinic acid 2 procyanidin dimer B (I) 3 procyanidin dimer A 4 catechin 5 procyanidin dimer B (II) 6 quercetin-3,4′-diglucoside 7 quercetin 3-O-rutinoside 8 quercetin-3-O-arabinosyl- glucoside 9 quercetin-3-O-arabinoside 10 quercetin 3-O-galactoside 11 quercetin-3-O-glucoside 12 quercetin derivative (I) 13 quercetin derivative (II) 14 quercetin derivative (III) Avocado seed 15 3-O-caffeoylquinic acid 16 3-O-p-coumaroylquinic acid 17 procyanidin trimer A (I) 18 procyanidin trimer A (II) 19 catechin/epicatechin gallate

Retention time

UV ʎmax

[M-H]-

Fragment MS MS

Molecular Formula

15.4 17.3 18.6 20.2 23.8 26.4 27.2 29.6 29.7 33.9 35.5 40.3 40.9 44.4

324 278 279 278 279 356 354 355 354 354 356 353 353 355

353 577 575 289 577 625 609 595 433 463 463 479 609 565

191, 179 289 289 – 289 301 301 301 301 301 301 301 301 301

C16H18O9 – – C15H14O6 – C27H30O17 C27H30O16 – C20H18O11 C21H20O12 C21H20O12 – – –

10 13.5 19.1 21.7 33.8

326 314 280 280 266, 299

353 337 863 863 441

191, 179 191, 163 289 289 283, 269

C16H18O9 C16H18O8 – – C22H18O10

55

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Table 5 Polyphenol compounds proposed by López-Cobo et al. (2016) in avocado seed and peel. Peak

Proposed compound

Avocado peel 1 perseitol 2 quinic acid 3 penstemide 4 chlorogenic acid 5 quercetin-diglucoside 6 quercetin-3-O-arabinosyl-glucoside 7 rutin 8 perseitol 9 quinic acid Avocado seed 10 citric acid 11 hydroxytyrosol glucoside 12 1-caffeoylquinic acid 13 tyrosol glucoside 14 penstemide 15 3-O-p-coumaroylquinic acid 16 4-caffeoylquinic acid 17 vanillic acid glucoside 18 (1′S, 6′R)-8′-hydroxyabscisic acid beta-D-glucoside

Retention time

UV ʎmax

[M-H]-

Fragment MS MS

Molecular Formula

0.868 0.914 4.344 4.496 6.456 7.059 9.855 0.872 0.917

242/265 230/262 230/272 234/295/326 238/280/352 236/279/354 234/282/350 242/265 230/262

211.0823 191.0561 443.1923 353.0878 625.141 595.1305 609.1461 211.0827 191.0567

101 111 101, 113 191 301 301 301 101 111

C7H16O7 C7H12O6 C21H32O10 C16H18O9 C27H30O17 C26H28O16 C27H30O16 C7H16O7 C7H12O6

1.183 3.126 3.585 4.012 4.344 4.538 5.075 6.366 8.546

230 234/280 239/293/324 229/276 234/295/326 238/285/311 241/284/326 239/279 242/274

191.0197 315.1094 353.088 299.1138 443.1924 337.093 353.0887 329.0878 441.177

111, 101, 113 135, 153 191, 179, 135 119, 137 101,113 163 135, 173, 191 123, 167 330,139

C6H8O7 C14H20O8 C16H18O9 C14H20O7 C21H32O10 C16H18O8 C16H18O9 C14H18O9 C21H30O10

fatty acid derivatives known as acetogenins against Listeria monocytogenes. Pahua-Ramos et al. (2012) found that avocado seed flour had low toxicity and reduced cholesterol and low-density lipoprotein cholesterol in a model of hypercholesterolemic mice. This effect was attributed to the phenolic content, antioxidant activity and the dietary and crude fibre contents of the seeds. Adeyemi, Okpo, and Ogunti (2002) showed the anti-inflammatory activity of an aqueous avocado leaf extract on mice with Carrageenan-induced oedema and obtained 57% inhibition of the control writhes, similar to that of acetylsalicylic acid at 100 mg/ mL in, and 87% of that of morphine at 2 mg/kg with an aqueous extract at 1600 and 800 mg/mL. Reactive oxygen species production and antioxidative responses in unripe avocado fruits in response to wounding were reported by Castro-Mercado et al. (2009), while isolation and chemical identification of lipid derivatives with antiplatelet and antithrombotic activities were reported by Rodriguez-Sanchez et al. (2015). The antioxidant capacities of avocado seed and peel of different cultivars and various methods of extraction are summarized in Table 6. The contents of phenolic compounds and antioxidants reported in avocado seed and peel are high but can be increased with the use of advanced technologies, such as microwave supercritical fluid extraction, considering several parameters, such as the stability, degradation and biological activity, of the compounds extracted. It should be noted that most biological activities are associated with avocado seeds, but it has also been reported that extracts of avocado seeds possess toxic and genotoxic activity in mice at concentrations of 500 mg/kg (Camberos et al., 2013; Rodríguez-Carpena et al., 2011).

anticancer activity via induction of apoptosis of MDA-MB-231 cells by methanol extracts of avocado seeds, (Abubakar, Achmadi, & Suparto, 2017), while others have shown that triterpenoid compounds isolated from ethanol extract of avocado seed have significant cytotoxic activity against breast and liver cells MCF-7 and HepG2, respectively (Ambrosio, Han, Pan, Kinghorn, & Ding, 2011). demonstrated that two aliphatic acetogenins in synergism, isolated using chloroform from the mesocarp of avocados, inhibited the proliferation of the human oral cancer cell line 83-01-82CA. Others approaches were studied by (Guzmán-Rodríguez, López-Gómez, Salgado-Garciglia, Ochoa-Zarzosa, & López-Meza, 2016), who reported that the peptide PaDef, which is present in chemically synthesized avocados, has anticancer activity against the breast cancer cell line MCF-7, and (Brooke et al., 2011), who reported that synthetic analogues of the avocado toxin (+)-(R)-persin had anticancer activity on the same cancer cell line. Polyhydroxylated fatty alcohols extracted from seed and pulp of avocados with organic solvents have an important role as photo-protective agents against UVinduced damage in skin cells (Rosenblat et al., 2011). Avocatin B, a lipid derived from avocado fruit, is a novel compound with cytotoxic activity in acute myeloid leukemia and has been shown to inhibit fatty acid oxidation and decrease NADPH levels, resulting in ROS-dependent leukemia cell death, which is characterized by the release of mitochondrial proteins, apoptosis-inducing factors, and cytochrome c. Many studies have been carried out to verify the antimicrobial activity of avocado extracts (Chia & Dykes, 2010). demonstrated the antimicrobial activity of ethanol extracts of avocado seed (125–250 μg/ mL) in select gram positive and gram negative bacteria (Salmonella enteritidis, Citrobacter freudii, Pseudomonas aeruginosa and Enterobacter aerogenes) (Leite et al., 2009). used methanol and hexane extracts of avocado seeds (0.125–625 mg/L) to demonstrate their antifungal activity against Candida spp, Cryptococcus neoformans, and Malassezia pachydermatis and larvicidal activity against Artemia salina and Aedes aegypti in vivo. In the hexane extract, a higher larvicidal activity and higher concentration of β-sitosterol and 1,2,4-trihydroxy-nonadecane were detected, which were associated with a high larvicidal activity (Boadi, Saah, Mensah, Badu, & Addai-arhinand, 2015). showed that a methanolic extract of avocado leaves exhibited a high zone of inhibition (Falodun et al., 2014). isolated aliphatic fatty alcohol metabolites of avocado seeds and showed a moderate antimicrobial activity against Staphylococcus aureus, Escherichia coli, P. aeruginosa and Mycobacterium intracellulare, with IC50 values > 200 μg/mL, and strong activity against methicillin-resistant S. aureus (IC50 13.81 μg/mL). SalinasSalazar et al. (2017) reported the inhibitory activity of avocado seed

3.3. Avocado seed starch Avocado seeds have been reported to be a natural source of starch since they contain a high content of this polysaccharide, approximately 30%, making the seeds an alternative starch source (Domınguez et al., 2014; Lacerda et al., 2015). Commercial starches are obtained from seeds such as corn, wheat and rice and from some tubers and roots such as potatoes, sweet potatoes and cassava, all of which are essential foods. Starch is a natural biopolymer and the most important reserve of polysaccharides in avocado plants (seed); starch is composed of two polymers, amylose and amylopectin. Amylose is a linear polymer of α1,4-linked glucans, and amylopectin is a larger molecule with highly α −1,6 branched chains. The morphology, structure, size of starch granules and ratio between amylose and amylopectin vary according to 56

57

Shepared Fuerte Hass ND

Dry

Dry Dry Dry

Dry

Brazil

Australia Australia Spain

Nigeria

Fresh

Fresh Fresh Fresh Fresh Fresh Fresh Fresh Fresh Fresh Dry

Spain

ND

Dry

Dry

Florida Florida Florida Florida Florida Florida Florida Mexico Portugal Mexico

Singapore

ND

Slimcado Simmonds Loretta Choquette Booth 7 Booth 8 Tonnage Hass

Nigeria

ND

Fresh Dry

Portugal Brazil

Dry

Dry Dry Fresh

Australia Australia Spain

Spain

Fresh Fresh Fresh Fresh Fresh Fresh Fresh Fresh Dry

Fresh or Dry material

Florida Florida Florida Florida Florida Florida Florida Mexico Mexico

Region

ND

Shepared Fuerte Hass

Slimcado Simmonds Loretta Choquette Booth 7 Booth 8 Tonnage Hass

Cultivars

25.3 15.6 172.2 89.9 30.0

63.5

4.6 7.4 7.6 13.9 13.2 8.1 4.3 12.6 6.8 19.7

40

88.2

29.4

45.0

9.5 13.0 69.1 60.8 7.0 57.3

19.2 40.2 31.5 33.4 33.4 35.7 33.1 51.6 5.7

Total phenolic content (mg GAE g−1)

–

725.0b –

– – – –

616.5 – –

161.0 112.0 242300 103800 –

– – 199610 88940 –

470.0 290.0 – – –

791.5

310.0

–

– – – – – – – – – –

39.7 84.9 38 90.8 80 52.6 51.9 189.8 35%a –

58.2 226.8 92.3 174.8 164.9 110.5 187.6 631.4 – 0.866

200

–

94.0 91.0 194800 159300 – 645.8

210.0 350.0 – – – –

– – 167500 130600 43%a 410.7

ABTS (μmol TE g−1)

– – – – – – – – –

DPPH (μmol TE g−1)

128.3 240.2 159.7 157.8 188.1 207.3 162.9 164.6 –

229.0 459.3 229.0 348.9 319.8 368.7 464.4 428.8 0.006

ORAC (μmol TE g−1)

ND: Non-Defined. a Reported in percentage of inhibition of 0.1 mg/mL of extract. b Reported in μmol Ascorbic Acid Equivalent Antioxidant Capacity by g of matter: μmol AEAC g−1. c Reported in mg Trolox Equivalents by g of matter: mg TE g−1. d Reported in mg Ascorbic Acid equivalent by g of matter: mg A.

Peel

Seed

Portion

Table 6 Phenolic content and antioxidant capacities reported from avocado seed and peel of some cultivars.

d

– – – – 34.6d

–

– – – – – – – – – 23.1c

–

1484.0

27.7

–

– –

– – –

– – – – – – – – 9.5c

FRAP (μmol Fe (II)E g−1)

(Rodríguez-Carpena et al., 2011) (Oboh et al., 2013)

(Agnieszka et al., 2012)

(Vinha et al., 2013) (Calderón-Oliver et al., 2016) (Daiuto et al., 2014)

Water extraction by homogenization at 40 °C Agitation extraction with boiling water Water/ethanol (80:20, v/v) extraction by ultrasoundassisted at 25 °C Methanol (80%) extraction with ratio 1:8 (w/v) in a thermostatic shaking water bath at 60 °C Acetone/water (70:30, v/v) extraction by homogenization Extraction with 1M HCL and methanol (1:1, v/v)

(Wang et al., 2010)

(Segovia, Corral-Pérez, & Almajano, 2016) Vortex and sonication extraction with acetone/water/ acetic acid (70:29.7:0.3, v/v/v).

Refluxed Extraction with ethanol:water (1:1, v/v) at 70 °C Water extraction by ultrasound-assisted batch at 60 °C

(Oboh, Adelusi, & Akinyemi, 2013) (Soong & Barlow, 2004)

(Gómez et al., 2014)

(Rodríguez-Carpena et al., 2011) (Vinha et al., 2013) (Daiuto et al., 2014)

(Calderón-Oliver et al., 2016) (Agnieszka et al., 2012)

Agitation extraction with boiling water Methanol (80%) extraction with ratio 1:8 (w/v) in a thermostatic shaking water bath at 60 °C Acetone/water (70:30, v/v) extraction by homogenization Water extraction by homogenization at 40 °C Water/ethanol (80:20, v/v) extraction by ultrasoundassisted at 25 °C Agitation extraction with ethanol:water (56 and 44.7%) at 63 and 93.6 °C Extraction with 1M HCL and methanol (1:1, v/v)

(Wang et al., 2010)

Reference

Vortex and sonication extraction with acetone/water/ acetic acid (70:29.7:0.3, v/v/v).

Method of extraction

R.G. Araújo et al.

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R.G. Araújo et al.

applications have already been patented. Food industry

the botanic source, stage of development of the plant and environmental conditions, making starch granules a complex and variable polysaccharide. Starch has been shown to undergo thickening, gelling, stabilizing and binding, making it a widely used ingredient in the food industry as well as allowing it to be used in other industrial applications (textile, paper, biodegradable materials and other products) (ChelGuerrero et al., 2016; Henríquez et al., 2008; Lacerda et al., 2014, 2015). Bioethanol is a promising alternative to fossil fuels in the production of energy with the added advantages of being non-toxic, biodegradable, and a renewable fuel source. Currently, there are three generations of bioethanol production. The first generation includes essential feedstocks that are rich in sucrose, such as sugar cane and sweet sorghum, or in starch, such as corn, wheat, rice, potato, cassava, sweet potato and barley. The second generation uses lignocellulosic biomass, such as wood and straws, and the third generation uses algal biomass, including macroalgae and microalgae (Lennartsson, Erlandsson, & Taherzadeh, 2014; Mohd Azhar et al., 2017). Starch from fruit residues such as avocado seeds can be used to produce bioethanol; however, a physical, chemical, biological or physicochemical pretreatment must be carried out to liberate starch sugars and a subsequent fermentation must be performed to produce bioethanol (Aditiya, Mahlia, Chong, Nur, & Sebayang, 2016; Bahry et al., 2017). Avocado starch can thus be considered a second generation bioethanol product, which may become a new source of raw material for the production of bioethanol (Perea-Moreno, Aguilera-Ureña, & Manzano-Agugliaro, 2016).

- Application of avocado seeds in beverage and avocado seed internal heat-reducing tea (CN2017174030 20170210) - Culture medium derived from avocado seed material (WO2014IB66209 20141120) - Method for making avocado tea (CN20151887121 20151207) - Avocado vinegar and making method thereof (CN20151877929 20151204) - Preparation method of avocado and yoghurt juice (CN201611114285 20161207) - Apparatus and methods for cutting avocados (US201715449625 20170303) - Formulation based on roselle plant calices compounds for disinfecting or preserving avocado (MX20150017441 20151216) - Avocado paste elaboration process through the ultrafast expansion process (MX20150015352 20151105) - Nutritional fruit juice (CN20151866395 20151127) - Avocado wine (CN2017163431 20170203) Cosmetic industry - A herbal cream (PH20162000705U 20160923) - Process of producing herbal tea and the product derived thereof (PH2016200014 U20161215) - Traditional Chinese medicine mask (CN20171151714 20170315) - Avocado facial cleanser and preparation method thereof (CN201611075684 20161130)

3.4. Technological approach Through application of the proper technology, avocado seed and peel can be used as sources of potent natural ingredients and additives to provide new technological solutions. The physical and chemical properties of the lipid constituents, polyphenols, starch, and fibres and the low cost of avocado residues make this material a potential source of bioactive ingredients for use in the food, cosmetic and pharmaceutical industries. Currently, the use of environmentally friendly technologies to extract compounds from avocado residues is feasible. To reduce the negative effects on the bioactivity and structural modifications of bioactive compounds, in recent years, several promising technologies have been reported (Carciochi et al., 2017; Chemat, Vian, & Cravotto, 2012; Galankis, 2012; Wong-Paz et al., 2017). For instance, pulsed electric field, ohmic heat, ultrasound, microwave, pressurized liquids, and supercritical fluids can be quite interesting for such purposes (Carciochi et al., 2017). Additionally, biotechnological procedures can be used to extract bioactive compounds, particularly enzymeassisted extraction (Gómez-García, Martínez-Ávila, & Aguilar, 2012) and fermentation-assisted extraction (Martins et al., 2011). These technologies can be applied to avocado residues using hydrophilic or hydrophobic solvents to promote a better extraction of specific compounds. In vitro studies of the bioactivity of avocado residues, such as those assessing the bioavailability of bioactive compounds in a human gastric simulation, are essential to determine the potential use of these compounds in the food and cosmetic industries as bioactive or structural ingredients for various applications, such as antioxidants, antimicrobial agents, vegetable oils, or additives, or to extend the shelf life of certain foods.

Health - Avocado-derived lipids for use in treating leukemia (US201515517914 20151009) - Natural extracts for modulating pp2a methylation, and providing antioxidant and anti-inflammatory activity (US201515327875 20150722) - Topical mosquito control product with sunscreen (US201662281369P 20160121) - New hair repairing permanent process (KR20160084291 20160704) 5. Conclusions Avocado is a fruit that is distributed worldwide and recognized for its nutritional and bioactive composition and extensive health benefits. Avocado residues are also an important part of avocado because they are a potential source of nutritional food ingredients due to the high quality of their starches and oils and high content of compounds with high biological activity. The distribution of avocados worldwide and doubled production per year makes avocado residues an easily accessible raw material throughout the year. Research on avocado residues should be more intensive in the next few years to identify different phytochemicals and find new compounds by implementing more adequate recovery and extraction techniques. Bioactivity, nutritional and sensory studies are necessary to incorporate these compounds in a final product. It is also important to implement strategies of cooperation and awareness with the avocado business sector to better value the potential of these residues.

4. Patents with avocado uses 6. Future trends Currently there are many uses of avocado that are patented in foods, cosmetics and the medical field, but these uses mainly involve pulp or avocado oil. Patents published that use avocado residues include the application of avocado seeds to prepare a beverage as an antioxidant tea and the use of seeds as a culture medium. In the future, to increase the application of avocado residues, it is necessary to conduct more studies and promote the properties of these residues. The following

The promotion of avocado consumption in terms of its nutritional and beneficial properties as well as its different applications, for example, in cosmetic products, has led to the exponential growth of the avocado market, with trend that will continue in the upcoming years. Implementation of a biorefinery, such as that proposed by (Dávila, Rosenberg, Castro, & Cardona, 2017), with advanced and renewable 58

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technology to recover added compounds from total avocado residues (seed, peel and exhausted pulp), coupled with the avocado packaging and processing industry and the improvement in biotechnologies to obtain added value compounds, can lead to the development of an integral biorefinery of avocado residues. Isolation, purification, marketing and use of the specific compounds present in avocado residues that have high bioactivity can be way to better use and valorize these residues.

Carciochi, R. A., D'Alessandro, L. G., Vauchel, P., Rodriguez, M. M., Nolasco, S. M., & Dimitrov, K. (2017). Valorization of agrifood by-products by extracting valuable bioactive compounds using green processes. In Grumezescu Alexandru Mihai, & Holban Alina Maria (Eds.). Handbook of Food Bioengineering (pp. 191–228). Academic Press Ingredients Extraction by Physicochemical Methods in Food, ISBN 9780128115213. Carvalho, C. P., Bernal, J. E., Velásquez, M. A., & Cartagena, J. R. V. (2015). Fatty acid content of avocados ( Persea americana Mill . cv . Hass ) in relation to orchard altitude and fruit maturity stage. Agronomía Colombiana, 33(2), 220–227. Castro-Mercado, E., Martinez-Diaz, Y., Roman-Tehandon, N., & Garcia-Pineda, E. (2009). Biochemical analysis of reactive oxygen species production and antioxidative responses in unripe avocado (Persea americana Mill var Hass) fruits in response to wounding. Protoplasma, 235(1-4), 67–76. Chel-Guerrero, L., Barbosa-Martín, E., Martínez-Antonio, A., González-Mondragón, E., & Betancur-Ancona, D. (2016). Some physicochemical and rheological properties of starch isolated from avocado seeds. International Journal of Biological Macromolecules, 86, 302–308. Chemat, F., Vian, M. A., & Cravotto, G. (2012). Green extraction of natural products: Concept and principles. International Journal of Molecular Sciencce, 13, 8615–8627. Chia, T. W. R., & Dykes, G. A. (2010). Antimicrobial activity of crude epicarp and seed extracts from mature avocado fruit. (Persea Americana) of Three Cultivars Pharmaceutical Biology, 48(7), 753–756. Cowan, A. K., & Wolstenholme, B. N. (2016). Avocado. In B. Caballero, P. M. Finglas, & F. Toldrá (Eds.). Encyclopedia of food and health (pp. 294–300). Oxford: Academic Press. Dabas, D., Shegog, R. M., Ziegler, G. R., & Lambert, J. D. (2013). Avocado (Persea americana) seed as a source of bioactive phytochemicals. Current Pharmaceutical Design, 19(34), 6133–6140. Daiuto, É. R., Tremocoldi, M. A., Alencar, S. M. De, & Vieites, R. L. (2014). Composição química e atividade antioxidante da polpa e resíduos de abacate “Hass. Revista Brasileira de Fruticultura, 36(2), 417–424. Dalle, C., Santos, M., Pagno, C. H., Maria, T., Costa, H., Faccin, L., et al. (2016). Biobased polymer films from avocado oil extraction residue: Production and characterization. Journal of Applied Polymer Science, 43957, 1–9. Dávila, J. A., Rosenberg, M., Castro, E., & Cardona, C. A. (2017). A model biorefinery for avocado (Persea americana Mill.) processing. Bioresource Technology, 243, 17–29. Ding, H., Chin, Y. W., Kinghorn, A. D., & D'Ambrosio, S. M. (2007). Chemopreventive characteristics of avocado fruit. Seminars in Cancer Biology, 17(5), 386–394. Domınguez, M. P., Araus, K., Bonert, P., Sanchez, F., Miguel, G. S., & Toledo, M. (2014). The avocado and its waste: An approach of fuel potential/application. In G. Lefebvre, G. Jiménez, & B. Cabañas (Eds.). Environment, energy and climate change II: Energies from new resources and the climate change (pp. 199–223). Switzerland: Springer International Publishing. Dreher, M. L., & Davenport, A. J. (2013). Hass avocado composition and potential health effects. Critical Reviews in Food Science and Nutrition, 53(7), 738–750. Duarte, P. F., Chaves, M. A., Borges, C. D., & Mendonça, C. R. B. (2016). Avocado: Characteristics, health benefits and uses. Ciência Rural, 46(4), 747–754. Falodun, Erharuyi, O., V, I., Ahomafor, J., Akunyuli, C., Jacobs, M., et al. (2014). In vitro evaluation of aliphatic fatty alcohol metabolites of Perseaamericana seed as potential antimalarial and antimicrobial agents. Nig J. Biotech. 27, 1–7. FAO (2014). Food and agriculture organization of the United Nations. Agriculture Database http://www.fao.org/faostat/en/#data/QC, Accessed date: 23 August 2017. Galanakis, C. M. (2012). Recovery of high added-value components from food wastes: Conventional, emerging technologies and commercialized applications. Trends in Food Science & Technology, 26, 68–87. Gómez-García, R., Martínez-Ávila, G. C. G., & Aguilar, C. N. (2012). Enzyme-assisted extraction of antioxidative phenolics from grape (Vitis vinifera L.) residues. 3. Biotech, 2, 297–304. Gómez, F., Sánchez, S., Iradi, M., Azman, N., & Almajano, M. (2014). Avocado seeds: Extraction optimization and possible use as antioxidant in food. Antioxidants, 3(2), 439–454. Gutiérrez-Contreras, M., Lara-Chávez, M. B. N., Guillén-Andrade, H., & Chávez-Bárcenas, A. T. (2010). Agroecología de la franja aguacatera en Michoacán, México. Interciencia, 35(9), 647–653. Guzmán-Rodríguez, J. J., López-Gómez, R., Salgado-Garciglia, R., Ochoa-Zarzosa, A., & López-Meza, J. E. (2016). The defensin from avocado (Persea americana var . drymifolia) PaDef induces apoptosis in the human breast cancer cell line MCF-7. Biomedicine & Pharmacotherapy, 82, 620–627. Guzmán-Rodríguez, J. J., López-Gómez, R., Suárez-Rodríguez, L. M., Salgado-Garciglia, R., Rodríguez-Zapata, L. C., Ochoa-Zarzosa, A., et al. (2013). Antibacterial activity of defensin PaDef from avocado fruit (Persea americana var. drymifolia) expressed in endothelial cells against Escherichia coli and Staphylococcus aureus. BioMed Research International, 2013, 1–9. Henríquez, C., Escobar, B., Figuerola, F., Chiffelle, I., Speisky, H., & Estévez, A. M. (2008). Characterization of piñon seed (Araucaria araucana (Mol) K. Koch) and the isolated starch from the seed. Food Chemistry, 107(2), 592–601. Jiménez-Arellanes, A., Luna-Herrera, J., Ruiz-Nicolás, R., Cornejo-Garrido, J., Tapia, A., & Yépez-Mulia, L. (2013). Antiprotozoal and antimycobacterial activities of Persea americana seeds. BMC Complementary and Alternative Medicine, 13(109), 1–5. Lacerda, L. G., Colman, T. A. D., Bauab, T., Da Silva Carvalho Filho, M. A., Demiate, I. M., De Vasconcelos, E. C., et al. (2014). Thermal, structural and rheological properties of starch from avocado seeds (Persea americana, Miller) modified with standard sodium hypochlorite solutions. Journal of Thermal Analysis and Calorimetry, 115(2), 1893–1899. Lacerda, L. G., Da Silva Carvalho Filho, M. A., Bauab, T., Demiate, I. M., Colman, T. A. D., Andrade, M. M. P., et al. (2015). The effects of heat-moisture treatment on avocado starch granules: Thermoanalytical and structural analysis. Journal of Thermal Analysis

Acknowledgments Author Rafael G. Araújo would like to thank the National Council of Science and Technology of Mexico for the scholarship received for this project in the PhD program in Food Science and Technology at the Autonomous University of Coahuila, México. References Abubakar, A. N. F., Achmadi, S. S., & Suparto, I. H. (2017). Triterpenoid of avocado (Persea americana) seed and its cytotoxic activity toward breast MCF-7 and liver HepG2 cancer cells. Asian Pacific Journal of Tropical Biomedicine, 7(5), 397–400. Adeyemi, O. O. U., Okpo, S. O., & Ogunti, O. O. (2002). Analgesic and anti-inflammatory effects of the aqueous extract of leaves of Persea americana Mill (Lauraceae). Fitoterapia, 73, 375–380. Aditiya, H. B., Mahlia, T. M. I., Chong, W. T., Nur, H., & Sebayang, A. H. (2016). Second generation bioethanol production: A critical review. Renewable and Sustainable Energy Reviews, 66, 631–653. Agnieszka, K., Karamac, M., Estrella, I., Hernández, T., Bartolomé, B., & Dykes, G. A. (2012). Phenolic compound profiles and antioxidant capacity of Persea americana Mill. Peels and seeds of two varieties. Journal of Agricultural and Food Chemistry, 60, 4613–4619. Aguirre-Joya, J. A., Ventura-Sobrevilla, J., Martínez-Vazquez, G., Ruelas-Chacón, X., Rojas, R., Rodríguez-Herrera, R., et al. (2017). E ff ects of a natural bioactive coating on the quality and shelf life prolongation at di ff erent storage conditions of avocado (Persea americana) cv. Hass. Food Packaging And Shelf Life, 14, 102–107. Alvarez, L. D., Moreno, A. O., & Ochoa, F. G. (2012). Avocado. In M. Siddiq (Ed.). Tropical and subtropical fruits: Postharvest physiology, processing and packaging (pp. 437–454). Oxford: Wiley-Blackwell. Ambrosio, S. M. D., Han, C., Pan, L., Kinghorn, A. D., & Ding, H. (2011). Biochemical and Biophysical Research Communications Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/ MEK/ERK1/2 pathway. Biochemical and Biophysical Research Communications, 409(3), 465–469. Arriola, M., del C, De, Menchú, J. F., & Rolz, C. (1979). The avocado. In G. E. Inglett, & G. Charalambous (Vol. Eds.), Tropical foods: Chemistry and nutrition: 2, (pp. 609–624). Academic Press, Inc. Ayala-Zavala, J. F., Vega-Vega, V., Rosas-Domínguez, C., Palafox-Carlos, H., VillaRodriguez, J. A., Siddiqui, et al. (2011). Agro-industrial potential of exotic fruit byproducts as a source of food additives. Food Research International, 44(7), 1866–1874. Bahry, H., Pons, A., Abdallah, R., Pierre, G., Delattre, C., Fayad, N., et al. (2017). Valorization of carob waste: Definition of a second-generation bioethanol production process. Bioresource Technology, 235, 25–34. Bergh, B., & Ellstrand, N. (1986). Taxonomy of the avocado. California Avocado Society yearbook, 70, 135–146. Blakey, R. J., Bower, J. P., & Bertling, I. (2009). Influence of water and ABA supply on the ripening pattern of avocado (Persea americana Mill.) fruit and the prediction of water content using Near Infrared Spectroscopy. Postharvest Biology and Technology, 53(1–2), 72–76. Boadi, N. O., Saah, S. A., Mensah, J. K., Badu, M., & Addai-arhinand, S. (2015). Phytoconstituents , antimicrobial and antioxidant properties of the leaves of Persea americana Mill cultivated in Ghana. Journal of Medicinal Plants Research, 9(36), 933–939. Bressani, R., Rodas, B., & Ruiz, A. S. (2009). La Composición Química, Capacidad Antioxidativa y Valor Nutritivo de la Semilla de Variedades de AguacateFinal Report of the Project FODECYT 02-2006 (National Science and Technology Fund). Guatemala: Universidad del Valle. Brooke, D. G., Shelley, E. J., Roberts, C. G., Denny, W. A., Sutherland, R. L., & Butt, A. J. (2011). Synthesis and in vitro evaluation of analogues of avocado-produced toxin ( + ) - ( R ) -persin in human breast cancer cells. Bioorganic & Medicinal Chemistry, 19(23), 7033–7043. Bustos, M. C., Mazzobre, M. F., & Buera, M. P. (2015). Stabilization of refrigerated avocado pulp : Effect of Allium and Brassica extracts on enzymatic browning. Lebensmittel-Wissenschaft und -Technologie- Food Science and Technology, 61(1), 89–97. Calderón-Oliver, M., Escalona-Buendía, H. B., Medina-Campos, O. N., Pedraza-Chaverri, J., Pedroza-Islas, R., & Ponce-Alquicira, E. (2016). Optimization of the antioxidant and antimicrobial response of the combined effect of nisin and avocado byproducts. Lebensmittel-Wissenschaft und -Technologie- Food Science and Technology, 65, 46–52. Camberos, E., Velázquez, M., Fernández, J. M., & Rodríguez, S. (2013). Acute toxicity and genotoxic activity of avocado seed extract (Persea americana Mill., c.v. Hass). The Scientific World Journal, 2013, 1–4.

59

Trends in Food Science & Technology 80 (2018) 51–60

R.G. Araújo et al.

Sustainable Energy Reviews, 21, 35–51. Salinas-Salazar, C., Hernández-Brenes, C., Rodríguez-Sánchez, D. G., Castillo, E. C., Navarro-Silva, J. M., & Pacheco, A. (2017). Inhibitory activity of avocado seed fatty acid derivatives (Acetogenins) against listeria monocytogenes. Journal of Food Science, 82(1), 134–144. Saucedo-Pompa, S., Rojas-Molina, R., Aguilera-Carbó, A. F., Saenz-Galindo, A., Garza, H. de La, Jasso-Cantú, D., et al. (2009). Edible film based on candelilla wax to improve the shelf life and quality of avocado. Food Research International, 42(4), 511–515. Segovia, F. J., Corral-Pérez, J. J., & Almajano, M. P. (2016). Avocado seed: Modeling extraction of bioactive compounds. Industrial Crops and Products, 85, 213–220. SIAP (2015). Servicio de Información Agroalimentaria y Pesquera. http://infosiap.siap.gob. mx/aagricola_siap_gb/ientidad/index.jsp, Accessed date: 21 August 2017. Soong, Y. Y., & Barlow, P. J. (2004). Antioxidant activity and phenolic content of selected fruit seeds. Food Chemistry, 88(3), 411–417. Souza, D. S., Marques, L. G., Gomes, E. de B., & Narain, N. (2015). Lyophilization of avocado ( Persea americana Mill.): Effect of freezing and lyophilization pressure on antioxidant activity, texture, and browning of pulp. Drying Technology, 33(2), 194–204. Tango, J. S., Carvalho, C. R. L., & Soares, N. B. (2004). Physical and chemical characterization of avocado fruits aiming its potential for oil extraction. Revista Brasileira de Fruticultura, 26(1), 17–23. Tesfay, S. Z., & Magwaza, L. S. (2017). Evaluating the efficacy of moringa leaf extract, chitosan and carboxymethyl cellulose as edible coatings for enhancing quality and extending postharvest life of avocado (Persea americana Mill.) fruit. Food Packaging and Shelf Life, 11, 40–48. Toledo, L. C., & Aguirre, C. C. (2016). Enzymatic browning in avocado (Persea americana) revisited : History , advances and future perspectives. Critical Reviews in Food Science and Nutrition, 57(18), 3860–3872. USDA (U.S. Department of Agriculture) (2011). Avocado, almond, pistachio and walnut Composition. Nutrient Data Laboratory. USDA National Nutrient Database for standard reference, release 24. Washington, DC: U.S. Department of Agriculture. Vinha, A. F., Moreira, J., & Barreira, S. V. P. (2013). Physicochemical parameters, phytochemical composition and antioxidant activity of the Algarvian avocado (Persea americana Mill.). Journal of Agricultural Science, 5(12), 100–109. Wang, W., Bostic, T. R., & Gu, L. (2010). Antioxidant capacities, procyanidins and pigments in avocados of different strains and cultivars. Food Chemistry, 122(4), 1193–1198. Wong-Paz, J. E., Muñiz-Márquez, D. B., Aguilar-Zárate, P., Ascacio-Valdés, J. A., Cruz, K., Reyes-Luna, C., et al. (2017). Extraction of bioactive phenolic compounds by alternative technologies. In Grumezescu Alexandru Mihai, & Holban Alina Maria (Vol. Eds.), Handbook of food bioengineering. 2017. Handbook of food bioengineering (pp. 229–252). Academic Press Ingredients Extraction by Physicochemical Methods in Food, ISBN 9780128115213. Yahia, E. M., & Woolf, A. B. (2011). 8 – avocado (Persea americana Mill.). In E. M. Yahia (Ed.). Postharvest biology and technology of tropical and subtropical fruits (pp. 125–186). Cambridge: Woodhead Publishing Limited. Yasir, M., Das, S., & Kharya, M. (2010). The phytochemical and pharmacological profile of Persea americana Mill. Pharmacognosy Reviews, 4(7), 77. Zafar, T., & Sidhu, J. S. (2011). Avocado: Production, quality, and major processed products. In N. Sinha (Vol. Ed.), Handbook of vegetables and vegetable processing: 1871, (pp. 525–543). Oxford: Wiley-Blackwell. Zhang, Z., Huber, D. J., & Rao, J. (2013). Antioxidant systems of ripening avocado (Persea americana Mill.) fruit following treatment at the preclimacteric stage with aqueous 1methylcyclopropene. Postharvest Biology and Technology, 76, 58–64. Zhou, L., Tey, C. Y., Bingol, G., & Bi, J. (2016). Effect of microwave treatment on enzyme inactivation and quality change of defatted avocado puree during storage. Innovative Food Science & Emerging Technologies, 37, 61–67.

and Calorimetry, 120(1), 387–393. Lee, S. G., Yu, M. H., Lee, S. P., & Lee, I. (2008). Antioxidant activities and induction of apoptosis by methanol extracts from avocado. J Korean Soc Food Sci Nutr, 37(3), 269–275. Leite, J. J. G., Brito, É. H. S., Cordeiro, R. A., Brilhante, R. S. N., Sidrim, J. J. C., Bertini, L. M., et al. (2009). Chemical composition, toxicity and larvicidal and antifungal activities of Persea americana (avocado) seed extracts. Revista da Sociedade Brasileira de Medicina Tropical, 42(2), 110–113. Lennartsson, P. R., Erlandsson, P., & Taherzadeh, M. J. (2014). Integration of the first and second generation bioethanol processes and the importance of by-products. Bioresource Technology, 165, 3–8. Litz, R. E., Raharjo, S. H. T., & Lim, M. A. G. (2007). Avocado. In P. E. Chong, Davey, & M. R. Davey (Vol. Eds.), Biotechnology in agriculture and forestry: 60, (pp. 167–187). Berlim: Springer. López-Cobo, A., Gómez-Caravaca, A. M., Pasini, F., Caboni, M. F., Segura-Carretero, A., & Fernández-Gutiérrez, A. (2016). HPLC-DAD-ESI-QTOF-MS and HPLC-FLD-MS as valuable tools for the determination of phenolic and other polar compounds in the edible part and by-products of avocado. Lebensmittel-Wissenschaft und -TechnologieFood Science and Technology, 73, 505–513. Martins, S., Mussatto, S. I., Martínez-Avila, G., Montañez-Saenz, J., Aguilar, C. N., & Teixeira, J. A. (2011). Bioactive phenolic compounds: Production and extraction by solid-state fermentation. A review. Biotechnology Advances, 39, 365–373. Mohd Azhar, S. H., Abdulla, R., Azmah Jambo, S., Marbawi, H., Azlan Gansau, J., Mohd Faik, A. A., et al. (2017). Yeasts in sustainable bioethanol production: A review. Biochemistry and Biophysics Reports, 10, 52–61 November 2016. Morton, J. F. (2004). Fruits of warm climates. Miami: Creative Resource Systems Inc. Oboh, G., Adelusi, T. I., & Akinyemi, A. J. (2013). Inhibitory effect of phenolic extract from leaf and fruit of avocado pear (Persea americana) on Fe2+ induced lipid peroxidation in rats ’ pancreas in vitro. FUTA Journal of Research in Sciences, 9(2), 276–286. Pahua-Ramos, M. E., Ortiz-Moreno, A., Chamorro-Cevallos, G., Hernández-Navarro, M. D., Necoechea-Mondragón, H., & Hernández-Ortega, M. (2012). Hypolipidemic effect of avocado (Persea americana Mill) seed in a hypercholesterolemic mouse model. Plant Foods for Human Nutrition, 67, 10–16. Perea-Moreno, A.-J., Aguilera-Ureña, M.-J., & Manzano-Agugliaro, F. (2016). Fuel properties of avocado stone. Fuel, 186, 358–364. Pereira, M. E. C., Sargent, S. A., & Huber, D. J. (2015). Delayed and prolonged ethylene treatment alleviates firmness asynchrony enhanced by 1-methylcyclopropene exposure in Guatemalan-West Indian avocado. Postharvest Biology and Technology, 108, 54–60. Ranade, S. S., & Thiagarajan, P. (2015). A review on Persea americana Mill. (Avocado)- its fruit and oil. International Journal of PharmTech Research, 8(6), 72–77. Rodríguez-Carpena, J. G., Morcuende, D., Andrade, M.-J., Kylli, P., & Estévez, M. (2011). Avocado (Persea americana Mill.) phenolics, in vitro antioxidant and antimicrobial activities, and inhibition of lipid and protein oxidation in porcine patties. Journal of Agricultural and Food Chemistry, 59, 5625–5635. Rodriguez-Sanchez, D. G., Flores-García, M., Silva-Platas, C., Rizzo, S., Torre-Amione, G., De la Peña-Diaz, A., Hernández-Brenes, C., & García-Rivas, G. (2015). Isolation and chemical identification of lipid derivatives from avocado (Persea americana) pulp with antiplatelet and antithrombotic activities. Food & Function, 6(1), 192–202. Rosenblat, G., Meretski, S., Segal, J., Tarshis, M., Schroeder, A., Gilead, A. Z., et al. (2011). Polyhydroxylated fatty alcohols derived from avocado suppress in X ammatory response and provide non-sunscreen protection against UV-induced damage in skin cells. Archives of Dermatological Research, 303, 239–246. Ruiz, H. A., Rodríguez-Jasso, R. M., Fernandes, B. D., Vicente, A. A., & Teixeira, J. A. (2013). Hydrothermal processing, as an alternative for upgrading agriculture residues and marine biomass according to the biorefinery concept: A review. Renewable and

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