Pectin Removal and Clarification of Juices

Chapter 5

Pectin Removal and Clarification of Juices Sankha Karmakar and Sirshendu De Department of Chemical Engineering, Indian Institute of Technology, Kharagpur, West Bengal, India

Chapter Outline 5.1 Introduction 155 5.2 Various Processing or Preservation Techniques Used for Fruit and Vegetable Juice 157 5.2.1 Depectinization of Fruit Juices 163 5.3 Other Treatment Methods for Fruit Juice Clarification/ Depectinization 163 5.3.1 Membrane 164 5.3.2 Membrane Classification 166 5.3.3 Membrane Modules 166

5.4 Membrane Based Separation Processes 168 5.5 Depectinization and Membrane Based Clarification of Some Typical Fruit and Vegetable Juices 168 5.5.1 Enzymatic Depectinization of Juices 168 5.5.2 Membrane Based Clarification Process for Some Typical Fruit and Vegetable Juice 172 5.6 Conclusion 182 References 184

5.1 INTRODUCTION Fruits and vegetables are natural food products that have been quite popular since early times. In fact, production and preservation of fruits and vegetables are almost as old as human civilization (Skolnik, 1968). They are very susceptible to decay due to high moisture content and are characterized as easily perishable commodities. Preservation of fruits and vegetables dates back to 6000 BC, when people avoided microbial decay by drying and smoking the fruits. Ancient Chinese civilization started preservation of fruits around the first century and Plinius the Elder reportedly preserved white cabbage in earthenware pots in Italy (Derieux, 1988). In the modern era, people prefer to consume ready-made food products due to their busy lifestyle. Hence, fruit juice processing industries have experienced significant growth in the last few decades. Separation of Functional Molecules in Food by Membrane Technology. DOI: https://doi.org/10.1016/B978-0-12-815056-6.00005-X © 2019 Elsevier Inc. All rights reserved.

155

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In the juice processing industry, for most of fruits such as orange (Citrus sinensis), apple (Malus pumila), guava (Psidium guajava), litchi (Litchi chinensis), cranberry (Vaccinium oxycoccos), pineapple (Ananas comosus), mango (Mangifera indica), plum (Prunus domestica), mosambi (Citrus limetta), pomegranate (Punica granatum), peach (Prunus persica), banana (Musa acuminata), grape (Vitis vinifera), etc., the fruit pulp is extracted and mashed to create a homogenous mixture. The juice from plants like sugarcane (Saccharum officinarum) is taken out by crushing the plant using a mechanical crusher and in some cases, like coconut (Cocos nucifera), water is directly taken out and consumed. All these fruit juices have their own therapeutic values: G G G G G G

G

G

Orange juice helps in brain development. Apple aids in the growth of red blood cells. Guava boosts immunity. Litchi is very rich in vitamins. Cranberry helps in bladder problems. Pineapple is a rich source of vitamin C, vitamin A, fiber, calcium, potassium, and other essential minerals. Mango contains huge amount of proteins, fibers, vitamins, iron, and other essential minerals. Plum, pomegranate, and mosambi make the digestive system strong; peach improves vision in growing children.

Also, tender coconut is rendered as the most effective sports drink for young athletes (Karmakar and De, 2017). Fruit juices are rich in fibers, polysaccharides, pectin, gum, lignin, cellulose, starch, protein, and many other constituents. The presence of such composition makes the fruit juice very cloudy and viscous. Some of the major factors for consumer acceptability of the processed juice are: 1. juice with higher clarity and reduced viscosity, 2. natural flavor of the juice, 3. long shelf life of the juice. Keeping these things in mind, various separation and preservation methods have been employed to make the processed fruit juice more attractive to the consumers. Maintaining food quality according to the prescribed regulatory board while making the process economically viable is a major challenge in the food processing industry. As stated earlier, one of the key factors for consumer acceptability of a fruit juice is clear appearance of the juice in terms of color and clarity. Several conventional methods are already in use to ensure processed juice with higher clarity, reduced viscosity, and original flavor. Some of the conventional methods to achieve clear juice are centrifugation, enzymatic treatment, or addition of fining agents. But, these processes are generally

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operated manually and in batch mode, thus, making the process more labor intensive and less economically viable. Moreover, addition of external chemicals in the processed fruit juice is inadvisable since it may leave a slight after taste, thereby, lowering its acceptability. Many fruit juice regulatory boards have approved the addition of sugar and certain natural additives, like ascorbic and citric acid. Sugar acts as natural preservative when added in sufficiently high amount. Excess use of sugar causes diabetes and obesity (Guthrie and Morton, 2000; Ludwig et al., 2001; Malik et al., 2010; Imamura et al., 2015). Also, addition of many coloring agents and artificial flavors to maintain the sensory and aesthetic properties of the fruit juice is a common practice among the fruit juice processing industries. In recent decades, serious awareness has been raised in public due to the carcinogenic nature of additives. Hence, fruit juice with high shelf life without any additive or preservative is creating its market and the challenge lies in its economic production. Shelf life of the processed juice plays a key role in economical viability of the production process, since consumers nowadays are more attracted to natural juice without any additive or preservative. Generally, fruit juices are very susceptible to fouling even under refrigeration due to the presence of many potent sites for bacterial growth. The shelf life of some of the natural juices is presented in Table 5.1.

5.2 VARIOUS PROCESSING OR PRESERVATION TECHNIQUES USED FOR FRUIT AND VEGETABLE JUICE In recent decades, many conventional and nonconventional techniques have been developed to increase the shelf life of the naturally processed juices. As discussed earlier, the market for natural fruit juice without any external additive or preservative is growing and many new technologies have been developed for economic production of natural fruit juice. These technologies aim to produce safe, fresh, and nutritive beverages with good sensory properties in a cost effective method. Various thermal and nonthermal technologies have been developed and adopted to make the method less energy consuming, and have high production yield and low production cost to increase the profit margin. Some common technologies and their advantages and disadvantages are presented in Table 5.2. Apart from these, other conventional nonthermal fruit juice processing techniques include ultrasonic vibration, high-pressure homogenization, cold plasma technique, electroheating, and others (Aneja et al., 2014; Yıkmı¸s, 2016; Misra et al., 2017). Thermal processes like drying, blanching, pasteurization, or sterilization increase the shelf life of the juice at the expense of its sensory properties and nutritional values. Although nonthermal technologies improve the shelf life of the juice, they have other side effects, such as contamination, loss of

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TABLE 5.1 Shelf Life of Some Typical Natural Juices Fruit Name

Shelf Life

References

Natural Juice

Refrigerated Natural Juice (B4
C)

Processed Juice in Refrigeration (B4
C)

Orange

2h

1016 days

.90 days

Fellers (1988), Polydera et al. (2003)

Apple

2h

14 days

.67 days

Evrendilek et al. (2000), Sua´rezJacobo et al. (2010)

Guava puree

,2 days

10 days

40 days

Yen and Lin (1996), Ninga et al. (2018)

Litchi

23 days

15 days

45 days

Kumar et al. (2012)

Pomegranate



,7 days

2835 days

Varela-Santos et al. (2012), Vegara et al. (2013)

Mosambi



2 weeks

10 weeks

Khandpur and Gogate (2016)

Mango

Few hours

2 weeks

4 weeks

Mkandawire et al. (2016)

Grape

Few hours

7 days

161 days

Siricururatana et al. (2013)

Coconut water

Few hours

2 days

18 weeks

Karmakar and De (2017)

sensory properties, and formation of toxic compounds. Processes like UV-irradiation and ozone processing are not very effective and also the operational cost is huge. The addition of preservatives or additives (natural or synthetic) increases the shelf life of the juice but this scenario is not so attractive to the consumers. Hence, an economic clarification process would be preferable. In this regard, membrane based separation techniques have been proved to be one of the most profitable solutions, as they do not involve the addition of any chemical agents or thermal treatment, while they need low maintenance and unskilled labor, and they maintain the original flavor, aroma, smell, taste, and nutritional parameters of the fruit. The cost analysis comparison for membrane based processes and conventional fruit

TABLE 5.2 Conventional Processes for Fruit Juice Processing Process

Fruit Juice Processed

Advantages

Disadvantages

References

Thermal Process Blanching

Blueberry, strawberry

G G G

Preserve color and texture Tones down the strong taste Stops enzyme action responsible for loss of flavor or color

G

G

G

Thermal drying

Mushrooms, green chilies, tomato, kiwifruit

G

G

Pasteurization and sterilization

Apple, orange, white grape

G

Less storage space than canned or frozen foods No special equipment is required

G

All pathogenic (harmful) bacteria and most nonpathogenic bacteria are killed

G

G

G

Cannot be used for all types of fruits Also often needs to couple with other processes Loss of vitamins

Wrolstad et al. (1980), Rossi et al. (2003)

Loss of sensory properties Loss of nutritive values

Sharma et al. (1995), Maskan (2001)

Loss of sensory properties Loss of naturally occurring nutrients

Mazzotta (2001), Lee and Coates (2003), Fiore et al. (2005)

Nonthermal Process High hydrostatic pressure

Passion, apple, orange, pineapple, cranberry, grape, pomegranate

G

Causes no significant losses of functional compounds in foods

G

Several toxic compounds of abiotic origin can be present or formed in foods processed by pressure processing technologies

Raso et al. (2006), Laboissie`re et al. (2007), Ferrari et al. (2010), Escobedo-Avellaneda et al. (2011), VarelaSantos et al. (2012)

Pulsed electric field

Grapefruit, lemon, orange, tangerine, cranberry, pineapple, apple, tomato

G

Causes no significant losses of functional compounds in foods

G

Contamination of food products due to chemical products from electrolysis Disintegration of food particles due to shock waves

Raso et al. (1998, 2006), Cserhalmi et al. (2006), Aguilar-Rosas et al. (2007)

G

(Continued )

TABLE 5.2 (Continued) Process

Fruit Juice Processed

Advantages

Ultraviolet irradiation

Orange, guava, pineapple, apple

G

Ozone processing

Orange, kiwifruit, blackberry

G

Disadvantages

Does not produce chemical residues, byproducts, or radiation

G

Effective against various kinds of microorganism

G

G

G

G

Use of preservatives

Apple, raspberry, cranberry, grapefruit, mango, kiwi, pineapple peach, apricot, orange, tomato

G

High shelf life

G G

References

Generally effective in surface sterilization Not cost effective

Guerrero-Beltrn and Barbosa-Cnovas (2004), Keyser et al. (2008), Char et al. (2010)

Loss of sensory properties Sometimes produce bromate (a carcinogen) Not cost effective

Karaca and Velioglu (2007), Tiwari et al. (2008, 2009), Barboni et al. (2010)

Altered sensory properties Less attractive to consumers

Beuchat (1982), Komitopoulou et al. (1999), Kabasakalis (2000), Jordan et al. (2001), Shui and Leong (2002)

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´ lvarez et al. (2000) for juice clarification processes has been conducted by A apple juice clarification. This was performed on the basis of the annual maintenance cost, new profit, gross margin, and payback period. The cost comparison is presented in Fig. 5.1. As evident from this figure, the membrane based process was found to be more profitable with less payback period since the annual maintenance cost was lower than the conventional process, making it a viable economical alternative. However, membrane based processes are limited due to fouling. Because the operation is based on physical separation by size exclusion, formation of a fouling layer over the membrane surface reduces the productivity, thereby limiting its operational time and life. One of the major gel forming agents present in various fruits and vegetables is pectin (Huber and Lee, 1986; Thakur et al., 1997; Zhou et al., 2000; Willats et al., 2006; Sagu et al., 2014; Ninga et al., 2018). Pectin is found in all types of plants. It is a class of heteropolysaccharide found primarily in the cell walls of the plants (Mualikrishna and Tharanathan, 1994). It was first isolated in 1825 by a French scientist and pharmacist, Henri Braconnot (Keppler et al., 2006). Pectin is predominantly found in citrus fruits like apple, guava, oranges, pears, plums, peach, mosambi (Zhou et al., 2000; Rai et al., 2004; Willats et al., 2006; Ninga et al., 2018). Apart from these, pectin content is also high in banana (Vı´quez et al., 2007; Sagu et al., 2014). Pectins are a group of pectic polysaccharides rich in galacturonic acid (Prade et al., 1999; Ninga et al., 2018). Among the several polysaccharides, homogalacturonas are linear chains of α-(14)-linked D-galacturonic acids (Ridley et al., 2001; Golovchenko et al., 2002). D-Xylose or D-apiose in case 5.0

Conventional method Membrane based separation technique

4.5 4.0 3.5

4.1

3.716 3.432 3.0

3.0 2.5 2.0 1.5

1.365 1.175

1.0 0.5 0.0

AMC Net profit (million Euro/year) (million Euro/year)

0.32 0.37 Gross margin

Payback period (years)

FIGURE 5.1 Cost comparison of membrane based process and conventional method for apple juice processing.

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of xylogalacturonan and apiogalacturonan, respectively, can be present as substituted galacturonans (Schols et al., 1995). Many neutral sugars like D-galactose, L-arabinose, and D-xylose branch off from Rhamnogalacturonan I pectins (RG-I). RG-I pectin contains a backbone of repeating disaccharide, 4-α-D-galacturonic acid-(1,2)-α-L-rhamnose-1. Rhamnogalacturonan II pectins (RG-II) are a less frequently occurring pectin that are primarily made of D-galacturonic acid units (Willats et al., 2001; Deng et al., 2006). Pectins have molecular weights in the range of 30,000130,000 Da, depending on the source and extraction conditions. They can be classified into high or low ester pectins depending upon the amount of carboxyl groups present in galacturonic acid that can be esterified by methanol. The nonesterified galacturonic acid can be classified into: 1. Pectinates: salts of partially esterified pectin. 2. Pectates: if the degree of esterification is below 5%. 3. Pectic acid: it is the insoluble acid form. Acetylated galacturonic acid is present in some plants, such as potatoes and pears, along with pectin. Acetylation increases the stability and emulsifying effect of pectin while preventing gel formation. In some plants, amidated pectin, a modified form of pectin, is present. For amidated pectins, galacturonic acid is converted to carboxylic acid amide with the help of ammonia. These types of pectins are more resistant to fluctuating calcium concentration while forming gels. Pectin is a typical gelling agent that easily forms gel in the presence of Ca21 ions at low pH (Thakur et al., 1997). This property has found huge application in the fruit industry, typically in the preparation of jam and jelly. Depending upon the type of pectin and the gelling conditions, gels can be categorized as hard and soft gels. If the gel formation is too strong it results in a granular texture, whereas, if the gel is too soft it makes a weak gel. In case of high ester pectins (more than 60% solid content with pH 2.83.6), the individual chains are bound by hydrogen bonds and hydrophobic interactions. Sugar present in pectin binds water and compels the pectin strands to attach to each other resulting in a three-dimensional macromolecular gel. It is also known as low water activity gel or sugar acid pectin gel. In case of pectin with low ester content, the gelling mechanism is due to the ionic bridges formed between calcium ions and the ionized carboxyl groups of the galacturonic acid. This type of gel can form in pH range 2.67 and at a low soluble solid content (10%70%). Amidated pectins form reversible gels that are dependent on temperature. Also, it needs less calcium ions to form gels. The presence of pectin is undesirable in fruit juice due to following reasons: G

pectin interacts with protein in the juice forming a complex that acts as a potent source of microbial growth, thereby spoiling the juice fast;

Pectin Removal and Clarification of Juices Chapter | 5 G

G

163

pectin makes the juice viscous, thereby affecting flowability of juice making the processing difficult; pectin, being a natural gel forming agent, forms a thick cake type of layer, thereby, affecting the filtration performance.

Thus, complete depectinization of fruit juice is essential in view of its long shelf life.

5.2.1 Depectinization of Fruit Juices Pectin content is pretty high in most of the citrus fruits, guava, banana, and others (Rai et al., 2004; Sagu et al., 2014; Ninga et al., 2018). Conventionally, enzymes like pectinase and amylase are used to depectinize the fruit juices (Dingle et al., 1953; Alkorta et al., 1998; Prade et al., 1999; Hoondal et al., 2002; Gummadi and Panda, 2003; Jayani et al., 2005; Pedrolli et al., 2009; Visser and Voragen, 2009; Sagu et al., 2014; Ninga et al., 2018). Pectinase is usually obtained from microbial sources (Hoondal et al., 2002; Gummadi and Panda, 2003; Jayani et al., 2005; Pedrolli et al., 2009) and it is also used industrially for depectinization (Alkorta et al., 1998). Details of enzymatic depectinization are presented in subsequent sections.

5.3 OTHER TREATMENT METHODS FOR FRUIT JUICE CLARIFICATION/DEPECTINIZATION Fruit juices contain many constituents that affect the subsequent filtration efficiency. Suspended solids, proteins, and fibers are also present in fruit juice along with pectin. As already discussed, pectin concentration can be reduced significantly by treatment with enzymes. However, other pretreatment methods are also employed to devoid the feed of any solutes that might hamper the filtration process. The suspended solids generally contain insoluble pectinous solids, cellulose, hemicelluloses, and lignins (Kirk et al., 1983) and these constituents also affect the filtration performance (Girard and Fukumoto, 2000; Sagu et al., 2014). In most of the cases, centrifugation at high speed is employed as a suitable pretreatment method (Kratchanova et al., 2004; Rai et al., 2007; Chen et al., 2008; Chhaya et al., 2013; Domingues et al., 2014; Sagu et al., 2014; Biswas et al., 2016). Some fruit products that contain low suspended solids (like coconut water) can be pretreated using a fine food grade mesh (Karmakar and De, 2017). However, juice treatment with commercial pectinase enzyme is much more costly and it accounts for almost 30% of the total processing cost (Porter, 1990). Although the centrifugation cost is less than that of pectinase treatment (Rai et al., 2006), in most cases it is coupled with pectinase treatment to obtain the pretreated juice (Sagu et al., 2014). Treatment by fining agents, like

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bentonite (acts on pectin) and gelatin (acts on protein) and their combination, is also common for pectin and protein removal (Girard and Fukumoto, 2000). However, fining treatment causes addition of external chemicals that need to be removed by coarse filtration followed by fine filtration. These additional steps make the processing more complex and expensive. Membrane based processes can be an attractive alternative in this regard. Membrane based processes offer a wide range of separation processes starting from pretreatment to isolation of any specific bioactive agent from the fruit juice. Because these processes increase the shelf life of the juice, keeping the sensory and nutritional profile of the juice intact, they are revolutionizing the fruit juice processing industry. The processed juice, devoid of any external chemical agents, is also very appealing to the consumers.

5.3.1 Membrane Membrane is an interface separating two phases, restricting the transport of various species through it. Fruit juice clarification using membranes is a physical, rate-governed separation process based solely on size exclusion. Various grades of membranes (based on pore size) can be used for pretreatment, purification, extraction, and also typical ultrafiltration or nanofiltration membranes can be used to fractionate a specific bioactive agent. Porous membranes can be classified into two broad categories based on their structure, namely, symmetric and asymmetric membrane (Ladewig and Al-Shaeli, 2017). Symmetric membranes have uniform structure throughout the membrane cross-section. The thickness of the membrane governs the resistance to mass transfer thereby controlling the permeation rate. Asymmetric membranes have a 0.15-μm-thin skin layer at the top followed by a highly porous structure. This thin skin serves as the primary selective barrier for solute transport and the membrane characteristics are defined particularly by the property of the skin layer. In most of the pressure-driven membrane based operations, such as nanofiltration, ultrafiltration, and reverse osmosis (RO), asymmetric membranes are employed to achieve high throughput. Asymmetric membranes can be prepared by a simple phase inversion process leading to integral structure (Kesting, 1971). A schematic of symmetric and asymmetric porous membrane is presented in Fig. 5.2. (A)

(B)

Thick dense layer

FIGURE 5.2 Representative diagram of (A) symmetric and (B) asymmetric membrane.

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Based on the material of construction, membranes can be organic, inorganic, or a blend of both. Organic membranes are prepared from different organic polymers, like polysulfone (PSF), polyacrylonitrile (PAN), polyethylene (PE), etc. Organic membranes are more sensitive to heat and less stable at high temperature. Also, organic membranes are susceptible to mechanical damage and are very sensitive to harsh operating conditions. However, organic membranes can be easily tuned to obtain varying pore size ranging from angstrom to microns. These membranes can be backwashed easily to recover permeability. Hence, they find wide application in various fields of wastewater treatment, fruit juice clarification, purification of drinking water, desalination, and many more. Inorganic membranes are usually made from aluminum oxide (Al2O3), zirconium oxide (ZrO2), zeolites, porous glass, molybdenum, and stainless steel. Inorganic membranes have long-term stability at high temperature, are resistant to harsh chemical environments, and are resistant to high pressure drops. However, they are expensive and it is very difficult to prepare inorganic membranes with submicron pore size, thereby limiting their application in separation of fine solutes of low molecular weights. Another class of polymeric membranes is mixed matrix membranes. These are polymeric membranes incorporated with inorganic additives. Using these membranes, smaller sized molecules, such as fluoride, arsenic, phenol, etc., are removed by specific adsorption by inorganic compounds and at the same time, larger sized suspended solids and bacteria can be removed by size exclusion at higher throughput at lower pressure (Karmakar et al., 2017, 2018).

5.3.1.1 Membrane Based Processes: Advantages, Disadvantages, and Challenges There are several advantages of membrane based process including: 1. Operation is carried out at room temperature, thereby requiring less energy. 2. Filtration is conducted at room temperature, so heat sensitive solutes, like proteins, fruit juices, etc., can be easily processed. 3. Membrane setups are very simple in design and do not require any complex controls or auxiliary equipment, making them less labor intensive, easy to operate, and require less maintenance. 4. Membrane based separations are mostly physical in nature, hence, they do not produce any harmful byproducts. 5. Membrane based processes are easily scalable for industrial applications. Disadvantages of membrane based processes: 1. Membrane based processes are often coupled with various pretreatment processes, such as depectinization, centrifugation, cloth filtration, etc., to reduce the membrane load, thereby increasing the treatment cost.

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2. Major limitation of these processes is membrane fouling, hampering performance, and life of membrane. 3. Designing and implementing a membrane based system to handle high throughput at high pressure is often very complex and expensive. The major challenge for application of membranes in the fruit juice processing industry lies in tackling the membrane fouling, scaling up of the system for better productivity, and making the process economical with respect to commercial processing techniques.

5.3.2 Membrane Classification Based on pore size, molecular weight of solutes to be separated, and operating pressure, membranes can be categorized into four major classes, as presented in Table 5.3. Pervaporation (PV), osmotic dehydration, and membrane distillation (MD) are some other membrane based methods employed for fruit juice clarification. Some typical grades of membrane obtained from different base polymers are: G

G

G

G

Microfiltration: Obtained from cellulose acetate (CA), cellulose nitrate (CN), cellulose triacetate (CTA), blend of CA and CTA, polyvinyl chloride (PVC), polyvinyl alcohol (PVA), PAN, PAN-PVC copolymer, polyamide-aromatic, polycarbonate (PC), polyamide (PA), polypropylene (PP), PSF, polytetrafluoroethylene (PTFE), PTFE. Ultrafiltration: CA, CTA, PVA, PAN, PAN-PVC copolymer, polyamidearomatic, PA, PSF, polyvinylidene fluoride (PVDF), cellulose acetate phthalate (CAP). Nanofiltration: PVDF, polyethersulfone (PES), and blend membranes with different organic and inorganic additives. Reverse osmosis: CA, CTA, polyamide-aromatic, PA, PES.

5.3.3 Membrane Modules The equipment in which membranes are housed is known as the membrane module. The membrane modules are designed to have maximum filtration area in a relatively smaller volume for a compact design. Various configurations of membrane modules are used to achieve maximum productivity (flux). According to the configuration, membrane modules can be classified into four types: 1. 2. 3. 4.

plate and frame module spiral wound module tubular modules hollow fiber modules

TABLE 5.3 Comparison of Various Grades of Membranes Membrane Type

Pore Size (A˚)

MWCO (kDa)

Particle size of the Solutes Rejected (μm)

Operating Pressure (atm)

Characteristic of Permeate

Characteristic of Retentate

Applications

Microfiltration (MF)

.1000

100500

0.110

24

Solvent (water) 1 dissolved solutes

Large suspended particles, bacteria, clay, emulsion

Filtration of clay solution, latex, paint, pretreatment step in fruit juice processing

Ultrafiltration (UF)

201000

1100

0.0010.1

68

Water 1 ultra fine solutes dissolved in water

Mostly organic compound, macromolecules, proteins, viruses, bacteria, enzymes, polysaccharides and colloids

Filtration of protein, red blood cells and wide application in fruit juice processing

Nanofiltration (NF)

520

0.21

0.00010.001

1525

Water 1 nanomolecules of solute, glucose (if present)

High molecular weight compound, polyvalent anions, oligosaccharides

Filtration of dyes, small molecular weight organics and concentrating different clarified fruit juices

Reverse osmosis (RO)

210

,0.1

0.0001

.25

Water

Ions and most organic compounds, amino acids

Desalination

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Details of each module type are available in the literature (Morigami et al., 2001; Gu et al., 2011; Wang et al., 2011; Thakur and De, 2012).

5.4 MEMBRANE BASED SEPARATION PROCESSES Herein, a cold sterilization technique that produces fruit juices with longer shelf life is desired. The technology should be economical, having easy maintenance, as well as yielding processed fruit juice at superior quality and quantity. Membrane based separation processes (MSP) have emerged and gained popularity in the last decade to address this issue. Different grades of the membrane can be employed for fruit juice clarification starting from pretreatment (MF) to concentrate the clarified juice (RO). Size exclusion mechanism of the membranes is employed to retain suspended solids, colloids, lipids, high molecular weight proteins, and microorganisms. Smaller solutes, like salts, polyphenols, minerals, sugar, and vitamins are allowed to permeate, producing clarified juice with longer shelf life after being coupled with aseptic packaging along with full nutritional content. From the preceding sections, it can be inferred that MSPs have an edge over other conventional clarification technologies for fruit and vegetable juices. Several advantages of MSP can be exploited to obtain processed juice having similar nutritional profile and sensory properties as the natural one, having long shelf life. Since no external chemicals or preservatives are added in case of MSP, the processed juice is far more attractive to consumers. MSP not only improves the shelf life of the juice, but it also enhances its physicochemical characteristics in terms of clarity, total solid content, and protein concentration. Moreover, different configurations of the membrane separation modules can be utilized to improve product quality and quantity in a very economical fashion. NF and RO based membrane processes are often used to concentrate the juice, which is less energy intensive than traditional processes like multiple effect evaporation. Thus, MSP offers a better and greener alternative to the conventional processes and has huge potential in the sector of fruit and vegetable juice processing.

5.5 DEPECTINIZATION AND MEMBRANE BASED CLARIFICATION OF SOME TYPICAL FRUIT AND VEGETABLE JUICES 5.5.1 Enzymatic Depectinization of Juices As discussed earlier, pectin is present in almost all fruits. In citrus fruits, apple, pear, guava, banana, etc., it is more significant than in the others. The presence of negatively charged rhamnogalacturonans and neutral arabinogalactans imparts viscosity to the juices, but they also form haze in

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combination with different proteins. Haze formation not only retards the maximum recovery of the juice (Whitaker, 1984) but also acts as a potent site for microbial growth spoiling the juice. Due to its sticky nature and gel forming characteristics, many treatment methods have been employed to remove pectin from various fruit juices. One of the most widely used treatment methods for pectin removal is enzyme treatment. Enzymes like pectin methylesterase, pectate lyase, polygalacturonase, etc., obtained from Aspergillus niger can hydrolyze the pectin present in the juice (Whitaker, 1984). Tangerine juice had been depectinized at constant temperature using pectinase by Chamchong et al. (1991) before subjecting it to subsequent microfiltration (MF) and ultrafiltration (UF) process. Chang et al. (1995) used five different commercial pectinase enzymes to treat Stanley plum juice. They varied the enzyme concentration keeping the temperature and the time of operation constant. It was noted that the taste turns bitter with enzyme concentration. Banana puree has been depectinized by commercial pectinase along with other commercial enzymes, like pectinol and pectinol D by Viquez et al. (2007) at varying enzyme concentration at 45
C for 2 hours. Similar work was reported by Sagu et al. (2014). Another citrus fruit, mosambi, was subjected to primary treatment by pectinase by Rai et al. (2004). The optimum condition was selected based on minimum viscosity and alcohol insoluble solids (AIS) and maximum clarity. Ninga et al. (2018) had depectinized guava juice using commercial pectinase enzyme obtained from Aspergillus niger. The optimizing criteria for enzyme treatment are enzyme concentration, time, and temperature. For their study, the optimized time, temperature, and enzyme concentration were 45 minutes, 45
C, and 0.078% w/w, respectively. The hydrolysis of pectinous matter was also modeled using the Hill equation: v5

Vmax ½Sn K 1 ½Sn

ð5:1Þ

where Vmax and n refer to the maximum reaction rate and Hill coefficient, respectively. K is expressed as K 5 [S50]n (S50 is the substrate concentration for which the reaction rate is half of its maximum value). The value of n decreased from 7 to 4 with enzyme concentration. This is due to decrease in the binding sites of the enzyme. The enzymatic treatment increased the reducing sugar content by twofold and decreased the viscosity significantly. The developed depectinization kinetics provided insights about the molecular mechanism and helped in scaling up the system. Depectinization of apple juice was carried out by Alvarez et al. (1998) using commercial pectinase enzyme, Pectinex-3XL (pectin esterase, polygalacturonase, pectate lyase, pectin lyase, and hemicellulases). The process was carried out in a batch reactor with varying enzyme concentration and fixed time and temperature, 120 minutes and 55
C, respectively. It was found that 300 mg/L of pectinase dose was optimum for the process. The viscosity was reduced drastically (by 81%). Around 80%

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of reduction in pectin and turbidity was attained. Also, due to depectinization, flux of the subsequent membrane based process increased significantly. Influence of depectinization on fruit juices like West Indian cherry (Malpighia glabra) and pineapple was studied by Barrosi, Mendes, and Peres (2004). Citrozym Ultra-L, a mixture of pectinase, hemicellulase, and cellulase was used for enzyme treatment that was carried out in a batch reactor at 40
C for 90 minutes. At an enzyme concentration of 300 mg/L, around 82% and 26% of reduction in galacturonic acid concentration was obtained from West Indian cherry puree and pineapple juice, respectively. However, enzyme concentration of 20 mg/L, operated at 40
C for 60 minutes, was considered to be the optimum pretreatment step prior to UF. Mosambi juice was depectinized using commercial pectinase enzyme obtained from Aspergillus niger by Rai et al. (2004). Optimization of time, temperature, and concentration of enzyme was carried out by response surface methodology (RSM) based on apparent viscosity, AIS, and clarity. The optimized operating conditions were obtained as 99.27 minutes, 42
C, and 0.0004% w/v, for time, temperature, and enzyme concentration, respectively. Banana contains high amount of pectin making the juice viscous and turbid. Sagu et al. (2014) developed optimum low temperature extraction process of banana juice using commercial pectinase enzyme. The operating conditions were optimized using RSM and it was found to be 33
C temperature, 108 minutes of treatment at enzyme concentration of 0.03% v/w. The physicochemical parameters obtained at the optimum conditions were, viscosity: 1.42 6 0.04 mPa; clarity: 55.5 6 5%T; AIS: 0.52 6 0.02% w/w; total polyphenol: 14.8 6 0.4 mg GAE/100 mL, and protein concentration: 1341 6 71 mg/L. The extract also contained high amount of potassium and sugar. A first order kinetics of degradation of the substrate was proposed based on the amount of AIS: dC 5 2 kC dt

ð5:2Þ

where C is the concentration of AIS at any time point t with kinetic constant k. It was observed that the kinetic constant varied linearly with substrate concentration. Apart from this, depectinization is common in many other fruit juices, like grape, orange, grapefruit, tangerine, lemon, etc. Depectinization study of some typical fruit juices is summarized in Table 5.4. Depectinization not only reduces the viscosity and arrests haze formation, but it also increases the productivity of the subsequent membrane based processes significantly (Liew Abdullah et al., 2007; Pap et al., 2009; Domingues et al., 2014). These studies confirm the improvement in clarity, reduction in viscosity, and lowered pectin concentration using commercial pectinase enzyme. Hence, pectinase treatment is a viable pretreatment method before subjecting the fruit juice to subsequent membrane based operations. However, to remove the left over pectin, a suitably selected UF membrane has to be used to obtain a pectin free clarified juice.

TABLE 5.4 Depectinization Study of Some Typical Fruit Juice Fruit

Enzyme Used

Time (min)

Temperature (
C)

Enzyme Concentration

Properties of the Clarified Juice

References

Sour cherry juice (Prunes cerasm)

Pectinex-3XL

120

50



Reduced viscosity

S¸ ahin and Bayindirli (1993)

Black carrots (Daucus carota)

Panzym P5

120

50



Increase in shelf life

¨ zkan and Kırca, O Cemeroglu (2006)

Apple, grape, and lemon

Pectinex 3XL

90

50



Increase in shelf life

¨ zkan and Kırca, O Cemeroglu (2006)

Apple, pear, grape

Pectinmethylesterase, polygalacturonases, pectinlyase







Clear juice

Grassin and Fauquembergue (1996)

Cranberry

Crystalzyme Cran

60

45

0.12% w/v

Negative alcohol precipitation test

White, Howard and Prior (2011)

0.004% v/v

Increase in flux in subsequent MSP

Pap et al. (2009)

Blackcurrant (Ribes nigrum)

Panzym Super E and

720

25

Trenolin Rot DF

1440

25

Starfruit (Averrhoa carambola)

Pectinex Ultra SP-L

20

30

0.10% v/v

Reduction in viscosity, effectively increasing flux in subsequent MSP

Liew Abdullah et al. (2007)

Peach

Pectinex AFPL3 and Ultra SP WOP

60

25

240 mg/L

Reduction in pulp content and viscosity

Santin et al. (2008)

Passionfruit (Passiflora edulis f. flavicarpa)

Pectinex 3 XL

90

44

1 mL/L

Reduction in viscosity, effectively increasing flux in subsequent MSP

Domingues et al. (2014)

Orange

Pectinex Ultra SPL

240

Room temperature

20 mg/L

Reduction in viscosity, effectively increasing flux in subsequent MSP

Qaid et al. (2017)

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Separation of Functional Molecules in Food by Membrane Technology

5.5.2 Membrane Based Clarification Process for Some Typical Fruit and Vegetable Juice Fruits and vegetables are excellent source of nutrition and can be consumed in its raw form. The juice form of the fruits is preferred all around the world because it is easy to consume, easily digested, and the nutrients are easily assimilated in the body. Moreover, since many fruits are not available yearround, juice with long shelf life is preferred.

5.5.2.1 Apple Juice Apple (Malus pumila) is a well-known fruit, popular all over the world due to its health benefits. The plant, mainly originating from central Asia, has spread all over the world. The whole fruit is edible including the outer skin. Apple contains high amount of vitamins like vitamin C and vitamin B12, minerals like calcium and phosphorous, and a rich source of carbohydrate. Apple juice in various forms is popular among the masses and many studies have been conducted to improve the shelf life and nutritional parameters of this juice. Some of those studies are presented herein. An integrated membrane process including UF, MD, and osmotic distillation (OD) had been employed by Onsekizoglu et al. (2010) for clarification of apple juice. The feed apple juice containing total soluble sugar (TSS) of 12oBrix was clarified by a series of UF membrane (100 and 10 kDa) and % concentrated using an integrated MD and OD process. TSS of the final product was 65oBrix. Their physicochemical properties like, aroma, taste, texture, % color, and nutritional properties like, phenolic compounds, organic acids, and sugar were recovered after the integrated MSP. Moreover, formation of 5-hydroxymethylfurfural was significantly arrested in the case of the combined OD and MD process. Koza´k et al. (2006) also developed an integrated membrane process for the clarification of apple juice. The raw juice was initially subjected to MF followed by concentration by RO method. The concentrated juice was then subjected to RO-OD and RO-MD process using hydrophobic porous hollow fiber module. The feed juice had a TSS of 17.5oBrix, which was concentrated to 62 and 71oBrix, for RO-OD and RO-MD%process, respectively. The % physicochemical property of the final juice was also comparable with the raw juice in terms of aroma and flavor. Reverse osmosis is the most common MSP for concentrating fruit juices. Al-Obaidi et al. (2017) had developed a multistage RO using spiral wound modules. A series configuration of 12 elements of 1.03 m2 area was optimized for this multistage process. The product was concentrated to about 142% compared with the feed with a final TSS of 25.5oBrix. Moreover, the % study also revealed that the transmembrane pressure (TMP) and cross-flow rate play a major role in percentage rejection of sugar.

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UF is commonly used in MSP for secondary clarification of fruit juices and it serves as a posttreatment step. Gulec et al. (2017) used three polymeric UF membrane of molecular weight cutoff of 100, 50, and 30 kDa, respectively, for apple juice clarification. It was observed that 30 kDa membrane showed better recovery of hydraulic permeability compared with others. Also, the flux decline in case of 30 kDa membrane was quite less compared with the other two. Ninety percent TSS was recovered (9.7oBrix % of in permeate compared with 11.3oBrix in raw juice). The pore size % 30 kDa, being smaller in size, promoted cake filtration, which was removed easily. Often the MSP is coupled with enzymatic pretreatment of the juice. Alvarez et al. (1998) had developed a UF process for depectinized apple juice using a 15 kDa tubular module with an area of 0.023 m2. The process was carried out at TMP of 0.4 MPa. It was observed that the highest flux was obtained for the sample, which was depectinized using an enzyme concentration of 300 FDU/g pectin, where FDU is the ferment depectinization unit. Aguiar et al. (2012) had developed a coupled RO and osmotic evaporation (OE) method to treat depectinized apple juice. Initial pretreatment was carried out by a 0.3-μm MF membrane. RO and OE were carried out by plate and frame module and polymeric flat sheet module, respectively. The pretreated juice was successfully concentrated using both RO and OE yielding total solid concentration of 29 and 53 g/100 g, respectively. Hence, membrane based processes provide a viable alternative for clarification, treatment, sterilization, and concentration of the final product. Onsekizoglu et al. (2010) had shown a fivefold increase in the TSS removal using coupled membrane based processes while arresting the formation of undesired 5-hydroxymethylfurfural. Similar work has been demonstrated by Koza´k et al. (2006) where the TSS was concentrated fourfold compared with the value of the initial one while keeping the sensory profiles intact. Reverse osmosis process was also employed for apple juice concentration and TSS enhancement. Besides, UF membranes have been used as post or tertiary treatment methods to enhance the texture and smoothness of the juice. The polymeric membranes selected by Gulec et al. (2017) were composed of PSF, PES, and cellulose. The membranes with higher pore size and higher hydrophobicity experienced higher resistance due to reversible fouling whereas for the 30 kDa membrane cake filtration was the dominant mechanism, thereby yielding higher flux than more open pore size membranes. Moreover, the essential nutrients like TSS, salts, polyphenol, antioxidant fractions, amino acids, and others were easily permeated through the UF membrane pores due to their small size. As evident from their study, Gulec et al. (2017) had shown that there is only 14% decrease in the TSS after filtering through UF. Many pectinous fruits like apple, banana, guava, etc., tend to foul the membranes more due to their high pectin content. As

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Separation of Functional Molecules in Food by Membrane Technology

discussed earlier, pectin is a gel forming material that tends to develop a cake type layer over the membrane surface and thus imparting additional resistance to the permeate flow. It is a common practice nowadays to deploy depectinization methods to reduce the pectin content prior to membrane based process. Alvarez et al. (1998) had demonstrated filtration of depectinized apple juice using a 15 kDa membrane. Giovanelli and Ravasini (1993) processed laccase treatment of the apple juice to reduce its phenolic content and decolorize it subsequently by passing it through polyvinylpyrrolidone and activated charcoal. The processed apple juice was then passed through a cross-flow MF membrane, which stabilized the juice. Similar treatment had been adopted by Aguiar et al. (2012), where MF was followed by coupled reverse osmosis and OE to concentrate the juice. A comparative analysis between MF and UF of apple juice was carried out by Wu et al. (1990). The study concluded that based on the sensory properties MF was preferred rather than UF although the apple juice was more stable after UF. Mondor et al. (2000) had shown that in a batch process apple juice can be clarified using dead end ceramic filters with pore size ranging from 0.02 to 0.2 μm and the process throughput can be correlated to the volume concentration factor. For apple juice depectinization sometimes additives are used to reduce fouling enhancing the performance of ensuing membrane based processes. All these help in upscaling membrane based systems to industrial level in place of conventional treatment processes.

5.5.2.2 Orange Juice Orange (Citrus sinensis) is a citrus fruit and a hybrid of pomelo and mandarin orange. Relative ratio of sugar and acid determines the taste of the orange and the aroma is governed by volatile organic compounds like alcohols, ketones, terpenes, esters, etc. Orange juice is pulpy in nature with a pH of 2.94. Orange is a rich source of vitamin C along with potassium, carotenoids, flavonoids, and other phytoactive compounds. However, like most of the citrus juices orange contains a huge amount of pectin (Qaid et al., 2017). Hence, orange being a highly pectinous fruit is usually depectinized prior to MSP. A study by Mizrahi and Berk (1970) showed that orange juice exhibits non-Newtonian flow behavior due to the presence of pectin and suspended solids. Depectinized orange juice exhibits Newtonian flow-like (water like property and reduced viscosity) behavior. The following are some studies where depectinized orange juice was further treated with MSP. Destani et al. (2013) had clarified depectinized blood orange juice using 100 kDa cutoff UF membrane. Prior to clarification, the raw juice was depectinized for 4 hours at room temperature using 20 mg/L Pectinex Ultra SPL. TSS of the ultrafiltered juice had increased significantly (10.561.4oBrix). The UF membrane showed nominal rejection for phenolic %

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compounds. Following UF, the juice was evaporated by OD process but the phenolic compounds were significantly preserved. Blood orange juice was clarified using UF membrane by Conidi et al. (2015). The raw juice was depectinized using 1% w/w commercial pectinase enzyme (Pectinex Ultra SP-L) at room temperature for 4 hours. The resultant depectinized juice was subjected to UF using polymeric hollow fiber membranes of 100 and 50 kDa. Depending upon the physicochemical properties, nutritional quality, and the productivity of the membrane, 100 kDa PSF based UF membrane was found to be the most suitable. Moroccan Valencia orange juice was clarified by Qaid et al. (2017). Twenty mg/L of commercial pectinase enzyme (Pectinex Ultra SP-L) was used to depectinize the raw juice at room temperature and the process was carried out for 4 hours. Two UF membranes having molecular weight cutoff 30 and 20 kDa were used. Thirty kDa PES membrane was found to be the most suitable in terms of selectivity and productivity. PES membrane removed all the suspended solids and pectin while exhibiting a steady state flux of 27.43 l/m2.h. However, due to presence of pectinous material the flux decline was around 61%. Orange also contains huge amounts of anthocyanins, which are responsible for their red color and are widely used as food colorants. However, anthocyanins are highly reactive and form undesirable colorless or brown colored compounds. Many studies have been carried out to stabilize the anthocyanins and observe their properties dependent on temperature (Jackman et al., 1987; Mazza and Brouillard, 1987; Fabroni et al., 2016). Anthocyanins have also been recovered and concentrated using membrane based technology by various researchers (Gilewiczlukasik et al., 2007; Martı´n et al., 2018). The molecular structures as well as the intra- and intermolecular interaction of anthocyanins dictate their stability and coloring attributes. Anthocyanins are significantly affected by change in environmental conditions, for example, pH, temperature, chemical composition, etc. Hence, a safe, nonthermal technology has been required for the successful concentration of anthocyanins. Membrane based processes, being nonthermal, provide several advantages for the recovery of delicate nutritional and bioactive agents; thus they are widely used to recapture anthocyanins from pomegranate, grape, radish, raspberry, cranberry, blackberry, potato, orange, etc. Blood orange juice was subjected to UF using a 15-kDa tubular PVDF membrane and the resultant permeate was analyzed in terms of TSS, antioxidant activity, anthocyanins, and flavonoids (Cassano et al., 2007). Permeate and feed streams were almost identical in properties except for insoluble solids, attributed to high pectin content. More than 90% of the anthocyanins and around 94% TSS were recovered in permeate and the insoluble solids rejected completely. Membrane fouling was attributed to partial and complete pore blocking. Similar work has been carried out by Galaverna et al. (2008). In their work, an MSP was employed as an alternative to thermal

176

Separation of Functional Molecules in Food by Membrane Technology

evaporation to concentrate blood orange juice. Initially the orange juice was subjected to UF using a 15-kDa membrane. The ultrafiltered juice was then concentrated in two stages, using RO followed by OD. The recovery of anthocyanin and antioxidant fraction was more than that of thermal treatment. Therefore, membrane based processes can be aptly utilized for the clarification of orange juice and recovery of the nutritional parameters. However, due to the high pectin content of the juices it is preferable to be coupled with enzymatic treatment. As discussed above, depectinized orange juice yields higher productivity than raw juice. In most cases, MF is used as a pretreatment step before applying a suitable cutoff UF membrane. The processed juice can be concentrated using RO or OD to enhance its nutritional properties.

5.5.2.3 Pineapple Juice Pineapple (Ananas comosus) is a tropical fruit and it is the most economically significant plant in the Bromeliaceae family. The largest producer of pineapple in the world is Costa Rica, closely followed by countries like, Brazil, Philippines, Indonesia, and India. It is a rich source of vitamins, primarily vitamin C and vitamin B6. Pineapple juice also contains a huge array of bioactive compounds, like gallic acid, tyrosine, genistin, chlorogenic acid, epicatechin, chavicol, and many others (Sopie Edwige Salome et al., 2011). Some studies for combined depectinization and subsequent membrane based clarification are presented herein. Barrosi, Mendes and Peres (2004) clarified wild cherry and pineapple juice using Citrozym Ultra-L enzyme. The optimum enzyme concentration for pineapple juice was found to be 20 mg/L, at 40
C for 60 minutes. The resulted juice was then further processed using a ceramic tubular membrane and a PSF hollow fiber membrane of 100 kDa MWCO. It was observed that the recovery of ascorbic acid was much higher in the case of PSF membrane. Also, depectinization led to higher clarity and lower viscosity in case of pineapple and hence, the productivity had increased manifold in case of both hollow fiber and tubular membranes. A combined cold sterilization process coupled with clarification by MF membrane was developed by Carneiro et al. (2002). The raw juice was depectinized using a 0.03%v/v connotation of Pectinex SP-L and Celuclast 1.5-L. Depectinization was carried out for 60 minutes at 30
C. The enzymatic treatment reduced the viscosity drastically and the pulpy nature of the juice, yielding higher productivity in the subsequent MF process. PES based MF membrane, with pore size 0.3 μm, was used for further clarification of the depectinized juice. MF was carried out at 100 kPa TMP resulting in a flux of 100 l/m2.h. The treated juice had an extended shelf life (28 days) compared with the raw juice.

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177

De Barros et al. (2003) used ceramic tubular module and PSF based hollow fiber (MWCO: 100 kDa) to clarify depectinized pineapple juice. Depectinization was carried out using 20 3 1023 kg/m3 Citrozym Ultra-L enzyme at 40
C for 90 minutes. The productivity of the ceramic membrane was higher than that of the PSF based hollow fibers. The temperature and TMP were selected as 40
C and 80 kPa, respectively. Carvalho and Silva (2010) hydrolyzed the pineapple juice using commercial pectinase (Ultrazym). A tubular PES MF membrane with 0.3 μm was employed for the postdepectinization step. At low TMP, the productivity was higher, since, at higher TMP, the formation of gel layer over the membrane surface was more compact imparting additional resistance to solute permeation. Formation of a dynamic layer decreased the productivity significantly. Retention of sugar from pineapple juice was reported by de Carvalho et al. (2008). The raw juice was initially hydrolyzed using commercial pectinase and a combination of cellulase and pectinase. Plate and frame and tubular modules were used for UF of the depectinized juice. The best recovery of sugar was observed in juices clarified by 50 kDa PSF membrane operating at 7.5 bar.

5.5.2.4 Banana Juice Banana (Musa acuminata) is one of the most widely consumed fruit in the world. India is one of the major producers of banana with total production volume of 29.1 million tons per year. This fruit is a staple food in developing countries. Due to its high potassium, magnesium, and sugar content, it acts as an alternative to a full course meal. However, storage of banana is a problem as it starts deteriorating in 23 days. Pectin is another major constituent in banana, for example, unripe fruits contain huge amount of pectin in their peels. The cell wall degradation of the fruit during ripening is primarily caused by solublization and depolymerization of pectins and hemicelluloses (Asif and Nath, 2005). Hence, during ripening of the banana the pectin content decreases. On the other hand, during ripening water soluble pectin concentration increases whereas acid soluble pectin content gradually reduces (Duan et al., 2008). Also, hot water homogenization of banana results in greater pectin content in ripe bananas (Prabha and Bhagyalakshmi, 1998). As discussed in the earlier sections, pectin being a gel forming agent is undesired for MSPs. Although the addition of fining agents like bentonite, gelatin, and others can stop browning and turbidity as well as can maintain the physicochemical properties of the juice (Lee et al., 2007), these external additives are not desired during processing. One of the major reasons for the browning of banana juice and its increment in turbidity is the presence of polyphenoloxidases (PPO) (Koffi et al., 1991). The latest enzymes or tyrosinases are tetramers with four copper atoms per molecule and provide binding sites for aromatic compounds and oxygen. PPO produce black, brown, or red

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Separation of Functional Molecules in Food by Membrane Technology

pigments by rapid polymerization of o-quinones. Suitable membrane based processes coupled with proper depectinization treatment are able to remove PPO and ensure high throughput. As discussed in the earlier section, depectinization of banana can be performed using various enzymes, like pectinase, amylase, cellulase, hemicellulase, and others. A judicious combination of pectinase, cellulose, and hemicellulase was adapted by Koffi et al. (1991) who studied the effects of other additives, too. It was seen that the right combination of enzymes and the addition of preservatives like sulfite completely stops the browning. However, the addition of external preservative is not desired in the current scenario of fruit juice processing industry. MF was used by Valliant et al. (2008) to process pulpy fruits like, banana, pineapple, and blackberry. The turbidity of the feed was reduced after MF, but the physicochemical properties of the juice remain almost the same. Therefore, MF can only be used as a pretreatment method after depectinization to reduce membrane fouling in the subsequent membrane processes. Mature banana juice has also been subjected to UF and heat treatment to compare the two processes by evaluating physicochemical properties like color, PPO activity, sensory property of the juice, and browning (Sims et al., 1994). It was observed that 10 kDa UF membrane successfully removed all PPO and stopped the browning of the juice. The heat treatment increased the browning and also altered the flavor significantly. A complete formulation from extraction of banana juice from raw banana, and comparisons between preclarification methods such as MF and centrifugation, and selection of suitable UF membrane and optimized operating conditions, were undertaken by Sagu and his coworkers. Enzymatic pretreatment of the banana pulp was done using commercial pectinase obtained from Aspergillus niger. Optimized time, temperature, and enzyme concentration were 108 minutes, 33
C, and 0.03% (v/w), respectively (Sagu et al., 2014). Depectinized pulp was then processed by centrifugation and MF. Centrifugation was carried out in a batch centrifuge whereas MF was done using a PAN based hollow fiber module. The optimum operating conditions of both the processes were determined by RSM based on the physicochemical properties, such as viscosity, clarity, AIS, polyphenol, and protein. The optimized centrifugal speed and time were obtained as 46 minutes and 6065 g, respectively. The optimum TMP and cross-flow rate for MF were 76 kPa and 20 L/h, respectively. MF was found to be more economical, less power consuming, and produced better results in terms of physicochemical properties compared with centrifugation (Sagu et al., 2014). The microfiltered product was then subjected to UF using polymeric hollow fiber membranes of different MWCO ranging from 10 to 44 kDa. UF with MWCO 27 kDa was found to be the most suitable. The flux obtained at 104 kPa TMP was 82 L/m2 h. The processed juice had a shelf life of more than 1 month (Sagu et al., 2014).

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Since membrane based processes do not require temperature for the clarification of juice’s bioactive fractions, a depectinization process followed by pre- and posttreatment by subsequent MF or UF process ensures higher shelf life for the juice without sacrificing its aroma, flavor, or sensory properties.

5.5.2.5 Mosambi Juice Mosambi (Citrus limetta) is a cultivar of sweet lime variation. Due to high vitamin C content and sweet taste, this fruit is gradually gaining popularity all over the world. Extraction, depectinization, pretreatment, and final clarification of the preprocessed juice has been studied by Rai and coworkers. Pretreatment of mosambi was undertaken using pectinase from Aspergillus niger with activity 3.57 units/mg. The process parameters were optimized by RSM taking into account the apparent viscosity, clarity, and AIS. The optimum process parameters were obtained as 42
C temperature, 0.0004% (w/v) enzyme concentration, and 99 minutes of operation (Rai et al., 2004). The best pretreatment step prior to UF was found to be enzymatic treatment followed by adsorption using bentonite (Rai et al., 2007). UF experiments were carried out using commercial membranes with MWCO ranging from 10 to 100 kDa. Prior to UF, the juice was subjected to MF using a 0.2-μm membrane. Due to partial or complete pore blocking, the permeate flux for MF was less than that of any subsequent UF process. The microfiltered juice was subjected to further clarification using UF membranes and 50-kDa UF membrane was found to be the most suitable (Rai et al., 2006). The clarified juice had a high shelf life of 30 days in refrigerated condition (Rai et al., 2008). 5.5.2.6 Other Juices Other than the aforementioned fruit juices, many studies revealed that combined depectinization and membrane based operation improved the quality, texture, and flavor of the juice. Moreover, coupled depectinization followed by MSP increased the shelf life of the juice significantly. A combined process of depectinization and subsequent membrane based separation for some fruit juice is presented in Table 5.5. Most of the citrus fruits are rich in pectin content and require depectinization prior to tertiary treatments like MF or UF. As stated in Table 5.5, many studies had been conducted for the depectinization and clarification of citrus fruits like lemon, kiwi, passionfruit, tangerine, pomegranate, and blackcurrant. For instance, lemon juice has been subjected to depectinization using the commercial enzyme Novozyme 33095 (Uc¸an et al., 2014). At the optimized condition of 35
C and concentration of 40 μL/100 mL depectinization was carried out for 15 minutes followed by separation using a commercial filter paper plate MinifiltroF6 from Italy. It was observed that the depectinized and clarified juice had zero pectin content after the process. The

TABLE 5.5 Coupled Depectinization of Some Fruit Juices and Subsequent MSP Fruit Juice

Enzyme Treatment

Membrane Based Clarification Process

References

Enzyme Used

Time (min)

Temperature (
C)

Concentration

Filtration Process

MWCO (kDa)

TMP (kPa)

Cross-Flow Rate

Lemon

Novozym 33095

15

35

40 μL/100 mL

Filter paper



By gravity



Uc¸an et al. (2014)

Passionfruit

Pectinex Ultra SP-L

60

50

150 mg/L

0.3 μm MF



100



de Oliveira et al. (2012)

Kiwifruit

Pectinex Ultra SP-L

240

Room temperature

10 g/kg

PVDF UF membrane

15

85

800 L/h

Cassano et al. (2004)

Tangerine

Pectinex Ultra SP-L

180

Room temperature

130 mg/L

0.1 μm MF



194

0.9 m/s

Chamchong and Noomhorm (1991)

Pomegranate

Fungus (F. fomentarius)

300

20

5 units/mL

Carbosep M2

15

200

1 m/s

Neifar et al. (2011)

Blackcurrant

Panzym Super E

720

25

0.004% (v/v)



Pap et al. (2009)

1440

25

Reverse osmosis membrane (salt rejection .80%)



Trenolin Rot DF

Tubular AFC80 PA membrane

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clarified juice was then stored for 180 days at 25
C. Passionfruit is a rich source of carbohydrates, carotenes, vitamin C, iron, and other minerals. Its juice was depectinized using commercial enzyme Pectinex Ultra SP-L (de Oliveira et al., 2012). The operating parameters were 150 mg/L of enzyme at 50
C, whereas the depectinization was carried out for 60 minutes. Depectinized passionfruit juice was then subjected to MF using a 0.3-μm ceramic tubular module. The processed juice was analyzed in terms of turbidity, color, sensory properties, etc. It was observed that the permeate possessed low turbidity, low suspended solids content and was readily acceptable in terms of sensory qualities. As evident from earlier discussions, membrane based processes could be used to concentrate the fruit juice and it is a better alternative to thermal treatment. In another approach, kiwi fruit juice had been concentrated using OD process by Cassano et al. (2004). Prior to concentration the kiwi fruit juice was depectinized using 10 g/kg of Pectinex Ultra SP-L at room temperature and the process was carried out for 4 hours. The resultant depectinized juice was subjected to UF using a 15-kDa PVDF membrane. TMP and cross-flow rate were varied as 85 kPa and 800 L/h, respectively. The clarified kiwi fruit juice was concentrated using OD to a TSS of more than 60oBrix. Similar works have been carried out for tangerine, pomegranate, and % blackcurrant fruit juices (Chamchong and Noomhorm, 1991; Pap et al., 2009; Neifar et al., 2011). Tangerine juice was subjected to UF with MWCO ranging from 25 to 100 kDa and MF with pore size 0.10.2 μm. Enzymatic pretreatment was performed using Pectinex Ultra SP-L at acidic condition (pH 2). By analyzing the permeate quality and membrane productivity, 0.1-μm membrane was selected as optimum. It was evident that by increasing TMP the productivity increases without compromising the quality. However, with y increasing the cross-flow velocity the productivity increased by 9%; however the quality of permeate was deteriorated. Pomegranate juice on the other hand has been ultrafiltered using a 15-kDa Carbosep membrane. The raw juice was depectinized using laccase treatment to prevent browning or haze formation during storage. The ultrafiltered juice was processed at 200 kPa TMP and a clear, stable liquid was obtained. Similarly, blackcurrant juice was concentrated using a polyamide RO membrane. Prior to RO process, the juice was subjected to enzymatic depectinization using two different commercial enzymes, Panzym Super E and Trenolin Rot DF. The raw juice, depectinized by Panzym Super E and concentrated by RO yielded a TSS of 28.6oBrix. Depectinization is one of the necessary% pretreatment steps to reduce the pectin content in the fruit juice thereby reducing the fouling of the membranes effectively. Coupled depectinization and membrane based clarification have been successfully employed for several fruit juices, namely apple, orange, banana, mosambi, pineapple, kiwi, passion, lemon, etc. Since membrane based processes are easily scalable at industrial scale, they possess a huge potential as alternative to conventional fruit juice remediation. Hence,

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it is quite evident that membrane based systems could be widely used for the clarification and concentration of different fruit juices.

5.6 CONCLUSION Membrane based processes are more economical and less energy intensive than conventional juice clarification technologies. One of the conventional methods to concentrate fruit juices is thermally intensive multieffect evaporation operation. It basically utilizes heat from steam to evaporate water, thus making the juice concentrated. MSP, particularly RO, is an economical alternative to this. Since RO can be conducted at normal room temperature, the processed juice does not undergo any thermal degradation. In case of RO, most of the times the stream of importance is the retentate stream, which gets gradually concentrated with time of operation. pH and ionic characteristics of the juice are also preserved. Although RO based processes require high pressure, their energy requirements are relatively fewer compared with multiple effect evaporator systems, leading to significantly lower operating costs. Nanofiltration based MSP are generally used to concentrate the clarified juices. Also, nanofiltration is often used to fractionate and purify bioactive fractions of the juice. The MWCO of the NF membranes vary from 0.2 to ˚ . Nanofiltration was used to 1 kDa with the pore size ranging from 10 to 20 A clarify and concentrate apple and pear juice (Warczok et al., 2004), green tea extract (Ekanayake et al., 1999), cactus pear juice (Cassano et al., 2007), sea buckthorn juice (Vincze et al., 2006), red fruit juice (Koroknai et al., 2008), sugarcane juice (Nene et al., 2002), kiwifruit juice (Cassano et al., 2004), and others (Girard and Fukumoto, 2000; Cisse´ et al., 2011; Echavarrı´a et al., 2011). NF is also known for separation of sugar (Black and Bray, 1995). UF of fruit juices is the most common membrane based clarification process. Since the MWCO of the UF membranes vary from 1 to 100 kDa, a wide range of fruit juices can be processed using UF technology. Some typical applications of UF in clarification of juices for fruits and vegetables include passionfruit (Jiraratananon and Chanachai, 1996), potato (Zwijnenberg et al., 2002), mosambi (Rai et al., 2005), starfruit (Liew Abdullah et al., 2007), pineapple (de Barros et al., 2003), pear (Kirk et al., 1983), apple (Vladisavljevi´c et al., 2003), grape, lemon, orange (Chatterjee et al., 2004), banana (Sagu et al., 2014), bottle gourd (Mondal et al., 2016), coconut water (Karmakar and De, 2017), and many others. UF has also been applied on the other way around, for example, to clarify a pectin-rich extract recovered from olive mill wastewater (i.e., collected in the retentate stream) from potassium and other coextracted compounds (Galanakis et al., 2010). UF based MSP effectively eliminates microorganisms, improves the clarity and texture of the juice, and also removes potent sites for bacterial growth, thereby enhancing the shelf life of the processed juice.

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MF is generally carried out by membranes having pore size of 0.2 μm and above. Generally, MF is used as a pretreatment step prior to subsequent polished filtration. MF eliminates all the suspended solids, high molecular weight proteins, and bacteria, improving the clarity of the juice significantly. Many fruit and vegetable juices from passionfruit (Vaillant et al., 1999), mango, pineapple, naranjilla, blackberry (Vaillant et al., 2001), cashew apple (Campos et al., 2002), acerola (Matta et al., 2004), pineapple (Carneiro et al., 2002), cactus pear (Cassano et al., 2010), orange (Cisse et al., 2005), pomegranate (Mirsaeedghazi et al., 2010), watermelon (Rai et al., 2010), banana (Sagu et al., 2014), bottle gourd (Biswas et al., 2016) and many others (Chatterjee et al., 2004; Vaillant et al., 2008) were pretreated using MF. Also, in most cases, MF is more effective and economical than other commonly used pretreatment methods like centrifugation. One of the major advantages of MSP is that the process and the technology are more economical than the majority of conventional methods and they also yield better results in terms of product quality and quantity. As dis´ lvarez et al. (2000) had shown that a membrane cussed in section 5.2, A based process is much more economical than conventional methods and it also results in less payback period (refer to Fig. 5.1). Sotoft et al. (2012) had developed a pilot scale plant for blackcurrant juice. The integrated membrane system includes vacuum MD, RO, NF, and direct contact MD. It was perceived that for the membrane based process the operational cost is 43% less than that of the conventional method. In view of the above discussion, it can be envisaged that membrane based processes can be utilized for processing of fruit juice for two purposes, clarification and concentration. But, the major bottleneck of the technology is membrane fouling leading to severe flux decline and making the system operationally unviable to commercial scale. Presence of pectinous materials (natural gelling agents) in raw juice causes this fouling. Using suitably selected enzymes (e.g., pectinase) at optimum operating conditions (reaction time and temperature), depectinization can be undertaken effectively to enhance membranes’ performance. However, the incomplete removal of pectin is harmful for fermentation of the juice affecting its shelf life adversely. Thus, leftover pectin (even after depectinization) should be ultrafiltered with an appropriately selected UF membrane to be completely removed. The processed juice is then coupled with an aseptic packaging to have a high shelf life. The selection of UF membrane depends on the juice’s nature, its content, and pectin concentration after depectinization. Thus, the role of UF is mainly the clarification. Next, important application of membrane based processes is concentration. For concentration purposes, reverse osmosis, low cutoff nanofiltration or osmotic dehydration could be implemented. The major purpose is to remove water from juice without any thermal treatment; thereby preventing degradation of essential nutritional and sensory components of the juice. However, in most cases, the UF-clarified juice is used for

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RO, NF, or OD processes to reduce the fouling of the membrane, enhancing its performance by processing large volume in short time. In such cases, UF is considered as a pretreatment prior to RO/NF/OD. The selection of operating conditions is quite critical, too. Two main operating parameters are TMP drop and cross-flow rate. Beyond a particular TMP drop, the permeate flux is independent of pressure (known as limiting flux) due to the formation of a gel layer. Thus, the identification of TMP drop corresponding to limiting permeate flux is also of vital importance. The actual operating pressure should not exceed the limiting TMP drop. Increase in cross-flow rate improves the mass transfer, thereby pushing up the limiting conditions realizing higher permeate flux. However, the positive effect of increase in cross-flow rate would not enhance the limiting flux beyond 20%30%. In fact, there exists a phase space that clearly shows the envelope of TMP drop and cross-flow rate under limiting conditions (Roy and De, 2015; Karmakar and De, 2017). Selection of membrane modules is another important consideration. Although high TMP can be generated in spiral wound membrane modules, hollow fiber modules are recently gaining more attention. There are three distinct advantages of hollow fibers. First, the performance of laboratory scale experiments is directly scalable due to similarity in flow geometry. In case of spiral wound module, laboratory experiments in flat sheet membranes may not be a direct representative to actual module performance due to complication of flow geometry and flow path by spacer and winding of the membranes about a central axis. Secondly, hollow fibers are operated at much lower operating pressure compared with NF and RO, thereby reducing the power requirement tremendously, lowering the operating cost significantly. High throughput in the hollow fiber modules can be realized by packing large number of fibers or placing a large number of modules in parallel configuration. Thirdly, the fouling of the membrane is also significantly less at lower operating pressure. Thus, the selection of membrane modules and operating conditions are important issues in membrane based processes. With a prudent and judicial selection of membrane, module, and operating conditions, MSPs offer better alternative to conventional thermal and nonthermal processing technologies. They have distinct advantages over other conventional methods in terms of product quality, quantity, economical viability, and maintenance. Therefore, it is envisaged that MSP will have a lasting impact on the fruit juice processing industry in the future.

REFERENCES Aguiar, I.B., et al., 2012. Physicochemical and sensory properties of apple juice concentrated by reverse osmosis and osmotic evaporation. Innovative Food Sci. Emerg. Technol. 16, 137142. Available from: https://doi.org/10.1016/j.ifset.2012.05.003.

Pectin Removal and Clarification of Juices Chapter | 5

185

Aguilar-Rosas, S.F., et al., 2007. Thermal and pulsed electric fields pasteurization of apple juice: effects on physicochemical properties and flavour compounds. J. Food Eng. 83 (1), 4146. Available from: https://doi.org/10.1016/j.jfoodeng.2006.12.011. Al-Obaidi, M.A., Kara- Zaı¨tri, C., Mujtaba, I.M., 2017. Optimum design of a multi-stage reverse osmosis process for the production of highly concentrated apple juice. J. Food Eng. 214, 4759. Available from: https://doi.org/10.1016/j.jfoodeng.2017.06.020. Alkorta, I., et al., 1998. Industrial applications of pectic enzymes: a review. Process Biochem. 33 (1), 2128. Available from: https://doi.org/10.1016/S0032-9592(97)00046-0. ´ lvarez, S., et al., 1998. Influence of depectinization on apple juice ultrafiltration. Colloids A Surfaces A Physicochem. Eng. Aspects 138 (23), 377382. Available from: https://doi. org/10.1016/S0927-7757(98)00235-0. ´ lvarez, S., et al., 2000. A new integrated membrane process for producing clarified apple juice A and apple juice aroma concentrate. J. Food Eng. 46 (2), 109125. Available from: https:// doi.org/10.1016/S0308-8146(00)00139-4. Aneja, K.R., et al., 2014. Emerging preservation techniques for controlling spoilage and pathogenic microorganisms in fruit juices. Int. J. Microbiol. 2014, 114. Available from: https:// doi.org/10.1155/2014/758942. Asif, M.H., Nath, P., 2005. Expression of multiple forms of polygalacturonase gene during ripening in banana fruit. Plant. Physiol. Biochem. 43 (2), 177184. Available from: https://doi. org/10.1016/j.plaphy.2005.01.011. Barboni, T., Cannac, M., Chiaramonti, N., 2010. Effect of cold storage and ozone treatment on physicochemical parameters, soluble sugars and organic acids in Actinidia deliciosa. Food. Chem. 121 (4), 946951. Available from: https://doi.org/10.1016/j. foodchem.2010.01.024. Barrosi, S.T.D., Mendes, E.S., Peres, L., 2004. Influence of depectinization in the ultrafiltration of West Indian cherry (Malpighia glabra L.) and pineapple (Ananas comosus (L.) Meer) juices. Cieˆncia e Tecnologia de Alimentos 24 (2), 194201. Available from: https://doi.org/ 10.1590/S0101-20612004000200006. Beuchat, L.R., 1982. Thermal inactivation of yeasts in fruit juices supplemented with food preservatives and sucrose. J. Food. Sci. 47 (5), 16791682. Available from: https://doi.org/ 10.1111/j.1365-2621.1982.tb05010.x. Biswas, P.P., Mondal, M., De, S., 2016. Comparison between centrifugation and microfiltration as primary clarification of bottle gourd (Lagenaria siceraria) juice. J. Food Proces. Preservation 40 (2), 226238. Available from: https://doi.org/10.1111/jfpp.12599. Black, H.F., Bray, R.G., 1995. Sugar separation from juices and product thereof. Google Patents. Available at: https://www.google.com/patents/US5403604. Campos, D.C.P., et al., 2002. Cashew apple juice stabilization by microfiltration. Desalination 148 (13), 6165. Available from: https://doi.org/10.1016/S0011-9164(02)00654-9. Carneiro, L., et al., 2002. Cold sterilization and clarification of pineapple juice by tangential microfiltration. Desalination 148 (13), 9398. Available from: https://doi.org/10.1016/ S0011-9164(02)00659-8. Carvalho, L.M.Jde, Silva, C.A.Bda, 2010. Clarification of pineapple juice by microfiltration. Cieˆncia e Tecnologia de Alimentos 30 (3), 828832. Available from: https://doi.org/ 10.1590/S0101-20612010000300040. Cassano, A., Jiao, B., Drioli, E., 2004. Production of concentrated kiwifruit juice by integrated membrane process. Food Res. Int. 37 (2), 139148. Available from: https://doi.org/10.1016/ j.foodres.2003.08.009.

186

Separation of Functional Molecules in Food by Membrane Technology

Cassano, A., et al., 2007. A membrane-based process for the clarification and the concentration of the cactus pear juice. J. Food Eng. 80 (3), 914921. Available from: https://doi.org/ 10.1016/j.jfoodeng.2006.08.005. Cassano, A., Marchio, M., Drioli, E., 2007. Clarification of blood orange juice by ultrafiltration: analyses of operating parameters, membrane fouling and juice quality. Desalination 212 (13), 1527. Available from: https://doi.org/10.1016/j.desal.2006.08.013. Cassano, A., Conidi, C., Drioli, E., 2010. Physico-chemical parameters of cactus pear (Opuntia ficus-indica) juice clarified by microfiltration and ultrafiltration processes. Desalination 250 (3), 11011104. Available from: https://doi.org/10.1016/j.desal.2009.09.117. Chamchong, M., Noomhorm, A., 1991. Effect of pH and enzymatic treatment on microfiltration and ultrafiltration of tangerine juice. J. Food Process Eng. 14 (1), 2134. Available from: https://doi.org/10.1111/j.1745-4530.1991.tb00079.x. Chang, T., et al., 1995. Commercial pectinases and the yield and quality of stanley plum juice. J. Food Process. Preservation 19 (2), 89101. Available from: https://doi.org/10.1111/j.17454549.1995.tb00280.x. Char, C.D., et al., 2010. Use of high-intensity ultrasound and UV-C light to inactivate some microorganisms in fruit juices. Food Bioprocess Technol. 3 (6), 797803. Available from: https://doi.org/10.1007/s11947-009-0307-7. Chatterjee, S., et al., 2004. Clarification of fruit juice with chitosan. Process Biochem. 39 (12), 22292232. Available from: https://doi.org/10.1016/j.procbio.2003.11.024. Chen, J., et al., 2008. Role of phenylalanine ammonia-lyase in heat pretreatment-induced chilling tolerance in banana fruit. Physiol. Plant. 132 (3), 318328. Available from: https://doi.org/ 10.1111/j.1399-3054.2007.01013.x. Chhaya, Majumdar, G.C., De, S., 2013. Primary clarification of stevia extract: a comparison between centrifugation and microfiltration. Sep. Sci. Technol. 48 (1), 113121. Available from: https://doi.org/10.1080/01496395.2012.674605. Cisse, M., et al., 2005. The quality of orange juice processed by coupling crossflow microfiltration and osmotic evaporation. Int. J. Food Sci. Technol. 40 (1), 105116. Available from: https://doi.org/10.1111/j.1365-2621.2004.00914.x. Cisse´, M., et al., 2011. ) Selecting ultrafiltration and nanofiltration membranes to concentrate anthocyanins from roselle extract (Hibiscus sabdariffa L.). Food Res. Int. 44 (9), 26072614. Available from: https://doi.org/10.1016/j.foodres.2011.04.046. Conidi, C., Destani, F., Cassano, A., 2015. Performance of hollow fiber ultrafiltration membranes in the clarification of blood orange juice. Beverages 1 (4), 341353. Available from: https://doi.org/10.3390/beverages1040341. Cserhalmi, Z., et al., 2006. Study of pulsed electric field treated citrus juices. Innovative Food Sci. Em. Technol. 7 (12), 4954. Available from: https://doi.org/10.1016/j.ifset.2005.07.001. de Barros, S., et al., 2003. Study of fouling mechanism in pineapple juice clarification by ultrafiltration. J. Memb. Sci. 215 (12), 213224. Available from: https://doi.org/10.1016/ S0376-7388(02)00615-4. de Carvalho, L.M.J., de Castro, I.M., da Silva, C.A.B., 2008. A study of retention of sugars in the process of clarification of pineapple juice (Ananas comosus, L. Merril) by micro- and ultra-filtration. J. Food Eng. 87 (4), 447454. Available from: https://doi.org/10.1016/j. jfoodeng.2007.12.015. Deng, C., O’Neill, M.A., York, W.S., 2006. Selective chemical depolymerization of rhamnogalacturonans. Carbohydr. Res. 341 (4), 474484. Available from: https://doi.org/10.1016/j. carres.2005.12.004.

Pectin Removal and Clarification of Juices Chapter | 5

187

de Oliveira, R.C., Doceˆ, R.C., de Barros, S.T.D., 2012. Clarification of passion fruit juice by microfiltration: analyses of operating parameters, study of membrane fouling and juice quality. J. Food Eng. 111 (2), 432439. Available from: https://doi.org/10.1016/j. jfoodeng.2012.01.021. Derieux, J., 1988. Histoire de la panification et de levure dans Levure et panification Fould. Springer. Tecno-Nathant, Arbrissel, France. Destani, F., et al., 2013. Recovery and concentration of phenolic compounds in blood orange juice by membrane operations. J. Food Eng. 117 (3), 263271. Available from: https://doi. org/10.1016/j.jfoodeng.2013.03.001. Dingle, J., Reid, W.W., Solomons, G.L., 1953. The enzymic degradation of pectin and other polysaccharides. II—Application of the “Cup-plate” assay to the estimation of enzymes. J. Sci. Food Agric. 4 (3), 149155. Available from: https://doi.org/10.1002/jsfa.2740040305. Domingues, R.C.C., et al., 2014. Microfiltration of passion fruit juice using hollow fibre membranes and evaluation of fouling mechanisms. J. Food Eng. 121, 7379. Available from: https://doi.org/10.1016/j.jfoodeng.2013.07.037. Duan, X., et al., 2008. Modification of pectin polysaccharides during ripening of postharvest banana fruit. Food. Chem. 111 (1), 144149. Available from: https://doi.org/10.1016/j. foodchem.2008.03.049. Echavarrı´a, A.P., et al., 2011. Fruit juice processing and membrane technology application. Food Eng. Rev. 3 (34), 136158. Available from: https://doi.org/10.1007/s12393-0119042-8. Ekanayake, A., Bunger, J.R., Mohlenkamp, M.J., 1999. Green tea extract subjected to cation exchange treatment and nanofiltration to improve clarity and color. Google Patents. Available at: https://www.google.com/patents/US5879733. Escobedo-Avellaneda, Z., et al., 2011. Benefits and limitations of food processing by highpressure technologies: effects on functional compounds and abiotic contaminants Beneficios y limitaciones del procesamiento de alimentos por tecnologı´as de alta presio´n: efectos en componentes funcionale. CyTA - J. Food 9 (4), 351364. Available from: https://doi.org/ 10.1080/19476337.2011.616959. Evrendilek, G.A., et al., 2000. Microbial safety and shelf-life of apple juice and cider processed by bench and pilot scale PEF systems. Innovative Food Sci. Emerg. Technol. 1 (1), 7786. Available from: https://doi.org/10.1016/S1466-8564(99)00004-1. Fabroni, S., et al., 2016. Anthocyanins in different Citrus species: an UHPLC-PDA-ESI/MS n -assisted qualitative and quantitative investigation. J. Sci. Food. Agric. 96 (14), 47974808. Available from: https://doi.org/10.1002/jsfa.7916. Fellers, P.J., 1988. Shelf life and quality of freshly squeezed, unpasteurized, polyethylene-bottled citrus juice. J. Food. Sci. 53 (6), 16991702. Available from: https://doi.org/10.1111/j.13652621.1988.tb07819.x. Ferrari, G., Maresca, P., Ciccarone, R., 2010. The application of high hydrostatic pressure for the stabilization of functional foods: pomegranate juice. J. Food Eng. 100 (2), 245253. Available from: https://doi.org/10.1016/j.jfoodeng.2010.04.006. Fiore, A., et al., 2005. Antioxidant activity of pasteurized and sterilized commercial red orange juices. Mol. Nutr. Food. Res. 49 (12), 11291135. Available from: https://doi.org/10.1002/ mnfr.200500139. Galanakis, C.M., Tornberg, E., Gekas, V., 2010. Clarification of high-added value products from olive mill wastewater. J. Food Eng. 99 (2), 190197. Available from: https://doi.org/ 10.1016/j.jfoodeng.2010.02.018.

188

Separation of Functional Molecules in Food by Membrane Technology

Galaverna, G., et al., 2008. A new integrated membrane process for the production of concentrated blood orange juice: effect on bioactive compounds and antioxidant activity. Food. Chem. 106 (3), 10211030. Available from: https://doi.org/10.1016/j.foodchem.2007.07.018. Gilewiczlukasik, B., Koter, S., Kurzawa, J., 2007. Concentration of anthocyanins by the membrane filtration. Sep. Purif. Technol. 57 (3), 418424. Available from: https://doi.org/ 10.1016/j.seppur.2006.03.026. Giovanelli, G., Ravasini, G., 1993. Apple juice stabilization by combined enzyme—membrane filtration process. LWT - Food Sci. Technol. 26 (1), 17. Available from: https://doi.org/ 10.1006/fstl.1993.1001. Girard, B., Fukumoto, L.R., 2000. Membrane processing of fruit juices and beverages: a review. Crit. Rev. Biotechnol. 20 (2), 109175. Available from: https://doi.org/10.1080/ 07388550008984168. Golovchenko, V.V., et al., 2002. Structural studies of the pectic polysaccharide from duckweed Lemna minor L. Phytochemistry 60 (1), 8997. Available at: http://www.ncbi.nlm.nih.gov/ pubmed/11985856. Grassin, C., Fauquembergue, P., 1996. Application of pectinases in beverages. In pp. 453462. doi: 10.1016/S0921-0423(96)80275-9. Gu, B., et al., 2011. Mathematical model of flat sheet membrane modules for FO process: plateand-frame module and spiral-wound module. J. Memb. Sci. 379 (12), 403415. Available from: https://doi.org/10.1016/j.memsci.2011.06.012. Guerrero-Beltrn, J.A., Barbosa-Cnovas, G.V., 2004. Advantages and limitations on processing foods by UV light. Food Sci. Technol. Int. 10 (3), 137147. Available from: https://doi.org/ 10.1177/1082013204044359. Gulec, H.A., Bagci, P.O., Bagci, U., 2017. Clarification of apple juice using polymeric ultrafiltration membranes: a comparative evaluation of membrane fouling and juice quality. Food Bioprocess Technol. 10 (5), 875885. Available from: https://doi.org/10.1007/s11947-0171871-x. Gummadi, S.N., Panda, T., 2003. Purification and biochemical properties of microbial pectinases—a review. Process Biochem. 38 (7), 987996. Available from: https://doi.org/ 10.1016/S0032-9592(02)00203-0. Guthrie, J.F., Morton, J.F., 2000. Food sources of added sweeteners in the diets of Americans. J. Am. Diet. Assoc. 100 (1), 4351. Available from: https://doi.org/10.1016/S0002-8223(00)00018-3. Hoondal, G., et al., 2002. Microbial alkaline pectinases and their industrial applications: a review. Appl. Microbiol. Biotechnol. 59 (45), 409418. Available from: https://doi.org/ 10.1007/s00253-002-1061-1. Huber, D.J., Lee, J.H., 1986. Comparative analysis of pectins from Pericarp and Locular Gel in developing tomato fruit. In pp. 141156. https://doi.org/10.1021/bk-1986-0310.ch012. Imamura, F., et al., 2015. Consumption of sugar sweetened beverages, artificially sweetened beverages, and fruit juice and incidence of type 2 diabetes: systematic review, metaanalysis, and estimation of population attributable fraction. BMJ h3576. Available from: https://doi.org/10.1136/bmj.h3576. Jackman, R.L., et al., 1987. Anthocyanins as food colorantsa review. J. Food Biochem. 11 (3), 201247. Available from: https://doi.org/10.1111/j.1745-4514.1987.tb00123.x. Jayani, R.S., Saxena, S., Gupta, R., 2005. Microbial pectinolytic enzymes: a review. Process Biochem. 40 (9), 29312944. Available from: https://doi.org/10.1016/j.procbio.2005.03.026. Jiraratananon, R., Chanachai, A., 1996. A study of fouling in the ultrafiltration of passion fruit juice. J. Memb. Sci. 111 (1), 3948. Available from: https://doi.org/10.1016/0376-7388(95) 00270-7.

Pectin Removal and Clarification of Juices Chapter | 5

189

Jordan, S.L., et al., 2001. Inactivation and injury of pressure-resistant strains of Escherichia coli O157 and Listeria monocytogenes in fruit juices. J. Appl. Microbiol. 91 (3), 463469. Available from: https://doi.org/10.1046/j.1365-2672.2001.01402.x. Kabasakalis, V., 2000. Ascorbic acid content of commercial fruit juices and its rate of loss upon storage. Food. Chem. 70 (3), 325328. Available from: https://doi.org/10.1016/S0308-8146 (00)00093-5. Karaca, H., Velioglu, Y.S., 2007. Ozone applications in fruit and vegetable processing. Food Rev. Int. 23 (1), 91106. Available from: https://doi.org/10.1080/87559120600998221. Karmakar, S., De, S., 2017. Cold sterilization and process modeling of tender coconut water by hollow fibers. J. Food Eng. 200, 7080. Available from: https://doi.org/10.1016/j.jfoodeng.2016.12.021. Karmakar, S., Bhattacharjee, S., De, S., 2017. Experimental and modeling of fluoride removal using aluminum fumarate (AlFu) metal organic framework incorporated cellulose acetate phthalate mixed matrix membrane. J. Environ. Chem. Eng. 5 (6), 60876097. Available from: https://doi.org/10.1016/j.jece.2017.11.035. Karmakar, S., Bhattacharjee, S., De, S., 2018. Aluminium fumarate metal organic framework incorporated polyacrylonitrile hollow fiber membranes: spinning, characterization and application in fluoride removal from groundwater. Chem. Eng. J. 334, 4153. Available from: https://doi.org/10.1016/j.cej.2017.10.021. Keppler, F., et al., 2006. Methane emissions from terrestrial plants under aerobic conditions. Nature 439 (7073), 187191. Available from: https://doi.org/10.1038/nature04420. Kesting, R., 1971. Synthetic Polymeric Membranes. McGraw-Hill, New York. Keyser, M., et al., 2008. Ultraviolet radiation as a non-thermal treatment for the inactivation of microorganisms in fruit juice. Innovative Food Sci. Emerg. Technol. 9 (3), 348354. Available from: https://doi.org/10.1016/j.ifset.2007.09.002. Khandpur, P., Gogate, P.R., 2016. Evaluation of ultrasound based sterilization approaches in terms of shelf life and quality parameters of fruit and vegetable juices. Ultrason. Sonochem. 29, 337353. Available from: https://doi.org/10.1016/j.ultsonch.2015.10.008. Kirk, D.E., Montgomery, M.W., Kortekaas, M.G., 1983. Clarification of pear juice by hollow fiber ultrafiltration. J. Food. Sci. 48 (6), 16631667. Available from: https://doi.org/ 10.1111/j.1365-2621.1983.tb05055.x. Koffi, E.K., Sims, C.A., Bates, R.P., 1991. Viscosity reduction and prevention of browning in the preparation of clarified banana juice. J. Food. Qual. 14 (3), 209218. Available from: https://doi.org/10.1111/j.1745-4557.1991.tb00062.x. Komitopoulou, E., et al., 1999. Alicyclobacillus acidoterrestris in fruit juices and its control by nisin. Int. J. Food Sci. Technol. 34 (1), 8185. Available from: https://doi.org/10.1046/ j.1365-2621.1999.00243.x. Koroknai, B., et al., 2008. Preservation of antioxidant capacity and flux enhancement in concentration of red fruit juices by membrane processes. Desalination 228 (13), 295301. Available from: https://doi.org/10.1016/j.desal.2007.11.010. ´ ., Rektor, A., Vatai, G., 2006. Integrated large-scale membrane process for producing Koza´k, A concentrated fruit juices. Desalination 200 (13), 540542. Available from: https://doi.org/ 10.1016/j.desal.2006.03.428. Kratchanova, M., Pavlova, E., Panchev, I., 2004. The effect of microwave heating of fresh orange peels on the fruit tissue and quality of extracted pectin. Carbohyd. Polym. 56 (2), 181185. Available from: https://doi.org/10.1016/j.carbpol.2004.01.009. Kumar, S., et al., 2012. Inhibition of pericarp browning and shelf life extension of litchi by combination dip treatment and radiation processing. Food. Chem. 131 (4), 12231232. Available from: https://doi.org/10.1016/j.foodchem.2011.09.108.

190

Separation of Functional Molecules in Food by Membrane Technology

¨ zkan, M., Cemeroglu, B., 2006. Stability of black carrot anthocyanins in various Kırca, A., O fruit juices and nectars. Food. Chem. 97 (4), 598605. Available from: https://doi.org/ 10.1016/j.foodchem.2005.05.036. Laboissie`re, L.H.E.S., et al., 2007. Effects of high hydrostatic pressure (HHP) on sensory characteristics of yellow passion fruit juice. Innovative Food Sci. Emerg. Technol. 8 (4), 469477. Available from: https://doi.org/10.1016/j.ifset.2007.04.001. Ladewig, B., Al-Shaeli, M.N.Z., 2017. Fundamentals of membrane processes. In pp. 1337. https://doi.org/10.1007/978-981-10-2014-8_2. Lee, H.S., Coates, G.A., 2003. Effect of thermal pasteurization on Valencia orange juice color and pigments. LWT - Food Sci. Technol. 36 (1), 153156. Available from: https://doi.org/ 10.1016/S0023-6438(02)00087-7. Lee, W.C., et al., 2007. Effects of fining treatment and storage temperature on the quality of clarified banana juice. LWT - Food Sci. Technol. 40 (10), 17551764. Available from: https://doi.org/10.1016/j.lwt.2006.12.008. Liew Abdullah, A.G., et al., 2007. Response surface optimization of conditions for clarification of carambola fruit juice using a commercial enzyme. J. Food Eng. 81 (1), 6571. Available from: https://doi.org/10.1016/j.jfoodeng.2006.10.013. Ludwig, D.S., Peterson, K.E., Gortmaker, S.L., 2001. Relation between consumption of sugarsweetened drinks and childhood obesity: a prospective, observational analysis. Lancet 357 (9255), 505508. Available from: https://doi.org/10.1016/S0140-6736(00)04041-1. Malik, V.S., et al., 2010. Sugar-sweetened beverages, obesity, type 2 diabetes mellitus, and cardiovascular disease risk. Circulation 121 (11), 13561364. Available from: https://doi.org/ 10.1161/CIRCULATIONAHA.109.876185. Martı´n, J., Dı´az-Montan˜a, E.J., Asuero, A.G., 2018. Recovery of anthocyanins using membrane technologies: a review. Crit. Rev. Analyt. Chem. 48 (3), 143175. Available from: https:// doi.org/10.1080/10408347.2017.1411249. Maskan, M., 2001. Kinetics of colour change of kiwifruits during hot air and microwave drying. J. Food Eng. 48 (2), 169175. Available from: https://doi.org/10.1016/S0260-8774(00)00154-0. Matta, V.M., Moretti, R.H., Cabral, L.M.C., 2004. Microfiltration and reverse osmosis for clarification and concentration of acerola juice. J. Food Eng. 61 (3), 477482. Available from: https://doi.org/10.1016/S0260-8774(03)00154-7. Mazza, G., Brouillard, R., 1987. Recent developments in the stabilization of anthocyanins in food products. Food. Chem. 25 (3), 207225. Available from: https://doi.org/10.1016/03088146(87)90147-6. Mazzotta, A.S., 2001. Thermal inactivation of stationary-phase and acid-adapted Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in fruit juices. J. Food. Prot. 64 (3), 315320. Available from: https://doi.org/10.4315/0362-028X-64.3.315. Mirsaeedghazi, H., et al., 2010. Clarification of pomegranate juice by microfiltration with PVDF membranes. Desalination 264 (3), 243248. Available from: https://doi.org/10.1016/j. desal.2010.03.031. Misra, N.N., et al., 2017. Landmarks in the historical development of twenty first century food processing technologies. Food Res. Int. 97, 318339. Available from: https://doi.org/ 10.1016/j.foodres.2017.05.001. Mizrahi, S., Berk, Z., 1970. Flow behaviour of concentrated orange juice. J. Texture Stud. 1 (3), 342355. Available from: https://doi.org/10.1111/j.1745-4603.1970.tb00735.x. Mkandawire, W., et al., 2016. Estimation of shelf life of mango juice produced using small-scale processing techniques. J. Food Res. 5 (6), 13. Available from: https://doi.org/10.5539/jfr. v5n6p13.

Pectin Removal and Clarification of Juices Chapter | 5

191

Mondal, M., Biswas, P.P., De, S., 2016. Clarification and storage study of bottle gourd (Lagenaria siceraria) juice by hollow fiber ultrafiltration. Food Bioprod. Process. 100, 115. Available from: https://doi.org/10.1016/j.fbp.2016.06.010. Mondor, M., Girard, B., Moresoli, C., 2000. Modeling flux behavior for membrane filtration of apple juice. Food Res. Int. 33 (7), 539548. Available from: https://doi.org/10.1016/S09639969(00)00089-2. Morigami, Y., et al., 2001. The first large-scale pervaporation plant using tubular-type module with zeolite NaA membrane. Sep. Purif. Technol. 25 (13), 251260. Available from: https://doi.org/10.1016/S1383-5866(01)00109-5. Mualikrishna, G., Tharanathan, R.N., 1994. Characterization of pectic polysaccharides from pulse husks. Food. Chem. 50 (1), 8789. Available from: https://doi.org/10.1016/0308-8146 (94)90098-1. Neifar, M., et al., 2011. Effective clarification of pomegranate juice using laccase treatment optimized by response surface methodology followed by ultrafiltration. J. Food Process Eng. 34 (4), 11991219. Available from: https://doi.org/10.1111/j.1745-4530.2009.00523.x. Nene, S., et al., 2002. Membrane distillation for the concentration of raw cane-sugar syrup and membrane clarified sugarcane juice. Desalination 147 (13), 157160. Available from: https://doi.org/10.1016/S0011-9164(02)00604-5. Ninga, K.A., et al., 2018. Kinetics of enzymatic hydrolysis of pectinaceous matter in guava juice. J. Food Eng. 221, 158166. Available from: https://doi.org/10.1016/j. jfoodeng.2017.10.022. Onsekizoglu, P., Bahceci, K.S., Acar, M.J., 2010. Clarification and the concentration of apple juice using membrane processes: a comparative quality assessment. J. Memb. Sci. 352 (12), 160165. Available from: https://doi.org/10.1016/j.memsci.2010.02.004. Pap, N., et al., 2009. Concentration of blackcurrant juice by reverse osmosis. Desalination 241 (13), 256264. Available from: https://doi.org/10.1016/j.desal.2008.01.069. Pedrolli, D.B., et al., 2009. Pectin and pectinases: production, characterization and industrial application of microbial pectinolytic enzymes. Open Biotechnol. J. 3 (1), 918. Available from: https://doi.org/10.2174/1874070700903010009. Polydera, A., Stoforos, N., Taoukis, P., 2003. Comparative shelf life study and vitamin C loss kinetics in pasteurised and high pressure processed reconstituted orange juice. J. Food Eng. 60 (1), 2129. Available from: https://doi.org/10.1016/S0260-8774(03)00006-2. Porter, M.C., 1990. Handbook of Industrial Membrane Technology. Noyes Publication, IL, Park Ridge, New Jersey. Prabha, T., Bhagyalakshmi, N., 1998. Carbohydrate metabolism in ripening banana fruit. Phytochemistry 48 (6), 915919. Available from: https://doi.org/10.1016/S0031-9422(97) 00931-X. Prade, R.A., et al., 1999. Pectins, pectinases and plant-microbe interactions. Biotechnol. Genetic Eng. Rev. 16 (1), 361392. Available from: https://doi.org/10.1080/ 02648725.1999.10647984. Qaid, S., 2017. Ultrafiltration for clarification of Valencia orange juice: Comparison of two flat sheet membranes on quality of juice production. J. Mater. Environ. Sci. 8, 11861194. Rai, C., et al., 2010. Mechanism of permeate flux decline during microfiltration of watermelon (Citrullus lanatus) juice. Food Bioprocess Technol. 3 (4), 545553. Available from: https:// doi.org/10.1007/s11947-008-0118-2. Rai, P., et al., 2004. Optimizing pectinase usage in pretreatment of mosambi juice for clarification by response surface methodology. J. Food Eng. 64 (3), 397403. Available from: https://doi.org/10.1016/j.jfoodeng.2003.11.008.

192

Separation of Functional Molecules in Food by Membrane Technology

Rai, P., et al., 2005. Modeling the performance of batch ultrafiltration of synthetic fruit juice and mosambi juice using artificial neural network. J. Food Eng. 71 (3), 273281. Available from: https://doi.org/10.1016/j.jfoodeng.2005.02.003. Rai, P., Majumdar, G.C., Jayanti, V.K., et al., 2006. Alternative pretreatment methods to enzymatic treatment for clarification of mosambi juice using ultrafiltration. J. Food Process Eng. 29 (2), 202218. Available from: https://doi.org/10.1111/j.1745-4530.2006.00058.x. Rai, P., Majumdar, G.C., Sharma, G., et al., 2006. Effect of various cutoff membranes on permeate flux and quality during filtration of mosambi (Citrus sinensis (L.) Osbeck) juice. Food Bioprod. Process. 84 (3), 213219. Available from: https://doi.org/10.1205/ fbp.05181. Rai, P., et al., 2007. Effect of various pretreatment methods on permeate flux and quality during ultrafiltration of mosambi juice. J. Food Eng. 78 (2), 561568. Available from: https://doi. org/10.1016/j.jfoodeng.2005.10.024. Rai, P., et al., 2008. Storage study of ultrafiltered mosambi (Citrus sinensis (l.) Osbeck) juice. J. Food Process. Preservation 32 (6), 923934. Available from: https://doi.org/10.1111/j.17454549.2008.00222.x. Raso, J., et al., 1998. Inactivation of mold ascospores and conidiospores suspended in fruit juices by pulsed electric fields. LWT - Food Sci. Technol. 31 (78), 668672. Available from: https://doi.org/10.1006/fstl.1998.0426. Raso, J., et al., 2006. Inactivation of Zygosaccharomyces bailii in fruit juices by heat, high hydrostatic pressure and pulsed electric fields. J. Food. Sci. 63 (6), 10421044. Available from: https://doi.org/10.1111/j.1365-2621.1998.tb15850.x. Ridley, B.L., O’Neill, M.A., Mohnen, D., 2001. Pectins: structure, biosynthesis, and oligogalacturonide-related signaling.Phytochemistry 57 (6), 929967. Available at. Available from: http://www.ncbi.nlm.nih.gov/pubmed/11423142. Rossi, M., et al., 2003. Effect of fruit blanching on phenolics and radical scavenging activity of highbush blueberry juice. Food Res. Int. 36 (910), 9991005. Available from: https://doi. org/10.1016/j.foodres.2003.07.002. Roy, A., De, S., 2015. Resistance-in-series model for flux decline and optimal conditions of Stevia extract during ultrafiltration using novel CAP-PAN blend membranes. Food Bioprod. Process. 94, 489499. Available from: https://doi.org/10.1016/j.fbp.2014.07.006. Sagu, S.T., Nso, E.J., et al., 2014. Optimisation of low temperature extraction of banana juice using commercial pectinase. Food. Chem. 151, 182190. Sagu, S.T., Karmakar, S., Nso, E.J., De, S., 2014. Primary clarification of banana juice extract by centrifugation and microfiltration. Sep. Sci. Technol. (Philadelphia) 49 (8), 11561169. Available from: https://doi.org/10.1080/01496395.2013.877932. Sagu, S.T., Karmakar, S., Nso, E.J., Kapseu, C., et al., 2014. Ultrafiltration of banana (Musa acuminata) juice using hollow fibers for enhanced shelf life. Food Bioprocess Technol. 7 (9), 27112722. Available from: https://doi.org/10.1007/s11947-014-1309-7. Sahin, ¸ S., Bayindirli, L., 1993. The effect of depectinization and clarification on the filtration of sour cherry juice. J. Food Eng. 19 (3), 237245. Available from: https://doi.org/10.1016/ 0260-8774(93)90045-L. Santin, M.M., et al., 2008. Evaluation of enzymatic treatment of peach juice using response surface methodology. J. Sci. Food. Agric. 88 (3), 507512. Available from: https://doi.org/ 10.1002/jsfa.3114. Schols, H.A., et al., 1995. A xylogalacturonan subunit present in the modified hairy regions of apple pectin. Carbohydr. Res. 279, 265279. Available from: https://doi.org/10.1016/00086215(95)00287-1.

Pectin Removal and Clarification of Juices Chapter | 5

193

Sharma, V.K., Colangelo, A., Spagna, G., 1995. Experimental investigation of different solar dryers suitable for fruit and vegetable drying. Renew. Energy 6 (4), 413424. Available from: https://doi.org/10.1016/0960-1481(94)00075-H. Shui, G., Leong, L.P., 2002. Separation and determination of organic acids and phenolic compounds in fruit juices and drinks by high-performance liquid chromatography. J. Chromatogr. A. 977 (1), 8996. Available from: https://doi.org/10.1016/S0021-9673(02)01345-6. Sims, C.A., Bates, R.P., Arreola, A.G., 1994. Color, polyphenoloxidase, and sensory changes in banana juice as affected by heat and ultrafiltration. J. Food. Qual. 17 (5), 371379. Available from: https://doi.org/10.1111/j.1745-4557.1994.tb00158.x. Siricururatana, P., et al., 2013. Shelf-life evaluation of natural antimicrobials for concord and niagara grape juices. J. Food. Prot. 76 (1), 7278. Available from: https://doi.org/10.4315/ 0362-028X.JFP-12-144. Skolnik, H., 1968. History, evolution, and status of agriculture and food science and technology. J. Chem. Doc. 8 (2), 9598. Sopie Edwige Salome, Y., et al., 2011. Phenolic profiles of pineapple fruits (Ananas comosus L. Merrill) Influence of the origin of suckers. Aust. J. Basic Appl. Sci. 5, 13721378. Sotoft, L.F., et al., 2012. Full scale plant with membrane based concentration of blackcurrant juice on the basis of laboratory and pilot scale tests. Chem. Eng. Processing: Process Intensif. 54, 1221. Available from: https://doi.org/10.1016/j.cep.2012.01.007. ´ ., et al., 2010. Effect of UHPH on indigenous microbiota of apple juice. Int. J. Food Sua´rez-Jacobo, A Microbiol. 136 (3), 261267. Available from: https://doi.org/10.1016/j.ijfoodmicro.2009.11.011. Thakur, B.K., De, S., 2012. A novel method for spinning hollow fiber membrane and its application for treatment of turbid water. Sep. Purif. Technol. 93, 6774. Available from: https:// doi.org/10.1016/j.seppur.2012.03.032. Thakur, B.R., et al., 1997. Chemistry and uses of pectin — a review. Crit. Rev. Food. Sci. Nutr. 37 (1), 4773. Available from: https://doi.org/10.1080/10408399709527767. Tiwari, B.K., et al., 2008. Modelling colour degradation of orange juice by ozone treatment using response surface methodology. J. Food Eng. 88 (4), 553560. Available from: https:// doi.org/10.1016/j.jfoodeng.2008.03.021. Tiwari, B.K., et al., 2009. Anthocyanin and colour degradation in ozone treated blackberry juice. Innovative Food Sci. Emerg. Technol. 10 (1), 7075. Available from: https://doi.org/ 10.1016/j.ifset.2008.08.002. Uc¸an, F., Akyildiz, A., A˘gc¸am, E., 2014. Effects of different enzymes and concentrations in the production of clarified lemon juice. J. Food Process. 2014, 114. Available from: https:// doi.org/10.1155/2014/215854. Vaillant, F., et al., 1999. Crossflow microfiltration of passion fruit juice after partial enzymatic liquefaction. J. Food Eng. 42 (4), 215224. Available from: https://doi.org/10.1016/S02608774(99)00124-7. Vaillant, F., et al., 2001. Strategy for economical optimisation of the clarification of pulpy fruit juices using crossflow microfiltration. J. Food Eng. 48 (1), 8390. Available from: https:// doi.org/10.1016/S0260-8774(00)00152-7. Vaillant, F., et al., 2008. Turbidity of pulpy fruit juice: a key factor for predicting cross-flow microfiltration performance. J. Memb. Sci. 325 (1), 404412. Available from: https://doi. org/10.1016/j.memsci.2008.08.003. Varela-Santos, E., et al., 2012. Effect of high hydrostatic pressure (HHP) processing on physicochemical properties, bioactive compounds and shelf-life of pomegranate juice. Innovative Food Sci. Emerg. Technol. 13, 1322. Available from: https://doi.org/10.1016/j. ifset.2011.10.009.

194

Separation of Functional Molecules in Food by Membrane Technology

Vegara, S., et al., 2013. Effect of pasteurization process and storage on color and shelf-life of pomegranate juices. LWT - Food Sci. Technol. 54 (2), 592596. Available from: https:// doi.org/10.1016/j.lwt.2013.06.022. Vincze, I., Stefanovits-Ba´nyai, E´., Vatai, G., 2006. Using nanofiltration and reverse osmosis for the concentration of seabuckthorn (Hippophae rhamnoides L.) juice. Desalination 200 (13), 528530. Available from: https://doi.org/10.1016/j.desal.2006.03.423. Vı´quez, F., Lastreto, C., Cooke, R.D., 2007. A study of the production of clarified banana juice using pectinolytic enzymes. Inter. J. Food Sci. Technol. 16 (2), 115125. Available from: https://doi.org/10.1111/j.1365-2621.1981.tb01003.x. Visser, J., Voragen, A.G., 2009. In: Schols, H.A., Visser, R.G.F., Voragen, A.G.J. (Eds.), Pectins and Pectinases. Wageningen Academic Publishers, The Netherlands. Available from: https:// doi.org/10.3920/978-90-8686-677-9. Vladisavljevi´c, G.T., Vukosavljevi´c, P., Bukvi´c, B., 2003. Permeate flux and fouling resistance in ultrafiltration of depectinized apple juice using ceramic membranes. J. Food Eng. 60 (3), 241247. Available from: https://doi.org/10.1016/S0260-8774(03)00044-X. Wang, L.K., et al., (Eds.), 2011. Membrane and Desalination Technologies. Humana Press, Totowa, NJ. Available from: https://doi.org/10.1007/978-1-59745-278-6. Warczok, J., et al., 2004. Concentration of apple and pear juices by nanofiltration at low pressures. J. Food Eng. 63 (1), 6370. Available from: https://doi.org/10.1016/S0260-8774(03) 00283-8. Whitaker, J.R., 1984. Pectic substances, pectic enzymes and haze formation in fruit juices. Enzyme Microb. Technol. 6 (8), 341349. Available from: https://doi.org/10.1016/01410229(84)90046-2. White, B.L., Howard, L.R., Prior, R.L., 2011. Impact of different stages of juice processing on the anthocyanin, flavonol, and procyanidin contents of cranberries. J. Agric. Food. Chem. 59 (9), 46924698. Available from: https://doi.org/10.1021/jf200149a. Willats, W.G., et al., 2001. Pectin: cell biology and prospects for functional analysis. Plant Mol. Biol. 47 (12), 927. Available at: http://www.ncbi.nlm.nih.gov/pubmed/11554482. Willats, W.G., Knox, J.P., Mikkelsen, J.D., 2006. Pectin: new insights into an old polymer are starting to gel. Trends Food Sci. Technol. 17 (3), 97104. Available from: https://doi.org/ 10.1016/j.tifs.2005.10.008. Wrolstad, R.E., Lee, D.D., Poei, M.S., 1980. Effect of microwave blanching on the color and composition of strawberry concentrate. J. Food. Sci. 45 (6), 15731577. Available from: https://doi.org/10.1111/j.1365-2621.1980.tb07566.x. Wu, M.L., Zall, R.R., Tzeng, W.C., 1990. Microfiltration and ultrafiltration comparison for apple juice clarification. J. Food. Sci. 55 (4), 11621163. Available from: https://doi.org/10.1111/ j.1365-2621.1990.tb01622.x. Yen, G.-C., Lin, H.-T., 1996. Comparison of high pressure treatment and thermal pasteurization effects on the quality and shelf life of guava puree. Int. J. Food Sci. Technol. 31 (2), 205213. Available from: https://doi.org/10.1111/j.1365-2621.1996.331-32.x. Yıkmı¸s, S., 2016. New approaches in non-thermal processes in the food industry. Int. J. Nutr. Food Sci. 5 (5), 344. Available from: https://doi.org/10.11648/j.ijnfs.20160505.15. Zhou, H.-W., Ben-Arie, R., Lurie, S., 2000. Pectin esterase, polygalacturonase and gel formation in peach pectin fractions. Phytochemistry 55 (3), 191195. Available from: https://doi.org/ 10.1016/S0031-9422(00)00271-5. Zwijnenberg, H.J., et al., 2002. Native protein recovery from potato fruit juice by ultrafiltration. Desalination 144 (13), 331334. Available from: https://doi.org/10.1016/S0011-9164(02) 00338-7.