Bioenergy systems for the future 13 integration of membrane technologies into conventional existing systems in the food industry

Bioenergy systems for the future 13 integration of membrane technologies into conventional existing systems in the food industry Bioenergy systems for the future 13 integration of membrane technologies into conventional existing systems in the food industry Bioenergy systems for the future 13 integration of membrane technologies into conventional existing systems in the food industry Bioenergy systems for the future 13 integration of membrane technologies into conventional existing systems in the food industry Bioenergy systems for the future 13 integration of membrane technologies into conventional existing systems in the food industry

Integration of membrane

technologies into conventional

existing systems in the food

industry

A Cassano, C Conidi

Institute on Membrane Technology (ITM-CNR), Rende (Cosenza), Italy

Abbreviations

BMR biocatalytic membrane reactor

DCMD direct contact membrane distillation

MOD membrane osmotic distillation

MWCO molecular weight cutoff

Bioenergy Systems for the Future http://dx.doi.org/10.1016/B978-0-08-101031-0.00013-2

© 2017 Elsevier Ltd All rights reserved.

TOC total organic carbon

TSS total soluble solids

VRF volume reduction factor

WPCs whey protein concentrates

13.1 Introduction

Membrane technologies are today very well-established tools in the food industry Inthis field, membrane filtration is the state-of-the-art technology for clarification, con-centration, fractionation (separation of components), desalting, and purification of avariety of food products It is also applied to improve the food safety of products whileavoiding heat treatment

The global market for membrane technologies in the food industry is increasing at acompound annual growth rate of 6.7% between 2015 and 2020 In particular, the mar-ket of membranes in food and beverage processing was estimated at more than$4.0billion in 2014, and it was expected to reach 5.8 billion in 2020 (BCC Research, 2016).The reason of the fast and rapid increase of membrane systems in food processingindustry is mainly related to the advantages of these technologies in comparisonwith the traditional ones such as high selectivity, easy scale-up, modularity, lowoperating temperature with minimization of thermal damage, gentle product treat-ment, no phase change and use of chemical additives, and low energy consumption(Li and Chase, 2010)

The most common membrane technologies applied in the food industry are thepressure-driven membrane processes including microfiltration (MF), ultrafiltration(UF), nanofiltration (NF), and reverse osmosis (RO) Recently, other membrane tech-nologies such as electrodialysis (ED), membrane contactors (MCs), pervaporation(PV), and forward osmosis (FO) have been also investigated in this field

These processes and their combination in integrated systems or also with tional techniques (centrifugation, evaporation, solvent extraction, adsorption, etc.)found a large application in different areas of food production, including dairy, fruitjuice and pulp production, beer and wine, beet and cane sugar, meat, and water andwastewaters (Fig 13.1)

conven-The implementation of hybrid-membrane-based processes in these areas permits

to rationalize both direct and indirect energy consumptions, with improvedproduct quality, process capacity, and selectivity and decreased equipment size/production-capacity ratio and waste production so resulting in cheaper and sustainabletechnical solutions (Drioli and Romano, 2001)

In this chapter, specific applications of integrated membrane processes for ing the quality of agrofood products (i.e., fruit juices and wine) and the recovery ofhigh-added value compounds from agrofood by-products are presented and discussedhighlighting their key advantages over conventional technologies

improv-13.2 Fruit juice processing

Nowadays, there is a worldwide increasing tendency for the consumption of fruits,juices, and fruit drinks, due to consumer interest in healthy and natural products thatare practical and ready to be consumed

The implementation of membrane filtration processes in the manufacture of fruitjuices represents one of the technological answers to the problem of producingadditive-free juices with standard organoleptic quality and natural fresh taste Inparticular, juice clarification, stabilization, depectinization, and concentration aretypical steps in which membrane processes such as MF, UF, NF, RO, and membranedistillation (MD) have been successfully utilized (Cassano et al., 2007a)

In fruit juice production, a clarification step is needed to prevent the haze formationduring storage; on the other hand, the juice’s clear appearance is a determinant factor forconsumers In addition, the removal of suspended solids is a necessary pretreatment inorder to increase the efficiency of posttreatments such as bitterness, tartness, and acidremoval with adsorbent resins or concentration with membrane technologies.Conventional clarification processes typically involve the addition of fining agentssuch as gelatin and bentonite Gelatin is positively charged at the low pH range of fruitjuices and reacts with negatively charged phenolics such as tannin species The maineffect of bentonite on clarification depends on its adsorption capacity, mainly proteins

MF and UF processes represent a valid alternative to the traditional clarification andstabilization methodologies, resulting in increased juice yield, improved product qualityand possibility to avoid fining agents and filter aids leading to the minimization of

Beet and cane sugar

Meat

Water and wastewater treatment

Beer and wine

Fig 13.1 Applications

of membrane processes

in the food industry

related costs and disposal problems The possibility to operate in a single step, reduction

in enzyme utilization and working times, and easy cleaning and maintenance of theequipment are additional advantages

UF and MF membranes separate the juice into a fibrous concentrated pulp(retentate) and a clarified fraction free of spoilage microorganisms (permeate).Several studies concerning the clarification of fruit and vegetable juices with UFand MF membranes and their impact on the juice composition in comparison withtraditional technologies have been reported in literature UF processes have beeninvestigated for the clarification of acerola (Milani et al., 2015), blood orange(Conidi et al., 2015a), carrot (Ennouri et al., 2015), passion (De Oliveira et al.,

2012), kiwifruit (Cassano et al., 2008), pineapple (De Barros et al., 2003), banana(Sagu et al., 2014), mosambi (Rai et al, 2007), and lemon (Maktouf et al., 2014) juices

MF membranes have been used for the clarification of umbu (Ushikubo et al., 2007),tropical fruit (mango, pineapple, naranjilla, Castillas blackberry, passion fruit, andtangerine) (Vaillant et al., 2001), bottle gourd (Biswas et al., 2016), and red raspberry(Vladisavljevi
c et al., 2013) juices The potential of these processes for the better pres-ervation of the quality of the raw material has been clearly confirmed

A limiting factor of MF and UF processes is the decline of permeate flux (J) withtime (t) that reduces the process efficiency This phenomenon is caused by the accumu-lation of macromolecular or colloidal species (such as pectins and proteins) on themembrane surface (concentration polarization and gel layer) or by physicochemicalinteractions with the membrane such as adsorption on the membrane pore walls andpore plugging (membrane fouling) (Cassano et al., 2007b) Membrane foulingdecreases itself, permeate flux, and membrane longevity; therefore, it is a key factoraffecting the economic and commercial viability of a membrane system (Baker, 2000).Several approaches have been proposed to minimize membrane fouling mecha-nisms including the optimization of operating conditions, the pretreatment of the feedsolution, and the selection of appropriate membranes (in terms of molecular weightcutoff, morphology, and hydrophobicity/hydrophilicity) Among these availableapproaches, the optimization of operating and fluid dynamic conditions such as tem-perature, transmembrane pressure, and cross flow velocity in the clarification of fruitjuices has been investigated by several authors (de Oliveira et al., 2012; Rezzadori

et al 2014; Verma and Sarkar, 2015; Bahceci, 2012; Cassano et al., 2007c) in order

to maximize permeate fluxes and the permeate quality

Fruit juice processing and preservation consist of several different steps including theconcentration step in which the solid content of the juice is increased from 10%–12% up

to 65%–75% of weight Fruit juices are concentrated in order to reduce their volumeand consequently to minimize handling, packaging, and transportation costs Theincreased concentration of soluble solids leads also to a higher resistance to microbialand chemical as a result of water activity reduction The industrial concentration offruit juices is usually performed by multistage vacuum evaporation at high temperature,followed by recovery and concentration of volatile flavors and their addition back tothe concentrated product This technique results in degradation of thermosensitivecompounds and loss of valuable compounds (e.g., aroma and antioxidant compounds)with a significant reduction of the final product quality (Onsekizoglu, 2015)

Membrane operations such as UF, NF, RO, and MD can be considered today a validalternative to thermal concentration of fruit juices and natural extracts (Ciss
e et al.,

2011) These processes offer several advantages in terms of preservation of nutritionaland sensorial compounds since they can operate at moderate temperature and pressureconditions

Pressure-driven membrane operations, such as UF, NF, and RO have been largelyinvestigated, also in integrated systems, for the clarification and concentration of dif-ferent types of fruit juices An integrated process UF/RO was studied byEchavarria

et al (2012)for the clarification and concentration of peach, pear apple, and mandarinjuices The depectinized juices were at first clarified with a polysulfone (PS) UF mem-brane in tubular configuration with a molecular weight cutoff (MWCO) of 8 kDa; theclarified juice was concentrated by using a tubular RO membrane in polyamide (PA)with a NaCl rejection of 99% Both processes were evaluated in terms of permeateflux and product quality

Gunathilake et al (2014)studied the RO process for the concentration of bioactivecompounds in cranberry, blueberry, and apple juices by using a Dow Filmtec BW30-

2540 RO membrane (Dow Chemical Company, Minnesota, the United States) Theeffects of the processing parameters on physicochemical and antioxidant properties

of the concentrated juices were also analyzed Results showed that the antioxidantcapacity of the different juices increased in the concentrated fractions in the range

of 30%–40% According to the obtained results, RO can be considered as an efficienttool for enhancing the health-promoting properties of fruit juices

The concentration of bioactive compounds in watermelon by cross flow NF branes was evaluated byArriola et al (2014)by using an HL2521TF membrane from

mem-GE Osmonics (Minnetonka, the United States) Most of bioactive compounds wereconcentrated in the retentate side due the high rejection coefficient of the membrane(99% toward lycopene and 96% and 65% for flavonoids and low phenolic compounds,respectively) A strict correlation between the concentration level and the increasing

of the antioxidant activity was also observed

The concentration of fruit juices by RO is limited by the product osmotic pressurethat increases with increasing concentration Indeed, the final concentration of juices

in a single-stage RO system is limited to about 25–30°Bx, which is notably below thevalue obtained by thermal evaporation This suggests the implementation ofintegrated processes in which RO is used as a preconcentration step before a finalconcentration with other technologies (freeze concentration, thermal evaporation,and osmotic distillation)

Technological advances related to the development of new membranes andimprovements in process engineering have been proved to overcome these limitations.New membrane processes including osmotic distillation (OD) and MD have attractedattention for the production of concentrated juices at high concentration level underatmospheric pressure and low temperature (Jiao et al., 2004)

The OD process is based on the use of hydrophobic macroporous membranesseparating two liquid phases that differ greatly in terms of solute concentration.The hydrophobic nature of the membrane prevents penetration of the pores by aqueoussolutions, creating air gaps within the membrane The difference in solute

concentration, and consequently in water activity between the two sides of the brane, induces a vapor pressure difference causing a water vapor transfer across thepores from the high-vapor pressure phase to the low one (Nagaraj et al., 2006) Thismigration of water vapor results in the concentration of the feed solution and the dilu-tion of the osmotic agent.

mem-The typical OD process involves the use of a concentrated brine at the downstreamside of the membrane as a stripping solution A number of salts such as MgSO4, CaCl2,and K2HPO4are suitable

Similarly to OD, in MD, two aqueous solutions at different temperatures are arated by a macroporous hydrophobic membrane Due to the hydrophobicity of themembrane material, the liquid water cannot enter the pores, and a liquid interface

sep-is formed on either side of the membrane pores (Khayet, 2011) In these conditions,

a net pure water flux from the warm side to the cold side occurs The process takesplace at atmospheric pressure and at a temperature that may be much lower thanthe boiling point of the solutions The driving force is a vapor pressure differencebetween the two solutions—membrane interfaces due to the existing temperaturegradient

The integration of pressure-driven membrane processes with OD and MD asalternative to the conventional juice processing systems has been largely investi-gated An integrated process or the clarification and concentration of pomegranatejuice based on the use of UF and OD processes was investigated byCassano et al.(2011) Fresh pomegranate juice, was at first, clarified by modified poly(ether-ether-ketone) hollow fiber UF membranes prepared in laboratory The clarified juice, with

an initial content of total soluble solids (TSS) of 16.2°Bx, was then concentrated

by OD at room temperature until 52.0°Bx The concentration step was performed

by using a Liqui-Cel Extra-Flow 2.5
8 in membrane contactor (Membrana,Charlotte, the United States) containing macroporous polypropylene (PP) hollowfibers (having external and internal diameters of 300 and 220μm, respectively) with

an average pore diameter of 0.2μm and a total membrane surface area of 1.4 m2.Calcium chloride dehydrate at 60% w/w was used as brine solution The UF processproduced a very clear juice depleted of total suspended solids and with physico-chemical and nutritional properties similar to those of the fresh fruit The concen-trated juice presented a content of total polyphenols and organic acids similar to that

of the clarified juice The total antioxidant activity (TAA) of the OD retentatewas only 4% lower than the TAA of the clarified juice confirming the particularmildness of the treatment

The impact of different concentration processes including OD, coupled operation

of OD and MD, and thermal evaporation (TE) on the quality of pomegranate juice wasinvestigated byOnsekizoglu (2013) The process involved a preliminary clarification

of pomegranate juice with a combination of fining agents and UF The clarified tion with an initial TSS of 17°Bx was concentrated up to 54–56°Bx MD and OD pro-cesses resulted very efficient in maintaining the original characteristics of the freshjuice in terms of pH, total acidity, color, antioxidant activity, total polyphenol, totalmonomeric anthocyanins, and organic acids On the other hand, the concentration by

frac-TE produced a significant loss of TAA and color and the formation of a

hydroxymethylfurfural (HMF), an important intermediate of Maillard reactionswidely used as an indicator of thermal exposure.

The coupled operation of MD and OD resulted as the most feasible approach for theconcentration of pomegranate juice, allowing to reach higher concentration levels inshorter periods of operation time with a slight increase (5°C) in temperature of thejuice in comparison with OD

A similar approach was studied for the concentration of cornelian cherry fruit juice(B
elafi-Bako´ and Boo´r, 2011) The raw juice, after a preliminary clarification with apolyethersulfone (PES) UF membrane, was concentrated by combining MD and OD(the process is also defined as membrane osmotic distillation, MOD) The clarifiedjuice was concentrated by using a membrane contactor containing 34 polypropylenecapillary membranes (Microdyn-Nadir, Wiesbaden, Germany) with a total effectiveinternal area of 68 cm2, nominal pore size of 0.2μm, 70% porosity, 0.8 mm outerand 0.6 mm inner diameter, thickness of 0.2 mm, and a length of 80 mm A 6 M ofcalcium chloride dihydrate solution was used as stripping solution; temperaturewas fixed at 35°C and 22°C in the feed and osmotic side, respectively

The clarified juice with a TSS content of 12.59°Bx was concentrated up to 51.45°

Bx in an operation time of 15 h and an average water flux of about 5.33 kg/m2h.Despite the quite long operation time to reach high concentration levels, theantioxidant capacity and the total phenol and anthocyanin content of the juice werepreserved, and thermal degradation was avoided

An integrated process for the clarification and concentration of blood orange juicewas proposed byQuist-Jensen et al (2016) In this approach, the raw juice was pre-viously clarified by UF; the clarified juice, with an initial TSS content of 9.5°Bx, wasconcentrated up to 65°Bx through a two-step direct contact membrane distillation(DCMD) process by using a laboratory bench plant equipped with two polypropylenehollow fiber membrane modules (Enka Microdyn MD-020-2 N-CP) having a nominalpore size of 0.2μm and a membrane surface area of 0.1 m2

in the final retentate was similar to that of the UF permeate Similarly, the final MDretentate at 65°Bx still showed a high TAA value (about 6.6 mM Trolox) when com-pared with the raw juice and the UF permeate (6.52 and 6.40 mM Trolox, respec-tively), confirming the validity of the process in preserving the original quality ofthe fresh juice

An integrated membrane process for the clarification and concentration of bloodorange juice was also investigated byGalaverna et al (2008) The integrated systemconsisted of an initial clarification of the raw juice by UF in order to removesuspended solids and to separate the liquid serum for the pulp Afterward, the clarifiedjuice was preconcentrated by RO up to 25–30°Bx The final concentration up to 60°Bxwas carried out by OD A direct concentration by OD of the clarified juice was also

Table 13.1 General composition of blood orange juice clarified and concentrated

by integrated membrane process

Raw juice

Clarified

MD retentate(preconcentration)

MD retentate(concentration)

UF, ultrafiltration; MD, membrane distillation.

a Values referred to a TSS content of 9.5 °Bx.

investigated The concentrated fractions presented a decrease of about 15% of theinitial TAA due to the partial decrease of ascorbic acid and flavonoids On the con-trary, the juice concentrated by thermal evaporation (TE) presented a TAA reduction

of about 26% The concentrated juice by OD presented a red brilliant color and apleasant aroma that were completely lost in the thermal treatment

Integrated UF/OD processes for the clarification and concentration of kiwifruit andcactus pear juices were also investigated (Cassano et al., 2004, 2007a) In these pro-cesses the concentration step was performed by using a Liqui-Cel Extra-Flow2.5
8 in membrane contactor As reported inTable 13.2, the content of ascorbic acidand the antioxidant activity of both juices were very well preserved during the mem-brane treatment The OD retentate fractions were considered a good source of bioac-tive compounds with high antioxidant value and of interest for potential applications

in food and pharmaceutical industries

A general flow sheet of an integrated membrane process for the clarification andconcentration of fruit juices is illustrated in Fig 13.2 The process includes apreconcentration step based on the use of RO membranes followed by a final concen-tration by OD The UF retentate can be processed for microbiological stabilization(pasteurization)

Being the retentate composition less sensitive to heat than small aroma molecules,vitamins, and sugars, it can be pasteurized to inactivate enzymes and microorganismsand then added in adequate proportions to the concentrated juice

The wine industry is one of the most important agroindustrial activities in the world In

2015, the world production was of about 275.5 mhL Italy is the leader country with aproduction of 48.9 mhL followed by France (47.4 mhL), Spain (36.6 mhL), the UnitedStates (22.1 mhL), Argentine (13.4 mhL), and Chile (12.87 mhL) (OrganisationInternationale de la Vigne et du Vin, 2015)

samples of cactus pear and kiwifruit juices clarified and

concentrated by integrated membrane process

UF, ultrafiltration; OD, osmotic distillation.

a Value referred to a TSS content of 13 °Bx.

b Value referred to a TSS content of 12.5 °Bx.

The winemaking process includes several unit operations (pressing, decanting, tion, and bottling) and processes (alcoholic and malolactic fermentations) that convertgrapes into wine The crude wine is a very complex solution with numerous solutes(organic acids, salts, and polyphenols), macromolecules and colloidal particles, micro-organisms, yeasts, and large particles as potassium hydrogen tartrate In addition, itpresents a turbid aspect that is not very well accepted by consumers, and usually, it needs

filtra-to be clarified Traditional clarification processes involve centrifugation, dead-endfiltration (filter presses, filtration on sheets, and diatomaceous earth filtration), andthe use of exogenic additives Diatomaceous earth used for traditional filtration has anegative impact on the environment It is difficult to handle and thus represents a poten-tial health hazard Also, it needs to be properly disposed after usage and involves addi-tional filtration steps and disposal costs (Cook et al., 2005)

Membrane processes for wine treatment are considered an emerging and validalternative to traditional technology (Daufin et al., 2001; Galanakis et al., 2013) Inparticular, cross flow MF and UF are widely used in winemaking industry as clarifi-cation and microbiological stabilization techniques They offer several advantagesover traditional processes such as elimination of filter aids and their associated envi-ronmental problems; the combination of clarification, stabilization, and sterile filtration

in one single continuous operation; and economic and operational benefits (Czekaj

et al., 2000) However, the main limiting factor of these processes is the permeate fluxdecay over time caused by the accumulation of wine compounds in the pores (mem-brane fouling) and on the membrane surface (concentration polarization and gel forma-tion) These phenomena lead not only to a reduction of the membrane productivity soaffecting the economic viability of the process but also to a possible retention of somecomponents with a loss of organoleptic characteristics (Czekaj et al., 2001)

The mechanism of membrane fouling and the methods to control or limit it have beenlargely investigated Particularly, these studies have been addressed to the selection ofthe most suitable membranes (in terms of membrane material, configuration, and pore

Clarified juice

Pulp Raw juice

Preconcentrated juice

Diluted brine Concentratedbrine

Concentrated juice

dimension) and operating conditions to be selected in wine treatment Wine compoundsinvolved in membrane fouling have been also analyzed (El Rayess et al., 2011a).

Ulbricht et al (2009)studied the influence of membrane material on the adsorption

of polyphenols and polysaccharide in the cross flow MF of wine Polypropylene (PP)and PES membranes in capillary and flat-sheet configurations and with a pore size of0.2μm were tested and compared in terms of productivity and membrane fouling(adsorption of foulants) Experimental results indicated that polyphenols and polysac-charides are only marginally adsorbed by PP but strongly adsorbed by PES mem-branes The adsorption of polyphenols in PES membranes is regulated by twodifferent mechanisms: polar interactions (van der Waals and electron donor-acceptorinteractions) and multiple hydrogen bonds toward the additive polyvinylpyrrolidone(PVP) The low adsorption tendency of wine compounds to PP membranes results inhigher fluxes and longer service life of the respective filtration modules

El Rayess et al (2011b)investigated factors affecting membrane fouling duringwine MF with a 0.2μm multichannel ceramic membrane Critical fouling conditionswere studied in order to limit membrane fouling due to wine colloids (tannins, pectin,and mannoproteins) and to increase the process performance For each fouling com-ponent, critical fouling conditions were also optimized Results provided evidencethat the main fouling mechanisms involved in the clarification of wine are the adsorp-tion of colloids on the membrane surface or inside pores and the formation of a depositlayer with mannoproteins at the membrane surface An increase in pressure alsoincreases the gel layer compaction or deformation without promoting the membraneproductivity Membrane fouling in the presence of these wine molecules occurredfrom the first minute of filtration and even at low pressures

Dynamic filtrations such as rotating and vibrating filtration (RVF technology) havebeen also recently investigated byEl Rayess et al (2016)in order to reduce membranefouling and enhance the permeate flux during the cross flow MF of wine with PES(hydrophilic) and polytetrafluoroethylene (PTFE) (hydrophobic) membranes of0.2μm The impact of wine composition and operating conditions (transmembranepressure and rotational frequency) on membrane fouling was also evaluated Workingwith filtered wines, an irreversible fouling was observed independently by themembrane material In addition, the increase of rotational frequency or water rinsinghad no positive influence on membrane fouling but, on the contrary, promoted itscompression and membrane plugging PTFE membranes seem to be greatly affected

by the molecules/membrane interactions; on the other hand, fouling of PES branes is mainly affected by a balance between the hydrodynamics of the systemand the deposited material

mem-The natural alcohol of wine can be increased in several ways including the ment of grape must with additive (i.e., addition of sugars or ethanol) or subtractivetechniques (i.e., reduction of water content) The addition of must concentrate(MC) or rectified must concentrate (RMC) is a typical practice to increase the sugarcontent of grape must However, the addition of MC could affect the quality of winedue to the presence of several nonsugar compounds (e.g., polyphenols, organic acids,and salts) On the other hand, the addition of RMC causes a dilution effect RO and NFprocesses represent a valid alternative for grape juice concentration if compared with

treat-traditional methodologies Moreover, costs of must concentration by RO and NF arelow if compared with concentration by thermal evaporation.

These processes allow to increase the amount of sugars without the addition of grape components that can increase the wine volumes and modify its organolepticcharacteristics The possibility to operate at room temperature, preserving the quality

non-of wine, the absence non-of caramelization reactions, and the maintenance non-of sensorial andnutritional properties of the product are additional advantages Musts concentrated by

RO at a low temperature (10°C) and at an operating pressure of 75 bar revealed a ter quality when compared with those obtained by the addition of sucrose(chaptalization) (Mietton-Peuchot et al., 2002)

bet-Membrane-based integrated processes can play an important role in wineprocessing by creating new prospects for development, reengineering, or retrofitting

of traditional processes

An integrated process for the clarification and concentration of must was oped byKiss et al (2004) The fresh grape juice was clarified by MF in order toremove microorganisms and suspended particles The clarified fraction with a sugarcontent of 12°Bx was preconcentrated by RO up to 25°Bx; the RO retentate was thenprocessed by NF up to produce a concentrated fraction with a final sugar content ofabout 45°Bx (Fig 13.3) The estimated total costs (investment and operation costs) of

Concentrated must (45°Bx)

NF permeate (5°Bx)

Preconcentrated

must (25°Bx)

RO permeate (0.01°Bx)

Fig 13.3 Integrated membrane process for must concentration in wine processing

Modified from Kiss, I., Vatai, G., Bekassy-Molnar, E., 2004 Must concentrate using membranetechnology Desalination 162, 295–300

the membrane-based process resulted much lower (6000€/year) than those of vacuumevaporation (17,300€/year) mostly because of the high price of the heat energyinvolved in this process.

Membrane-based processes have been also investigated for wine dealcoholization.The reduction of alcohol content in wine is a world trend among consumers that preferwines with an alcohol content between 9 and 13 vol%, tendency reinforced by newtrends of limiting alcohol consumption In addition, the alcohol concentration caninterfere with flavor perception and impact negatively on wine complexity

Strategies to reduce alcohol concentration in wine include viticultural or fermentation practices, microbiological techniques (i.e., development of yeast inoculathat reduce the efficiency of ethanol production), postfermentation practices (i.e., blend-ing of high and low alcohol wine), and membrane processes in which alcohol isphysically removed after fermentation (Go´mez-Plaza et al., 1999; Pickering, 2000)

pre-RO and NF processes are the most used techniques at present for reducing the alcoholcontent in wine (Catarino and Mendes, 2011; Labanda et al., 2009; Salgado et al., 2015).Other membrane technologies such as OD and pervaporation (PV) have been alsoproposed at this purpose (Diban et al., 2008; Taka´cs et al., 2007)

An integrated membrane process for the production of wine with a low alcohol tent was investigated byCatarino and Mendes (2011) Several NF and RO membraneswere used in the first approach for removing ethanol in red wine from ca 12 vol% toc.7–8 vol% operating in a diafiltration (DF) mode NF membranes showed highereffectiveness in alcohol removal from wine, due to their good permeability to ethanoland high aroma compounds’ rejection, resulting in dealcoholized wine samples withpromising organoleptic properties

con-Selected NF membranes were used to obtain dealcoholized wines (up to c.5 vol%)that were blended with the original wine to produce reconstituted wine samples

A pervaporation (PV) unit was used to recover aroma compounds from the originalwine; the aroma extract (0.3 vol%) was added to the dealcoholized wine samplesimproving their aroma and taste profiles

Global results indicated that a combination of NF and PV membranes is effectivefor dealcoholizing wine and preserving its original characteristics

A two-stage process as a combination of RO and OD for wine dealcoholization wasdeveloped by the Australian enterprise Memstar and patented (Memstar, 2016) In thisprocess, the permeate alcohol from RO is withdrawn by OD and afterward is mixedagain with the RO retentate (Fig 13.4)

The food industry produces every year considerable amounts of solid and liquidwastes that mainly result from production, preparation, consumption, and disposalprocesses

The characteristics of a specific waste depend mainly on the product beingprocessed (e.g., fruit, vegetable, oils, dairy, meat, and fish) and the processingmethods Generally, these wastes contain large amount of macropollutants such as

biochemical (BOD) and chemical oxygen demand (COD) and suspended solids (SS),

in addition to nitrogen, phosphorous, pesticides, herbicides, and cleaning chemicals(Darlington et al., 2009)

The inadequate disposal of these wastes raises serious management problems, bothfrom the economic and environmental point of view (Mirabella et al., 2014).Industrial ecology concepts such as “cradle to cradle” are considered leading prin-ciple for eco-innovation, aiming at “zero-waste economy” where wastes are used asraw material for new products and applications (Lee and Okos, 2011) Indeed, foodwastes are considered promising sources of valuable compounds that can be extractedand recycled into the different food chains where their recovery may be economicallyattractive to the food processing industry (Schieber et al., 2001)

Several techniques are available for the treatment of food processing wastewaters;they can be categorized into physical and physicochemical, biological, and advancedtreatments Combinations of treatment technologies are often used to develop the mostcost-effective and environmentally acceptable solutions for waste management.Physical and physicochemical processes (screening, sedimentation, centrifugation,adsorption, etc.) are used as primary separation (as pretreatment) to remove suspendedsolids or other impurities; biological treatment processes (aerobic or anaerobic, acti-vated sludge, aerated lagoon treatment, etc.) are mainly devoted to the removal of sol-uble pollutants; sustainable treatments, including membrane technology, aim torecover the raw materials or to convert them into new products

In the last three decades, driven by economic factors, environmental concernand technological advancement, membrane technology has been playing a majorrole in attaining a zero level waste discharge in various industrial activities(Galanakis, 2012)

Water enriched with alcohol

Permeate

Wine

Water

RO permeate with depleted alcohol content

RO

OD

Fig 13.4 Combination of reverse osmosis (RO) and osmotic distillation (OD) for winedealcoholization (Memstar method)