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 BOD COD DCMD DF ED FO MBMR MCs MD ME MF MOD MWCO NF OD OMWs PA PES PP PS PTFE PV PVDF PVP RO TAA TE biocatalytic membrane reactor biochemical oxygen demand chemical oxygen demand direct contact membrane distillation diafiltration electrodialysis forward osmosis multiphase biocatalytic membrane reactor membrane contactors membrane distillation membrane emulsification microfiltration membrane osmotic distillation molecular weight cutoff manofiltration osmotic distillation olive mill wastewaters polyamide polyethersulfone polypropylene polysulfone polytetrafluoroethylene pervaporation polyvinyldifluoride polyvinylpyrrolidone reverse osmosis total antioxidant activity thermal evaporation Bioenergy Systems for the Future http://dx.doi.org/10.1016/B978-0-08-101031-0.00013-2 © 2017 Elsevier Ltd All rights reserved 13 452 TOC TSS UF VRF WPCs 13.1 Bioenergy Systems for the Future total organic carbon total soluble solids ultrafiltration volume reduction factor whey protein concentrates Introduction Membrane technologies are today very well-established tools in the food industry In this field, membrane filtration is the state-of-the-art technology for clarification, concentration, fractionation (separation of components), desalting, and purification of a variety of food products It is also applied to improve the food safety of products while avoiding heat treatment The global market for membrane technologies in the food industry is increasing at a compound annual growth rate of 6.7% between 2015 and 2020 In particular, the market of membranes in food and beverage processing was estimated at more than $4.0 billion 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 processing industry is mainly related to the advantages of these technologies in comparison with the traditional ones such as high selectivity, easy scale-up, modularity, low operating temperature with minimization of thermal damage, gentle product treatment, 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 the pressure-driven membrane processes including microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) Recently, other membrane technologies 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 conventional techniques (centrifugation, evaporation, solvent extraction, adsorption, etc.) found a large application in different areas of food production, including dairy, fruit juice and pulp production, beer and wine, beet and cane sugar, meat, and water and wastewaters (Fig 13.1) The implementation of hybrid-membrane-based processes in these areas permits to rationalize both direct and indirect energy consumptions, with improved product quality, process capacity, and selectivity and decreased equipment size/ production-capacity ratio and waste production so resulting in cheaper and sustainable technical solutions (Drioli and Romano, 2001) In this chapter, specific applications of integrated membrane processes for improving the quality of agrofood products (i.e., fruit juices and wine) and the recovery of high-added value compounds from agrofood by-products are presented and discussed highlighting their key advantages over conventional technologies Integration of membrane technologies into conventional existing systems in the food industry Fig 13.1 Applications of membrane processes in the food industry Beet and cane sugar Dairy 453 Meat Membranes in food processing industry Fruit juices and pulps production Water and wastewater treatment Beer and wine 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 that are practical and ready to be consumed The implementation of membrane filtration processes in the manufacture of fruit juices represents one of the technological answers to the problem of producing additive-free juices with standard organoleptic quality and natural fresh taste In particular, juice clarification, stabilization, depectinization, and concentration are typical steps in which membrane processes such as MF, UF, NF, RO, and membrane distillation (MD) have been successfully utilized (Cassano et al., 2007a) In fruit juice production, a clarification step is needed to prevent the haze formation during storage; on the other hand, the juice’s clear appearance is a determinant factor for consumers In addition, the removal of suspended solids is a necessary pretreatment in order to increase the efficiency of posttreatments such as bitterness, tartness, and acid removal with adsorbent resins or concentration with membrane technologies Conventional clarification processes typically involve the addition of fining agents such as gelatin and bentonite Gelatin is positively charged at the low pH range of fruit juices and reacts with negatively charged phenolics such as tannin species The main effect of bentonite on clarification depends on its adsorption capacity, mainly proteins MF and UF processes represent a valid alternative to the traditional clarification and stabilization methodologies, resulting in increased juice yield, improved product quality and possibility to avoid fining agents and filter aids leading to the minimization of 454 Bioenergy Systems for the Future 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 the equipment 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 UF and MF membranes and their impact on the juice composition in comparison with traditional technologies have been reported in literature UF processes have been investigated 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, and tangerine) (Vaillant et al., 2001), bottle gourd (Biswas et al., 2016), and red raspberry (Vladisavljevic et al., 2013) juices The potential of these processes for the better preservation 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) with time (t) that reduces the process efficiency This phenomenon is caused by the accumulation of macromolecular or colloidal species (such as pectins and proteins) on the membrane surface (concentration polarization and gel layer) or by physicochemical interactions with the membrane such as adsorption on the membrane pore walls and pore plugging (membrane fouling) (Cassano et al., 2007b) Membrane fouling decreases itself, permeate flux, and membrane longevity; therefore, it is a key factor affecting the economic and commercial viability of a membrane system (Baker, 2000) Several approaches have been proposed to minimize membrane fouling mechanisms including the optimization of operating conditions, the pretreatment of the feed solution, and the selection of appropriate membranes (in terms of molecular weight cutoff, morphology, and hydrophobicity/hydrophilicity) Among these available approaches, the optimization of operating and fluid dynamic conditions such as temperature, transmembrane pressure, and cross flow velocity in the clarification of fruit juices 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 the concentration 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 volume and consequently to minimize handling, packaging, and transportation costs The increased concentration of soluble solids leads also to a higher resistance to microbial and chemical as a result of water activity reduction The industrial concentration of fruit juices is usually performed by multistage vacuum evaporation at high temperature, followed by recovery and concentration of volatile flavors and their addition back to the concentrated product This technique results in degradation of thermosensitive compounds and loss of valuable compounds (e.g., aroma and antioxidant compounds) with a significant reduction of the final product quality (Onsekizoglu, 2015) Integration of membrane technologies into conventional existing systems in the food industry 455 Membrane operations such as UF, NF, RO, and MD can be considered today a valid alternative to thermal concentration of fruit juices and natural extracts (Cisse et al., 2011) These processes offer several advantages in terms of preservation of nutritional and sensorial compounds since they can operate at moderate temperature and pressure conditions Pressure-driven membrane operations, such as UF, NF, and RO have been largely investigated, also in integrated systems, for the clarification and concentration of different types of fruit juices An integrated process UF/RO was studied by Echavarria et al (2012) for the clarification and concentration of peach, pear apple, and mandarin juices The depectinized juices were at first clarified with a polysulfone (PS) UF membrane in tubular configuration with a molecular weight cutoff (MWCO) of kDa; the clarified 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 permeate flux and product quality Gunathilake et al (2014) studied the RO process for the concentration of bioactive compounds in cranberry, blueberry, and apple juices by using a Dow Filmtec BW302540 RO membrane (Dow Chemical Company, Minnesota, the United States) The effects of the processing parameters on physicochemical and antioxidant properties of the concentrated juices were also analyzed Results showed that the antioxidant capacity 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 efficient tool for enhancing the health-promoting properties of fruit juices The concentration of bioactive compounds in watermelon by cross flow NF membranes was evaluated by Arriola et al (2014) by using an HL2521TF membrane from GE Osmonics (Minnetonka, the United States) Most of bioactive compounds were concentrated 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 pressure that 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 the value obtained by thermal evaporation This suggests the implementation of integrated processes in which RO is used as a preconcentration step before a final concentration with other technologies (freeze concentration, thermal evaporation, and osmotic distillation) Technological advances related to the development of new membranes and improvements in process engineering have been proved to overcome these limitations New membrane processes including osmotic distillation (OD) and MD have attracted attention for the production of concentrated juices at high concentration level under atmospheric pressure and low temperature ( Jiao et al., 2004) The OD process is based on the use of hydrophobic macroporous membranes separating two liquid phases that differ greatly in terms of solute concentration The hydrophobic nature of the membrane prevents penetration of the pores by aqueous solutions, creating air gaps within the membrane The difference in solute 456 Bioenergy Systems for the Future concentration, and consequently in water activity between the two sides of the membrane, induces a vapor pressure difference causing a water vapor transfer across the pores from the high-vapor pressure phase to the low one (Nagaraj et al., 2006) This migration of water vapor results in the concentration of the feed solution and the dilution of the osmotic agent The typical OD process involves the use of a concentrated brine at the downstream side of the membrane as a stripping solution A number of salts such as MgSO4, CaCl2, and K2HPO4 are suitable Similarly to OD, in MD, two aqueous solutions at different temperatures are separated by a macroporous hydrophobic membrane Due to the hydrophobicity of the membrane material, the liquid water cannot enter the pores, and a liquid interface 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 takes place at atmospheric pressure and at a temperature that may be much lower than the boiling point of the solutions The driving force is a vapor pressure difference between the two solutions—membrane interfaces due to the existing temperature gradient The integration of pressure-driven membrane processes with OD and MD as alternative to the conventional juice processing systems has been largely investigated An integrated process or the clarification and concentration of pomegranate juice based on the use of UF and OD processes was investigated by Cassano et al (2011) Fresh pomegranate juice, was at first, clarified by modified poly(ether-etherketone) 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  in membrane contactor (Membrana, Charlotte, the United States) containing macroporous polypropylene (PP) hollow fibers (having external and internal diameters of 300 and 220 μm, respectively) with an average pore diameter of 0.2 μm and a total membrane surface area of 1.4 m2 Calcium chloride dehydrate at 60% w/w was used as brine solution The UF process produced a very clear juice depleted of total suspended solids and with physicochemical and nutritional properties similar to those of the fresh fruit The concentrated 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 retentate was only 4% lower than the TAA of the clarified juice confirming the particular mildness 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 was investigated by Onsekizoglu (2013) The process involved a preliminary clarification of pomegranate juice with a combination of fining agents and UF The clarified fraction with an initial TSS of 17°Bx was concentrated up to 54–56°Bx MD and OD processes resulted very efficient in maintaining the original characteristics of the fresh juice in terms of pH, total acidity, color, antioxidant activity, total polyphenol, total monomeric anthocyanins, and organic acids On the other hand, the concentration by TE produced a significant loss of TAA and color and the formation of a Integration of membrane technologies into conventional existing systems in the food industry 457 hydroxymethylfurfural (HMF), an important intermediate of Maillard reactions widely used as an indicator of thermal exposure The coupled operation of MD and OD resulted as the most feasible approach for the concentration of pomegranate juice, allowing to reach higher concentration levels in shorter periods of operation time with a slight increase (5°C) in temperature of the juice in comparison with OD A similar approach was studied for the concentration of cornelian cherry fruit juice (Belafi-Bako´ and Boo´r, 2011) The raw juice, after a preliminary clarification with a polyethersulfone (PES) UF membrane, was concentrated by combining MD and OD (the process is also defined as membrane osmotic distillation, MOD) The clarified juice was concentrated by using a membrane contactor containing 34 polypropylene capillary membranes (Microdyn-Nadir, Wiesbaden, Germany) with a total effective internal area of 68 cm2, nominal pore size of 0.2 μm, 70% porosity, 0.8 mm outer and 0.6 mm inner diameter, thickness of 0.2 mm, and a length of 80 mm A M of calcium chloride dihydrate solution was used as stripping solution; temperature was 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, the antioxidant capacity and the total phenol and anthocyanin content of the juice were preserved, and thermal degradation was avoided An integrated process for the clarification and concentration of blood orange juice was proposed by Quist-Jensen et al (2016) In this approach, the raw juice was previously clarified by UF; the clarified juice, with an initial TSS content of 9.5°Bx, was concentrated up to 65°Bx through a two-step direct contact membrane distillation (DCMD) process by using a laboratory bench plant equipped with two polypropylene hollow fiber membrane modules (Enka Microdyn MD-020-2 N-CP) having a nominal pore size of 0.2 μm and a membrane surface area of 0.1 m2 In Table 13.1, the analytic properties of clarified and concentrated fractions are reported Suspended solids of the original juice were completely removed by the UF membrane with a production of a clear juice with a brilliant red color Flavonoids and polyphenols were recovered in the UF permeate, and the antioxidant activity of the clarified juice was very well preserved The concentration process did not induce significant changes in these components Indeed, the content of polyphenols and TSS in the final retentate was similar to that of the UF permeate Similarly, the final MD retentate at 65°Bx still showed a high TAA value (about 6.6 mM Trolox) when compared with the raw juice and the UF permeate (6.52 and 6.40 mM Trolox, respectively), confirming the validity of the process in preserving the original quality of the fresh juice An integrated membrane process for the clarification and concentration of blood orange juice was also investigated by Galaverna et al (2008) The integrated system consisted of an initial clarification of the raw juice by UF in order to remove suspended solids and to separate the liquid serum for the pulp Afterward, the clarified juice was preconcentrated by RO up to 25–30°Bx The final concentration up to 60°Bx was carried out by OD A direct concentration by OD of the clarified juice was also 458 General composition of blood orange juice clarified and concentrated by integrated membrane process Table 13.1 Total soluble solids (°Bx) Naringin (mg/L) Hesperidin (mg/L) Narirutin (mg/L) Total polyphenols (GAE) Total antioxidant activity (mM Trolox) Raw juice Clarified juice UF retentate MD retentate (preconcentration) MD retentate (concentration) – 5.32 Ỉ 0.085 116.0 Ỉ 0.71 26.8 Ỉ 0.64 610.0 Ỉ 0.35 6.52 Ỉ 1.2 9.5 Ỉ 0.095 5.12 Ỉ 0.026 112.37 Æ 2.46 25.7 Æ 0.42 606.0 Æ 0.12 6.40 Æ 0.8 – 6.12 Ỉ 0.24 117.09 Ỉ 2.57 28.33 Ỉ 1.57 810 Ỉ 3.2 8.53 Ỉ 0.4 24.0 Ỉ 0.24 5.51 Ỉ 0.67a 117.11 Ỉ 0.28a 26.0 Ỉ 1.15a 716 Æ 0.45a 6.2 Æ 0.2a 65.0 Æ 0.65 5.72 Æ 0.46a 115.24 Ỉ 2.25a 25.52 Ỉ 0.12a 725 Ỉ 2.45a 6.6 Ỉ 0.5a Bioenergy Systems for the Future UF, ultrafiltration; MD, membrane distillation a Values referred to a TSS content of 9.5°Bx Integration of membrane technologies into conventional existing systems in the food industry 459 Determination of TAA and ascorbic acid content in samples of cactus pear and kiwifruit juices clarified and concentrated by integrated membrane process Table 13.2 Fruit juice Sample TSS (°Bx) Ascorbic acid (mg/L) TAA (mM Trolox) Cactus pear Raw juice UF permeate OD retentate Raw juice UF permeate OD retentate 13.4 13.0 58.0 12.5 9.4 66.6 39.3 37.3 36.0a 696 693 696b 4.8 4.6a 16.0 15.3 14.1b Kiwifruit 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 investigated The concentrated fractions presented a decrease of about 15% of the initial TAA due to the partial decrease of ascorbic acid and flavonoids On the contrary, 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 a pleasant aroma that were completely lost in the thermal treatment Integrated UF/OD processes for the clarification and concentration of kiwifruit and cactus pear juices were also investigated (Cassano et al., 2004, 2007a) In these processes the concentration step was performed by using a Liqui-Cel Extra-Flow 2.5  in membrane contactor As reported in Table 13.2, the content of ascorbic acid and the antioxidant activity of both juices were very well preserved during the membrane treatment The OD retentate fractions were considered a good source of bioactive 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 and concentration of fruit juices is illustrated in Fig 13.2 The process includes a preconcentration step based on the use of RO membranes followed by a final concentration 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 microorganisms and then added in adequate proportions to the concentrated juice 13.3 Wine processing 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 a production of 48.9 mhL followed by France (47.4 mhL), Spain (36.6 mhL), the United States (22.1 mhL), Argentine (13.4 mhL), and Chile (12.87 mhL) (Organisation Internationale de la Vigne et du Vin, 2015) 460 Bioenergy Systems for the Future Pulp Raw juice Clarified juice UF Preconcentrated juice Permeate RO Diluted brine Concentrated brine OD Concentrated juice Fig 13.2 Integrated membrane process for the clarification and concentration of fruit juices The winemaking process includes several unit operations (pressing, decanting, filtration, and bottling) and processes (alcoholic and malolactic fermentations) that convert grapes into wine The crude wine is a very complex solution with numerous solutes (organic acids, salts, and polyphenols), macromolecules and colloidal particles, microorganisms, yeasts, and large particles as potassium hydrogen tartrate In addition, it presents a turbid aspect that is not very well accepted by consumers, and usually, it needs to be clarified Traditional clarification processes involve centrifugation, dead-end filtration (filter presses, filtration on sheets, and diatomaceous earth filtration), and the use of exogenic additives Diatomaceous earth used for traditional filtration has a negative impact on the environment It is difficult to handle and thus represents a potential health hazard Also, it needs to be properly disposed after usage and involves additional filtration steps and disposal costs (Cook et al., 2005) Membrane processes for wine treatment are considered an emerging and valid alternative to traditional technology (Daufin et al., 2001; Galanakis et al., 2013) In particular, cross flow MF and UF are widely used in winemaking industry as clarification and microbiological stabilization techniques They offer several advantages over traditional processes such as elimination of filter aids and their associated environmental 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 flux decay over time caused by the accumulation of wine compounds in the pores (membrane fouling) and on the membrane surface (concentration polarization and gel formation) These phenomena lead not only to a reduction of the membrane productivity so affecting the economic viability of the process but also to a possible retention of some components with a loss of organoleptic characteristics (Czekaj et al., 2001) The mechanism of membrane fouling and the methods to control or limit it have been largely investigated Particularly, these studies have been addressed to the selection of the most suitable membranes (in terms of membrane material, configuration, and pore Integration of membrane technologies into conventional existing systems in the food industry 465 Pressure-driven membrane operations, such as MF, UF, NF, and RO, are wellknown established technologies for the treatment of high-strength wastewaters aimed at the production of purified water for recycle or reuse and the recovery of valuable compounds The integration of membrane unit operations with conventional systems or with other membrane processes in the treatment of wastewaters from food processing industries has been widely studied (Mudimu et al., 2012; Ochando-Pulido and Martinez-Ferez, 2015) Typical applications in the field of olive oil extraction, citrus juice, artichoke, and milk processing are reported in the following 13.4.1 Olive mill wastewaters The olive oil extraction is a water-intensive process that generates a huge quantity of polluted effluents commonly referred to as olive mill wastewaters (OMWs) OMWs are dark liquid effluents characterized by high concentrations of organic compounds, including organic acids, sugars, tannins, pectins, and phenolic substances that make them phytotoxic and inhibit bacterial activity OMWs are notoriously rich in polyphenols including benzoic acid and hydroxycinnamic acid derivatives and, in larger amounts, tyrosol and hydroxytyrosol Although to different extents, these compounds are characterized by antioxidant activity and are, therefore, of great interest to the cosmetic and pharmaceutical industries and in food processing and food product conservation (Lozano-Sa´nchez et al., 2011) Membrane operations represent promising technologies for the recovery of water, organic compounds, and antioxidants from OMWs (Takac¸ and Karakaya, 2009) MF and UF processes are used mainly for primary purposes, while NF and RO are used for final treatment (Galanakis et al., 2010; Zirehpour et al., 2012) These processes, mostly, in a sequential form or combined with other separation technologies, successfully meet the requirement for the recovery, purification, and concentration of antioxidants with regard to their specific MWCO values Suspended solids of raw OMWs can be removed by centrifugation The UF treatment of the centrifuged supernatant with a flat-sheet PES membrane of 17 kDa allows a complete separation of fats, completely rejected by the membrane, from salts, sugars, and polyphenols, contained in the permeate A COD reduction of about 90% is reached through the combination of both processes (Turano et al., 2002) Paraskeva et al (2007) investigated a combination of UF and NF or RO membranes for a complete fractionation of OMWs Raw wastewaters were prefiltered with a PP screen (80 μm) and then ultrafiltered by using multichannel ceramic membranes with pore sizes of 100 nm The UF process produced a separation of high-molecular-weight constituents including fats, lipids, and suspended solid particles The following NF treatment of the UF permeate with spiral-wound polymeric membranes (MWCO 200 Da) produced a concentrated stream containing more than 95% of phenolic compounds of the initial value A better efficiency of the OMWs treatment was achieved by applying RO (spiral-wound membrane modules 100 MWCO) after UF Permeate fractions from NF and RO treatments exhibited quality characteristics to be 466 Bioenergy Systems for the Future discharged in aquatic systems according to EU regulations or to be reused for irrigation (75%–80% of the initial volume) A membrane-based process for the selective fractionation and total recovery of polyphenols, water, and organic substances from OMWs was investigated by Russo (2007) Before membrane-filtering processes, OMWs were acidified with hydrochloric acid and citric acid from pH 5.5 to 3.5 to prevent phenols oxidation The acidified waters were at first prefiltered by MF and then submitted to the UF treatment Productivity, fouling, and cleaning of membranes with different pore size and MWCO and material and configuration were compared A final concentration step of the UF permeate was performed by RO Among the different processes investigated, the MF process was considered as a critical step for the selective separation of OMWs due to the rapid decrease of the permeate flux, low cleaning efficiency of ceramic membranes, and irreversible fouling of polymeric ones The integration of UF and NF membranes for the recovery of water and bioactive compounds from OMWs was investigated by Cassano et al (2013a) The initial UF step was devoted to the removal of suspended solids from the raw OMWW It was performed by using a hollow fiber membrane module (HFS, Toray) with a nominal pore size of 0.02 μm Afterward, the UF permeate was fed to a UF unit equipped with a flat-sheet membrane having a MWCO of 1000 Da (Etna 01 PP, Alfa Laval) The UF permeate was finally concentrated by using a spiral-wound NF membrane (NF90, Filmtec, Dow) The UF membranes showed rejections of about 26% and 31% toward polyphenols; for the NF membrane, the rejection was of about 93% These results were in agreement with the evaluation of TAA In addition, the NF membrane showed a complete retention of low-molecular-weight polyphenols; this result was in agreement with the estimated MWCO of the membrane (200 Da) and the MW of the analyzed compounds (138–284 g/mol) Therefore, the treatment of the UF permeate by NF allowed to produce a permeate stream depleted in phenolic compounds This fraction could be reused as process water in the olive oil extraction process or for membrane cleaning The NF retentate enriched in phenolic compounds is suitable for cosmetic, food, and pharmaceutical industries as liquid, frozen, dried, or lyophilized formulations A third fraction containing organic substances at high molecular weight (retentate of both UF processes), depleted of polyphenolic compounds by DF, could be submitted to an anaerobic digestion for the production of biogas In Table 13.3, the evaluation of total organic carbon (TOC), TAA, total polyphenols, and low-molecular-weight polyphenols in samples of OMWs treated by the integrated UF/NF process is reported A general process scheme for the treatment of OMWs based on the use of pressuredriven membrane operations is depicted in Fig 13.5 In addition to conventional pressure-driven membrane operations, OD, MD, membrane emulsification (ME), and biocatalytic membrane reactor (BMR) have emerged as new technologies with great potential in OMWs treatment (El-Abbassi et al., 2013; Gebreyohannes et al., 2016) In the approach investigated by Garcia-Castello et al (2010), MF and NF membranes were combined with OD or vacuum (VMD) in order to recover valuable compounds from OMWs Raw wastewaters were pretreated by Integration of membrane technologies into conventional existing systems in the food industry 467 Analyses of TOC, TAA, total polyphenols and low molecular weight polyphenols in samples of OMWWs treated by integrated UF/NF process Table 13.3 Membrane type UF (0.02 μm) UF (1000 Da) NF (200 Da) Sample TOC (g/L) TAA (mg/L Trolox) Total polyphenols (mg/L gallic acid) Feed Permeate Retentate Feed Permeate Retentate Feed Permeate Retentate 13.4 8.9 21.3 9.0 2.5 13.1 2.8 0.095 7.9 3000 2750 3850 2965 1750 4075 1825 125 2175 1409 1033 1578 960.8 654.6 1236 627.4 43.3 960.1 Lowmolecularweight polyphenols (mg/L) 81.3 79.5 81.3 75.5 62.2 77.4 65.6 – 86.2 Formulations for food, cosmetic and phytoterapic industry Anaerobic digestion Purification Organic fractions Phenolic fractions OMWs Pretreatment MF UF NF RO Purified water Fig 13.5 Combination of pressure-drive membrane operations in the treatment of olive mill wastewaters MF by using a tubular Al2O3 membrane with a pore size of 200 nm This step produced a reduction of suspended solids and total organic carbon (TOC) of 91% and 26%, respectively Moreover, 78% of the initial content of polyphenols was recovered in the permeate stream The MF permeate was treated by NF by using a PES spiral-wound membrane (Nadir N30F); in this step, TOC was reduced from 15 to 5.6 g/L, and almost all polyphenols were recovered in the permeate stream The NF permeate was finally concentrated by OD by using a Liqui-Cel Extra-Flow 2.5  in membrane contactor and calcium chloride dihydrate as stripping solution The final solution contained about 468 Bioenergy Systems for the Future 0.5 g/L of free low-molecular-weight polyphenols, with hydroxytyrosol representing 56% of the total content In the process developed by Conidi et al (2014a), MF and UF membranes in flatsheet configurations were coupled with a multiphase biocatalytic membrane reactor (MBMR) for the selectively recovery of biophenols from OMWs In the pretreatment step, a selected MF membrane (cellulose acetate with pore size of 0.2 μm) was used in order to remove all the suspended solids in the raw wastewater The MF permeate was then processed by a PES UF membrane with a MWCO of 10 kDa In both MF and UF processes, bioactive compounds were recovered in the permeate streams due to the low retention of the membranes toward these components (in the UF permeate, oleuropein was the most represented low-molecular-weight-phenolic compound) In the last step, oleuropein was converted to oleuropein aglycone by β-glucosidase immobilized in the polymeric membrane of the MBMR; the isomer of oleuropein aglycone was isolated from the phenolic fraction in the organic phase An aqueous phase containing water-soluble biophenols was also produced The maximum oleuropein conversion reached was about 45.7%, and the reaction rate was of about  10À4 mmol/min cm3 13.4.2 Artichoke wastewaters The artichoke (Cynara scolymus L.) processing industry generates large amounts of agricultural solid wastes (leaves, stems, and bracts of the artichoke plant) and wastewaters These wastes are considered a rich source of bioactive phenolic compounds (with mono- and dicaffeoylquinic acids being the major components) and also inulin, fibers, and minerals (Lattanzio et al., 2009; Llorach et al., 2002; Zuorro et al., 2016) Due to these characteristics, artichoke by-products represent a very useful source of high-added value compounds of potential interest as food additives and nutraceuticals The use of membrane technology for the recovery of bioactive compounds from artichoke by-products has been recently investigated as alternative to conventional technologies In the process developed by Conidi et al (2014b), artichoke wastewaters were fractionated on laboratory scale by using UF and NF membranes In the first step, the raw wastewater was ultrafiltered by using a PES hollow fiber membrane module (DCQ III-006C, China Blue Star Membrane Technology) with an MWCO of 50 kDa in order to produce a clear solution depleted in suspended solids The UF permeate was then processed by two different NF membranes in spiral-wound configuration (NP030, PES, 400 Da from Mycrodin Nadir and Desal DL, cross-linked aromatic polyamide, 150–300 Da, from GE Water & Process As reported in Fig 13.6, both membranes showed a high rejection toward the analyzed phenolic compounds (chlorogenic acid, cynarin, and apigenin 7-O-glucoside) and total antioxidant activity (TAA) A different behavior was observed for sugar compounds; the permeate produced with the Desal DL membrane was completely depleted in glucose, fructose, and sucrose due to the high retention measured (100%); on the other hand, most of these compounds can be recovered in the permeate stream of the NP030 membrane (the observed retention was in the range of 3.4%–5.5%) Integration of membrane technologies into conventional existing systems in the food industry 469 Desal DL NP030 100 Rjection (%) 80 60 40 20 Glu Fru Suc Cyn Chl Api TAA Fig 13.6 Rejections of NF membranes toward sugars and phenolic compounds (glu, glucose; fru, fructose; suc, sucrose; chl, chlorogenic acid; cyn, cynarin; api, apigenin 7-O-glucoside; TAA, total antioxidant activity) According to the experimental results, a conceptual process design for the fractionation of artichoke wastewaters was proposed In this process, the UF permeate is firstly treated by a 400 Da NF membrane producing a retentate fraction enriched in phenolic compounds of potential interest for nutraceutical, cosmeceutical, or food applications The NF permeate is then processed a with a 200 Da NF membrane producing a retentate fraction enriched in sugar compounds of interest for food applications and a clear permeate reusable as process water or for membrane cleaning The selective purification of phenolic compounds from artichoke wastewaters has been also recently investigated through the integration of membrane operations and polymeric resins (Conidi et al., 2015b) In this approach, artichoke wastewaters coming from the blenching step were previously clarified by UF with a 15 kDa tubular membrane in TiO2 (Tami Industries, Nyons, France); the clarified fraction depleted in suspended solids and macromolecular compounds was concentrated by a spiralwound NF membrane in polyamide with a MWCO in the range of 200–300 Da (NF270, Dow Filmtec, the United States) The retentate fraction, enriched in polyphenols and sugars, was submitted to an adsorption/desorption treatment by using three different macroporous resins based on polystyrene (Lewatit S 6328 A, Lewatit S 2328, and Lewatit S 7968, from Lanxess Leverkusen, Germany) in order to purify phenolic compounds from sugars The S-7968 resin offered the best total adsorption/desorption yield for chlorogenic acid (63.39%); for the apigenin 7-O-glucoside, S 7968 and S 2328 resins showed a total adsorption/desorption yield in the range of 68.31%– 78.45% Results indicated that the integration of membrane processes with adsorbents produces a more purified fractions of phenolic compounds when compared with an integrated system fully based on the use of membrane operations 470 Bioenergy Systems for the Future Suspedended solids, macromolecular compounds NF Ethanol Desorption UF Adsorption NF retentate Artichoke wastewaters Sugars Polyphenols Fig 13.7 Purification of polyphenols from artichoke wastewaters by combination of membrane operations and polymeric resins The general scheme of the proposed process is illustrated in Fig 13.7 The production of canned artichoke is based on the use of acidulated brines (pH lower than 4.6) in order to limit the growth of Clostridium botulinum The management of exhausted brines represents a serious environmental problem for the artichoke processing industry that must withstand high treatment costs and disposal Artichoke brines, after a preliminary UF step, were processed with different spiralwound NF membranes in order to identify a suitable protocol for the purification of bioactive compounds from salts Selected membranes were evaluated for their productivity and selectivity toward the compounds of interest (Cassano et al., 2016) Experimental results revealed that membranes with a MWCO of 200 Da (FilmtecDow NF 200 and Desal DL membranes) are able to separate caffeoylquinic acid from salt compounds Indeed, these membranes showed low retention toward dry residues (in the range of 14%–18%), while retentions toward phenolic compounds were higher than 92% The NF permeate with low amounts of caffeoylquinic acids can be reused in the processing cycle, after the adjustment of the standard salt concentration; on the other hand, the NF retentate enriched in bioactive compounds is of interest for the production of functional foods or pharmaceutical formulations Prebiotic sugars have been recently purified and concentrated from artichoke extracts by using a sequential combination of MF and NF on laboratory scale (Machado et al., 2016) PES MF membranes with a pore size of 0.05 μm presented the lowest flux decline and were able to clarify the extract with a recovery of the total content of prebiotic sugars in the permeate stream NF polyamide membranes with a MWCO of 150–300 Da exhibited high retention toward oligosaccharides producing a concentrated fraction of interest for foodstuff applications 13.4.3 Citrus by-products The citrus juice processing is accompanied by the production of large amounts of by-products such as peels and seed residues that may account for up to 50% of the total fruit weight Most of the waste residue from commercial juice extractors is Integration of membrane technologies into conventional existing systems in the food industry 471 shredded, limed, cured, and pressed into press liquors and press cakes that are then processed independently Press liquors are a complex mixture containing soluble sugars (sucrose, glucose, and fructose), insoluble carbohydrates, fibers, organic acids, essential oils, flavonoids, and carotenoids Among these compounds flavonoids and phenolic acids have been recognized for their beneficial implications in human health due to their antioxidant activity (Bocco et al., 1998) Therefore, methodologies able to convert the potential of these wastes into profitable products and to offset the disposal costs are of great interest for both producers and consumers The recovery and concentration of flavonoids from orange press liquor by using a combination of membrane operations such as UF, NF, and OD was investigated by Cassano et al (2014) The UF pretreatment produced a removal of suspended solids from the raw press liquor, while flavonoids and anthocyanins were recovered in the clarified liquor (rejections toward flavanones and anthocyanins were lower than 1%) The clarified liquor with a TSS content of 10°Bx was preconcentrated by nanofiltration (NF) up to 32°Bx by using a PES spiral-wound membrane (NF-PES 10, 2440 C, Microdyn-Nadir, Germany) The NF process was operated at bar and 20°C according to a batch concentration mode up to reach a volume reduction factor (VRF) of The NF process produced concentrated extracts enriched of bioactive compounds due to the high rejection measured (rejections in the range of 97.4% and 98.9% toward flavanones and anthocyanins, respectively) Moreover, the ratio between flavanones and anthocyanins decreased by increasing the VRF This result allows to balance the flavonoid content in relation to that of the anthocyanins and, consequently, to modify the characteristics of the final product in terms of bittering capacity (for the presence of flavonoids) and coloring power (for the presence of anthocyanins) The NF retentate was concentrated by OD up to 47°Bx operating in conditions of low mechanical and thermal damage The concentration factor of anthocyanins in the final OD retentate was in agreement with that of the TSS content due to water removal A lower concentration factor observed for flavanones was attributed to the adsorption phenomena of these compounds on the NF membrane The production of bergamot is a flagship product of Calabrian agriculture, and its volatile fraction is still used in the cosmetic and perfumery industries The juice because of its bitter taste has not found a real use in the food industry, and it is considered a waste of the essential oil production However, its beneficial properties have been widely recognized and attributed to the presence of phenolic compounds, especially in terms of flavonoids such as naringin, hesperidin, neohesperidin, neoeriocitrin, brutieridin, and melitidin (Mandalari et al., 2006; Pernice et al., 2009) Membrane processes in sequential design have been investigated to produce concentrated extracts enriched in bioactive compounds from bergamot juice An integrated process based on the use of UF and OD was investigated on laboratory scale by Cassano et al (2013b) The depectinized juice was clarified by using a UF hollow fiber membrane module (PS, 100 kDa, China Blue Star Membrane Technology Co Ltd., China) in optimized operating conditions; the clarified juice was then concentrated by OD by using a Liqui-Cel Extra-Flow 2.5  in membrane contactor and calcium chloride dehydrate at 60% w/w as stripping solution The clarified juice 472 Bioenergy Systems for the Future with an initial TSS content of 9.5°Bx was concentrated up to 54.0°Bx Ascorbic acid and flavonoids were well preserved during the OD process, and their content remained unchanged independently by the TSS content of the juice A slight decrease of the TAA (about 5.4%) was observed in the concentrated juice in comparison to the clarified juice confirming the particular mildness of the treatment The concentrated juice fraction is of interest for the formulation of anticholesterolemic products due to the presence of neohesperidosides of hesperetin and naringenin that exhibit statin-like properties (Di Donna et al., 2009) In a previous study, the clarified juice was processed with a UF membrane (Etna 01PP, flat-sheet fluoropolymer, 1000 Da, Alfa Laval) and two different ceramic NF membranes (monotubular TiO2 membranes, 750 and 450 Da, Inopor) in order to evaluate the effect of the MWCO on the rejection of the membranes toward sugars, organic acids, and polyphenols (Conidi et al., 2011) According with the obtained results, the best separation of polyphenols from sugars occurred with the 450 Da membrane This membrane showed high rejection toward flavonoids and moderate rejection toward sugars (around 52% of sugars were recovered on the permeate side) An integration of conventional technologies and membrane operations in citrus processing is depicted in Fig 13.8 Fruit Fresh or thawed Peel Cleaning/washing Milling Sorting/culling Preheater Juice extraction Pressing-decanting Enzymatic treatment Cloudy juice Coarse filtering centrifuging Oil removal UF Water-oil Press liquor Pasteurization Separation Clarified juice Or equivalent nonthermal treatment Brine Diluted brine UF Desludging Filling and storage (Single strength juice) OD Polishing NF Concentrated juice Essential oil Pasteurization Enriched phenolic solution Sugars, minerals Filling and storage Fig 13.8 Integration of conventional technologies and membrane operations in citrus processing Integration of membrane technologies into conventional existing systems in the food industry 473 13.4.4 Dairy by-products Membrane technology has been applied in the dairy industry since the early 1960s as viable alternatives for more traditional dairy processes like distillation, evaporation, or extraction About two-thirds of the membrane area installed in the dairy industry is used for the treatment of whey and about one-third for milk (Saxena et al., 2009) Pressure-driven membrane operations are largely used for milk clarification, fractionation, and concentration and for the separation of the specific valuable components from milk or dairy by-products showing improved separation capabilities when compared with traditional technologies (Kumar et al., 2013) Whey is a by-product of the cheese industry with a low content of solids (up to 5%–6%) and high biological oxygen demand (BOD5 ¼ 30–50 g/L for 1000 L of whey) that make difficult and costly its disposal Whey concentration, fractionation, demineralization, and purification can be achieved by using a combination of different pressure-driven membrane processes At the same time, the development of high-value-added products from whey compounds is of great interest (CuartasUribe et al., 2009) MF membranes can be used to produce defatted whey in order to reduce membrane fouling in the following UF step during the manufacture of whey protein concentrates (WPCs) Lipoproteins tend to form aggregates through calcium bridging when subjected to moderate heat treatment and then aggregates can be removed with MF membranes having a pore size of 0.14 μm The MF process exhibits a higher defatting efficiency when compared with centrifugation and allows also a significant removal of bacteria UF membranes are used for the production of whey protein concentrates (WPCs) and their separation from lactose and minerals In order to increase the purification of whey proteins from these components, the UF process is combined with a DF step in which water is continually added to the retentate, while lactose and minerals are recovered in the UF permeate In particular, the protein content of WPCs can be modified in the range of 35%–85% through a proper combination of UF and DF WPCs are used in food industry for their ability to improve the functional properties (emulsifying, foaming, and gelling) of the food products or to fortify baby foods, health foods, and beverages (Zydney, 1998) The concentration of whey or its partial demineralization can be achieved by NF + NF membranes retain larger ions such as Ca2+ or PO3À allowing univalent ions (Na , + À K , and Cl ) to pass through Desalination degrees up to 40% can be achieved through a combination of NF with DF Therefore, the NF treatment of the UF permeate allows to recover lactose in the retentate stream together with a partial demineralization Finally, mineral salts can be concentrated by RO membranes with a simultaneous production of purified water Atra et al (2005) evaluated the potential of UF and NF membranes in the fractionation of whey for the recovery of valuable components The UF of whey was performed by using a polyvinyldifluoride (PVDF) flat-sheet membrane with a MWCO of 6–8 kDa (FS10, Zoltek Rt MAVIBRAN) The protein rejection was of 93%–98% at 474 Bioenergy Systems for the Future higher transmembrane pressures (3 and bar) and lower at low pressure (1 bar) The permeate flux of whey increased by increasing the operating pressure Similarly, higher cross flow velocities produced an increasing of permeate flux due to a decrease in the deposit layer resistance Permeate flux increased by increasing the operating temperature until 50°C, where the viscosity of the processed whey reaches its minimum value (higher temperatures were not evaluated since they can cause heat denaturation of whey proteins) The concentrated whey with a protein content of 8%–10% can be introduced into the cheese production in order to improve its nutritional value and increase the economic effect The whey permeate was processed by using a NF spiral-wound membrane in PA (RA55, Millipore) The MWCO of the membrane of about 400 Da allowed to reject the lactose molecules, which are smaller than proteins Permeate fluxes at 20 bar were of the order of 40 L/m2h The lactose yield decreased by increasing the operating temperature as the result of lower lactose retention of the NF membrane at higher temperature By selecting proper operation parameters (temperature, 30°C, VRF, 5), a lactose yield higher than 90% could be achieved The NF permeate contained only 0.1%–0.3% lactose, which makes possible its reuse for other purposes (cleaning and irrigation) or its discharging directly into the sewer A combination of different UF, NF, and RO spiral-wound membrane modules in the treatment of white and curd cheese whey was investigated by Yorgun et al (2008) in order to reduce the organic content and to recover whey proteins for reuse NF, when operated as single stage, produced the best results in terms of COD removal (about 97%) and protein recovery (the protein rejection was 88%) The combination of NF and RO allowed to recover both proteins and lactose separately with a production of a clean effluent 13.5 Conclusions and future trends The combination of conventional and innovative membrane separation technologies offers a wide range of advantages in the agrofood productions in terms of improvement of the product quality, energy saving, and reduction of water consumption and environment impact Integrated membrane systems in specific areas of the agrofood production have been reviewed and discussed, highlighting their potential with respect to the separation, concentration, and purification of high-added value compounds Conceptual process flow-sheets based on a combination of membrane systems in a sequential design have been proposed in order to rationalize and redesign conventional productive cycles of the agrofood production providing an essential contribution to the concept of process intensification and zero discharge strategies The efforts for the development of superior membranes and process engineering breakthroughs will further expand the role of membrane technology in the agrofood industry Integration of membrane technologies into conventional existing systems in the food industry 475 References Arriola, N.A., dos Santos, G.D., Prudencio, E.S., Vitali, L., Petrus, C.C., Amboni, R.D.M., 2014 Potential of nanofiltration for the concentration of bioactive compounds from watermelon juice Int J Food Sci Technol 49, 2052–2060 Atra, R., Vatai, G., Bekassy-Molnar, E., Balint, A., 2005 Investigation of ultra- and nanofiltration for utilization of whey protein and lactose J Food Eng 67, 325–332 Bahceci, K.S., 2012 Effects of pretreatment and various operating parameters on permeate flux and quality during ultrafiltration of apple juice Int J Food Sci Technol 47, 315–324 Baker, W.R., 2000 Membrane Technologies and Applications Mc-Graw-Hill, New York BCC Research, 2016 Membrane Technology for Food and Beverage Processing: Global Markets https://www.reportbuyer.com/product/3662110/ Accessed 15 November 2016) Belafi-Bako´, K., Boo´r, A., 2011 Concentration of Cornelian cherry fruit juice by membrane osmotic distillation Desalin Water Treat 35, 271–274 Biswas, P.P., Mondal, M., De, S., 2016 Comparison between centrifugation and microfiltration as primary clarification of bottle gourd (Lagenaria siceraria) juice J Food Process Preserv 40, 226–238 Bocco, A., Cuvelier, M.E., Richard, H., Berset, C., 1998 Antioxidant activity and phenolic composition of citrus peel and seed extract J Agric Food Chem 46, 2123–2129 Cassano, A., Jiao, B., Drioli, E., 2004 Production of concentrated kiwifruit juice by integrated membrane processes Food Res Int 37, 139–148 Cassano, A., Conidi, C., Timpone, R., D’Avella, M., Drioli, E., 2007a A membrane-based process for the clarification and the concentration of the cactus pear juice J Food Eng 80, 914–921 Cassano, A., Donato, L., Drioli, E., 2007b Ultrafiltration of kiwifruit juice: operating parameters, juice quality and membrane fouling J Food Eng 79, 612–621 Cassano, A., Marchio, M., Drioli, E., 2007c Clarification of blood orange juice by ultrafiltration: analyses of operating parameters, membrane fouling and juice quality Desalination 212, 15–27 Cassano, A., Donato, L., Conidi, C., Drioli, E., 2008 Recovery of bioactive compounds in kiwifruit juice by ultrafiltration Innovative Food Sci Emerg Technol 9, 556–562 Cassano, A., Conidi, C., Drioli, E., 2011 Clarification and concentration of pomegranate juice (Punica granatum L.) using membrane processes J Food Eng 107, 366–373 Cassano, A., Conidi, C., Giorno, L., Drioli, E., 2013a Fractionation of olive mill wastewaters by membrane separation techniques J Hazard Mater 248–249, 185–193 Cassano, A., Conidi, C., Drioli, E., 2013b A membrane-based process for the valorization of the bergamot juice Sep Sci Technol 48, 537–546 Cassano, A., Conidi, C., Ruby-Figueroa, R., 2014 Recovery of flavonoids from orange press liquor by an integrated membrane process Membranes 4, 509–524 Cassano, A., Cabri, W., Mombelli, G., Peterlongo, F., Giorno, L., 2016 Recovery of bioactive compounds from artichoke brines by nanofiltration Food Bioprod Process 98, 257–265 Catarino, M., Mendes, A., 2011 Dealcoholizing wine by membrane separation processes Innovative Food Sci Emerg Technol 12, 330–337 Cisse, M., Vaillant, F., Bouquet, S., Pallet, D., Lutin, F., Reynes, M., Dornier, M., 2011 Athermal concentration by osmotic evaporation of roselle extract, apple and grape juices and impact on quality Innovative Food Sci Emerg Technol 12, 352–360 Conidi, C., Cassano, A., Drioli, E., 2011 A membrane-based study for the recovery of polyphenols from bergamot juice J Membr Sci 375, 182–190 476 Bioenergy Systems for the Future Conidi, C., Mazzei, R., Cassano, A., Giorno, L., 2014a Integrated membrane system for the production of phytotherapics from olive mill wastewaters J Membr Sci 454, 322–329 Conidi, C., Cassano, A., Garcia-Castello, E., 2014b Valorization of artichoke wastewaters by integrated membrane process Water Res 48, 363–374 Conidi, C., Destani, F., Cassano, A., 2015a Performance of hollow fiber ultrafiltration membranes in the clarification of blood orange juice Beverages 1, 341–353 Conidi, C., Rodriguez-Lopez, A.D., Garcia-Castello, E.M., Cassano, A., 2015b Purification of artichoke polyphenols by using membrane filtration and polymeric resins Sep Purif Technol 144, 153–161 Cook, A.G., Weinstein, P., Centeno, J.A., 2005 Health effects of natural dusts: role of trace elements and compounds Biol Trace Elem Res 103, 1–15 Cuartas-Uribe, B., Alcaina-Miranda, M.I., Soriano-Costa, E., Mendoza-Roca, J.A., IborraClar, M.I., Lora-Garcı´a, J., 2009 A study of the separation of lactose from whey ultrafiltration permeate using nanofiltration Desalination 241, 244–255 Czekaj, P., Lo´pez, F., G€uell, C., 2000 Membrane fouling during microfiltration of fermented beverage J Membr Sci 166, 199–212 Czekaj, P., Lo´pez, F., G€uell, C., 2001 Membrane fouling by turbidity constituents of beer and wine: characterization and prevention by means of infrasonic pulsing J Food Eng 49, 26–36 Darlington, R., Staikos, T., Rahimifard, S., 2009 Analytical methods for waste minimization in the convenience food industry Waste Manag 29, 1274–1281 Daufin, G., Escudier, J.P., Carre`re, H., Berot, S., Fillaudeau, L., Decloux, M., 2001 Recent and emerging applications of membrane processes in the food and dairy industry Trans IChemE 79, 89–102 de Barros, S.T.D., Andrade, C.M.G., Mendes, E.S., Peres, L., 2003 Study of fouling mechanism in pineapple juice clarification by ultrafiltration J Membr Sci 215, 213–224 de Oliveira, R.C., Doce, 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, 432–439 Di Donna, L., De Luca, G., Mazzotti, F., Napoli, A., Salerno, R., Taverna, D., Sindona, G., 2009 Stain-like principles of bergamot fruit (Citrus bergamia): isolation of 3-hydroxymethylglutaryl flavonoid glycosides J Nat Prod 72, 1352–1354 Diban, N., Athes, V., Bes, M., Souchon, I., 2008 Ethanol and aroma compounds transfer study for partial dealcoholization of wine using membrane contactor J Membr Sci 311, 136–146 Drioli, E., Romano, M., 2001 Progress and new perspectives of integrated membrane operations for sustainable industrial growth Ind Eng Chem Res 40, 1277–1300 Echavarria, A.P., Falguera, V., Torras, C., Berdun, C., Pagan, J., Ibarz, A., 2012 Ultrafiltration and reverse osmosis for clarification and concentration of fruit juices at pilot plant scale LWT Food Sci Technol 46, 189–195 El Rayess, Y., Albasia, C., Bacchin, P., Taillandier, P., Raynala, J., Mietton-Peuchote, M., Devatine, A., 2011a Cross-flow microfiltration applied to oenology: a review J Membr Sci 382, 1–19 El Rayess, Y., Albasia, C., Bacchin, P., Taillandier, P., Mietton-Peuchote, M., Devatine, A., 2011b Cross-flow microfiltration of wine: effect of colloids on critical fouling conditions J Membr Sci 385–386, 177–186 El Rayess, Y., Manon, Y., Jitariouk, N., Albasi, C., Mietton-Peuchot, M., Devatine, A., Fillaudeau, L., 2016 Wine clarification with Rotating and Vibrating Filtration (RVF): Integration of membrane technologies into conventional existing systems in the food industry 477 investigation of the impact of membrane material, wine composition and operating conditions J Membr Sci 513, 47–57 El-Abbassi, A., Khayet, M., Kiai, H., Hafidi, A., Garcı´a-Payo, M.C., 2013 Treatment of crude olive mill wastewaters by osmotic distillation and osmotic Sep Purif Technol 104, 327–332 Ennouri, M., Ben Hassan, I., Ben Hassen, H., Lafforgue, C., Schmitz, P., Ayadi, A., 2015 Clarification of purple carrot juice: analysis of the fouling mechanisms and evaluation of the juice quality J Food Sci Technol 52, 2806–2814 Galanakis, C.M., 2012 Recovery of high added-value components from food wastes: conventional, emerging technologies and commercialized applications Trends Food Sci Technol 26, 68–87 Galanakis, C.M., Tornberg, E., Gekas, V., 2010 Clarification of high-added value products from olive mill wastewater J Food Eng 99, 190–197 Galanakis, C.M., Markouli, E., Gekas, V., 2013 Recovery and fractionation of different phenolic classes from winery sludge using ultrafiltration Sep Purif Technol 107, 245–251 Galaverna, G., Di Silvestro, G., Cassano, A., Sforza, S., Dossena, A., Drioli, E., Marchelli, R., 2008 A new integrated membrane process for the production of concentrated blood orange juice: effect on bioactive compounds and antioxidant activity Food Chem 106, 1021–1030 Garcia-Castello, E., Cassano, A., Criscuoli, A., Conidi, C., Drioli, E., 2010 Recovery and concentration of polyphenols from olive mill wastewaters by integrated membrane system Water Res 44, 3883–3892 Gebreyohannes, A.Y., Mazzei, R., Giorno, L., 2016 Trends and current practices of olive mill wastewater treatment: application of integrated membrane process and its future perspective Sep Purif Technol 162, 45–60 Go´mez-Plaza, E., Lo´pez-Nicola´s, J.M., Lo´pez-Roca, J.M., Martinez-Cutillas, A., 1999 Dealcoholization of wine Behavior of the aroma components during the process LWT Food Sci Technol 32, 384–386 Gunathilake, K.D.P.P., Yu, L.J., Ruoasinghe, H.P.V., 2014 Reverse osmosis as a potential technique to improve antioxidant properties of fruit juices used for functional beverages Food Chem 148, 335–341 Jiao, B., Cassano, A., Drioli, E., 2004 Recent advances on membrane processes for the concentration of fruit juices A review J Food Eng 63, 303–324 Khayet, M., 2011 Membrane and theoretical modeling of membrane distillation: a review Adv Colloid Interface Sci 164, 56–88 Kiss, I., Vatai, G., Bekassy-Molnar, E., 2004 Must concentrate using membrane technology Desalination 162, 295–300 Kumar, P., Sharma, N., Ranjan, R., Kumar, S., Bhat, Z.F., Jeong, D.K., 2013 Perspective of membrane technology in dairy industry: a review Asian Australas J Anim Sci 26, 1347–1358 Labanda, J., Vichi, S., Llorens, J., Lope-Tamames, E., 2009 Membrane separation technology for the reduction of alcoholic degree of a white model wine LWT Food Sci Technol 42, 1390–1395 Lattanzio, V., Kroon, P.A., Linsalata, V., Cardinali, A., 2009 Globe artichoke: a functional food and source of nutraceutical ingredients J Funct Foods 1, 131–144 Lee, W.L., Okos, R.M., 2011 Sustainable food processing systems—path to a zero discharge: reduction of water, waste and energy Procedia Food Sci 1, 1768–1777 Li, J., Chase, H.A., 2010 Applications of membrane technique for purification of natural products Biotechnol Lett 32, 601–608 478 Bioenergy Systems for the Future Llorach, R., Espı´n, J.C., Tomas-Barberan, F.A., Ferreres, F., 2002 Artichoke (Cynara scolymus L.) by-products as a potential source of health-promoting antioxidant phenolics J Agric Food Chem 50, 3458–3464 Lozano-Sa´nchez, J., Giambanelli, E., Quirantes-Pine, R., Cerretani, L., Bendini, A., SeguraCarretero, A., Ferna´ndez-Gutierrez, A., 2011 Wastes generated during the storage of extra virgin olive oil as a natural source of phenolic compounds J Agric Food Chem 59, 11491–11500 Machado, M.T.C., Trevisan, S., Pimentel-Souza, J.D.R., Pastore, G.M., Hubinger, M.D., 2016 Clarification and concentration of oligosaccharides from artichoke extract by a sequential process with microfiltration and nanofiltration membranes J Food Eng 180, 120–128 Maktouf, S., Neifar, M., Drira, S.J., Baklouti, S., Fendri, M., Ch^aabouni, S.E., 2014 Lemon juice clarification using fungal pectinolytic enzymes coupled to membrane ultrafiltration Food Bioprod Process 92, 14–19 Mandalari, G., Bennett, R.N., Bisignano, G., Saija, A., Dugo, G., Lo Curto, R.B., Faulds, C.B., Waldron, K.W., 2006 Characterization of flavonoids and pectins from bergamot (Citrus bergamia risso) peel, a major byproduct of essential oil extraction J Agric Food Chem 54, 197–203 Memstar Pty Ltd, 2016 Alcohol reduction in beverages US patent 2016/0097024 A1 Mietton-Peuchot, M., Milisic, V., Noilet, P., 2002 Grape must concentration by using reverse osmosis Comparison with chaptalization Desalination 148, 125–129 Milani, P.G., Prato, A.M., Monteiro, A.R.G., Maioral, M.F., Marchi, L.B., da Costa, S.C., 2015 Assessment of operating parameters, membrane fouling and juice quality during acerola ultrafiltration Chem Eng Trans 44, 325–330 Mirabella, N., Castellani, V., Sala, S., 2014 Current options for the valorization of food manufacturing waste: a review J Clean Prod 65, 28–41 Mudimu, O.A., Peters, M., Brauner, F., Braun, G., 2012 Overview of membrane processes for the recovery of polyphenols from olive mill wastewater Am J Environ Sci 8, 195–201 Nagaraj, N., Patil, B.S., Biradar, P.M., 2006 Osmotic membrane distillation—a brief review Int J Food Eng 2, 1–22 Ochando-Pulido, J.M., Martinez-Ferez, A., 2015 On the recent use of membrane technology for olive mill wastewater purification Membranes 5, 513–531 Onsekizoglu, P., 2013 Production of high quality clarified pomegranate juice concentrate by membrane processes J Membr Sci 442, 264–271 Onsekizoglu, P., 2015 Potential of membrane distillation for production of high quality fruit juice concentrate Crit Rev Food Sci Nutr 55, 1098–1113 Organisation Internationale de la Vigne et du Vin, 2015 Global economic vitiviniculture data www.oiv.int/public/medias/2256/en-communique-de-presse-octobre-2015 Accessed 15 November 2016 Paraskeva, C.A., Papadakis, V.G., Tsarouchi, E., Kanellopoulou, D.G., Koutsoukos, P.G., 2007 Membrane processing for olive mill wastewater fractionation Desalination 213, 218–229 Pernice, R., Borriello, G., Ferracane, R., Borrelli, R., Cennamo, F., Ritieni, A., 2009 Bergamot: a source of natural antioxidants for functionalised fruit juices Food Chem 112, 545–550 Pickering, G.J., 2000 Low- and reduced-alcohol wine: a review J Wine Res 11, 129–144 Quist-Jensen, C.A., Macedonio, F., Conidi, C., Cassano, A., Aljlil, S., Alharbi, O.A., Drioli, E., 2016 Direct contact membrane distillation for the concentration of clarified orange juice J Food Eng 187, 37–43 Rai, P., Majumdar, G.C., Das Gupta, S., De, S., 2007 Effect of various pre-treatment methods on permeate flux and quality during ultrafiltration of mosambi juice J Food Eng 78, 561–568 Integration of membrane technologies into conventional existing systems in the food industry 479 Rezzadori, K., Serpa, L., Penha, F.M., Petrus, R.R., Petrus, J.C.C., 2014 Crossflow microfiltration of sugarcane juice—effects of processing conditions and juice quality J Food Sci Technol 34, 210–217 Russo, C., 2007 A new membrane process for the selective fractionation and total recovery of polyphenols, water and organic substances from vegetation waters (VW) J Membr Sci 288, 239–246 Sagu, S.T., Karmakar, S., Nso, J.E., Kapseu, C., De, S., 2014 Ultrafiltration of banana (Musa acuminata) juice using hollow fibers for enhanced shelf life Food Bioprocess Technol 7, 2711–2722 Salgado, C.M., Ferna´ndez-Ferna´ndez, E., Palacio, L., Herna´ndez, A., Pra´danosa, P., 2015 Alcohol reduction in red and white wines by nanofiltration of musts before fermentation Food Bioprod Process 96, 285–295 Saxena, A., Tripathi, B.P., Kumar, M., Shahi, V.K., 2009 Membrane-based techniques for the separation and purification of proteins: an overview Adv Colloid Interface Sci 145, 1–22 Schieber, A., Stintzing, F.C., Carle, R., 2001 By-products of plant food processing as a source of functional compounds e recent developments Trends Food Sci Technol 12, 401–413 Takac¸, S., Karakaya, A., 2009 Recovery of phenolic antioxidants from olive mill wastewater Recent Pat Chem Eng 2, 230–237 Taka´cs, L., Vatai, G., Kora´ny, K., 2007 Production of alcohol free wine by pervaporation J Food Eng 78, 118–125 Turano, E., Curcio, S., De Paola, M.G., Calabro`, V., Iorio, G., 2002 An integrated centrifugation-ultrafiltration system in the treatment of olive mill wastewater J Membr Sci 209, 519–531 Ulbricht, M., Ansorge, W., Danielzik, I., K€onig, M., Schuster, O., 2009 Fouling in microfiltration of wine: the influence of the membrane polymer on adsorption of polyphenols and polysaccharides Sep Purif Technol 68, 335–342 Ushikubo, F.Y., Watanabe, A.P., Viotto, L.A., 2007 Microfiltration of umbu (Spondias tuberosa Arr Cam.) juice J Membr Sci 288, 61–66 Vaillant, F., Millan, A., Dornier, M., Decloux, M., Reynes, M., 2001 Strategy for economical optimization of the clarification of pulpy fruit juices using crossflow microfiltration J Food Eng 48, 83–90 Verma, S.P., Sarkar, B., 2015 Analysis of flux decline during ultrafiltration of apple juice in a batch cell Food Bioprod Process 94, 147–157 Vladisavljevic, G.T., Vukosavljevic, P., Mile, S., Veljovic, M.S., 2013 Clarification of red raspberry juice using microfiltration with gas backwashing: a viable strategy to maximize permeate flux and minimize a loss of anthocyanins Food Bioprod Process 91, 473–480 Yorgun, M.S., Akmehmet Balcioglu, I., Saygin, O., 2008 Performance comparison of ultrafiltration, nanofiltration and reverse osmosis in whey treatment Desalination 229, 204–216 Zirehpour, A., Jahanshahi, M., Rahimpour, A., 2012 Unique membrane process integration for olive oil mill wastewater purification Sep Purif Technol 96, 124–131 Zuorro, A., Maffei, G., Lavecchia, R., 2016 Reuse potential of artichoke (Cynara scolymus L.) waste for the recovery of phenolic compounds and bioenergy J Clean Prod 111, 279–284 Zydney, A., 1998 Protein separations using membrane filtration: new opportunities for whey fractionation Int Dairy J 8, 243–250 ... their key advantages over conventional technologies Integration of membrane technologies into conventional existing systems in the food industry Fig 13. 1 Applications of membrane processes in. .. to the selection of the most suitable membranes (in terms of membrane material, configuration, and pore Integration of membrane technologies into conventional existing systems in the food industry. .. Wine clarification with Rotating and Vibrating Filtration (RVF): Integration of membrane technologies into conventional existing systems in the food industry 477 investigation of the impact of