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Membrane-based processes are increasingly used to clarify and concentrate thermo-sensitive fruit juices and plant extracts as alternatives to conventional processes. This work aimed to evaluate the quality of red fruit juices clarified and concentrated by an integrated membrane process with special regard to the preservation of valuable compounds. A red fruit juice obtained from a blend of pomegranate, cactus pear, and red orange juices of Sicilian origin was clarified by microfiltration (MF) and then pre-concentrated up to 33 °Brix by nanofiltration (NF). The pre-concentrated juice was finally concentrated by osmotic distillation (OD) up to 50 and 60 °Brix. Samples of clarified, pre-concentrated, and concentrated juice were analyzed for their physico-chemical composition and in terms of the antioxidant activity and inhibitory activity against α-amylase and lipase. The results clearly confirmed the assumption of a mild fruit juice processing method, allowing us to preserve the original nutritional and functional properties of the fresh juice. In particular, the OD retentate at 60 °Brix resulted the most active sample against pancreatic lipase and α-amylase inhibitory activity with IC50 values of 44.36 and 214.65 μg/mL, respectively. [ABSTRACT FROM AUTHOR]

The fruit juice industry is one of the food sectors that has invested the most in the implementation of new technologies, such as non-thermal technologies. Among them, membrane processes are considered today well-established separation techniques to support the production and marketing of innovative fruit juices designed to exploit the sensory characteristics and nutritional peculiarities of fresh fruits. Pressure-driven membrane operations, membrane distillation, osmotic distillation and pervaporation have been widely investigated in the last few decades to replace conventional technologies used in fruit juice processing industry (i.e., clarification, stabilization, concentration and recovery of aroma compounds). This paper will review the significant progresses on the use of membrane-based operations in fruit juice processing industry in the light of the growing interest towards products with improved safety, quality and nutritional value and sustainable processes characterized by low energy consumption and low environmental impact. [ABSTRACT FROM AUTHOR]

The valorisation of food wastes is a challenging opportunity for the green, sustainable, and competitive development of industry. The recovery of phenols contributes to the sustainability of olive waste sector, reducing its environmental impact and promoting the development of innovative formulations of interest for pharmaceutical, nutraceutical, and cosmeceutical applications. In this work, olive mill wastewater was treated through a combination of microfiltration (MF), nanofiltration (NF), and reverse osmosis (RO) in a sequential design to produce polyphenol-enriched fractions that have been investigated for their chemical profile using ultra-high-performance liquid chromatography (UHPLC), and their potential antioxidant, hypolipidemic, and hypoglycaemic activities. RO retentate exhibited the highest content of hydroxytyrosol, tyrosol, oleuropein, verbascoside, vanillic acid, and luteolin. In particular, a content of hydroxytyrosol of 1522.2 mg/L, about five times higher than the MF feed, was found. RO retentate was the most active extract in all in vitro tests. Interestingly, this fraction showed a 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS) radicals scavenging activity with an IC50 value of 6.9 μg/mL and a potential inhibition of lipid peroxidation evaluated by the β-carotene bleaching test with IC50 values of 25.1 μg/mL after 30 min of incubation. Moreover, RO retentate inhibited α-amylase and α-glucosidase with IC50 values of 65.3 and 66.2 μg/mL, respectively.

The fruit juice industry is one of the food sectors that has invested the most in the implementation of new technologies, such as non-thermal technologies. Among them, membrane processes are considered today well-established separation techniques to support the production and marketing of innovative fruit juices designed to exploit the sensory characteristics and nutritional peculiarities of fresh fruits. Pressure-driven membrane operations, membrane distillation, osmotic distillation and pervaporation have been widely investigated in the last few decades to replace conventional technologies used in fruit juice processing industry (i.e., clarification, stabilization, concentration and recovery of aroma compounds). This paper will review the significant progresses on the use of membrane-based operations in fruit juice processing industry in the light of the growing interest towards products with improved safety, quality and nutritional value and sustainable processes characterized by low energy consumption and low environmental impact.

Orange press liquor is a by-product generated by the citrus processing industry containing huge amounts of natural phenolic compounds with recognized antioxidant activity. In this work, an integrated membrane process for the recovery of flavonoids from orange press liquors was investigated on a laboratory scale. The liquor was previously clarified by ultrafiltration (UF) in selected operating conditions by using hollow fiber polysulfone membranes. Then, the clarified liquor with a total soluble solids (TSS) content of 10 g·100 g−1 was pre-concentrated by nanofiltration (NF) up to 32 g TSS 100 g−1 by using a polyethersulfone spiral-wound membrane. A final concentration step, up to 47 g TSS 100 g−1, was performed by using an osmotic distillation (OD) apparatus equipped with polypropylene hollow fiber membranes. Suspended solids were completely removed in the UF step producing a clarified liquor containing most part of the flavonoids of the original press liquor due to the low rejection of the UF membrane towards these compounds. Flavanones and anthocyanins were highly rejected by the NF membrane, producing a permeate stream with a TSS content of 4.5 g·100 g−1. An increasing of both the flavanones and anthocyanins concentration was observed in the NF retentate by increasing the volume reduction factor (VRF). The final concentration of flavonoids by OD produced a concentrated solution of interest for nutraceutical and pharmaceutical applications.

Fruit juices are generally concentrated in order to improve the stability during storage and to reduce handling, packaging, and transportation costs. Thermal evaporation is the most widely used technique in industrial fruit juice concentrate production. In addition to high energy consumption, a large part of the characteristics determining the quality of the fresh juice including aroma, color, vitamins, and antioxidants undergoes remarkable alterations through the use of high operation temperatures. Increasing consumer demand for minimally or naturally processed stable products able to retain as much possible the uniqueness of the fresh fruit has engendered a growing interest for development of nonthermal approaches for fruit juice concentration. Among them, membrane distillation (MD) and its variants have attracted much attention for allowing very high concentrations to be reached under atmospheric pressure and temperatures near ambient temperature. This review will provide an overview of the current status and recent developments in the use of MD for concentration of fruit juices. In addition to the most basic concepts of MD variants, crucial suggestions for membrane selection and operating parameters will be presented. Challenges and future trends for industrial adaptation taking into account the possibility of integrating MD with other existing processes will be discussed. [ABSTRACT FROM AUTHOR]

Orange press liquor is a by-product generated by the citrus processing industry containing huge amounts of natural phenolic compounds with recognized antioxidant activity. In this work, an integrated membrane process for the recovery of flavonoids from orange press liquors was investigated on a laboratory scale. The liquor was previously clarified by ultrafiltration (UF) in selected operating conditions by using hollow fiber polysulfone membranes. Then, the clarified liquor with a total soluble solids (TSS) content of 10 g⋅100 g-1 was pre-concentrated by nanofiltration (NF) up to 32 g TSS 100 g-1 by using a polyethersulfone spiral-wound membrane. A final concentration step, up to 47 g TSS 100 g-1, was performed by using an osmotic distillation (OD) apparatus equipped with polypropylene hollow fiber membranes. Suspended solids were completely removed in the UF step producing a clarified liquor containing most part of the flavonoids of the original press liquor due to the low rejection of the UF membrane towards these compounds. Flavanones and anthocyanins were highly rejected by the NF membrane, producing a permeate stream with a TSS content of 4.5 g⋅100 g-1. An increasing of both the flavanones and anthocyanins concentration was observed in the NF retentate by increasing the volume reduction factor (VRF). The final concentration of flavonoids by OD produced a concentrated solution of interest for nutraceutical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

An integrated membrane process for the production of highly concentrated bergamot juice was investigated. The depectinized bergamot juice, with an initial total soluble solids (TSS) content of 95 g kg−1was previously clarified by ultrafiltration (UF) by using polysulphone hollow fibers membranes having a nominal molecular weight cut-off of 100 kDa. The analyses of flux decay, according to fouling models reported in literature, revealed that the resistance of a cake layer covering the entire surface of the UF membrane well describes the fouling phenomenon in the treatment of bergamot juice. The clarified juice was concentrated in an osmotic membrane distillation (OMD) system by using a hollow fiber membrane contactor and calcium chloride dehydrate as extraction brine. In isothermal conditions (25°C) transmembrane vapor water fluxes were between 0.4 and 1.45 kg m−2 h−1producing a concentrated juice with a final TSS content of 540 g kg−1. Suspended solids were completely removed in the UF process. Flavonoids and ascorbic acid were recovered in the UF permeate and well preserved during the subsequent concentration process. The evaluation of the total antioxidant activity (TAA) in clarified and concentrated samples confirmed the assumption of a mild integrated membrane process able to produce a concentrated juice without modifying the main quality criteria of the fresh juice. [ABSTRACT FROM PUBLISHER]

Abstract: The integrated membrane system (UF–NF) was constructed and used for olive oil mill wastewater (OMW) purification. OMW was pre-filtered by three steps microfiltration (MF) membranes with nominal pore size of 50, 5 and 0.2μm in series mode. Filtration experiments in concentration mode of the filtration (with recycling of the retentate stream) were performed in laboratory scale, by using two and three ultrafiltration (UF) and nanofiltration (NF) membranes respectively. The effectiveness of the filtration treatments was determined by the evaluation of the rejection coefficients based on several parameters, which measure the global pollutant content of the OMW namely chemical oxygen demand (COD), UV absorbance at 254nm, total phenols, color as well as conductivity. The analysis of fouling behavior of the UF and NF membranes was also performed by assessment of the flux recovery ratio (FRR) and degree of the total flux loss (Rt ) during volume reduction factor (VRF) experiments. In the case of UF membranes, the commercial UF membrane had shown higher permeate flux than the self-made (home-made) UF membrane, while the antifouling properties and rejections efficiency of self-made UF membrane was significantly better. As for NF membranes, the NF-270 had resulted higher permeate flux than the other examined NF membranes, while the rejection efficiency of both NF-90 and self-made NF were better than that NF-270. The NF membranes provided variable rejection of the organic and inorganic contaminants and had significantly lower rejection for conductivity after membrane fouling during VRF experiments. Finally, in order to achieve higher filtration efficiency, a specific arrangement of the integrated membrane system (IMS) with UF membrane followed by two-step NF membranes in series mode was carried out. In the first NF step a high flux NF membrane (NF-270) was used, while in the second NF step a high rejection NF membrane (NF-90) was exploited. [Copyright &y& Elsevier]

Abstract: The present study was intended to determine the usefulness of the zero liquid discharge (ZLD) approach in treating textile dye bath wastewater via integrated membrane processes. These processes included various combinations of ultrafiltration (UF), loose nanofiltration (NF1), tight nanofiltration (NF2) and reverse osmosis (RO). The technological and economic performance of four scenarios (UF/NF2 (S (I)), NF1/NF2 (S (II)), NF1/RO (S (III)) and UF/NF2/RO (S (IV))), each followed by membrane distillation (MD), were comparatively analysed. The factors considered were capital and operating costs, revenues, benefit/cost (B/C) ratios and pay-back times. The last two scenarios, those including RO, provided the best effluent quality at the end of the pressure-driven membrane filtration process. However, these scenarios were not the most economical options because of the decreased benefits of recycling soda ash and NaCl obtained from the treated wastewater. The unit treatment costs of the scenarios were 1.37, 1.38, 2.16 and 2.01$/m3 of influent for S (I), S (II), S (III) and S (IV), respectively, with return periods of 0.87, 0.91, 2.07 and 1.51 years. The best technological and economic performance was estimated for S (I) and S (II), as indicated by the B/C ratios 3.58 and 3.55, respectively. At the break-even point of 15 years, S (I) required an incineration cost of 77.5$/m3 of MD concentrate, whereas the corresponding costs associated with the other three scenarios were estimated to be 75.7, 43.0 and 35.5$/m3 of MD concentrate, respectively. It was finally concluded that the ZLD approach is most useful in processing textile dye bath waste and recycling treated wastewater. This process is both technically feasible and economically viable, as indicated by the high B/C ratio. However, the unit incineration cost associated with the concentrate would limit the return period of the investment, and the success of this method would also depend principally on the real volume of MD processed due to its large contribution (70–90%) to the B/C ratio. [Copyright &y& Elsevier]

Abstract: The production of concentrated pomegranate juice was investigated by using a two-step membrane process based on: (1) a clarification step of the fresh non-depectinized juice performed by hollow-fiber ultrafiltration (UF) membranes; (2) a concentration step of the clarified juice by using an osmotic distillation (OD) apparatus. Both processes were performed at ambient temperature (25±2°C) producing a clear juice and a concentrated juice with a total soluble solids (TSS) content of 162gkg−1 and 520gkg−1, respectively. The performance of UF and OD operations was evaluated in terms of productivity (permeate and evaporation fluxes) and quality of the processed juice. Suspended solids were completely removed in the clarification step, while soluble solids and organic acids were recovered in the permeate stream of the UF process. Rejections of the UF membrane towards polyphenols and anthocyanins were of 16.5% and 11.7%, respectively. The antioxidant activity of pomegranate aril juice, attributed to a great extent to total phenols and anthocyanins content, was efficiently preserved during the concentration step independently on the achieved level of total soluble solids. An integrated membrane process scheme for the production of concentrated pomegranate juice with potential applications for food, pharmaceutical and cosmetic sectors was proposed. [Copyright &y& Elsevier]

Abstract: Due to the increasing of water shortage problems, the need for inland brackish water RO will continue to increase in future. However, the primary limitations to further application of RO inland are the cost and technical feasibility of concentrate disposal. In this work, Membrane Crystallizer (MCr) and Wind-Aided Intensified eVaporation (WAIV) technologies have been applied in order to mitigate the impact of concentrates on the environment. In particular, the research activity has been carried out on a desalination system in which brackish water was first pre-treated, then desalinated through reverse osmosis (RO) operation. Finally, RO concentrates were further treated in WAIV and MCr units. The effect of the presence of organic contaminants and antiscalants were studied by analysing RO operations working at different recovery factors and with different pre-treatments. In the absence of an antiscalant, RO operates at 75% recovery factor and at a pH low enough to ensure no calcium carbonate precipitation. In the presence of an antiscalant, RO process might work until a recovery factor of 88%. The analysed integrated RO+WAIV+MCr system allowed to reach recovery factors as high as 76.6–88.9% and limit brine discharge to less than 0.75–0.27% of the raw water fed to the system. [Copyright &y& Elsevier]

Abstract: Diffusion dialysis (DD) is an ion-exchange membrane (IEM) separation process driven by concentration gradient and has been applied for separation and recovery of acid/alkali waste solutions in a cost-effective and environmentally friendly manner. This review of DD covers the principles, models, applications (strong acid/weak acid/alkali separation and recovery), and its integration with other techniques, such as electrodialysis, ion exchange membrane-electrowinning, continuous membrane extraction, vacuum membrane distillation, and ceramic membrane micro-filtration. Notably, different factors including properties of the membranes, nature of the waste solution and running conditions are discussed and correlated with the DD performances. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the exergetic analysis of a seawater membrane-based desalination plant has been carried out. The desalination plant has been described in detail, then the exergy of the various saline water streams has been determined and a comprehensive analysis towards the exergy distribution of the major process components has been conducted. The examination of the exergy losses throughout the plant revealed that exergy destruction was mainly due to pressure drops in the membrane modules, valves and brine lines. Moreover, 12.9% of the exergy input to the system was supplied by the heater. Therefore, the most reasonable way to reduce power input to the plant, thus improving its performance and cost, has been shown (i) to be replacing the valves on the reverse osmosis brine stream by an energy recovery system, and (ii) to have thermal energy available in the plant. With the identified technical changes, energy consumption decreased from 18.3 to 2.05kWh/m3, resulting in an annual saving of 0.17$/m3. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this work was to analyse the potentialities of an integrated membrane system for the recovery, purification and concentration of polyphenols from olive mill wastewater (OMW). The proposed system included some well-known membrane operations such as microfiltration (MF) and nanofiltration (NF), as well as others not yet investigated for this specific application, such as osmotic distillation (OD) and vacuum membrane distillation (VMD). The OMW was directly submitted to a MF operation without preliminary centrifugation. This step allowed to achieve a 91% and 26% reduction of suspended solids and total organic carbon (TOC), respectively. Moreover, 78% of the initial content of polyphenols was recovered in the permeate stream. The MF permeate was then submitted to a NF treatment. Almost all polyphenols were recovered in the produced permeate solution, while TOC was reduced from 15 g/L to 5.6 g/L. A concentrated solution enriched in polyphenols was obtained by treating the NF permeate by OD. In particular, a solution containing about 0.5 g/L of free low molecular weight polyphenols, with hydroxytyrosol representing 56% of the total, was produced by using a calcium chloride dihydrate solution as brine. The obtained solution is of interest for preparing formulations to be used in food, cosmetic and pharmaceutical industry. Besides the OD process, VMD was applied as another way for concentrating the NF permeate and the performance of both processes was compared in terms of evaporation fluxes. [Copyright &y& Elsevier]

Abstract: The aim of this study has been to design, on a laboratory scale, an integrated membrane process for the production of concentrated kiwi juice and its aroma recovery. Fresh depectinised kiwifruit juice was clarified by the ultrafiltration (UF) process. The clarified juice was concentrated by osmotic distillation (OD), as an alternative to the traditional vacuum evaporation, up to a total soluble solids (TSS) content higher than 60 °Brix at 25°C. Pervaporation (PV) runs were carried out before and after each membrane unit operation in order to identify the best configuration giving the minimal loss of aroma compounds. For the majority of the aroma compounds detected, the enrichment factor in the permeate of the fresh juice was higher than the clarified and concentrated juice. This result suggests the use of PV for the removal and enrichment of aroma compounds directly from the fresh juice, before any concentration process. The effect of UF and OD on the total antioxidant activity (TAA) and ascorbic acid content of the kiwifruit juice was also evaluated. On the basis of the obtained results, an integrated membrane process scheme for the production of highly nutritional kiwifruit juice has been proposed. [Copyright &y& Elsevier]

Membrane science and technology are recognized today as powerful tools in resolving some important global problems, and developing newer industrial processes, needed from the imperative of sustainable industrial growth. In seawater desalination, for resolving the dramatic increase of freshwater demand in many regions of the world, membrane unitary operations or the combination of some of them in integrated systems are already a real means for producing water from the sea, at lower costs and minimum environmental impact, with a very interesting prospective in particular for poor economy countries. However, membranes are used or are becoming used in some important industrial fields, for developing more efficient productive cycles, with reduced waste of raw-material, reducing the polluting charge by controlling byproduct generation, and reducing overall costs. In the present paper, other than for seawater desalination applications, some industrial applications where membrane technology has led already to match the goal of process intensification are discussed. [ABSTRACT FROM AUTHOR]

Fruit juices have been traditionally concentrated by multi-stage vacuum evaporation, resulting in a loss of fresh juice flavors, color degradation and a “cooked” taste due to the thermal effects. The promising alternative is reverse osmosis concentration. However, it cannot reach concentrations larger than 25–30°Brix with a single-stage RO system due to high osmotic pressure limitation, which is quite below the value of 45–65°Brix for standard products obtained by evaporation. Technological advances related to the development of new membranes and improvements in process engineering have been proved to overcome this limitation. New membrane processes, including membrane distillation and osmotic distillation, and integrated membrane processes are still being identified and developed in concentrated fruit juice processing to improve product quality and reduce energy consumption. Recent advances and developments of the use of membrane processes for concentrating fruit juice are reviewed and discussed in this paper. Major attentions are focused on the application of new membrane processes and integrated membrane systems. [Copyright &y& Elsevier]

The concentration of fruit juices is industrially performed in order to reduce storage, packaging, handling and shipping costs. This paper describes the research efforts to develop and optimise an integrated membrane process, on laboratory scale, for the production of concentrated kiwifruit juice as alternative to the traditional vacuum evaporation. Fresh depectinated kiwifruit juice was previously clarified by ultrafiltration (UF) process. In experimental tests performed according to the total recycle mode the effect of transmembrane pressure, axial flow-rate and temperature on permeate fluxes were studied. Clarified kiwifruit juice was produced in experimental tests carried out according to the batch concentration mode working in optimal operating and fluid dynamic conditions. The osmotic distillation (OD) process was used to concentrate the clarified juice up to a total soluble solids (TSS) content higher than 60 °Brix at 25 °C. The effect of various operating parameters on vapour flux was studied. An average evaporation flux of almost 1 kg/m2 h was obtained using a calcium chloride dihydrate at 60 w/w% as brine solution. The effects of UF and OD processes on the total antioxidant activity (TAA) and other analytical parameters of the kiwifruit juice were also studied. A little reduction of the TAA was measured during the membrane treatment; vitamin C content was well preserved in the concentrated juice. On the basis of the results obtained on laboratory scale an integrated membrane process scheme for the clarification and the concentration of kiwifruit juice is proposed. [Copyright &y& Elsevier]

Spinach and orange by-products are well recognized for their health benefits due to the presence of natural polyphenols with antioxidant activity. Therefore, the demand to produce functional products containing polyphenols recovered from vegetables and fruits has increased in the last decade. This work aims to use the integrated membrane process for the recovery of polyphenols from spinach and orange wastes, implemented on a laboratory scale. The clarification (microfiltration and ultrafiltration, i.e., MF and UF), pre-concentration (nanofiltration, NF), and concentration (reverse osmosis, RO) of the spinach and orange extracts were performed using membrane technology. Membrane experiments were carried out by collecting 1 mL of the permeate stream after increasing the flow rate in 1 mL/min steps. The separation and concentration factors were determined by HPLC-DAD in terms of total polyphenol content and by polyphenol families: hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids. The results show that the transmembrane flux depended on the feed flow rate for MF, UF, NF, and RO techniques. For the spinach and orange matrices, MF (0.22 µm) could be used to remove suspended solids; UF membranes (30 kDa) for clarification; NF membranes (TFCS) to pre-concentrate; and RO membranes (XLE for spinach and BW30 for orange) to concentrate. A treatment sequence is proposed for the two extracts using a selective membrane train (UF, NF, and RO) to obtain polyphenol-rich streams for food, pharmaceutical, and cosmetic applications, and also to recover clean water streams.

The industrial validated technology used in gold mining that deals with copper‑gold ores is the SART process, which allows a viable treatment for these complex minerals. The clarification or thickening stage in this processing, in which copper precipitates are separated, has several challenges such as copper losses (as solids in the overflow or by re-dissolution due to the high residence time) and large size pieces of equipment due to the complex settling characteristics of the copper precipitates. In this regard, this study presents a change in the traditional process by replacing conventional equipment with membrane-based unit operations. This new integrated membrane process, called SuCy process, is based on metal sulfide precipitation, as the SART process, and comprises a sequence of stages including microfiltration to clarify the copper precipitates, gas-filled membrane absorption (GFMA) to produce a concentrated cyanide solution, and a final membrane ultrafiltration stage to clarify the gypsum generated in the neutralization of the treated solution. This study includes sequential tests for each membrane stage at laboratory scale, treating three synthetic cyanide solutions containing different contents of copper (1800 and 1000 mg/L), a mixture of copper and zinc (616 mg/L Cu and 316 mg/L Zn), and a real cyanide solution from a gold mine. Permeate flux for the microfiltration stage ranged from 0.1 L/m2s to 1.4 L/m2s, where the highest values were achieved for copper precipitates suspensions. The characteristics of zinc precipitates promoted a decrease in permeate flux. The HCN flux in the GFMA stage was higher than 0.9 mg/m2s, with cyanide recovery values higher than 98% at 60 min. The permeate flux for the ultrafiltration stage for gypsum clarification was higher than 0.25 L/m2s for all synthetic solutions tested, with a severe decline by one order of magnitude for the real solution due to its high sulfate content. These results were compared with the SART process, both at laboratory scale, including process design and economic estimation, showing a plant size reduction up to 90% for the SuCy process with respect to the SART process, in addition to decreasing the capital cost by over 25% and keeping the operational costs under similar evaluation conditions. Thus, the integrated membrane process proposed here could be a promising alternative for the conventional SART process, enhancing the clarification effectiveness and reducing equipment size requirements and capital costs. • A novel integrated membrane process to recover copper and cyanide is proposed. • Copper and cyanide recoveries were higher than 95%. • Permeate flux of copper precipitates ranged from 0.1 L/m2s to 1.4 L/m2s. • Plant design resulted in a reduction of 90% the plan size compared with SART. • Capex was reduced in around 30% with respect to the SART process. [ABSTRACT FROM AUTHOR]

Pomegranate (Punica granatum L.) juice is well recognized for its high content of phytochemicals with proven health-promoting effects. Conventional processing techniques including clarification with fining agents, pasteurization and thermal concentration have significant influences on bioactive compounds and antioxidant activity of the juice. The growing consumers demand for high-quality pomegranate juice as well as the industrial interest for the production of functional foods, nutraceuticals, and cosmetics from its bioactive compounds have promoted the interest for minimal processing technologies. In this context, membrane-based operations represent an innovative approach to improve the overall quality of pomegranate juice production. This review focuses on the recent advances and developments related to the application of membrane technology in pomegranate juice processing. Conventional pressure-driven membrane operations and innovative membrane operations, such as osmotic distillation and pervaporation, are discussed in relation to their potential in juice clarification, fractionation, concentration and aroma recovery. Their implementation in integrated systems offer new opportunities to improve the healthiness and quality of the juice as well as to recover, purify and concentrate bioactive compounds for the formulation of functional ingredients. [ABSTRACT FROM AUTHOR]

The valorisation of food wastes is a challenging opportunity for the green, sustainable, and competitive development of industry. The recovery of phenols contributes to the sustainability of olive waste sector, reducing its environmental impact and promoting the development of innovative formulations of interest for pharmaceutical, nutraceutical, and cosmeceutical applications. In this work, olive mill wastewater was treated through a combination of microfiltration (MF), nanofiltration (NF), and reverse osmosis (RO) in a sequential design to produce polyphenol-enriched fractions that have been investigated for their chemical profile using ultra-high-performance liquid chromatography (UHPLC), and their potential antioxidant, hypolipidemic, and hypoglycaemic activities. RO retentate exhibited the highest content of hydroxytyrosol, tyrosol, oleuropein, verbascoside, vanillic acid, and luteolin. In particular, a content of hydroxytyrosol of 1522.2 mg/L, about five times higher than the MF feed, was found. RO retentate was the most active extract in all in vitro tests. Interestingly, this fraction showed a 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS) radicals scavenging activity with an IC50 value of 6.9 μg/mL and a potential inhibition of lipid peroxidation evaluated by the β-carotene bleaching test with IC50 values of 25.1 μg/mL after 30 min of incubation. Moreover, RO retentate inhibited α-amylase and α-glucosidase with IC50 values of 65.3 and 66.2 μg/mL, respectively. [ABSTRACT FROM AUTHOR]