Concentration of phenolic compounds from strawberry (Fragaria X ananassa Duch) juice by nanofiltration membrane

Can Storage Stability and Simulated Gastrointestinal Behavior Change the Cytotoxic Effects of Concentrated Guava Leaves Extract against Human Lung Cancer Cells?

The influence of storage stability and simulated gastrointestinal behavior of different extracts of guava leaves extracts (NC: not concentrated, and C10 and C20: concentrated by nanofiltration) was evaluated based on their total phenolic compound (TPC) contents and antioxidant activity as well as on their cytotoxic effects on A549 and Vero cells. The results showed that C10 and C20 presented high stability for 125 days probably due to their high TPC contents and antioxidant activity. The simulated gastrointestinal behavior modified their TPC contents; however, after all digestion steps, the TPC values were higher than 70%, which means that they were still available to exert their bioactivities. Additionally, the cytotoxic effects of these extracts were evaluated before and after the simulated gastrointestinal behavior or under different storage conditions. C10 presented the best selectivity indices (SI) values (IC50 Vero cells/IC50 A549 cells) at both conditions suggesting that it can be considered a potential extract to be developed as a functional food due to its resistance to the gastrointestinal digestion and storage conditions tested.

Encapsulation of pomegranate polyphenols by ionic gelation: Strategies for improved retention and controlled release

This study aimed at producing pectin hydrogel beads by ionic gelation proce to carry pomegranate extract (PE) evaluating approaches to increase its retention and protect the polyphenols from environmental conditions that interfere in the stability and color of these compounds, such as the pH of the medium. Several strategies were tested to reduce the mass transfer and consequently increase its retention. The insertion of a filler (gelatinized starch), the employment of different concentrations from the external environment, the adsorption using blank pectin-starch beads, and the electrostatic coating using chitosan were performed. The release of entrapped compounds over time was employed to evaluate the release pattern of PE in water media. Diffusion coefficients calculated from these experiments were then used to estimate the PE release behavior. The encapsulation efficiency (EE) was significantly improved (42 % to 101 %) when equalizing the concentration of the external medium with that from the beads formulation. Furthermore, the increase in the PE concentration was proportional to the rise in the mechanical strength (MS) of the beads which indicates a modification of internal structure due to the presence of polyphenols. The adsorption was efficient in entrapping the active compound, and despite the high PE content observed for all beads (average value of 2960.26 mg of gallic acid equivalent/100 g sample), they had the lowest diffusion coefficient from the release in water media. Finally, the coating was able to reduce the release rate in most of the tests (DAB uncoated = 0.5 DAB coated), however, during the electrostatic deposition a loss of about 32 % of the phenolic compounds in the chitosan solution was observed which led to a reduced EE. Despite the obtention of retarded release, coating studies need to be improved. Some adjustments in the execution of this technique are necessary so that the losses are reduced and the process becomes viable for the use of beads in food.

Ultrasonication and thermosonication applied in the processing of jalapeno pepper (Capsicum annuum var. annuum) sauce

Ultrasonication is one of the non-thermal physical methods that can be used on foods and when used in synergy with temperature (thermosonication), this technique proves to be more effective, thus reducing the duration and intensity of heat treatment and the consequent damage to the foods. This work aimed to use the technique of ultrasonication and thermosonication in the processing of jalapeno pepper sauces in comparison with pasteurization. Two types of sauces were produced, one with pre-cooking (a) and the other without cooking (b), and the influence of time and temperature was analyzed by applying ultrasonication and thermosonication. Times of 15 and 30 min and temperatures of 25 and 65 °C were used. Both treatments stood out for their effectiveness when compared to the traditional method (pasteurization 65 °C and 30 min). The results demonstrate that, in general, the sauces are good sources of phenolic compounds (141.83 ± 0.10 mg gallic acid equivalent/100 g), flavonoids (50.40 ± 0.30 mg quercetin equivalent/100 g) and carotenoids (2.39 ± 0.07 mg β-carotene/100 g). The sauces had an increase in carotenoids by about 25% (thermosonicated at 15 and 30 min and pre-cooked) and in antioxidant activity (ferric reducing antioxidant power) with about 12% and 13% (thermosonicated at 30 min with and without cooking, respectively) in relation to control (pasteurization). On comparing thermosonication with ultrasound process total phenolics had improved by around 14% and flavonoids by 55%. At the first time, capsantin, capsaicin, dihydrocapsaicin, and nordihydrocapsaicin were identified by ultra-high performance liquid chromatography-MS/MS (UHPLC-MS/MS). Finally, as both treatments demonstrate efficiency (thermosonication at 15 and 30 min), the use of 15 min is indicated as feasible by the reduced process time and in preventing the loss of bioactive compounds in the sauces when compared to the pasteurization treatment.

Antioxidant and Antibacterial Properties of a Functional Sports Beverage Formulation

Athletes often consume functional beverages in order to improve performance and reduce oxidative stress caused by high-intensity exercise. The present study aimed to evaluate the antioxidant and antibacterial properties of a functional sports beverage formulation. The beverage's antioxidant effects were assessed on human mesenchymal stem cells (MSCs) by determining thiobarbituric acid reactive substances (TBARS; TBARS levels decreased significantly by 52.67% at 2.0 mg/mL), total antioxidant capacity (TAC; TAC levels increased significantly by 80.82% at 2.0 mg/mL) and reduced glutathione (GSH; GSH levels increased significantly by 24.13% at 2.0 mg/mL) levels. Furthermore, the beverage underwent simulated digestion following the INFOGEST protocol to assess its oxidative stability. The analysis of the total phenolic content (TPC) using the Folin-Ciocalteu assay revealed that the beverage contained a TPC of 7.58 ± 0.066 mg GAE/mL, while the phenolics identified by HPLC were catechin (2.149 mg/mL), epicatechin (0.024 mg/mL), protocatechuic acid (0.012 mg/mL), luteolin 7-glucoside (0.001 mg/mL), and kaempferol-3-O-β-rutinoside (0.001 mg/mL). The beverage's TPC was strongly correlated with TAC (R² = 896). Moreover, the beverage showcased inhibitory and bacteriostatic effects against Staphylococcus aureus and Pseudomonas aeruginosa. Lastly, the sensory acceptance test demonstrated that the functional sports beverage was well accepted by the assessors.

Antimicrobial and antioxidant activity of phenolic extracts from walnut (Juglans regia L.) green husk by using pressure-driven membrane process

In this study, antioxidant (DPPH and metal chelating), DNA cleavage, biofilm, and antimicrobial properties of extracted phenol from the walnut green husk (WGH) and its different concentrate and permeate samples were evaluated. For maximum phenolic compound extraction from the WGH first, the effects of solvent type (deionized water, methanol, n-hexane, acetone, and ethanol), solvent temperature (25-75 °C), and extraction time (0.5-24 h) were optimized. Then to concentrate phenolic compounds a pressure-driven membrane process was used with four different membrane types. The phenol contents of the concentrate samples were found to be microfiltration (MF) concentrate 4400 mg/L, ultrafiltration (UF) concentrate 4175 mg/L, nanofiltration (NF) concentrate 8155 mg/L, and reverse osmosis (RO) concentrate 8100 mg/L. LC-MSMS was used to determine the quantification of phenolic compounds in permeate and concentrate streams. In addition, all of the concentrate samples with high phenol content showed a high antioxidant activity as 100% with MF concentrate, UF concentrate, NF concentrated and RO concentrated. Likewise, concentrate samples were found to have very high antibiofilm activity as 82.86% for NF concentrate againts S. aureus, 85.80% for NF concentrate against P. aureginosa, 80.95% for RO concentrate against S. aureus, and 83.61% for RO-concentrate against P. aureginosa. When the antimicrobial activity of the extracted phenol from WGH and its different concentrate and permeate samples were evaluated by micro dilution and disk diffusion methods, it was found that the ability of the concentrate samples to inhibit bacterial growth was much higher than permeate ones. In addition, extracted phenol from WGH and its different concentrate and permeate samples showed significant DNA nuclease activity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05588-w.

A review on membrane separation processes focusing on food industry environment-friendly processes

Food processing industries have led to several environmental impacts due to their high water and energy consumption, as well as soil and water bodies' contamination through improper waste disposal. Membrane Separation Processes (MSP) emerge as an important alternative to enable the adoption of sustainable processes by food industries, since satisfying the requests of innovative processes and equipment design, such as smaller, cleaner, more energy-efficient processes (mild conditions) without the usage of chemical agents. Membrane-based processes fulfill these requirements, and their potential has been broadly recognized in the last few years. This review provides a comprehensive and up-to-date overview of the application of MSP in sustainable processes in the different segments of the food industry over the last 10 years. Waste and wastewater treatment, recovery of valuable compounds and water for reuse, and alternatives to high energy consumption processes were identified as sustainable processes in this context. One trend found is the potential for adding value to production chains by obtaining valuable compounds that have not been explored yet. As a perspective for future research, this review showed that it is advisable to implement MSP in different industrial environments in order to make current processes environmentally sustainable and less polluting.

Membrane techniques in the production of beverages

The most important developments in membrane techniques used in the beverage industry are discussed. Particular emphasis is placed on the production of fruit and vegetable juices and nonalcoholic drinks, including beer and wine. This choice was dictated by the observed consumer trends, who increasingly appreciate healthy food and its taste qualities.

Advances and Applications of Hollow Fiber Nanofiltration Membranes: A Review

Hollow fiber nanofiltration (NF) membranes have gained increased attention in recent years, partly driven by the availability of alternatives to polyamide-based dense separation layers. Moreover, the global market for NF has been growing steadily in recent years and is expected to grow even faster. Compared to the traditional spiral-wound configuration, the hollow fiber geometry provides advantages such as low fouling tendencies and effective hydraulic cleaning possibilities. The alternatives to polyamide layers are typically chemically more stable and thus allow operation and cleaning at more extreme conditions. Therefore, these new NF membranes are of interest for use in a variety of applications. In this review, we provide an overview of the applications and emerging opportunities for these membranes. Next to municipal wastewater and drinking water processes, we have put special focus on industrial applications where hollow fiber NF membranes are employed under more strenuous conditions or used to recover specific resources or solutes.

Phenolic compounds in Nordic berry species and their application as potential natural food preservatives

An increasing demand for natural food preservatives is raised by consumers. For Nordic berry species, abundance of phenolic compounds and potent activities of anti-oxidation and anti-bacteria enables a great potential as food preservatives. This review provides a systematic examination of current literature on phenolic profiles, anti-oxidative and anti-bacterial activities of various extracts of Nordic berry species, as well as the impact of various structure features of phenolics on the bioactivities. Special attention is placed on exploitation of leaves of berry species and pomaces after juice-pressing as side-streams of berry production and processing. The current progress and challenges in application of Nordic berry species as food preservatives are discussed. To fully explore the potential application of Nordic berry species in food industry and especially to valorize the side-streams of berry cultivation (leaves) and juice-pressing industry (pomaces), it is crucial to obtain extracts and fractions with targeted phenolic composition, which have high food preserving efficacy and minimal impact on sensory qualities of food products.

Identification of Anthocyanins and Their Fouling Mechanisms during Non-Thermal Nanofiltration of Blueberry Aqueous Extracts

Organic fouling in the nanofiltration (NF) process, which is a non-thermal technology to recover active components, is a critical problem limiting its applications. This study seeks to identify the anthocyanins on the NF membrane and explore their fouling mechanisms during concentration of blueberry extracts. Seven kinds of monomeric anthocyanins in foulants-delphinidin-3-O-galactoside, delphinidin-3-O-glucoside, delphinidin-3-O-arabinoside, cyanidin-3-O-galactoside, petunidin-3-O-galactoside, peonidin-3-O-glucoside, and malvidin-3-O-glucoside-were identified. Moreover, chalcone, myricetin derivative, and an unknown substance with [M⁺H]⁺ at m/z 261.1309, which is the fragment ion corresponding to the break of glycoside bond of anthocyanins, were obtained. Interactions between anthocyanins and membrane made from polyamide were principally governed by the CH-π and π-π stacking of aromatic rings, the establishment of hydrogen bonds, and electrostatic interaction. This study will be helpful to further control fouling and choice of cleaning agents in concentration of anthocyanins-rich extracts.

Bioactive Compounds from Jambolan (Syzygium cumini (L.)) Extract Concentrated by Ultra- and Nanofiltration: a Potential Natural Antioxidant for Food

Jambolan is an unexplored fruit rich in bioactive compounds like anthocyanins, catechin, and gallic acid. Thus, the extraction of bioactive compounds allows adding value to the fruit. In this context, the present study reports the recovery and concentration of jambolan fruit extract by ultra and nanofiltration for the first time. Acidified water was used to extract polyphenols from the pulp and peel of jambolan. The extracts were concentrated using ultrafiltration and nanofiltration membranes with nominal molecular weight cut-off ranging from 180 to 4000 g mol^-1. Total monomeric anthocyanin, total phenolic compounds, and antioxidant capacity were analyzed. Phenolic compounds were quantified, and anthocyanins were identified by high-performance liquid chromatography coupled to diode-array detection and mass spectrometry (HPLC-DAD-MS). Concentration factors higher than 4.0 were obtained for anthocyanins, gallic acid, and catechin after nanofiltration of the extracts. Other compounds such as epicatechin, p-Coumaric acid, and ferulic acid were quantified in the concentrated extract, and the main anthocyanins identified were 3,5-diglucoside: petunidin, malvidin, and delphinidin. Therefore, jambolan extract showed a high potential to be used as a natural dye and antioxidant in food products.

Anthocyanins, Vibrant Color Pigments, and Their Role in Skin Cancer Prevention

Until today, numerous studies evaluated the topic of anthocyanins and various types of cancer, regarding the anthocyanins' preventative and inhibitory effects, underlying molecular mechanisms, and such. However, there is no targeted review available regarding the anticarcinogenic effects of dietary anthocyanins on skin cancers. If diagnosed at the early stages, the survival rate of skin cancer is quite high. Nevertheless, the metastatic form has a short prognosis. In fact, the incidence of melanoma skin cancer, the type with high mortality, has increased exponentially over the last 30 years, causing the majority of skin cancer deaths. Malignant melanoma is considered a highly destructive type of skin cancer due to its particular capacity to grow and spread faster than any other type of cancers. Plants, in general, have been used in disease treatment for a long time, and medicinal plants are commonly a part of anticancer drugs on the market. Accordingly, this work primarily aims to emphasize the most recent improvements on the anticarcinogenic effects of anthocyanins from different plant sources, with an in-depth emphasis on melanoma skin cancer. We also briefly summarized the anthocyanin chemistry, their rich dietary sources in flowers, fruits, and vegetables, as well as their associated potential health benefits. Additionally, the importance of anthocyanins in topical applications such as their use in cosmetics is also given.

Camu-camu bioactive compounds extraction by ecofriendly sequential processes (ultrasound assisted extraction and reverse osmosis)

Technical feasibility of an ecofriendly sequential process (ultrasound assisted extraction and reverse osmosis, or UAE and RO) was evaluated in order to obtain a functional Camu-camu (Myrciaria dubia) product with high vitamin C content. Water was used in the assisted extraction by probe ultrasound (UAE) in an experimental design to evaluate different times, amplitudes and temperatures. The best region for total phenolic (TP) and vitamin C (VC) extraction was 5 min, 60 °C and 30% amplitude. Following extraction, the sample was concentrated by reverse osmosis (R25a, 500 Da, polyamide, and 5 bar area 3 ft2), obtaining a relatively low fouling of 19%. At the end of the sequential process (by HPLC-DAD/UV vis), was obtained a concentrated camu-camu (CC) with high Vitamin C (52.01 ± 0.889 mg/g) and cyanidin-3-glucoside, being respectively 7.0 and 4.5 times higher; also the concentration of phenolic compounds was increased by 3.2 times (25.798 mg GAE/g), and anthocyanins in 6.5 times (66.169 mg of cyanidin-3-glucoside/100 g) as well as high antioxidant activity by all three methods evaluated (increased 3.0, 4.6 and 2.38 times for ABTS, DPPH, FRAP, respectively) by comparing the CC with the initial extract (CS). Twenty compounds were identified by UHPLC-QTOF-MS/MS, highlighting quercetin, gallic acid, p- coumaric, ellagic acid and cyanidin-3-glucoside, and at the first time alnusiin was detected in camu-camu. Therefore, the combination of ultrasound assisted extraction and reverse osmosis can be a promising profitable alternative in order to apply bioactive compounds in food, nutraceuticals and cosmetic matrices, bringing their benefits to consumers.

Membrane-Based Operations in the Fruit Juice Processing Industry: A Review

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.

Evaluation of phenolic and antioxidant properties of strawberry as a function of extraction conditions

Abstract We studied the extraction of antioxidant phenolic compounds, anthocyanins and the evaluation of antioxidant activity of strawberries in different extraction conditions, varying the type of solvent (ethanol:water (50%) and acetone:water (60%), the extraction time (15 and 60 min) and the solvent volume to sample mass ratio (5 mL/g and 20 mL/g). In addition, we performed principal component analysis and cluster analysis. The results showed that, although the two solvents tested had similar influence on total phenolic compounds extraction and antioxidant activity, the 60 minutes of extraction and the use of the solvent volume/sample mass ratio of 20 mL/g were the best extraction conditions, both for the 1st and 2nd recovered extracts. However, the solvent had a marked effect on anthocyanins’ extraction, so that acetone/water extracted almost the double as compared to ethanol/water, for the same extraction conditions. Finally, factor analysis allowed identifying a grouping structure of two components, which was confirmed by the dendogram obtained from cluster analysis.

A green separation mode of synephrine from Citrus aurantium L. (Rutaceae) by nanofiltration technology

Thermal breakage of alkaloid ingredients was a common problem to which attention should be paid in the application of fruit ingredients separation. In this study, the mathematical models were established to predict the rejection of synephrine from Citrus aurantium L. (Rutaceae). The experiment showed that there was a linear relationship between operation pressure and membrane flux. Meanwhile, under the influence of solution-diffusion effect and the charge effect, the mass transfer coefficient was power functioned with initial concentration. The mathematical model showed that the predicted rejections of synephrine from Citrus aurantium extract were well approximate to real ones, and the lipid-lowering active ingredient had effectively enriched. The predicted model of nanofiltration separation has a preferable applicability to synephrine and provides references for nanofiltration separation, especially for raw food materials with synephrine.

The Effects of Storage on Quality and Nutritional Values of Ehrenberg's Snapper Muscles (Lutjanus Ehrenbergi): Evaluation of Natural Antioxidants Effect on the Denaturation of Proteins

Protein denaturation in frozen minced fillets (Ehrenberg’s Snapper), stored at −25 °C was studied; 50.0 mg biomass/50g mince fillets treated with cinnamon, cumin, turmeric, garlic, ginger and 25.0 mg of vitamin C were used to slow protein denaturation. FT-IR stretching vibration of Amide-A (νNH) at 3300 cm⁻¹; Amide-I stretching (νC=O) between 1600−1690 cm⁻¹ and Amide-II stretching (νCN) and bending (δNH) between 1480 and 1575cm⁻¹ were used as marker peaks. Garlic was the most significant (p ≤ 0.01) in controlling the rate of protein denaturation when νNH was used as a marker peak. DSC analysis showed that turmeric presented the highest effect on delaying the denaturation of sarcoplasmic proteins with a ΔH0=73.7J/g  followed by garlic-treated mince fillets ΔH0=70.1J/g. All spices used were efficient in stopping the denaturation of myosin with the highest ΔH0=769.3 J/g registered for cinnamon-treated mince fillets. Actin was less vulnerable to denaturation in comparison to myosin and sarcoplasmic proteins.

Schistocerca piceifrons piceifrons (Orthoptera: Acrididae) as a Source of Compounds of Biotechnological and Nutritional Interest

The Central American locust, Schistocerca piceifrons piceifrons (Walker) is a major agricultural pest in Mexico and Central America. Control measures against this pest have generated much environmental damage and substantial financial costs because chemical insecticides are used. Yet various Orthoptera species also appear to be a potential source of nutrients and a source of bioactive metabolites. Here, we studied the presence of secondary metabolites in the adult stage of S. p. piceifrons by applying different colorimetric techniques. Adults were collected from the southern region of Tamaulipas, Mexico, during September-December 2017. These samples were subjected to sequential processes of eviscerating, drying, pulverizing, extracting, and detecting of metabolites. Extractions were carried out in water, 50% ethanol, and absolute ethanol. The presence of phenolic compounds, alkaloids, tannins, saponins, flavonoids, and quantity of antioxidants against the DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS (2, 2'-azino-bis, 3-ethylbenzothiazoline-6-sulfonic acid) radicals were determined and reported. Proximate analysis showed that S. p. piceifrons has a high protein content (80.26%), low fat content (6.21%), and fiber content (12.56%) similar to other Orthoptera species. Chitin and chitosan contents of S. p. piceifrons were 11.88 and 9.11%, respectively; the recovery percentage of chitosan from chitin was 76.71%. Among the Orthoptera, the protein content of this pest is among the highest while its contents of chitin and chitosan are similar to those of other insect species (e.g., Bombix mori Linnaeus [Lepidoptera: Bombycidae]). Our results suggest this pest species is a potential source of bioactive compounds of biotechnological interest for use by pharmaceutical and food industries.

Combined Osmotic and Membrane Distillation for Concentration of Anthocyanin from Muscadine Pomace

Bioactive anthocyanins from aqueous extracts of muscadine grape pomace were concentrated using osmotic distillation (OD) and direct contact membrane distillation (DCMD) using polypropylene (PP) and poly(ethylene chlorotrifluoroethylene) (ECTFE) membranes. The driving force for OD is created by using a high concentration brine solution while the driving force for DCMD is generated by elevating the feed temperature relative to the permeate temperature. The brine concentration used was 4 M. The lowest fluxes were obtained for OD. Given the temperature sensitive nature of anthocyanins, the maximum temperature difference during DCMD was limited to 30 °C. The feed temperature was 40 °C and the permeate at 10 °C. Consequently, the maximum flux during DCMD was also limited. A combination of OD and DCMD was found to give the highest fluxes. High-performance liquid chromatography (HPLC) and HPLC-electrospray mass spectrometry were used to identify and quantify anthocyanins, cyanidin-3,5-O-diglucoside, delphinidin-3,5-O-diglucoside, petunidin-3,5-O-diglucoside, peonidin-3,5-O-diglucoside, and malvidin-3,5-O-diglucoside. The results obtained here suggest that, though water fluxes for DI water feed streams for PP and ECTFE membrane were similar, the fluxes obtained for the two membranes when using muscadine pomace extracts were different. Concentration factors of close to 3 was obtained for anthocyanins. Membranes also showed slightly different performance in the concentration process. Membrane surfaces were analyzed using scanning electron microscopy and Fourier-transformed infrared spectroscopy. The results suggest that adsorption of these anthocyanins on the membrane surface lead to performance differences. In an actual operation, selection of an appropriate membrane and regeneration of the membrane will be important for optimized performance. PRACTICAL APPLICATIONS: Anthocyanins are valuable therapeutic compounds, which are found in the solid residue left following fruit juice pressing. However, recovery and concentration of these therapeutic compounds remains challenging due to their stability. Here, a novel membrane-based unit operation has been investigated in order to concentrate the anthocyanins that have been extracted into aqueous solutions. The unit operation investigated here use mild processing conditions. Insights into the factors that need to be considered when optimizing of the unit operation for commercialization are discussed.

Exploring the nanofiltration mass transfer characteristic and concentrate process of procyanidins from grape juice

In order to separate procyanidins from grape juice at room temperature, a separation prediction model was established based on nanofiltration. The mass transfer coefficient was positively correlated with the initial concentration. Nanofiltration performance of procyanidins was affected by filtration conditions, membrane properties, and molecular states. The correlation between mass transfer coefficient and initial concentration was established based on the linear equations of the rejection and mass transfer coefficient. The rejection of procyanidins predicted with the mass transfer model was in accordance with the experimental value, and the antioxidant activity was preserved effectively. The mathematical model could predict the rejection of procyanidins. The nanofiltration technology for procyanidin separation from grape juice was characterized by fast separation, low energy consumption, and zero oxidization loss. The nanofiltration technology could greatly improve the utilization efficiency of food products and decrease the energy consumption.

Preparation and characterization of a novel positively charged composite hollow fiber nanofiltration membrane based on chitosan lactate

A positively charged composite hollow fiber nanofiltration (NF) membrane was prepared via interfacial polymerization by using chitosan lactate and trimesoyl chloride (TMC).

Concentration of Polyphenolic Compounds from Grape Seed by Nanofiltration Technology

In order to evaluate the applicability of nanofiltration (NF) polyphenols determined by total phenolic compounds content with application of Folin method in grape seed extract, response surface analysis methodology was used to analyze the concentration process with the indices of membrane fouling and antioxidant activity. In addition to the influencing factors of molecular weight cut-off (MWCO) of NF membrane, procyanidin concentration and pH value, the evaluation index of procyanidin rejection was taken into account for the process optimization by Box-Behnken response surface method on the basis of single factor test. According to Box-Behnken central composite experiment design, the optimal conditions were obtained as follows: NF MWCO of 400 Da, 27.66 μg/mL procyanidins, and pH 5.20. The predicted rejection of procyanidins under the optimum conditions was 97.17% and the experimental value was 96.36 ± 0.87%, which was in accordance with the predicted value. The experimental value of total polyphenolic content (TPC) was 91.09 ± 0.46%. The antioxidant activity was increased about 2.24 times and the antioxidant activity was correlated with the procyanidin content. Moreover, it was easy to clean membrane fouling. The NF was an effective method for concentrating polyphenolic compounds from grape seed extracts without the loss of polyphenolic compounds. The agricultural product utilization was improved greatly and the power consumption was decreased by the NF technology.

Berries grown in Brazil: anthocyanin profiles and biological properties

BACKGROUND

Phytochemical profiles of two Brazilian native fruits - pitanga (red and purple) and araçá (yellow and red) - as well as strawberry cultivars Albion, Aromas and Camarosa, blackberry cultivar Tupy and blueberry cultivar Bluegen cultivated in Brazil were characterized for total phenolic content and total anthocyanin content by liquid chromatography coupled to a photodiode array and a quadrupole time-of-flight mass spectrometer. Radical scavenging, antiherpes and cytotoxic activities of these berry extracts were also evaluated.

RESULTS

Blueberry presented the highest total anthocyanin content (1202 mg cyanidin-O-glucoside equivalents kg^-1 fresh fruit), while strawberry cultivar Aromas presented the highest total phenolic content (13 550 mg gallic acid equivalents kg^-1 fresh fruit). Liquid chromatographic-mass spectrometric analysis resulted in the identification of 21 anthocyanins. To the best of our knowledge this is the first report of cyanidin-O-glucoside in yellow and red Araçá fruit and the first time eight anthocyanins have been reported in pitanga fruits. DPPH and ABTS assays showed that blueberry cultivar Bluegen, blackberry cultivar Tupy and pitanga (red and purple) showed the most promising antiradical activities, respectively. No relevant cytotoxicity against three cancer cell lines or antiherpes activity was detected under the experimental conditions tested.

CONCLUSION

Total anthocyanin content of all fruits had a strong positive correlation with their free radical scavenging activity, suggesting anthocyanins contribute to the antioxidant potential of these fruits. © 2018 Society of Chemical Industry.

Membrane-based technologies for meeting the recovery of biologically active compounds from foods and their by-products

To date, according to the latest literature inputs, membranes-based technologies (microfiltration, ultrafiltration and nanofiltration) have demonstrated to meet the recovery of biologically active compounds, mainly phenolic compounds and their derivatives, from agro-food products and by-products. The goal of this paper is to provide a critical overview of the on ongoing development works aimed at improving the separation, fractionation and concentration of phenolic compounds and their derivatives from their original sources. The literature data are analyzed and discussed in relation to separation processes, molecule properties, membrane characteristics and key factors affecting the performance of such technologies. Technological advances and improvements over conventional technologies, as well as critical aspects to be further investigated are highlighted and discussed. Finally, a critical outlook about the current status for a large-scale application and the role of these processes from an environmental viewpoint is provided.