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Pomegranate ( Punica granatum L.) is a rich source of constituents with confirmed strong biological activities. However, pomegranate peel, which encompasses approximately 30-40% of its weight, is treated as a biological waste. The aim of this paper was to evaluate the potential of pomegranate peel extracts and to propose its functional properties that can be used for development of functional products. Eight ethanol extracts of pomegranate peels (PPEs) were characterized by use of direct infusion quadrupole-time of flight (Q-TOF), and afterwards tested on their antioxidant, antibacterial and antiproliferative activities. Mass spectrometry analysis revealed that the most prevalent compounds in pomegranate peels were punicalagin, granatin and their derivatives. Analysed extracts had high total phenolic contents that ranged from 5766.44 to 10599.43 mg GAE/100 g, and strong antioxidant activity (7551.31-7875.42 and 100.25-176.60 μmol TE/100 g for DPPH and FRAP assays, respectively). The results of biological activity assays showed that all PPEs possessed antibacterial activity, and that S. aureus was the most sensitive specie with minimum inhibitory concentration and minimum bactericidal concentrations ranging from 0.8 to 6.4 mg/mL. Additionally, the analysis of antiproliferative activity revealed high potency of PPEs, as the IC50 values ranged from 0.132 mg/mL to 0.396 mg/mL. Multivariate analysis pointed out the most discriminative metabolites for antioxidant or antiproliferative activity. Overall, the pomegranate peel confirmed to be a highly valuable source of bioactive compounds that could be used to improve the food functional characteristics.

Pomegranate (Punica granatum L.) is extensively cultivated in Middle East especially in Iran. For centuries, this fruit has been used in Iranian herbal medicine. Pomegranate peel, seed and juice contain considerable amounts of phenolic compounds and have antioxidant activity. Pomegranate peels, juice and seeds from three regions of Natanz, Shahreza, and Doorak were obtained. Antioxidant activity, total phenolic, flavonoids, and flavonols contents of pomegranate peels, seeds and juices extracts were analyzed. The β-carotene bleaching test and Folin-Ciocalteu method were applied in this study. The pomegranate peel extract showed high levels of antioxidant activity in comparison to seeds and juices. Doorak peel by 58% had the highest antioxidant activity among two other peels. Total phenolics, flavonoids, and flavonols contents of pomegranate peel were evaluated much more higher than seeds and juices. The significant positive correlation between antioxidant activity and total phenolics was reported. According to achieved results, high antioxidant capacity of pomegranate especially peel, had shed light to use them as natural food preservatives., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Pomegranate peel, a waste generated from fruit processing industry, is a potential source of phenolic compounds that are known for their anti-oxidative properties. In this study, a continuous high voltage electrical discharge (HVED) extraction system was for the first time designed and optimized for phenolic compounds from pomegranate peel. The optimal conditions for HVED were: flow rate of materials 12mL/min, electrodes gap distance 3.1mm (corresponding to 29kV/cm of electric field intensity) and liquid to solid ratio 35mL/g. Under these conditions, the experimental yield of phenolic compounds was 196.7±6.4mg/g, which closely agreed with the predicted value (199.83mg/g). Compared with the warm water maceration, HVED method possessed higher efficiency for the extraction of phenolic compounds. The results demonstrated that HVED technique could be a very effective method for continuous extraction of natural compounds., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The present study aims at highlighting the nutritive potential of pomegranate peel and its possible utilization as an ingredient of choice to nutritionally enrich cookies. Biochemical composition and free radical scavenging features of pomegranate peel powder (PoP) and PoP supplemented cookies were measured. PoP supplementation significantly (p < 0.05) improved dietary fibers (0.32-1.96 g/100 g), total phenols (90.7-161.9 mg GAE/100 g) and inorganic residues (0.53-0.76 g/100 g) of cookies. Similarly, significant increase in Ca, K, Fe and Zn levels was noted in supplemented cookies. Almost 50% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was recorded in cookies carrying highest concentration of PoP and phenolic contents. PoP phenolics of supplemented cookies were shown to reduce oxidative degradation during four months storage. Present study suggests PoP supplementation in baked products as a potential source of micro and macronutrients. Application of PoP in ready to serve foods seems to be a potential disease preventive and ameliorative approach in tandem with its preservation and nutritional enhancement features.

Today, food is considered as a source of nutrition. Foods are known as health -giving substances for consumers due to their natural bioactive substances. Phenolic compounds that are found in the peel of pomegranate fruit are among the bioactive compounds. These materials can be used by nanocarriers to enrich food. The purpose of this study is to investigate the phenolic compounds present in five cultivar of Iranian pomegranate peels using the nano method and to further investigate the chemical properties of pomegranate peel extract, including antioxidant, extract extraction efficiency and phenolic properties. This investigation was done by standard curve of gallic acid according to folin -ciocalteu method. Also, the characteristics of the resulting encapsulation were investigated using particle size analysis and zeta potential. The purpose of their comparison is to achieve the highest efficiency among five pomegranate cultivars. The results of the study showed that the peels of the collected pomegranates have significant differences (at the probability level of one percent p<0.05) in terms of physicochemical properties. Examining the results obtained from the physicochemical properties of pomegranate peel extract indicated that white peel pomegranate (Grech Shahwar) had the highest amount of phenolic compounds (78.00±6.72 mg equivalent to gallic acid per 100 grams). It also had the highest antioxidant property of 42%. According to the results obtained from this research, it can be said that the capsules containing pomegranate peel extract (white skin type of Gherch Shahwar) have the best encapsulation efficiency (71%). The use of nanocarriers containing this cultivar of pomegranate in food can have a significant effect on the preservation and stability of compounds sensitive to environmental changes. [ABSTRACT FROM AUTHOR]

Pomegranate (Punica granatum L.), commonly known as a seeded or granular apple, is a delectable fruit eaten worldwide. Pomegranate is one of the healthiest fruits, with a high concentration of phenolic compounds. Large quantities of byproducts, such as seeds and peels, are produced during the pomegranate juice extraction process, which causes disposal problems and environmental contamination. Pomegranate peel (PoP), which accounts for around 30%–40% of the fruit component, is a byproduct of the fruit juice manufacturing industry. PoP is a rich source of polyphenols including phenolic acids, tannins, and flavonoids, especially anthocyanin. These peels offer several functional and nutraceutical qualities owing to their bioactive ingredients, including lowering blood pressure, reducing oxidative stress, lowering cholesterol levels, and restoring heart health. PoPs have a variety of biological effects, including the ability to resist pathogenic microbes effectively, and used as an additive in various food applications. The current review focuses on the PoP's nutritional and practical attributes, as well as their functions as food additives and functional food preparations. [ABSTRACT FROM AUTHOR]

Polyphenols are a broad group of bioactive phytochemicals with powerful antioxidant, anti-inflammatory, immunomodulatory, and antiviral activities. Numerous studies have demonstrated that polyphenol extracts obtained from natural sources can be used for the prevention and treatment of cancer. Pomegranate peel extract is an excellent source of polyphenols, such as punicalagin, punicalin, ellagic acid, and caffeic acid, among others. These phenolic compounds have antineoplastic activity in in vitro models of cervical cancer through the regulation of cellular redox balance, induction of apoptosis, cell cycle arrest, and modulation of different signaling pathways. The current review summarizes recent data from scientific reports that address the anticancer activity of the predominant polyphenol compounds present in PPE and their different mechanisms of action in cervical cancer models. [ABSTRACT FROM AUTHOR]

The purpose of this research was to investigate how common carp (Cyprinus carpio) fingerlings' growth performance, survival rate, chemical composition, and serum biochemical were influenced by pomegranate (Punica granatum) peel powder and its extracts (aqueous and alcoholic). A commercial meal with ~35% crude protein was supplemented with 0.5 and 1% of raw pomegranate peel (RPP), aqueous (PPW), and alcohol (PPA), respectively (three replicates for each treatment). Fish were stocked in aquariums (60 x 40 x 50 cm) at a density of 15 fingerlings per group, and they were fed twice daily for 70 days. The results for specific growth rate (SGR) showed that, excluding RPP0.5 and PPW0.5, as well as for feed conversion (FCR) and protein efficiency (PER), all groups (P<0.05) outperformed the control group (C). Near-infrared spectroscopy (NIR) measurements revealed that protein improved in the RPP1, PPA0.5, and PPW1 groups (P<0.05), whereas fat was improved in the RPP0.5 and PPA1 groups (P<0.05). Ash did not change significantly (P>0.05). PPA showed a significant difference (P<0.05) for AST, however, RPP0.5 and PPW1 did not demonstrate a significant difference (P>0.05) for ALT or ALP compared to the control (C). Regarding kidney efficiency, it was found that RPP, PPA, and PPW were preferable to urea, uric acid, and creatinine. Summary of findings: pomegranate peel enhanced growth as well as chemical composition and biochemical serum parameters when added at a rate between 0.5 and 1%. [ABSTRACT FROM AUTHOR]

Pomegranate peels contain a considerable amount of bioactive chemicals, such as phenolic compounds including gallic acid and ellagic acid. The current study aims to optimize the extraction of total phenolic content (TPC) and its antioxidant capacity from a Pomegranate peel using various approaches involving enzyme and ultrasound, also focusing on process intensification using combination. The optimal parameters for ultrasound treatment were established as treatment time of 25 min, 130 W power, 50 % duty cycle, and a liquid–solid ratio of 50:1 at a fixed 22 kHz frequency, resulting in maximum TPC (21.521 mg GAE/ml) and antioxidant capacity (17.962 mg GAE/ml). Similarly, enzymatic treatment was optimized resulting in best conditions of a time of 55 min, 50 °C as temperature, pH of 5, and a 2 % enzyme concentration. Ultrasound-assisted enzymatic extraction (UAEE) experiments revealed that combining 25 min of ultrasonic treatment with 25 min of enzymatic treatment yielded the highest TPC (30.608 mg GAE/ml) and antioxidant capacity (27.703 mg GAE/ml). It was clearly demonstrated that UAEE outperformed EAE and UAE in terms of Total Phenolic Compound extraction and antioxidant capacity, with the order of efficiency being UAEE > EAE > UAE. [ABSTRACT FROM AUTHOR]

Pomegranate peel enriched with high value of bioactive phenolics with valuable health benefits. However, after extraction of the phenolic compounds, diverse factors can affect their stability. Therefore, we, herein, aimed to prepare W1/O/W2 double nanoemulsions loaded with phenolic-rich extract from pomegranate peel in the W1 phase. Double emulsions were fabricate during a two-step emulsification technique. Furthermore, the influence of sodium carboxymethyl cellulose (CMC) in the outer aqueous phase was also investigated. We found that W1/O/W2 emulsions containing phenolic-rich extract showed good physical stability, especially in the particle size, polydispersity index, zeta potential, and creaming index. Intriguingly, high encapsulation rates of pomegranate polyphenols >95% were achieved; however, emulsion with CMC had the best encapsulation stability during storage. Thus, our study provides helpful information about the double nanoemulsions delivery system for polyphenols generated from pomegranate peel, which may lead to the development of innovative polyphenol-enriched functional foods. [ABSTRACT FROM AUTHOR]

Currently, the synergistic interactions between plant polyphenols and probiotic bacteria are gaining interest with diverse perspectives of applications of both functional ingredients. This study aims to explore and optimize the interaction between pomegranate peel polyphenols and the probiotic strain Lactobacillus rhamnosus ATCC 53103, throughout the co-optimization of the extraction/probiotication techniques. In this context, the response surface methodology (RSM) was applied to find the suitable extraction conditions to obtain phenolic extracts exhibiting a synergistic interaction when fermented with the probiotic strain. A ß-Cyclodextrin ultrasound-assisted extraction technique has been applied for pomegranate polyphenols extraction, followed by the probiotic fermentation of extracts. Results of RSM indicate that for all chosen design responses, the experimental values are in good agreement with the predicted one, with R squared values above 0.8 for all prediction models. Using optimal conditions predicted by the desirability function, it has been found that after probiotication of optimized phenolic extracts, the growth of probiotic strain at presence of polyphenols was possible. Moreover, a significant (p < 0.05) improvement of in vitro antioxidant activity of probioticated extracts was confirmed (an increase on in vitro free radical scavenging activity up to 51.37%). Results of this study, demonstrate for the first time, the feasibility of RSM approach to perform simultaneously the optimization of extraction and probiotication processes of phenolic compounds with the perspective to develop a new bioprocess aiming to produce functional food ingredient or novel nutraceutical products containing both bioactive polyphenols and beneficial probiotic bacteria. [ABSTRACT FROM AUTHOR]

The aim of this research was to investigate the extract of antioxidant and antimicrobial properties of pomegranate peel (PP) wastes and their effect on the E. coli, S. aureus, S.mutans at different concentrations of 10-100%. Total phenolic compound substance and antioxidant modification were inspected using Folin Ciocalteau and ABTS methods respectively. The antimicrobial activity was tested on the microorganisms using diffusion method and the scanning of the phenolic compounds were analyzed using HPLC-DAD and the most abundant compound was estimated to be the punicalin, gallic acid, ellagic acid and quercetin. The most common phenolic compound was detected to bepunicalin and the highest antioxidant activity was about 821.72 mmoltrolox/mg with (60%) acetone extract and the effect on the phenol increased up to 445.04 GAEq (mg GA/g) when PP extracted with ethanol, methanol and (60%)acetone. The results were evaluated and statistically analyzed according to antioxidant and antimicrobial effect of each extract on the E. coli, S. aureus and S.mutans which were found to be the most abundant when PP extracted with (10%-60%) acetone [ABSTRACT FROM AUTHOR]

In this study, a pulsed mode ultrasound assisted extraction was performed for the extraction of bioactive compounds from Pomegranate (Punica granatum L.) peel. Box-Behnken experimental design combined with response surface methodology, was applied for the optimization of process conditions. The independent variables investigated were ultrasound amplitude (50–80%), sonication time (5–15 min), duty cycle (0.2–0.8), and methanol concentration (30–70%) to maximize the yield of total phenolic content, flavonoid content, total condensed and hydrolysable tannin (TCT and THT respectively), and antioxidant activity (DPPH and FRAP). The experimental results were fitted to quadratic models, and statistical analysis in terms of multiple regression, and analysis of variation was carried out for each response variable. The optimum predicted values of the response variables were obtained at 70% methanol concentration, 12.8 min of sonication treatment at a duty cycle of 0.58, and 80% ultrasound amplitude. A comparative analysis at optimized condition showed better recovery of bioactive compounds in pulsed mode, compared to continuous mode of sonication. Correlation analysis of the response variables was done to find the associations among the variables. Multivariate analysis using principal component analysis, and hierarchical cluster analysis was done for better understanding of interactions among experimental treatments and responses. [ABSTRACT FROM AUTHOR]

An environmentally friendly field-portable approach based on small-scale ultrasound-assisted extraction and micro-volume colorimetry was proposed for the determination of iron using natural reagent extracts from pomegranate peels. Ultrasound technology was utilized for the extraction of pomegranate peels in acetate buffer pH 5.5. Sonication parameters influencing the extraction process of natural reagents from pomegranate peel were investigated, including the type of solvent, mass/volume ratio of solvent, sonication time, temperature, and power. The efficiency of the ultrasound-assisted procedure for the extraction of iron from pharmaceutical formulations was evaluated by comparing to their label value and the reference method for pharmaceutical formulations. A linear calibration graph ranging from 1.0 to 10.0 mg L−1 Fe(III) was obtained from micro-volume colorimetric determination (at 530 nm) with limits of detection and quantification of 0.31 and 0.78 mg L−1, respectively. The reproducibility for 3.0 mg L−1 Fe(III) was 3.8% as the relative standard deviation. This developed system was successfully applied to determine the iron content in pharmaceutical formulations and the results agreed well with those obtained by a reference method. Good recoveries between 97 and 105% were obtained. [ABSTRACT FROM AUTHOR]

Due to the use of organic solvents is associated with environmental pollution, toxicological and safety concerns, alternative extraction methods have been investigated. In this study, the efficacy of application of β-Cyclodextrin (β-CD) and ultrasound-assisted extraction (UAE) as an eco-friendly, cost-effective and safe method for extraction of bioactive compounds from pomegranate peel compared to the aqueous extraction method was studied. The response surface method (RSM) was used to optimize extraction conditions. Designed experiments were done based on the Box-Behnken design with three independent variables, including temperature (30, 50 and 70°C), time (10, 25 and 40 min) and concentration of β-CD solution (0, 0.9 and 1.8%). The optimum extracting temperature and time and β-CD concentration were 55.7°C, 15.38 min, 1.8% respectively. In the optimum condition, the following characteristics of extracted bioactive compounds were obtained: total phenolic compounds 158.10 (mgGAE/gDW) with an extraction efficiency of 65.20%, total flavonoids 82.30 (mgQE/gDW) with an extraction efficiency of 60.30%, total flavonols 69.40 (mgQE/gDW) with an extraction efficiency of 58.50%, total anthocyanin 0.52 (mgC–3–gE/gDW) with the extraction efficiency of 42.60%. The Hydrogen Peroxide Radical scavenging activity was 22.90% and the DPPH Radical scavenging activity was 74.40%. The result of the HPLC analysis indicated that β-CD solution improved extraction efficiency of bioactive compounds. As a result, Aqueous β-CDand UAE can effectively be used in recovering bioactive compounds from by-products of fruit processing and therefore for functional foods and nutraceutical applications. [ABSTRACT FROM AUTHOR]

Pomegranate is an important source of bioactive compounds (antioxidant and antimicrobial) and has been used for folk medicine for many centuries. Pomegranate peel had the highest antioxidant activity among the peel, pulp and seed fractions of 28 kinds of fruits commonly consumed. Polyphenols represent the predominant class of phyto-chemicals. Pomegranate peel mainly consists of hydrolysable tannins. Phenolic compounds may exert beneficial effects through their free radical scavenging and antioxidant potential. Among these are hydrolysable tannins, which are mainly located in the fruit peel and mesocarp. In the present study, effect of ethanolic extract of pomegranate peel (PPE) at different levels (0.1 to 0.5%) on functional characteristics of lesser sardine (Sardinella spp.) surimi of was analysed. There was an increasing trend in gel strength values with increase in concentration of PPE but only upto a concentration of 0.4%. Also with the addition of different levels of PPE the value of whiteness decreased with increase in the concentration as compared to control. Effect on expressible moisture, -SH group content and texture analysis were also analysed. Addition of pomegranate peel extract has enhanced gel strength of lesser sardine surimi and other functional properties were also improved that may serve as one of the natural additives in enhancing functional properties of surimi. [ABSTRACT FROM AUTHOR]

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Graphical abstract Highlights • Pomegranate peel and orange waste could be used as biosorbents. • The biosorbents were used after the extraction of their own phenolics. • The sorption followed the intra-particle diffusion model. • The sorption was described better by the Freundlich sorption isotherm. Abstract Several wastes and residues have been studied for the adsorption of phenolic compounds with varying success. However, new economical, easily available, and highly effective adsorbents are still needed. The purpose of this work is to consider the potential of two food wastes derived from agricultural activities, the non-modified pomegranate peel and orange juice by-product, after the removal of their own phenolic content, for phenolics sorption from olive mill wastewater. This procedure is the second step of an integrated approach for complete utilization of these wastes in recovering valuable ingredients, while succeeding total depollution. Initially, the equilibrium time was investigated and afterwards, the effects of sorbent mass concentration (0.01–0.02 g/mL), temperature (20–60 °C), solution's pH (4–7), initial sorbate concentration (50–500 mg/L), and sorbent particle size on total phenols uptake were studied. The highest adsorption efficiencies obtained were 93.13 and 89.59% using pomegranate peel and orange juice by-product, respectively. Total phenols removal efficiency was maximum at pH 4.75 and was improved by decreasing adsorbents dosage, initial sorbate concentration, temperature, and sorbents particle size. The sorption followed the intra-particle diffusion model and was described better by the Freundlich sorption isotherm. The results indicated that the studied materials could be employed as alternative low-cost biosorbents. [ABSTRACT FROM AUTHOR]

In this study, phenolic, flavonoid, antioxidant and antimicrobial properties of pomegranate peel were investigated. The extraction conditions (temperature, time and ethanol concentration) of phenolic and flavonoid compounds obtained under 17 different conditions were optimized using the response surface method. At the end of optimization studies; for pomegranate peels; 78°C, 33% ethanol concentration 113 minutes were determined as the optimum conditions. The obtained extracts were found to have high antioxidant and antimicrobial activity. Phenolic compounds of the extracts obtained under optimum conditions were analyzed by high pressure liquid chromatography and pomegranate peels extracts were found to contain the most quercetin and epicatechin. The results support that pomegranate peels may be potentially useful as an important source of food or nonfood industries. [ABSTRACT FROM AUTHOR]

Steam explosion (SE) pretreatment was applied to modify the physicochemical characterization of pomegranate peel, and the mechanism and kinetics of phenolic compounds extraction was investigated. The SE pretreatment conditions included pressure (0.5, 1.5, and 2.0 Mpa) and time (60, 120, and 180 s). Compared to untreated samples, the SE pretreatment at 1.5 and 2.0 Mpa pressure strengths significantly altered the appearance color, damaged the fiber structure, altered the composition of the cell wall, increased phenolic compounds extraction, and improved the phenolics release and antioxidant activity of pomegranate peel. Based on Fick's second law, the rise of SE strength resulted in the increase of kinetic constants and diffusion coefficients of phenolics, which increased from 1.55 × 10−3 to 3.55 × 10−3 min−1 and 1.97 × 10−9 to 10.35 × 10−9 m2/min, respectively. The activation energy of the extraction of the phenolic for 60, 120, and 180 s pretreatment groups were 11.64, 11.71, and 27.60 kJ/mol, respectively. • SE increased extraction yield of phenolics in pomegranate peel to 20.35% at most. • Phenolics' release kinetics were estimated by Fick's second law model. • D and k values respectively increased to 10.35 × 10−9 m2/min and 3.55 × 10−3 min−1. • At SE time of 180 s, activation energy of phenolics' extraction was 27.60 kJ/mol. • SE significantly improved antioxidant activities of pomegranate peel. [ABSTRACT FROM AUTHOR]

Food impregnation with nutraceutical components due to the health beneficial property is of great importance for food processing industry. In this study, osmotic dehydration was used to impregnate model food with phenolics extracted from pomegranate peel. Intermittent acoustic treatment was applied to enhance mass transfer. This process was carried out at three sucrose concentrations of 40, 50, and 60% and two levels of power ultrasound, 50 and 100% in an experimental setup, which was equipped with a pump circulating osmotic solution frequently. Results showed that increase in sucrose concentration resulted in an increase in the amounts of water loss and solutes gain. Additionally, application of higher power ultrasound led to higher values of water loss and solid gain. Mass transfer modeling using Azuara model predicts water loss and solid gain values at equilibrium. Results revealed the good correlation of experimental values with the model (due to the R2 values greater than 0.94). The microstructure of samples was investigated using scanning electron microscopy (SEM). Images revealed pores and cavities made by ultrasound waves as the result of spongy effects. Texture profile analysis (TPA) was applied for the determination of hardness, springiness, and gumminess of the samples. Results also showed significant effects of the sucrose concentration and ultrasound power on textural properties. Measurements of total phenolic content and antiradical activity, which were carried out by a colorimetric method and antiradical scavenging assay, EC50, respectively indicated that osmotic dehydration is a possible way for uptaking phenolic compounds of pomegranate peel presented in osmotic solution into food matrices. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate a pomegranate peel extract (PPE), selected for its level of phytochemical compounds and antioxidant activities, as a nitrite substitute in dry sausages, as well as its effect on lipid and protein oxidative changes and instrumental colour during the drying period (28 days). Of the extraction solvents screened, water: acetone 3:7 (v /v) was the most effective extraction solvent, yielding extracts with the highest content of phenolic compounds, flavonoids and condensed tannins and antioxidant activities (ABTS, DPPH and FRAP). Four batches of dry sausages were produced with different incoming amounts of sodium nitrite (NaNO 2) and PPE: 1) 150 ppm NaNO 2 ; 2) 0 ppm NaNO 2 ; 3) 0 ppm NaNO 2 + 1% PPE (v / w) and 4) 0 ppm NaNO 2 + 2% PPE (v/w). Nitrite removal increased lipid oxidation in uncured dry sausages, while nitrite and PPE caused lower TBA-RS values in cured and PPE treated sausages. During drying, both nitrite and PPE addition significantly decreased carbonyl and thiol contents compared to the uncured dry sausages. A dose-response was found for PPE, with lower carbonyl and thiol concentrations, the higher the level of PPE added. PPE significantly modified instrumental colour coordinates L*a*b* producing significant total colour changes compared to cured dry sausages. [ABSTRACT FROM AUTHOR]

Pomegranate peel is a valuable byproduct for phenolic extraction. However, comprehensive analysis on novel extraction methods is lacking. In this study, free and bound phenolics, extracted by thermal (heating) and non-thermal methods (conventional solvent, high pressure, and ultrasound), were systematically compared by UHPLC-QTOF-MS and UPLC-QQQ-MS. The total content of free phenolics, approximately 10 times to that of bound phenolics, showed no significant difference across different extraction methods. The highest yield of bound phenolics was obtained by heating and high-pressure methods and the composition was closely dependent on the degree of alkaline hydrolysis. Many of bound phenolics obtained by thermal extraction were small molecules. Meanwhile, a greater proportion of larger compounds were obtained by high-pressure extraction, indicating that high pressure was gentler than thermal extraction. Genistin, nicotiflorin and myricetin-3-galactoside were first reported in pomegranate peel. This study provides a solid foundation for purposeful extraction of phenolics from pomegranate peels for industry. • Free and bound phenolics in pomegranate peel differently extracted were compared. • Both of heating and high pressure methods had the highest yield of bound phenolics. • Alkali hydrolyzed bound phenolic compounds were greatly influenced by methods. • More large molecules of bound phenolics were obtained by high pressure extraction. • Three differential phenolic compounds were firstly reported in pomegranate peel. [ABSTRACT FROM AUTHOR]

• The use of encapsulation with VI technology was performed for the first time. • The diffusion rate increases significantly with the use of encapsulated extract. • Enhancing the diffusion rate increases the effectiveness of VI technology. • The stability of phenolics in impregnated strawberry is increased after use of EPPE during storage. Plant-based phenolic extracts have gained significant attention in the food industry due to their antimicrobial and health-promoting effects. However, their usage is limited because of poor water solubility and instability during processing. Therefore, encapsulation of phenolics with a suitable carrier system is essential for overcoming these problems and increasing their application in food products. In this study, encapsulated phenolic extracts were used for the first time in vacuum impregnation (VI). For this purpose, different phenolic extracts (cinnamon, turmeric, pomegranate peel) were obtained from the plant source. PPE was selected because it has the highest total phenolic content, antioxidant capacity, and antimicrobial activity against Botrytis cinerea. Then, PPE was encapsulated with different emulsifiers (T80, GMO, IN, WPI, and LEC). After the characterization and stability studies were performed, PPE encapsulated with T80 was used to produce a functional strawberry snack by VI technology. The results showed that the diffusion rate of EPPE was significantly increased compared to the control and PPE-VI group. EPPE-enriched strawberries were the preferred snack with high-quality characteristics. [ABSTRACT FROM AUTHOR]

Pomegranate peels of Ganesh variety were subjected to extraction using different solvents viz. water, methanol and ethanol either alone or in combination with water. The extraction yield, antioxidant activity (DPPH and ABTS inhibition) and total phenolic contents were evaluated. Highest yield was obtained from 50 % ethanol: 50 % water (16.3 ± 1.99 %). The DPPH and ABTS inhibition activity was found to be the highest for methanol and 70 % ethanol: 30 % water extract (79.5 ± 6.5; 94.6 ± 6.10), respectively. The phenolic content was the highest in the aqueous extract (438.3 ± 14.15). The antibacterial activity of peel extracts was tested against four bacterial strains, Staphylococcus aureus, Enterobacter aerogenes, Salmonella typhi and Klebsiella pneumoniae and the extracts demonstrated remarkable antibacterial activities against all the tested bacterial strains. The 70 % ethanol: 30 % water and 100 % water extract had a higher antioxidant activity and phenolic content and has the potential for nutraceutical application. [ABSTRACT FROM AUTHOR]

Abstract: The carcinogenic effects of synthetic antioxidants in foods have led to increased interest in natural sources of antioxidants. Food industries produce substantial quantities of phenolics-rich by-products, which have gained much attention due to their antioxidant properties. Ultrasound assisted extraction (UAE) was applied for the extraction of polyphenol and antioxidants from pomegranate (Punica granatum L.) peel using ethanol–water mixture as a food grade solvent. A central composite design (CCD) and response surface methodology (RSM) were used to optimize experimental conditions for extraction of polyphenol and antioxidants. The independent processing variables were solvent type, solvent to solid ratio, particle size, ethanol concentration (% v:v), temperature (°C) and time (min). The dependent variables were total phenolic content (TPC), ferric reducing antioxidant power (FRAP), scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and yield. TPC varied from 5506.42 to 8923.24mg gallic acid equivalent/100g of dry weight. FRAP and DPPH values varied from 24.30 to 63.37mmolFe2+/100g dry weight and 60.12–83.52% inhibition, respectively. Extraction yields ranged from 29.78% to 45.38%. The extract can be used as substitute of synthetic antioxidants for food products, color and oxidative stabilization. Therefore, the highest yield is recommended for industrial applications. The optimal conditions for this aim were 70% ethanol–water mixture as solvent, temperature of 60°C and extraction time of 30min. The experimental values agreed with those predicted by RSM models, thus indicating suitability of the model employed and the success of RSM in optimizing the extraction conditions. [Copyright &y& Elsevier]

Abstract: There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from the dry peel of pomegranate marc were studied using ultrasound-assisted extraction in continuous and pulsed modes and the results were compared with conventional extraction (CE) at a temperature of 25±2°C and water/peel ratio of 50/1, w/w. The studied factors were intensity level and treatment time for continuous ultrasound-assisted extraction (CUAE), and intensity level, number of pulse repetition, and pulse duration and interval for pulsed ultrasound-assisted extraction (PUAE). The results showed that all factors significantly affected the antioxidant yield, but only treatment time had a significant effect on the antioxidant activity. Compared to CE, PUAE at an intensity level of 59.2W/cm2, and a pulse duration of 5s and a resting interval of 5s increased the antioxidant yield by 22% and reduced the extraction time by 87%. Similarly, CUAE at the same intensity level increased the antioxidant yield by 24% and reduced the extraction time by 90%. Since PUAE had 50% energy saving compared to CUAE, we recommend using PUAE for the extraction with antioxidant yield of 14.5% and DPPH scavenging activity of 5.8g/g. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound-assisted extractions under PUAE and CUAE. This research clearly demonstrated the superiority of PUAE for producing antioxidants from peel of pomegranate marc. [Copyright &y& Elsevier]

Abstract: There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from dry peel of pomegranate marc were studied using ultrasound-assisted extraction in continuous and pulsed modes and the results were compared with conventional extraction (CE) at a temperature of 25±2°C and water/peel ratio of 50/1, w/w. The studied factors were intensity level and treatment time for continuous ultrasound-assisted extraction (CUAE), and intensity level, number of pulse repetition, and pulse duration and interval for pulsed ultrasound-assisted extraction (PUAE). The results showed that all factors significantly affected the antioxidant yield, but only treatment time had a significant effect on the antioxidant activity. Compared to CE, PUAE at intensity level of 59.2W/cm2, and the 5 and 5s of pulse duration and interval increased the antioxidant yield by 22% and reduced the extraction time by 87%. Similarly, CUAE at the same intensity level increased the antioxidant yield by 24% and reduced the extraction time by 90%. Since PUAE had 50% energy saving compared to CUAE, we recommend using PUAE for the extraction with antioxidant yield of 14.5% and DPPH scavenging activity of 5.8g/g. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound-assisted extractions under PUAE and CUAE. This research clearly demonstrated the superiority of PUAE for producing antioxidants from peel of pomegranate marc. [Copyright &y& Elsevier]

Pomegranate peel is an agro-industrial waste rich in phenolic compounds that can be employed like natural antioxidants in the food and pharmaceutical industry. In this study, five choline chloride-based natural deep eutectic solvents (NADES), which contained glucose, sucrose, glycerol, lactic acid, and citric acid as a hydrogen bond donor, were physicochemically characterized and tested for recovery of phenolics from pomegranate peel. The efficiency of the NADES in extracting phenolics from pomegranate peel has also been compared with that of conventional ethanolic extraction. The choline chloride and lactic acid (CC-LAC) NADES proved to be the most appropriate for the extraction of phenolics from pomegranate peel (4.14 mg EAG mL−1) if compared to the other tested NADES (range 0.81–3.84 mg EAG mL−1) and also if compared with the ethanolic solution (3.55 mg EAG mL−1). The optimization of the extraction conditions of phenolics from pomegranate waste peels using CC-LAC was carried out by multivariate strategies such as factorial design and response surface methodology. The optimal extraction conditions were 20 g of CC-LAC per g of pomegranate peel, 35% of lactic acid in relation to choline chloride, and 25 min of extraction at 45 °C. Under optimal extraction conditions, the phenolic recovery increased by 54.6%, when compared to CC-LAC non-optimized, and by 84.2%, when compared to ethanolic extraction. Our results, therefore, demonstrated that the use of NADES is a simple, cost-effective, more sustainable, and greener alternative for the extraction of the phenolics from pomegranate peel, over conventional extraction methods. [Display omitted] • NADES were used as alternative solvents to recover pomegranate peel phenolic compounds. • Extraction conditions were optimized using chemometric tools. • Temperature was the only variable with no significant effect on phenolic extraction. • Under optimized conditions, the phenolic content extracted was 54.6% higher. • NADES optimized extraction was an excellent green method by Eco-Scale assessment. [ABSTRACT FROM AUTHOR]

Pomegranate peel has substantial amounts of phenolic compounds, such as hydrolysable tannins (punicalin, punicalagin, ellagic acid, and gallic acid), flavonoids (anthocyanins and catechins), and nutrients, which are responsible for its biological activity. However, during processing, the level of peel compounds can be significantly altered depending on the peel processing technique used, for example, ranging from 38.6 to 50.3 mg/g for punicalagins. This review focuses on the influence of postharvest processing factors on the pharmacological, phytochemical, and nutritional properties of pomegranate (Punica granatum L.) peel. Various peel drying strategies (sun drying, microwave drying, vacuum drying, and oven drying) and different extraction protocols (solvent, super-critical fluid, ultrasound-assisted, microwave-assisted, and pressurized liquid extractions) that are used to recover phytochemical compounds of the pomegranate peel are described. A total phenolic content of 40.8 mg gallic acid equivalent (GAE)/g DM was recorded when sun drying was used, but the recovery of the total phenolic content was higher at 264.3 mg TAE/g when pressurised liquid extraction was performed. However, pressurised liquid extraction is costly due to the high initial investment costs and the limited possibility of carrying out selective extractions of organic compounds from complex peel samples. The effects of these methods on the phytochemical profiles of pomegranate peel extracts are also influenced by the cultivar and conditions used, making it difficult to determine best practice. For example, oven drying at 60 °C resulted in higher levels of punicalin of 888.04 mg CE/kg DM compared to those obtained 40 °C of 768.11 mg CE/kg DM for the Wonderful cultivar. Processes that are easy to set up, cost-effective, and do not compromise the quality and safety aspects of the peel are, thus, more desirable. From the literature survey, we identified a lack of studies testing pretreatment protocols that may result in a lower loss of the valuable biological compounds of pomegranate peels to allow for full exploitation of their health-promoting properties in potentially new value-added products. [ABSTRACT FROM AUTHOR]

• Pomegranate peel extract was encapsulated with orange juice by-products. • The stability of the crude and the encapsulated extract were evaluated during storage. • The extracts were used as functional components in cookies. • Encapsulation had a significant effect on the retention of phenolic compounds. • The extracts could be incorporated in cookies without negatively affecting sensory quality. Orange juice by-products are proposed as a "green" wall material for the encapsulation of pomegranate peel extract. Stability of crude and encapsulated peel extract was studied under accelerated storage conditions, in terms of phenolic content, antiradical activity, and color. The obtained extracts were used as biofunctional components in cookies, at a phenolics concentration of 5000 ppm. Their effects on phenolics content, antioxidant activity, color, and sensory attributes during baking and storage were examined. It was observed that a large amount of phenolic compounds was degraded during baking even if they were coated. However, encapsulation had a significant effect (p < 0.05) on the retention and the activities of phenolic compounds as compared to non encapsulated. Moreover, the results showed that the extracts could be incorporated in cookies without negatively affecting sensory quality. [ABSTRACT FROM AUTHOR]

The growing demand for natural food preservatives has promoted investigations on their application for preserving perishable foods. Consequently, the meat market is demanding natural antioxidants, free of synthetic additives and able to diminish the oxidation processes in high-fat meat and meat products. In this context, the present review discuss the development of healthier and shelf stable meat products by the successful use of pomegranate peel extracts containing phenolics as natural preservative agent in meat and meat products. This paper carries out an exhaustive review of the scientific literature on the main active phenolic compounds of pomegranate peel identified and quantified by advances in the separation sciences and spectrometry, and its biological activities evaluation. Moreover, the impact of pomegranate peel use on the quality and oxidative stability of meat products is also evaluated. As natural preservative, pomegranate peel phenolics could improve stored meat products quality, namely instrumental color retaining, limitaion of microflora growth, retardation of lipid and protein oxidation. [ABSTRACT FROM AUTHOR]

• CPE was proved as a green extraction method for determination of total phenolics and flavonoids. • CPE is novel, green, cost effective, enviro-friendly yet simple. • This method can be used for extraction of bioactives from food systems. • CPE extractives can be used for green and clean label. • CPE can be suitable technique for sample preparation of sophisticated analysis of food and pharmaceutical materials. Cloud point extraction (CPE) is one of the novel; environment-friendly; energy; time and cost-effective extraction technique. Therefore, in the present work preconcentration and separation of bioactive compounds from pomegranate peel, a major waste of the pomegranate processing industry was carried out using CPE. CPE works on the principle of entrapping the hydrophobic bioactive compound in the micelle. Surfactant concentration (5–11%), pH (4–8), temperature (30–60 °C), and salt concentration (4–12%) optimization was carried out to separate total phenols and flavonoids with maximum recovery (%R), partition coefficient (K s/a), fraction concentration (f c), and minimum loss (%L) using the rotatable central composite design (RCCD). The optimum levels were 8.22% surfactant (Triton X-114), 4% salt (NaCl) at temperature of 36.80 °C and pH 4 which resulted in 95% recovery, 14.59 K s/a , 0.95 f c and 5.27% loss of total phenols with the maximum desirability about 0.846. While in the case of total flavonoids at 8.27% Triton X-114 at pH 5.07/34.30 °C and 4.06% NaCl resulted, 98% recovery, 9.71 K s/a , 1.01 f c , and 2% loss with 0.842 desirability. The total yield obtained for total phenols was 205.2 mg of GAE/g while for total flavonoids it was 60.05 mg of QE/g of pomegranate peel powder. Therefore, it can be concluded that this method can be successfully applied in the extraction of bioactive from any food systems for clean and green extractives label. [ABSTRACT FROM AUTHOR]