Pomegranate peel as phenolic compounds source: Advanced analytical strategies and practical use in meat products

A robust and simple non-enzymatic electrochemical sensor based on carbon dots-metal oxide composite for the detection of metronidazole traces in food products

A facile and simple electrochemical composite sensor, CDs-Ag@Cu2O-GA, prepared from carbon dots stabilized silver nanoparticles and copper oxide, was used as an electrocatalyst and signal amplifier for the non-enzymatic detection of antibiotic traces in food products. The prepared composite demonstrated excellent stability, sensitivity, and cost-effectiveness. The sensor was constructed by modifying a glassy carbon electrode (GCE) with CDs-Ag@Cu2O-GA, and the electroanalytical response was determined for the precise determination of metronidazole (MTZ) drug traces in milk. The analytical response signified fast electron transfer and accessibility of several electroactive sites, producing an amplified response for the reduction of MTZ. The quantitative analysis by the sensor revealed a good linear range (10-110 μM), a low limit of detection (7.1 × 10-7 molL-1), and a high sensitivity (1.5 μA μM-1 cm-2). Furthermore, the sensor displayed excellent potential for practical applications, verified by the good recovery of the drug from spiked milk samples.

Effects of Fermented Pomegranate Peel Polyphenols on the Growth Performance, Immune Response, Hepatopancreatic Health, and Disease Resistance in White Shrimp (Litopenaeus vannamei)

This study evaluated the growth performance, immune response, hepatopancreatic health, and disease resistance in Litopenaeus vannamei fed diets supplemented with fermented pomegranate peel polyphenols (FPPP) for 45 days. Five diets were formulated to contain various levels of FPPP: FP0 (no FPPP), FPPP inclusion at 0.015% (FP1), 0.030% (FP2), 0.060% (FP3), and 0.120% (FP4). The results indicated there were no significant variations in weight gain rate (WGR), specific growth rate (SGR), and feed conversion rate (FCR) of shrimp in all treatment groups (p > 0.05), but the survival (SR) of shrimp was significantly higher in all groups with the addition of FPPP (p < 0.05). Compared with FP0 group, the contents of total protein (TP) and globulin (GLB) in serum biochemical indexes of FP3 and FP4 groups were significantly increased, and the content of blood urea nitrogen (BUN) was significantly decreased (p < 0.05). Compared with FP0 group, the activities of superoxide dismutase (SOD), catalase (CAT), alkaline phosphatase (AKP), acid phosphatase (ACP), and lysozyme (LZM) in the hepatopancreas and serum of FP3 and FP4 groups were significantly increased (p < 0.05). Similarly, the activities of glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and phenoloxidase (PO) in the hepatopancreas and serum of FP2 group were significantly higher than those of FP0 group (p < 0.05). In addition, the content of malondialdehyde (MDA) in the hepatopancreas and serum of shrimp in FPPP-added groups was decreased (p < 0.05). Compared with FP0 group, the expression levels of SOD, CAT, glutathione S-transferase (GST), LZM, prophenoloxidase (ProPO), penaeidin-3 (Pen3), Crustin, immune deficiency (Imd), Toll, and Relish genes were significantly upregulated in the hepatopancreas of shrimp in FP3 and FP4 groups (p < 0.05). Additionally, increasing the addition level of FPPP resulted in a more compact hepatosomal arrangement of the shrimp's hepatopancreas, a more visible star-shaped lumen structure, and a significantly higher number of B cells. Finally, the cumulative SR of shrimp in FPPP groups was significantly higher than that in FP0 group after 7 days of infection with Vibrio alginolyticus (p < 0.05). In summary, dietary supplementation of FPPP can improve SR, immunity, and hepatopancreatic health and resistance to Vibrio alginolyticus of L. vannamei.

Antibacterial Effect of Fermented Pomegranate Peel Polyphenols on Vibrio alginolyticus and Its Mechanism

Vibrio alginolyticus frequently breaks out in aquatic animal breeding operations involving shrimp, and it can endanger human health through food and wound infections. The antibacterial effect and mechanism of fermented pomegranate peel polyphenols (FPPPs) on V. alginolyticus were investigated. The results indicated that FPPPs had a strong inhibitory effect on the growth of V. alginolyticus, and their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were 2 and 4 mg/mL. FPPPs significantly reduced biofilm formation and biofilm metabolic activity in V. alginolyticus, down-regulated the expression levels of lafA, lafK, fliS and flaK genes involved in flagellar synthesis and inhibited swimming and swarming motility (p < 0.05). Meanwhile, under the treatment of FPPPs, the activities of catalase (CAT) and superoxide dismutase (SOD) in V. alginolyticus were significantly reduced, and the levels of reactive oxygen species (ROS) and extracellular malondialdehyde (MDA) were significantly increased (p < 0.05). FPPPs also resulted in a significant increase in alkaline phosphatase (AKP) activity, protein and nucleic acid content, as well as conductivity from V. alginolyticus cultures. Scanning electron microscopy (SEM) images further revealed that V. alginolyticus treated with FPPPs showed leakage of intracellular substances, abnormal cell morphology and damage to cell walls and cell membranes, with the severity of the damage in a clear dose-dependent manner. Therefore, FPPPs can be used as a promising food-grade antibacterial agent, notably in seafood to control V. alginolyticus.

In Vitro Assessment of the Neuroprotective Effects of Pomegranate (Punica granatum L.) Polyphenols Against Tau Phosphorylation, Neuroinflammation, and Oxidative Stress

BACKGROUND

Oxidative stress and chronic inflammation, at both the systemic and the central level, are critical early events in atherosclerosis and Alzheimer's disease (AD).

PURPOSE

To investigate the oxidative stress-, inflammation-, and Tau-phosphorylation-lowering effects of pomegranate polyphenols (PPs) (punicalagin, ellagic acid, peel, and aril extracts).

METHODS

We used flow cytometry to quantify the protein expression of proinflammatory cytokines (IL-1β) and anti-inflammatory mediators (IL-10) in THP-1 macrophages, as well as M1/M2 cell-specific marker (CD86 and CD163) expression in human microglia HMC3 cells. The IL-10 protein expression was also quantified in U373-MG human astrocytes. The effect of PPs on human amyloid beta 1-42 (Aβ1-42)-induced oxidative stress was assessed in the microglia by measuring ROS generation and lipid peroxidation, using 2',7'-dichlorofluorescein diacetate (DCFH-DA) and thiobarbituric acid reactive substance (TBARS) tests, respectively. Neuronal viability and cell apoptotic response to Aβ1-42 toxicity were assayed using the MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay and the annexin-V-FITC apoptosis detection kit, respectively. Finally, flow cytometry analysis was also performed to evaluate the ability of PPs to modulate Aβ1-42-induced Tau-181 phosphorylation (pTau-181).

RESULTS

Our data indicate that PPs are significantly (p < 0.05) effective in countering Aβ1-42-induced inflammation through increasing the anti-inflammatory cytokines (IL-10) in U373-MG astrocytes and THP1 macrophages and decreasing proinflammatory marker (IL-1β) expression in THP1 macrophages. The PPs were also significantly (p < 0.05) effective in inducing the phenotypic transition of THP-1 macrophages and microglial cells from M1 to M2 by decreasing CD86 and increasing CD163 surface receptor expression. Moreover, our treatments have a significant (p < 0.05) beneficial impact on oxidative stress, illustrated in the reduction in TBARS and ROS generation. Our treatments have significant (p < 0.05) cell viability improvement capacities and anti-apoptotic effects on human H4 neurons. Furthermore, our results suggest that Aβ1-42 significantly (p < 0.05) increases pTau-181. This effect is significantly (p < 0.05) attenuated by arils, peels, and punicalagin and drastically reduced by the ellagic acid treatment.

CONCLUSION

Overall, our results attribute to PPs anti-inflammatory, antioxidant, anti-apoptotic, and anti-Tau-pathology potential. Future studies should aim to extend our knowledge of the potential role of PPs in Aβ1-42-induced neurodegeneration, particularly concerning its association with the tauopathy involved in AD.

Electrospun Nanofibers with Pomegranate Peel Extract as a New Concept for Treating Oral Infections

Pomegranate peel extract is known for its potent antibacterial, antiviral, antioxidant, anti-inflammatory, wound healing, and probiotic properties, leading to its use in treating oral infections. In the first stage of this work, for the first time, using the Design of Experiment (DoE) approach, pomegranate peel extract (70% methanol, temperature 70 °C, and three cycles per 90 min) was optimized and obtained, which showed optimal antioxidant and anti-inflammatory properties. The optimized extract showed antibacterial activity against oral pathogenic bacteria. The second part of this study focused on optimizing an electrospinning process for a combination of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers loaded with the optimized pomegranate peel extract. The characterization of the nanofibers was confirmed by using SEM pictures, XRPD diffractograms, and IR-ATR spectra. The composition of the nanofibers can control the release; in the case of PVP-based nanofibers, immediate release was achieved within 30 min, while in the case of PCL/PVP, controlled release was completed within 24 h. Analysis of the effect of different scaffold compositions of the obtained electrofibers showed that those based on PCL/PVP had better wound healing potential. The proposed strategy to produce electrospun nanofibers with pomegranate peel extract is the first and innovative approach to better use the synergy of biological action of active compounds present in extracts in a patient-friendly pharmaceutical form, beneficial for treating oral infections.

Phytochemical profile, nutritional composition of pomegranate peel and peel extract as a potential source of nutraceutical: A comprehensive review

The current study focuses on Punica granatum L. (pomegranate) peel and peel extract and their use as functional foods, food additives, or physiologically active constituents in nutraceutical formulations. The pomegranate peel extract is a good source of bioactive substances needed for the biological activity of the fruit, including phenolic acids, minerals, flavonoids (anthocyanins), and hydrolyzable tannins (gallic acid). The macromolecules found in pomegranate peel and peel extract have been recommended as substitutes for synthetic nutraceuticals, food additives, and chemo-preventive agents because of their well-known ethno-medical significance and chemical properties. Moreover, considering the promises for both their health-promoting activities and chemical properties, the dietary and nutraceutical significance of pomegranate peel and pomegranate peel extract appears to be underestimated. The present review article details their nutritional composition, phytochemical profile, food applications, nutraceutical action, and health benefits.

Assessing the Impact of Pomegranate Peel Extract Active Packaging and High Hydrostatic Pressure Processing on Color and Oxidative Stability in Sliced Nitrate/Nitrite-Reduced Iberian Dry-Cured Loins

Our study aimed to assess the impact of active packaging with pomegranate peel extract (0.06 mg gallic acid eq./cm2) and/or high-pressure treatment (600 MPa, 7 min) on the instrumental color, lipid, and protein oxidation of Iberian dry loins formulated with reduced nitrate/nitrite levels (0, 37.5, and 150 mg/kg) during 100-day refrigerated storage (4 °C). CIE L*a*b* coordinates were measured, and malondialdehyde, carbonyls, and free thiol contents served as markers for lipid and protein oxidation. Active packaging lowered CIE L* (35.4 vs. 34.1) and a* (15.5 vs. 14.5) and increased yellowness (15.6 vs. 16.3) and hue (45.2 vs. 48.4), while pressurization increased CIE L* (33.1 vs. 36.3) and diminished a* values (16.1 vs. 13.9). Ongoing nitrate/nitrite amounts significantly influenced lipid peroxidation, protein carbonyl formation, and free thiol loss. Active packaging and high-pressure processing had varying effects on carbonyl and thiol contents. Neither pressurization nor active packaging impacted malondialdehyde formation. Pressurization enhanced the formation of 4-HNE (503 vs. 697 pg/g). Protein oxidation proved more sensitive to changes, with active packaging offering protection against protein carbonylation (15.4 vs. 14.7 nmol carbonyls/mg protein), while pressurization induced thiol loss (34.3 vs. 28.0 nmol Cys eq./mg protein). This comprehensive understanding provides essential insights for the meat industry, emphasizing the necessity for customized processing conditions to enhance color stability, lipid preservation, and protein integrity in dry-cured loin slices.

Potential usage of biosynthesized zinc oxide nanoparticles from mangosteen peel ethanol extract to inhibit Xanthomonas oryzae and promote rice growth

In recent decades, the biosynthesis of nanoparticles using biological agents, such as plant extracts, has grown in popularity due to their environmental and economic benefits. Therefore, this study investigated into utilizing ethanol crude extract sourced from mangosteen peel for the synthesis of zinc oxide nanoparticles (ZnO NPs) and assessing their efficacy against the rice blight pathogen (Xanthomonas oryzae pv. oryzae) through antibacterial evaluations. Additionally, the effects of the synthesized ZnO NPs on rice plant growth was investigated. The X-ray diffraction analysis revealed the production of wurtzite ZnO NPs under specific synthesis conditions, exhibiting a crystallite size of 38.71 nm (or 387.122 Å) without any contamination. Analysis of the ultraviolet-visible optical absorption spectrum indicated a characteristic absorption peak at 363 nm, suggesting a calculated band gap energy of 2.88 eV for the ZnO NPs. Furthermore, Fourier transform infrared spectroscopy analysis confirmed the presence of active compounds functional groups from mangosteen peel in the synthesized ZnO NPs. These biosynthesized ZnO NPs demonstrated significant inhibition of X. oryzae pv. oryzae growth, exhibiting an in vitro 50 % inhibitory concentration (IC50) value of 1.895 mg/mL and a minimum inhibitory concentration (MIC) value of 4 mg/mL. The ZnO NPs treatments at two-fold IC50 values significantly enhanced root length, dry biomass, and chlorophyll a content in rice plants. Consequently, the results demonstrated the potential application of biosynthesized ZnO NPs from mangosteen peel extract in green agriculture, as an alternative to excessive antibiotic use, for combating bacterial plant diseases, and for enhancing plant growth.

Development and characterization of pomegranate peel extract-functionalized jackfruit seed starch-based edible films and coatings for prolonging the shelf life of white grapes

In the current research, the pomegranate peel extract of varying concentrations (0.02, 0.04, 0.06, 0.08, and 0.1 g/mL) were incorporated into jackfruit seed starch (5 % w/w) based edible films and coatings for the evaluation their effects on the mechanical, physical, barrier and thermal properties. Furthermore, the effects of the optimized edible coating were investigated on the postharvest shelf life of white grapes at room storage (30 ± 5 °C, RH = 70 ± 5 %) conditions for up to 8 days. The obtained results showed a significant increment in thickness (p ≤ 0.05) with higher concentration (0.1 g/mL) of pomegranate peel extract (PPE), total phenolic content (959.33 ± 43.36 mg/100 g) and antioxidant activity (87.35 ± 1.64 %) of the prepared edible films but have negative impacts on the water vapor permeability (2.82 × 10-6 ± 6.48 × 10-7 g-1h-1pa-1) and oxygen permeability (1.62 × 10-14 ± 9.32 × 10-15 cm3·cm/cm2·s·cmHg), solubility (23.24 ± 3.21 %), and tensile strength (1.60 ± 0.43 MPa). The edible film enriched with 0.4 g/mL of PPE showed higher thermal stability in terms of glass transition temperature (98.2 ± 0.21 °C) and peak temperature (110.3 ± 0.35 °C). Additionally, the application of coating treatment significantly maintains the postharvest shelf life of white grapes throughout the storage period.

A review of experimental and clinical studies on the therapeutic effects of pomegranate (Punica granatum) on non-alcoholic fatty liver disease: Focus on oxidative stress and inflammation

Non-alcoholic fatty liver disease (NAFLD) is frequently linked to metabolic disorders and is prevalent in obese and diabetic patients. The pathophysiology of NAFLD involves multiple factors, including insulin resistance (IR), oxidative stress (OS), inflammation, and genetic predisposition. Recently, there has been an emphasis on the use of herbal remedies with many people around the world resorting to phytonutrients or nutraceuticals for treatment of numerous health challenges in various national healthcare settings. Pomegranate (Punica granatum) parts, such as juice, peel, seed and flower, have high polyphenol content and is well known for its antioxidant capabilities. Pomegranate polyphenols, such as hydrolyzable tannins, anthocyanins, and flavonoids, have high antioxidant capabilities that can help lower the OS and inflammation associated with NAFLD. The study aimed to investigate whether pomegranate parts could attenuate OS, inflammation, and other risk factors associated with NAFLD, and ultimately prevent the development of the disease. The findings of this study revealed that: 1. pomegranate juice contains hypoglycemic qualities that can assist manage blood sugar levels, which is vital for avoiding and treating NAFLD. 2. Polyphenols from pomegranate flowers increase paraoxonase 1 (PON1) mRNA and protein levels in the liver, which can help protect liver enzymes and prevent NAFLD. 3. Punicalagin (PU) is one of the major ellagitannins found in pomegranate, and PU-enriched pomegranate extract (PE) has been shown to inhibit HFD-induced hyperlipidemia and hepatic lipid deposition in rats. 4. Pomegranate fruit consumption, which is high in antioxidants, can decrease the activity of AST and ALT (markers of liver damage), lower TNF-α (a marker of inflammation), and improve overall antioxidant capacity in NAFLD patients. Overall, the polyphenols in pomegranate extracts have antioxidant, anti-inflammatory, hypoglycemic, and protective effects on liver enzymes, which can help prevent and manage NAFLD effects on liver enzymes, which can help prevent and manage NAFLD.

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.

Modulatory effect of pomegranate peel extract on key regulators of ovarian cellular processes in vitro

In this study, response of ovarian cells (human granulosa cell line HGL5, and human adenocarcinoma cell line OVCAR-3) to short-term pomegranate peel extract (PPE) treatment (for 24 hours in cell culture) was evaluated in vitro. Quantitative and qualitative screening of polyphenols revealed punicalagins α and β as major polyphenolic components. Total phenolic content (TPC) was 93.76 mg GAE/g d.w. with a high antioxidant activity of 95.30 mg TEAC/g d.w. In OVCAR-3, PPE treatment inhibited the metabolic activity, and increased cyclin-dependent kinase 1 (CDKN1A, p21) level at the highest dose, but not in HGL5. Flow cytometry analysis could not detect any significant difference between proportions of live, dead, and apoptotic cells in both cell lines. Reactive oxygen species (ROS) revealed an antioxidant effect on HGL5, and a prooxidant effect by stimulating ROS generation in OVCAR-3 cells at the higher doses of PPE. However, in contrast to HGL5, PPE treatment decreased release of growth factors - TGF-β2 and EGF at the highest dose, as well as their receptors TGFBR2 and EGFR in OVCAR-3 cells. PPE also influenced steroidogenesis in granulosa cells HGL5 by stimulating 17β-estradiol secretion at higher doses. In conclusion, the present study highlighted the bioactive compounds in pomegranate peels and the possible mechanisms of action of PPE, shedding light on its promising role in ovarian cancer (chemo)prevention and/or management.

Pomegranate Peel Phytochemistry, Pharmacological Properties, Methods of Extraction, and Its Application: A Comprehensive Review

Pomegranate peel, derived from the processing of Punica granatum L. (pomegranate), has traditionally been considered agricultural waste. However, recent studies have revealed its potential as a rich source of bioactive compounds with diverse pharmacological effects. Pomegranate peel is a rich reservoir of antioxidants, polyphenols, dietary fiber, and vitamins, which contribute to its remarkable bioactivity. Studies have demonstrated the anti-inflammatory, cardioprotective, wound healing, anticancer, and antimicrobial properties of pomegranate peel owing to the presence of phytochemicals, such as gallic acid, ellagic acid, and punicalagin. The extraction of bioactive compounds from pomegranate peel requires a careful selection of techniques to maximize the yield and quality. Green extraction methods, including pressurized liquid extraction (PLE), ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and enzyme-assisted extraction (EAE), offer efficient and sustainable alternatives to traditional methods. Furthermore, pomegranate peel has been utilized in the food industry, where it can significantly enhance the nutritional value, organoleptic characteristics, and shelf life of food products. Pomegranate peel has the potential to be used to develop innovative functional foods, nutraceuticals, and other value-added products, providing new opportunities for the pharmaceutical, cosmetic, and food industries.

Development of chicken tender pops by utilizing pomegranate peel powder

Pomegranate peel powder (PPP) is a rich source of many bioactive components particularly polyphenols that are interlinked to various technological and functional properties. In the present study, chicken tender pops were developed with incorporation of PPP, and its effect on quality attributes and storage stability of the product were evaluated. The treatments were formulated using 0%, 3%, 6%, and 9% PPP in replacement of chicken. The physicochemical properties, texture profile, instrumental color, sensory attributes, and storage stability were assessed for 21 days at refrigeration temperature, at a regular interval of 7 days. The results indicated that the inclusion of PPP significantly (p < .05) increased the dietary fiber from 0.25% in T0 to 1.45% in T3 at Day 0 and WHC 43.60% ± 0.02 in T0 to 49.36% ± 0.02 in T3 at Day 0, whereas the moisture content significantly reduced from 60.05% ± 0.03 in T0 to 55.08% ± 0.01 in T3 at the start of the study. In addition, the values of TBARS were significantly (p < .05) reduced for treated samples 0.72 mg MDA/Kg in T3 as compared to control 1.17 mg MDA/Kg on the 21st day of storage, whereas a significant increase (p < .05) in TPC from 0.90 mg GAE/g to 3.87 mg GAE/g in T0 to T3 was observed at the start of the study. For TPA, a significant (p < .05) increase was noticed in hardness, chewiness, and gumminess, whereas cohesiveness and springiness showed a non-significant (p > .05) change in treated samples in relation to control, and the instrumental color (L* and a*) decreased significantly. However, pH, crude fiber, fat, ash, and protein content showed non-significant (p > .05) variations over time. The sensory evaluation suggested that chicken tender pops supplemented with 6% PPP (T2) presented high overall acceptability and balanced organoleptic properties. Hence, it can be concluded that PPP can be effectively utilized as a natural fiber source, antioxidant, and antimicrobial agent in novel functional foods.

FTIR spectroscopy-based lipochemical fingerprints involved in pomegranate response to water stress

Pomegranate trees are known for their ability to withstand drought conditions, but there is still much to learn about how water stress affects the lipobiochemical behavior of their seeds. This study aimed to investigate how sustained deficit irrigation (SDI-50), equivalent to 50% of crop evapotranspiration, influences pomegranate seed oil attributes such as phenols, flavonoids, and tannins content, and the seeds' lipochemical fingerprints compared to fully irrigated trees. At the full ripening stage, pomegranate seeds were analyzed for their oil content, biochemical traits, and vibrational fingerprints using infrared radiation. The results indicated that there was a significant genotypic effect coupled with applied water stress on all the investigated traits. Interestingly, an increasing trend in seed oil yield was observed under water stress conditions compared to the control, with the highest oil yield increase observed in the 'Zheri Precoce' fruit seeds. Only two cultivars did not show the same pattern, with the oil yield increase ranging from 8% to 100%. Furthermore, SDI-50 induced a substantial increase in total phenolic content, coupled with a significant genotypic effect, and resulted in an average increase of 7.5%. This increase in total phenolics also correlated with an increase in antioxidant activity across all investigated cultivars. ATR-FTIR fingerprinting revealed eleven spectral fingerprints corresponding to functional groups present in pomegranate seeds oil, with a particular pattern of significant effects of both genotypic and SDI-50 factors. These results suggest that exploiting water scarcity conditions could be a viable approach to improve the quantitative and qualitative attributes of pomegranate seed oil. While there are still several aspects to be investigated further, this study provides a basis for pomegranate processing under water shortage conditions.

Nutritional importance and industrial uses of pomegranate peel: A critical review

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.

Pomegranate peel as a source of antioxidants for the control of lipid and protein oxidation during the ripening of Iberian dry uncured sausages

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 (NaNO₂) and PPE: 1) 150 ppm NaNO₂; 2) 0 ppm NaNO₂; 3) 0 ppm NaNO₂ + 1% PPE (v/w) and 4) 0 ppm NaNO₂ + 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.

Potential of phenolic compounds from pomegranate (Punica granatum L.) by-product with significant antioxidant and therapeutic effects: A narrative review

The wealth of epidemiological evidence in the scientific world underscores the possibility that a plant-based diet can reduce the prevalence of common diseases such as diabetes, cardiovascular disease, cancer, and stroke. The therapeutic effects of plant sources are partly explained by phenolic secondary metabolites or polyphenolic compounds. Therefore, polyphenolic compounds, which are widely distributed in plants, are of great interest for the development of effective specific drugs with antioxidant and anti-inflammatory effects. Moreover, polyphenol compounds have no harmful effects due to their natural biocompatibility and safety. Numerous studies have highlighted the potential of some industrial food wastes from plant material processing, including apple peels and mashed potatoes, grape skins, tomato and carrot peels, pomegranate peels and seeds, and many others. These byproducts are considered low-cost sources of natural biological compounds, including antioxidants, which have beneficial effects on human health. The polyphenol complex of pomegranate peel (Punica granatum L.), which makes up half of the pomegranate fruit, has more pronounced antioxidant and anti-inflammatory properties than other parts. And the most important active components of pomegranate peel, which are found only in this plant, are punicalagin, followed by ellagic acid and gallic acid. It is known that these polyphenolic compounds of pomegranate peel have the most pronounced therapeutic effect. Several studies have shown the protective effect of ellagic acid, punicalagin, against oxidative stress damage caused by free radicals. The potential of pomegranate peel as an antioxidant and therapeutic component in various biological systems is high, according to scientific sources. However, despite extensive research in recent years, a review of sources has shown that there is insufficient evidence to support the therapeutic effects of polyphenolic compounds from pomegranate peels. The role of pomegranate peel polyphenolic compounds, including flavonoids, as antioxidants in various biological systems also requires further research. Of particular importance are the mechanisms by which antioxidants influence the cellular response against oxidative stress. The purpose of this review was to report our current knowledge of plant polyphenolic compounds and their classification, and to evaluate the potential of phenolic compounds from pomegranate peels with significant antioxidant and therapeutic effects.

Effects of Dietary Supplementation of Pomegranate Peel with Xylanase on Egg Quality and Antioxidant Parameters in Laying Hens

Pomegranate contains bioactive compounds in all its parts. In this study, two levels of pomegranate peel byproduct (PPB) with or without the inclusion of xylanase enzyme were used to supplement laying hens' diet, in a 2 × 2 full factorial design. A total of 48 Isa brown laying hens were fed the following experimental diets for 8 weeks: T1 (2.5% PPB); T2 (2.5% PPB and xylanase); T3 (5% PPB); T4 (5% PPB and xylanase). Eggs collected were analyzed for egg quality parameters. Moreover, egg yolks were analyzed for Malondialdehyde content (MDA), fatty acid profile and total phenolic content. The T2 eggs showed enhanced yolk coloration and greater yolk total phenolic content. The T3 and T4 egg yolks showed lower MDA levels compared with T1, T2. Overall, results have shown that (a) xylanase inclusion affected egg yolk coloration and total phenolic content when combined with 2.5% PPB dietary supplementation; (b) dietary supplementation of 5% PPB resulted in eggs with reduced MDA levels.

The Therapeutic Alliance between Pomegranate and Health Emphasizing on Anticancer Properties

Pomegranate is a fruit bearing-plant that is well known for its medicinal properties. Pomegranate is a good source of phenolic acids, tannins, and flavonoids. Pomegranate juice and by-products have attracted the scientific interest due to their potential health benefits. Currently, the medical community has showed great interest in exploiting pomegranate potential as a protective agent against several human diseases including cancer. This is demonstrated by the fact that there are more than 800 reports in the literature reporting pomegranate's anticancer properties. This review is an update on the research outcomes of pomegranate's potential against different types of human diseases, emphasizing on cancer. In addition, perspectives of potential applications of pomegranate, as a natural additive aiming to improve the quality of animal products, are discussed.

Anticancer Effect of Pomegranate Peel Polyphenols against Cervical Cancer

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.

Effect of Extract of Perilla Leaves on the Quality Characteristics and Polycyclic Aromatic Hydrocarbons of Charcoal Barbecued Pork Patty

This study aimed to investigate the effect of ethanolic extracts from perilla leaves (PLE) on the quality attributes and polycyclic aromatic hydrocarbons (PAHs) in charcoal-barbecued pork patties. The PLE addition and doneness had no significant effect on the pH of pork patties (p>0.05). Regardless of the concentration, the PLE significantly lower malondialdehyde concentrations and reduced the CIE L*, CIE a*, and CIE b* when compared to control. The addition of 0.2% of PLE did not adversely affect the organoleptic properties of doneness of medium and well-done pork patties. Addition of PLE at 0.4% to medium-cooked pork patties had stronger suppressing effect on the formation of light PAHs compare to control (p<0.05), also adding it to well-done pork patties had the lowest concentration of 4 PAHs and 8 PAHs, and a total of 16 PAHs (p<0.05). Therefore, PLE at 0.4% can be used for suppressing the formation of PAHs and lipid oxidation in well-cooked pork patty.

Grape skin flour obtained from wine processing as an antioxidant in beef burgers

The objective of this study was to determine the best level of wine making by-product meal (WBM) as a natural antioxidant to replace butylhydroxytoluene (BHT) in beef burger stored at -20 °C for up to 120 days. The treatments consisted of control (basic formulation - BF, without antioxidant); BF with BHT; and BF with WBM0.5, WBM1.0, WBM1.5, and WBM2.0, with 0.5, 1.0, 1.5 and 2.0 g WBM/100 g BF, respectively. Up to 60 days of storage, the lipid oxidation value between BHT and WBM0.5 treatments did not differ and were lower than the values presented by the other treatments. On day 90 and 120, the lipid oxidation values of treatments BHT, WBM0.5, and WBM1.0 did not differ and were lower than the values presented by WBM1.5 and WBM2.0 treatments. Burgers from all treatments with WBM inclusion had crude fiber values above 3 g/100 g. WBM1.5 and WBM2.0 treatments had the worst scores for appearance, aroma, juiciness and tenderness, in addition to the highest cooking losses. WBM can be used at up to 1 g/100 g to replace BHT in frozen beef burgers. Higher levels of WBM inclusion increased lipid oxidation and negatively affected the sensory quality of burgers.

Pomegranate peel phenolics: One step water extraction, in vitro antiproliferative activity, and effect on sensory attributes of muffins and cheese

Pomegranate is one of the richest fruits species in bioactive compounds, including its non-edible parts. In this work, a simple, rapid and environmentally-friend is described. It allowed the recovery of 108 mg of bioactive per gram of enriched extract from pomegranate peel (PomPE). The quality of PomPE was assessed in terms of antiproliferative activity and its influence on the sensory attributes on muffins and cheese was evaluated. Results showed an IC50 of ∼ 50 µg/ml, which was equal to extract obtained by ethanol 70%. The incorporation of PomPE in muffins formulation improved some sensory attributes by 10%. However, overall, the supplementation of cheese led to a decrease of the sensory parameters. The results concluded that the described method could be an alternative to the conventional techniques to obtain enriched extract with high potential of valorization in food and pharmaceutical sectors.

Addition of Natural Extracts with Antioxidant Function to Preserve the Quality of Meat Products

Antioxidants are used to prevent oxidation reactions and inhibit the development of unwanted sensory characteristics that decrease the nutritional quality, acceptance, and shelf-life of processed meat products, improving their stability. Synthetic antioxidants, although efficient, are related to the development of diseases because they present toxic and carcinogenic effects. Thus, researchers and the meat industry are studying natural alternatives to synthetic antioxidants to be used in meat products, thus meeting the demand of consumers who seek foods without additives in their composition. These natural extracts have compounds that exert antioxidant activity in different meat products by different mechanisms. Thus, this review work aimed to gather studies that applied natural extracts derived from different plant sources as possible antioxidants in meat products and their action in preserving the quality of these products.

Integrated biorefinery development for pomegranate peel: Prospects for the production of fuel, chemicals and bioactive molecules

Current experimental evidence has revealed that pomegranate peel is a significant source of essential bio compounds, and many of them can be transformed into valorized products. Pomegranate peel can also be used as feedstock to produce fuels and biochemicals. We herein review this pomegranate peel conversion technology and the prospective valorized product that can be synthesized from this frequently disposed fruit waste. The review also discusses its usage as a carbon substrate to synthesize bioactive compounds like phenolics, flavonoids and its use in enzyme biosynthesis. Based on reported experimental evidence, it is apparent that pomegranate peel has a large number of applications, and therefore, the development of an integrated biorefinery concept to use pomegranate peel will aid in effectively utilizing its significant advantages. The biorefinery method displays a promising approach for efficiently using pomegranate peel; nevertheless, further studies should be needed in this area.

Natural Antimicrobials: A Clean Label Strategy to Improve the Shelf Life and Safety of Reformulated Meat Products

Meat is a nutrient-rich matrix for human consumption. However, it is also a suitable environment for the proliferation of both spoilage and pathogenic microorganisms. The growing demand to develop healthy and nutritious meat products with low fat, low salt and reduced additives and achieving sanitary qualities has led to the replacement of the use of synthetic preservatives with natural-origin compounds. However, the reformulation process that reduces the content of several important ingredients (salt, curing salts, etc.), which inhibit the growth of multiple microorganisms, greatly compromises the stability and safety of meat products, thus posing a great risk to consumer health. To avoid this potential growth of spoiling and/or pathogenic microorganisms, numerous molecules, including organic acids and their salts; plant-derived compounds, such as extracts or essential oils; bacteriocins; and edible coatings are being investigated for their antimicrobial activity. This review presents some important compounds that have great potential to be used as natural antimicrobials in reformulated meat products.

Effects of Garlic (Allium sativum L.) and Ramsons (Allium ursinum L.) on Lipid Oxidation and the Microbiological Quality, Physicochemical Properties and Sensory Attributes of Rabbit Meat Burgers

The aim of this study was to evaluate the quality of rabbit meat burgers with the addition of garlic (Allium Sativum L.) powder (G), ramsons (Allium ursinum L.) powder (R) or their combination (GR). The effects of additives on lipid oxidation, color parameters, microbiological quality and organoleptic properties of raw and oven-baked burgers were analyzed before and after refrigerated storage. Four meat formulations were prepared: control (C)-without additives, with the addition of G (0.35 g/100 g of meat), R (0.35 g/100 g of meat) and GR (0.35 g/100 g of meat each). The addition of GR induced an increase in pH and TBARS values in raw and oven-baked burgers. The pH of raw and oven-baked burgers was also affected by storage time (ST), and it was lower after 7 days of storage (ST7) than before storage (ST0). TBARS values were higher at ST7 only in raw burgers. The addition of R and GR decreased the values of color parameter L* (lightness) relative to G and C in raw and oven-baked burgers. The greatest changes in parameter a* (redness) were observed after the addition of R and GR, both before and after heat treatment. The values of parameter b* (yellowness) increased after the addition of R, GR (raw and oven-baked burgers) and G (raw burgers). In raw burgers, color saturation (C*) was higher in groups R and GR than in groups C and G, and the value of hue angle (h°) was lower in burgers with GR than in those with G and R. In oven-baked burgers, the values of C* and h° were lower in group GR than in the remaining treatments (C, G and R). In raw burgers, ST had no effect on the values of L*, whereas the values of parameters a*, b*, C* and h° were lower at ST7 than at ST0. In oven-baked burgers, the values of L* were higher at ST0 than at ST7, and the values of a*, b*, C* and h° were higher at ST7 than at ST0. The tested additives had no influence on the presence of off-odors in raw burgers. This parameter was affected by ST, and its value was lower at ST0 than at ST7. The appearance and overall acceptability of burgers were affected only by additives, and raw burgers containing GR received the lowest scores. After heat treatment, control burgers scored lowest for all attributes, whereas burgers with the addition of R and GR received the highest scores. The analyzed additives had no effect on the growth of Enterobacteriacea, Pseudomonas spp., lactic acid bacteria or total aerobic psychrotrophic bacteria. However, the counts of all identified bacteria increased at ST7. In conclusion, garlic powder and ramsons powder can be added to rabbit meat burgers to extend their shelf life and improve their eating quality.

Pomegranate Peels and Seeds as a Source of Phenolic Compounds: Effect of Cultivar, By-Product, and Extraction Solvent

The nutraceutical properties of Punica granatum L. are not restricted to the edible portion of the fruit but also to the peels and seeds, flowers, leaves, and tree bark. The recovery and valorization of the peel and seeds (ca. 50% of the whole fruit), besides the positive environmental impact, can be viewed as a source of natural bioactive compounds. Thus, the bioactive properties of extracts of pomegranate peel and seeds from Acco and Wonderful known cultivars, as well as of the novel Big Full cultivar, were evaluated. The dried and ground pomegranate by-products were submitted to a conventional solid/liquid extraction with ethanol/water mixtures (0%, 25%, 50%, and 75% of EtOH, v/v). The obtained extracts were characterized in terms of total phenolic compounds (TPC), total flavonoids (TF), and antioxidant activity (AA), determined by the DPPH radical scavenging activity and expressed as IC50 (half maximum inhibitory concentration). With the exception of the Acco cultivar, the extraction yield (EY) was higher for peels, whose extracts showed higher TPC, TF, and IC50 (lower AA). The extracts obtained from the by-products of the Big Full cultivar had a statistically higher overall bioactive potential (TPC: 0.36 mg GAE/mg extract; TF: 0.031 mg CATE/mg extract; IC50: 0.51 mg/mL) compared to the other two studied cultivars. Furthermore, the EY was enhanced by solvents richer in ethanol (50-75%), allowing obtaining extracts richer in TPC and TF with higher AA. Finally, it was shown that EY combined with bioactive data allowed a satisfactory principal component unsupervised differentiation of the pomegranate extracts according to the type of by-product used.

Effects of Faba Bean Hull Nanoparticles on Physical Properties, Protein and Lipid Oxidation, Colour Degradation, and Microbiological Stability of Burgers under Refrigerated Storage

The processing of faba beans generates great quantities of hulls, which are high in bioactive compounds with demonstrated radical-inhibiting properties. There is no research on the impact of using faba bean hull nanoparticles (FBH-NPs) to improve the quality and extend the shelf-life of beef products. Hence, the target of this investigation was to assess the inhibiting influence of adding FBH-NPs at two different concentrations (1 and 1.5%) on the physical attributes, lipid and protein oxidation, colour degradation, and microbiological safety of burgers during refrigerated storage (4 ± 1 °C/12 days). The FBH-NPs presented great phenolic content (103.14 ± 0.98 mg GAE/g dw) and antioxidant potential. The water holding capacity and cooking properties in burgers including FBH-NPs were improved during storage. The FBH-NPs significantly (p < 0.05) decreased the reduction rate of redness and lightness during the burger refrigerated storage and the FBH-NPs were more beneficial in preventing cold burger discolouration. In the FBH-NPs-treated burgers, peroxide values, TBARS, and protein carbonyl content were lower than in the control (up to 12 days). The microbiological load of burgers including FBH-NPs was lower than the load of the control during refrigerated storage. The findings revealed that FBH-NPs were more efficient in enhancing the cooking characteristics, retarding lipid or protein oxidation, preventing colour detrition and improving the microbial safety of burgers.

Fruit Pomaces as Functional Ingredients in Poultry Nutrition: A Review

Sustainable poultry intensification is economically constrained by several factors including high feed costs, which constitute more than 70% of total production costs. Functional feed ingredients such as fruit pomaces can be incorporated into poultry diets as natural sources of nutrients and biologically active substances to deliver sustainable production. Fruit pomaces are agro-industrial waste by-products that have no direct food value for humans. Their utilization as feed ingredients would reduce feed-food competitions, optimize poultry production systems, and promote environmental, economic, and social sustainability. Large quantities of fruit pomaces are generated and disposed in landfills or through incineration with little regard to the environment. Thus, their inclusion in poultry feeds could offer a long-term strategy to protect the environment. Valorising fruit pomaces to enhance poultry production would also contribute toward sustainable development goals and food security through the provision of affordable high-quality protein to the rapidly growing human population. Moreover, the use of fruit pomaces complements food production systems by ensuring that food animals are reared on human inedible feedstuffs. Thus, this review explores the nutritional composition and subsequent feeding values of various fruit pomaces, while examining their environmental benefits when used as feed ingredients in poultry nutrition. Furthermore, strategies that can be employed to negate the effect of anti-nutritional factors in the pomaces are presented. We postulate that the use of fresh or valorised fruit pomaces would improve poultry production and significantly reduce the amounts of waste destined for incineration and/or direct deposition in landfills.

Pomegranate trees quality under drought conditions using potassium silicate, nanosilver, and selenium spray with valorization of peels as fungicide extracts

The current study was performed on 8 years old "Succary" pomegranate cultivar (Punica granatum L.) during the 2019 and 2020 seasons. One hundred pomegranate trees were chosen and sprayed three times at the beginning of flowering, full bloom, and 1 month later with the following treatments: water as control, 0.025, 0.05 and 0.1 mg/L Se; 5 mL/L, 7.5 and 10 mL/L Ag NPs, and 0.5, 1 and 2 mg/L K₂Si₂O₅. The results showed that spraying of SE, Ag NPs, and K₂Si₂O₅ ameliorated the shoot length, diameter, leaf chlorophyll content, set of fruiting percentage, and fruit yield per tree and hectare compared to control through studying seasons. Moreover, they improved the fruit weight, length, and diameter, as well as total soluble solids, total, reduced, and non-reduced sugars percent, while they lessened the juice acidity percentage compared to control. The most obvious results were noticed with Se at 0.1 mg/L, Ag NPs at 10 mL/L, and K₂Si₂O₅ at 2 mg/L in both experimental seasons over the other applied treatments. By HPLC analysis, peel extracts showed the presence of several bioactive compounds of catechol, syringic acid, p-coumaric acid, benzoic acid, caffeic acid, pyrogallol, gallic acid, ferulic acid, salicylic acid, cinnamic acid, and ellagic acid. The extracts applied to Melia azedarach wood showed promising antifungal activity against Rhizoctonia solani and were considered wood-biofingicides.

Effect of Extraction Method on the Bioactive Composition, Antimicrobial Activity and Phytotoxicity of Pomegranate By-Products

Pomegranate by-products can be an asset to the food industry due to the richness in bioactive and antimicrobial compounds. This work studied the influence of conventional solvent and sonication-assisted extraction methods on the bioactive profile, antimicrobial properties, and phytotoxicity effect of the peels and seeds extracts from Acco, Big Full, and Wonderful pomegranate cultivars. The bioactive composition of the extracts was evaluated for the content of total phenolics, total flavonoids, and antioxidant activity (expressed as the half-maximal inhibitory concentration—IC₅₀) by spectrophotometric methods, while the tannins were determined by titration and the anthocyanins were estimated by the pH-differential method. For the evaluation of the antimicrobial activity, the disk diffusion method of Kirby-Bauer was adapted through inhibition halos against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Yarrowia lipolytica. The extracts’ phytotoxicity was evaluated in vitro on garden-cress seeds. Extracts from conventional extraction were richer in total phenolics, expressed as gallic acid equivalents (0.16–0.73 mg GAE/mg extract), while those from sonication-assisted extraction had higher contents of total flavonoids, expressed as catechin equivalents (0.019–0.068 mg CATE/mg extract); anthocyanins, expressed as cyanidin-3-glucoside (0.06–0.60 µg C3G/mg, dry basis); and antioxidant activity (IC₅₀, 0.01–0.20 mg/mL). All extracts were more effective against Gram-positive bacteria and yeasts than Gram-negative bacteria. In general, the sonication-assisted extracts led to higher inhibition halos (8.7 to 11.4 mm). All extracts presented phytotoxicity against garden-cress seeds in the tested concentrations. Only the lowest concentration (0.003 mg/mL) enabled the germination of seeds and root growth, and the sonication-assisted extracts showed the highest Munoo-Liisa vitality index (51.3%). Overall, sonication-assisted extraction obtained extracts with greater bioactive and antimicrobial potential and less phytotoxicity.

The bioactivity and applications of pomegranate peel extract: A review

Pomegranate peel (PP) is a by-product in the processing of pomegranate products, which is usually discarded as a waste. However, a large number of researches have shown that pomegranate peel extract (PPE) is rich in a variety of phenolic substances, among which ellagic acid (EA), as one of the main active components, has significant biological activities, such as anti-oxidation, anti-tumor, anti-inflammatory, neuroprotection, anti-viral, and anti-bacterial. We analyzed the mechanism of EA's biological activity, and discussed its application in the food industry, for instance, food preservation, food additives, and functional foods. Combined with the research status of PPE, we discussed the limitations and development potential of PPE, in order to provide theoretical reference and scientific basis for the development and utilization of pomegranate by-products. PRACTICAL APPLICATIONS: Pomegranate peel (PP), the inedible part of the fruit, is usually treated as waste. In recent years, researchers have been committed to exploring various bioactive ingredients in PP and exploring its potential benefits to human health, which has far-reaching significance. In this paper, the chemical constituents of polyphenols in PP were reviewed, mainly focusing on the biological activity and mechanism of ellagic acid (EA). We reviewed the applications and invention patents of pomegranate peel extract (PPE) in food field, including food preservation, food additive, and functional foods, providing reference for the recycling and reuse of PP.

Profiling Phenolic Composition in Pomegranate Peel From Nine Selected Cultivars Using UHPLC-QTOF-MS and UPLC-QQQ-MS

Pomegranate is widely cultivated across China, and the phenolics in its peel are principal components associated with health benefits. Ultra-high performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (UHPLC-QTOF-MS) and ultra-performance liquid chromatography coupled to a triple quadrupole mass spectrometer (UPLC-QQQ-MS) were used in this study, aiming at profiling the total phenolic composition in pomegranate peel from nine selected cultivars in 7 production areas. Sixty-four phenolic compounds were identified or annotated, and 23 of them were firstly reported in pomegranate peel. Principal component analysis (PCA) plots show differences and similarities of phenolics among nine cultivars. Furthermore, 15 phenolic compounds were quantified with the standards, and punicalagin, ellagic acid, gallocatechin, punicalin, catechin, and corilagin were found to be dominant. Punicalagin weighed the highest content (28.03–104.14 mg/g). This study can provide a deeper and more detailed insight into the phenolic composition in pomegranate peel and facilitate the health-promoting utilization of phenolics.

Fabrication and characterization of an economical active packaging film based on chitosan incorporated with pomegranate peel

Antioxidant and antimicrobial chitosan (CS) films incorporated with different concentrations (0, 3, 6 and 9% w/w based on chitosan) of pomegranate peel powder (PPP) were prepared through a simple and low-cost process and characterized. The physicochemical property, antioxidant and antibacterial properties of the films were investigated. Results showed that incorporation with PPP increased the thickness, water solubility (WS), water vapor permeability (WVP), opacity and total phenolic content (TPC) of chitosan films, but decreased the moisture content (MC) and mechanical property. Fourier transform infrared (FTIR) spectroscopy indicated the formation of hydrogen bonds between chitosan and PPP. In addition, scanning electron microscopy (SEM) analysis presented that microstructural attributes of chitosan film changed by enriching with pomegranate peel. The films with concentrations of PPP at 6 and 9% presented great ultraviolet-visible light barrier properties. Moreover, the antioxidant ability of films with PPP was significantly increased compared to the chitosan film. The addition of PPP also promoted the antibacterial capacity of the control film. These results revealed that incorporation of PPP in chitosan film could fabricate an economical active film with antioxidant and antibacterial properties, and which had the potential for developing food-grade packaging material.

Antimicrobial Properties of Lyophilized Extracts of Olive Fruit, Pomegranate and Orange Peel Extracts against Foodborne Pathogenic and Spoilage Bacteria and Fungi In Vitro and in Food Matrices

Several novel antimicrobials with different concentrations of olive, pomegranate, and orange fruit pulp extracts were produced from agricultural byproducts and, after lyophilization, their antimicrobial activity and potential synergistic effects were evaluated in vitro and in food samples against foodborne pathogenic and spoilage bacteria and fungi. The Minimum Inhibitory of the tested bacteria was 7.5% or 10%, while fungi were inhibited at a concentration of 10% or above. The optical density of bacterial and yeast cultures was reduced to a different extent with all tested antimicrobial powders, compared to a control without antimicrobials, and mycelium growth of fungi was also restricted with extracts containing at least 90% olive extract. In food samples with inoculated pathogens and spoilage bacteria and fungi, the 100% olive extract was most inhibitory against E. coli, S. typhimurium, and L. monocytogenes in fresh burger and cheese spread samples (by 0.6 to 1.8 log cfu/g), except that S. typhimurium was better inhibited by a 90% olive and 10% pomegranate extract in burgers. The latter extract was also the most effective in controlling the growth of inoculated fungi (Aspergillus niger, Penicillium italicum, Rhodotorula mucilaginosa) in both yogurt and tomato juice samples, where it reduced fungal growth by 1–2.2 log cfu/g at the end of storage period. The results demonstrate that these novel encapsulated extracts could serve as natural antimicrobials of wide spectrum, in order to replace synthetic preservatives in foods and cosmetics.

Corn Silage Supplemented with Pomegranate (Punica granatum) and Avocado (Persea americana) Pulp and Seed Wastes for Improvement of Meat Characteristics in Poultry Production

In the present study, pomegranate peels, avocado peels, and seed vacuum microwave extraction solid by-products were supplemented in corn silage in order to investigate the effects on meat quality and growth rate in broiler chicken. There were 50 broilers, divided in two groups, treated with experimental or usual feed for 43 days (group A: 25 broilers fed with avocado and pomegranate by-products and group B: 25 broilers fed with corn-silage used as control). The results showed that broiler chickens fed with a diet supplemented with a mixture of pomegranate avocado by-products (group A) showed significant differences in chicken leg meat quality, significantly improving the level of proteins and fatty acids content in breast and leg meat, respectively. More specific ω3 and ω6 fatty acids content were three times higher than in group B. Moreover, a protective effect on the decomposition of polyunsaturated fatty acids, induced by free radicals and presented in chicken meat, is based on the evaluation of lipid peroxidation by measuring thiobarbituric acid reactive substances. Pomegranate peels, avocado peels, and seed by-products appeared to have a slight reduction on meat production, while it was found to improve the qualitative chicken meat characteristics. Regarding the production costs, it was calculated that the corn-silage supplementation, used in this study, lead to a 50% lower cost than the commercial corn-silage used for the breeding of broilers.

Novel trends in extraction and optimization methods of bioactives recovery from pomegranate fruit biowastes: Valorization purposes for industrial applications

Pomegranate biowastes present potential economic value worldwide owing to their several health benefits mediated by a complex mixture of unique bioactives. The exploitation of these bioactives has motivated the exploration of eco-friendly, efficient, and cost-effective extraction techniques to maximize their recovery. The current review aims to provide updated technical information about bioactives extraction mechanisms from pomegranate wastes (seeds and peel), their advantages and disadvantages, and factors towards optimization. A comparative overview of the modern green extraction techniques viz., supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction, and eutectic solvent mixture as alternatives to conventional extraction methods for seeds and peel is presented. Approaches focused on biowastes modification for properties improvement are also discussed. Such comprehensive review shall provide the best valorization practices of pomegranate biowastes and its application in food and non-food areas focusing on original methods, innovation, protocols, and development to be considered for other fruit biowastes.

Chitosan Edible Films Enhanced with Pomegranate Peel Extract: Study on Physical, Biological, Thermal, and Barrier Properties

In the present study, pomegranate peel extract was used as a reinforcing agent in developing chitosan-based edible film. Different concentrations (0.2 g/mL, 0.4 g/mL, 0.6 g/mL, 0.8 g/mL, and 1.0 g/mL) of pomegranate peel extract were incorporated in chitosan-based edible film. A neat chitosan film was used as a control. This work covers the effect of pomegranate peel extract on the physical, biological, mechanical, thermal, and barrier properties of enriched chitosan-based edible film. The results showed that the thickness (0.142-0.159 mm), tensile strength (32.45-35.23 MPa), moisture (11.23-15.28%), opacity (0.039-0.061%), water (1.32-1.60 g·mm/m2), gas barrier properties (93.81-103.45 meq/kg), phenolic content (5.75-32.41 mg/g), and antioxidant activity (23.13-76.54%) of the films increased with increasing volume fraction of pomegranate peel extract. A higher concentration of incorporated pomegranate peel extracts significantly (p < 0.05) reduced the thermal stability of the film, along with its transparency, solubility, swelling, and color. This work revealed that the incorporation of a higher portion of pomegranate peel extract in chitosan film holds significant (p < 0.05) potential for the increase in biological activities of such films in terms of antioxidant and antimicrobial behavior. The properties of pomegranate peel extract-enriched chitosan films could be an excellent cure for free radicals, whereas they could also inhibit the growth of the foodborne pathogens during the processing and preservation of the food. Further studies are needed for the application of pomegranate peel extract-enriched edible films on food products such as fruits and vegetables in order to extend their storage life and improve the quality and safety of preserved food products.