Development and characterization of pomegranate peel extract-infused carboxymethyl cellulose composite films for functional, sustainable food packaging

Pomegranate peel (Punica granatum L.) is commonly disregarded as a byproduct in the juice industry despite its rich content of bioactive compounds. This study investigates the impact of incorporating pomegranate peel extract at concentrations of 0%, 1%, 2%, and 3% into rice starch-pectin-based films. Characterization of the films was conducted using Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy (FESEM). Physicochemical properties including thickness, color, opacity, moisture content, water solubility, and water vapor permeability were assessed. The results demonstrate that the incorporation of pomegranate peel extract significantly enhanced the properties of the rice starch-pectin-based films (p < 0.05). Moreover, antimicrobial assays revealed substantial inhibition of Escherichia coli by films containing 3% pomegranate peel extract. Furthermore, the efficacy of these films was evaluated using real tomato samples to assess their potential to extend the shelf life of perishable foods. The findings suggest that the inclusion of pomegranate peel extract in the film matrix contributes to natural pigment preservation, mitigates microbial contamination, and maintains the organoleptic attributes of tomatoes, thereby potentially enhancing their shelf life. These results underscore the promising applications of pomegranate peel extract in the development of sustainable and functional food packaging materials.

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.

The encapsulation of pomegranate peel extract (PPE) in chitosan nanoparticles (CSNPs) is an advantageous strategy to protect sensitive constituents of the extract. This study was aimed to develop PPE-loaded CSNPs and characterize their physical, structural morphology, antioxidant and antimicrobial properties. Spherical NPs were successfully synthesized with a mean diameter of 174–898 nm, a zeta potential (ZP) of +3 – +36 mV, an encapsulation efficiency (EE) of 26–70%, and a loading capacity (LC) of 14–21% depending on their loaded extract concentrations. Based on these results, CSNPs with chitosan:PPE ratio of 1:0.50 (w/w) exhibited good physical stability (ZP = 27 mV), the highest loading (LC = 20%) and desirable encapsulation efficiency (EE = 51%), and thus, selected as optimally loaded NPs. The FTIR analysis of PPE-CSNPs demonstrated no spectral changes indicating no possible chemical interaction between the PPE and CSNPs, which confirms that the PPE was physically entrapped within NPs. Moreover, FTIR spectra of pure PPE showed specific absorption bands (at 3293–3450 cm−1) attributed to the incidence of phenolic compounds, such as tannic acid, ellagic acid and gallic acid. Total phenolic content (TPC) and antioxidant analysis of selected CSNPs revealed that the encapsulated NPs had significantly lower TPC and antioxidant activity than those of pure PPE, indicating that CSNPs successfully preserved PPE from rapid release during the measurements. Antibacterial tests indicated that pure PPE and PPE-loaded CSNPs effectively retarded the growth of Gram-positive S. aureus with a minimum inhibitory concentration (MIC) of 0.27 and 1.1 mg/mL, respectively. Whereas Gram-negative E. coli, due to its protective cell membrane, was not retarded by pure PPE and PPE-CSNPs at the MIC values tested in this study. Gas chromatography-mass spectroscopy analysis confirmed the incidence of various phytochemicals, including phenolic compounds, fatty acids, and furfurals, with possible antioxidant or antimicrobial properties. Overall, CSNPs can be regarded as suitable nanomaterials for the protection and controlled delivery of natural antioxidants/antimicrobials, such as PPE in food packaging applications.

The experiment was undertaken to evaluate the effect of pomegranate (Punica granatum) juice and peel extract on antioxidant status in streptozotocin induced diabetic rats. The study included seven treatment groups comprising of ten albino Wistar rats each. The various groups in this study included normal control Group I (NC), diabetic control (Group II (DC), diabetic rats treated with metformin at the rate of 500 mg/kg bw Group III (MF), diabetic rats treated with pomegranate fresh juice at 1mL/day Group IV(PJ), diabetic rats treated with pomegranate peel extracts at 100mg/day Group V (PPE), diabetic rats treated with pomegranate fresh juice 1mL + pomegranate peel extracts (100mg) at 50 per-cent dosage and metformin (half dose) Group-VI (PJ+PPE+MF 50%), diabetic rats treated with pomegranate fresh juice (0.5mL) + pomegranate peel extracts extract (50mg) at 50 per-cent dosage and metformin (half dose) (Group-VII (PJ+PPE @ 50% +MF 50%). Antioxidant status of rats was evaluated by estimating product of oxidative injury (MDA) and endogenous antioxidant enzymes (CAT, SOD and GPx) in the liver on 3rd, 15th, 30th and 45th day. All the antioxidant enzymes (CAT, SOD and GPx) markedly reduced in diabetic control (DC) rats. However, treatment groups treated with pomegranate juice or pomegranate peel extract (Group IV to VII) individually or in combination showed a significant improvement in all the antioxidant enzymes (CAT, SOD and GPx) compared to the diabetic control rats. It was observed that metformin substantially alleviated the effects of STZ in diabetic rats compared to all the treatment groups. Pomegranate peel extract was observed to have marginally improve antidiabetic effects compared to pomegranate juice. Combination of pomegranate juice and pomegranate peel extract with metformin at half dose and full dose also alleviated STZ induced diabetic effects significantly. However, there was no dose dependent and synergistic effect. It could be inferred that bioactive compounds of pomegranate juice and pomegranate peel extract have antiperoxidative effect due to their ability to scavenge free radicals or chelate metal ions in STZ induced rats.

Pomegranate peel is food waste unfit to eat parts obtained during the production of pomegranate juice. The aim of this work is to study the effect of four different solvents (ethanol, isopropanol, hot and cold water) on phytochemicals screening, total phenolics content, total flavonoid content and antioxidants activity in pomegranate peels, as well as identification of phenolic compounds in extracts by HPLC. Phenolics, flavonoids, alkaloids, saponins, tannins, steroids and terpenoids were detected in all extracts. The highest total phenolics and total flavonoids were observed in ethanol extract of pomegranate peels (161.5 mg GAE/g and 70.65 mg Rutin/g), respectively. Furthermore, the ethanol extract of pomegranate peels showed the highest DPPH scavenging activity with the lowest IC50 value 14.6 μg/ml compared to other extracts. The high antioxidant activities may be due to the high contents of phenolics and flavonoids in pomegranate peel ethanol extract. HPLC analysis was used for the identification and quantitative determination of phenolic compounds in pomegranate peels extracts. The results revealed nine polyphenolic compounds including protocatechuic acid, p-coumaric acid, caffeic acid, ellagic acid, cinnamic acid, quinic acid, benzoic acid, syringic acid and iso-ferulic acid in pomegranate peels extracts. The obtained results confirmed that ethanol extract was the most abundant of phenolics compounds as compared to the other extracts. Finally, it can be concluded that pomegranate peel extracts can be used in various fields for being rich in natural antioxidants that have a medicinal and therapeutic impact.

In vivo study of pomegranate (Punica granatum) peel extract efficacy against Giardia lamblia in infected experimental mice

Physical, thermal, mechanical and barrier properties of pearl millet starch films as affected by levels of acetylation and hydroxypropylation

Nano-encapsulation of pomegranate (Punica granatum L.) peel extract and evaluation of its antimicrobial properties on coated chicken meat

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.

Here, the study was conducted to evaluate the effect of pomegranate (Punica granatum) peel extract on infected rats with Blastocystis spp. Anti-protozoan activities were determined by monitoring Blastocystis spp. shedding in stools and histopathological changes of intestine of infected rats. Additionally, we evaluated the antioxidant properties of pomegranate peel extract on different groups through measuring the concentration of Malondialdehyde (MDA). In this work, Punica granatum peel extract-treatment lowered the shedding of cysts very close to nitazoxanide (NTZ) treatment. These data were statistically significant P value ≤ 0.0001. Pomegranate peel extract was found to have the highest anti-lipid peroxidation effect, assessed by measuring MDA level. The inhibitory effect of pomegranate peel extract on lipid peroxidation was significant when compared to NTZ- treated group (P value ≤ 0.0003). As well, histolopathological examination of the intestine showing that Blastocystis spp. were often observed in the infected group without treatment either within the luminal material or at the tip of the epithelium compared to the infected treated groups. Pomegranate peel extract can be used as alternative therapy for blastocystosis and for developing novel anti Blastocystis drugs. Additionally, these results show clinical evidence that pomegranate peel extract has components act as powerful antioxidants.

Methylcellulose (MC) films were prepared by casting from its 1% aqueous solution containing 0.5% vegetable oil, 0.25% glycerol, and 0.025% Tween®80. Poly(caprolactone) (PCL) films were prepared by compression molding from its granules. Biodegradable composite films were fabricated using MC film as reinforcing agent and PCL as the matrix material by compression molding. One layer of MC film was reinforced with two layers of PCL films. The MC content in the composites was varied from 10 to 50% by weight. Mechanical, barrier, and degradation properties of PCL, MC, and composite films were evaluated. The values of puncture strength (PS), puncture deformation (PD), viscoelasticity (Y) coefficient, and water vapor permeability (WVP) of the composites (50% MC content) were found to be 124.3 N/mm, 3.2 mm, 31%, and 2.6 g·mm/m2·day·kPa, respectively. Oxygen transmission rate (OTR) of PCL, MC, and composites (50% MC) were found to be 175, 25, 22 cc/m2/d, respectively, which indicated that composite films showed significantly lower OTR than PCL films. Degradation tests of the composite films (50% MC) were performed for 6 weeks in aqueous medium (at 25°C), and it was found that composites lost its mass slowly with time. After 6 weeks, mass and PS of the composites were decreased to 13.4 and 12%, respectively. Composite interface was studied by scanning electron microscopy (SEM). The MC film had good adhesion with PCL matrix during compression molding and suggested strong interface of the composite system. SEM image after 6 weeks of degradation showed some openings in the interface and revealed slow degradation of the MC films. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Summary Nowadays, uncontrolled and frequent use of antibiotics may cause emergence of microbial resistance among pathogenic agents. Therefore, the use of new synthetic and natural antimicrobial compounds is inevitable. One source of natural compounds in this respect comes from plants. The purpose of this study was to examine the antibacterial effects of peel extracts from sour and sweet pomegranate. Methanolic extracts of sour and sweet pomegranate peels and aqueous solutions of tetracycline and chloramphenicol were prepared. Antibiogram tests using disk diffusion technique and serial dilution method were performed against ten pathogenic bacteria isolated from animals, and relative minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were also determined for the above compounds. The greatest zone of inhibition induced by the action of pomegranate peel extracts was obtained for Staphylococcus aureus (about 25 mm) and the smallest zone of inhibition was obtained for Pasteurella multocida (about 9 mm). In addition, the lowest MIC and MBC values of pomegranate peel extract were obtained for Staphylococcus aureus (7.8 and 62.5 mg/ml, respectively). Results of serial dilution tests indicate that bactericidal effect of sour pomegranate peel extract was more than that for sweet pomegranate peel extract; and sweet pomegranate peel extract exerts a bacteriostatic action against bacteria. The antibacterial effect was greater against Gram-positive bacteria compared to that for the Gram-negative bacteria. Effects of these extracts were considerably lower than those for tetracycline and chloramphenicol. In conclusion, methanolic extracts of pomegranate peels exhibit relatively good bacteriostatic and bactericidal effects.

Background: Denture stomatitis, caused primarily by Candida albicans overgrowth, is a common oral health issue among denture wearers. Maintaining denture hygiene is crucial for prevention. This study investigated the efficacy of red pomegranate (Punica granatum L.) peel and fruit extracts as natural denture cleansers compared to sodium bicarbonate, a standard denture cleansing agent. Methods: Heat-cured acrylic resin plates were fabricated and contaminated with C. albicans. Samples were divided into four groups and soaked for 8 hours in: 75% pomegranate peel extract, 75% pomegranate fruit extract, 5% sodium bicarbonate solution (positive control), and aquadest (negative control). C. albicans colony counts were performed using the spread plate technique and colony counter. Data were analyzed using Kruskal-Wallis and Mann-Whitney tests. Results: Both pomegranate peel and fruit extracts significantly reduced C. albicans growth compared to the negative control (p&lt;0.05). The peel extract showed comparable efficacy to sodium bicarbonate (p&gt;0.05), while the fruit extract demonstrated slightly lower but still substantial antifungal activity. Conclusion: Red pomegranate peel and fruit extracts hold promise as natural denture cleansers for inhibiting C. albicans and potentially preventing denture stomatitis. Further research is warranted to evaluate their long-term effects on denture materials and clinical efficacy.

Pomegranate (Punica granatum) peel extract supplementation in diet influences growth performance, haemato-immunological responses and cytokine expression in pathogen- aggravated Labeo rohita fingerlings

Plant extracts gained attention in the meat industry for their role in preventing microbial growth and oxidative deterioration. Antioxidant efficiency of various ratios (0.125, 0.25, 0.5, and 1%) of ethanolic or methanolic pomegranate peel (PP), beet leaf (BL), and broccoli flower (BF) extracts on cooked ground beef was investigated during refrigerated storage. Thiobarbituric acid reactive substances (TBARS), lipid hydroperoxide (LPO), p-anisidine, cooking loss (CL), pH, and color analysis were performed. Results revealed that CL increased (p < .05) with 0.5 and 1% PE or 1% BF extracts, whereas no CL change was observed in other extract applications. Although using 0.5% and 1% of ethanolic or methanolic PP extracts caused lower pH than control (p < .05), no pH difference was found among other treatments. L* values were not affected by extract applications, whereas a* decreased and increased with PP and BL extract addition, respectively (p < .05). Meantime, a* values decreased and b* values increased by elevation in extract ratio (p < .05). In terms of solvent impact, methanolic PP and ethanolic BL extracts caused higher b* (p < .05), whereas no difference in b* was obtained between ethanolic or methanolic BL extracts. TBARS, LPO, and p-anisidine analysis revealed that the highest lipid oxidation was obtained in control (p < .05). PP extract treatments exhibited the lowest lipid oxidation (p < .05). Lipid oxidation gradually increased in control and all extract-incorporated samples during storage (p < .05). In extract-incorporated samples, lipid oxidation decreased with increasing the extract ratio (p < .05). Lipid oxidation was inhibited more by all incorporation ratios for each tested extract compared to control (p < .05). Moreover, using 0.125% PP, 0.5% BL, or 1% BF extracts was more effective in lipid oxidation inhibition than BHT (p < .05). It may be concluded that PP, BL, and BF extracts may be utilized by the meat processors to achieve prolonged shelf life and improved quality features.