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Summary: Pomegranate peel contains bioactive ellagitannins including punicalagin, a major bioactive principle. However, studies have not optimally recovered and evaluated these ellagitannins for their antioxidant and glycaemic control potential. In the present study, a temperature‐dependent extraction was employed to optimally recover bioactive ellagitannins and punicalagin from pomegranate (variety 'Wonderful') peel. The peel was extracted with distilled water at different temperatures (25, 37, 50, 65, 78 and 95 °C) and evaluated for phenol and flavonoid contents, in vitro antioxidant and enzyme inhibitory activities. XAD16N resin was used to recover tannins from the extracts and punicalagin was purified from the tannin recovered from the 78 °C crude extract. LC–MS was used to characterise the ellagitannins profile. The dose‐dependent anti‐lipid peroxidative and glucose uptake potential of the punicalagin and its parent crude extract and tannin were measured. The extract obtained at 78 °C had the highest phenolic, flavonoid, tannin and punicalagin contents, which potentiated stronger radical scavenging, ORAC (IC50 = 9.64 vs. 15.6 and 25.6 μg/mL, respectively), anti‐linoleic acid peroxidative (IC50 = 9.97 vs. 19.9 and 27.3 μg/mL, respectively) and antiglycation (IC50 = 29.1 vs. 34.2 and 79.1 μg/mL, respectively) activities than the extract and the purified punicalagin. Similarly, the cellular anti‐lipid peroxidative and glucose modulatory effects of the recovered tannin (IC50 = 3.67 μg/mL; EC50 = 14.8 μg/mL) better than that of the extract (IC50 = 24.3 μg/mL; EC50 = 55.0 μg/mL) and the purified punicalagin (IC50 = 59.0 μg/mL; EC50 = 112 μg/mL), which may be attributed to the complementary action of the tannin's constituent compounds (punicalagin, ellagic acid, granatin A, corilagin, casuarinin, gallic acid and quercetin hexoside). The α‐amylase inhibitory data, however, suggest the purified punicalagin influences enzyme inhibitory potential of pomegranate peel. The study suggests tannin/ellagitannin purified from pomegranate peel aqueous extract obtained at 78 °C may be a promising dietary supplement for exerting glycaemic control and mitigating oxidative stress. [ABSTRACT FROM AUTHOR]

Summary: In this study, the antibacterial and antibiofilm properties of pomegranate (Punica granatum L.) extracts (PPLs) prepared by 10 g of pomegranate peels (PPL10) and 100 mL of different solvents (ethanol, methanol, and their acid combinations, and water) were investigated as sources of bioactive compounds against food‐related bacteria. The antimicrobial activities of the extracts were measured by using agar well diffusion assay. The acid‐treated extracts exhibited the highest antimicrobial activities (31–34 mm). The biofilm formations were assessed by using a microplate reader (570 nm) after crystal violet staining. The prevention and removal of bacterial biofilms were also evaluated by using extracts prepared by 5 g of initial pomegranate peel (PPL5) with the different solvents or 200 ppm chlorine solution. All PPL5 and PPL10 extracts diluted at different ratios inhibited and removed biofilms, and the highest antibiofilm effects were up to 80% by acid‐treated extracts. In addition, PPL5s and PPL10s were as effective as or more effective than chlorine for the prevention of biofilms. Therefore, from an economical perspective the PPL5s could represent promising candidates as natural antibiofilm agents for food industry. [ABSTRACT FROM AUTHOR]

Summary: Microbiological, chemical and sensory effects of pomegranate peel ethanol extract (EE) at 0.1, 0.5 and 1% (w w−1) on refrigerated minced beef meat were undertaken. Chemical analyses revealed that the treated meat underwent significant decrease (P < 0.05) of primary and secondary lipid oxidation. By the end of storage, EE at 1% reduced the MetMb, carbonyl group accumulation and the disappearance of sulphydryl proteins by 56.68, 65.71 and 59.69% respectively, compared with control samples. EE at 1% showed also the highest scores for colour, appearance, odour and overall acceptability (OA) attributes using a 9‐point hedonic scale. Chemometric approaches showed that lipid/protein oxidation analysis, sensory attributes and storage time allowed the samples discrimination. Oxidative stability parameters were equally used to predict OA by linear regression analysis. The reported data provide an approach to strengthen the interpretation of sensory quality and how they are affected by chemical changes in newly formulated meat products. [ABSTRACT FROM AUTHOR]

Summary: Pomegranate peel (PoP) is a byproduct of the fruit juice processing industry, comprising nearly 30–40% of fruit portion. PoP is rich in polyphenols (phenolic acids, tannins and flavonoids particularly anthocyanins) which are known to have diverse biological functions including effectiveness against pathogenic microorganisms. PoP has shown a broad spectrum antimicrobial activity (AMA) of PoP against both Gram‐positive and Gram‐negative bacteria. It also presented promising AMA against antibiotic resistant microbial strains such as methicillin‐resistant Staphylococcus aureus. The high levels of polyphenols, particularly punicalagin and ellagic acid, present in PoP have been responsible for its antifungal properties. PoP is effective against many fungi including both pathogenic (Aspergillus flavus) and opportunistic pathogens. These activities of PoP may be exploited as a phytomedicine for humans, in order to eliminate the use of antibiotics and reducing their cost. This review provides collective up‐to‐date information on the efficacy of plant‐derived AMA of PoP. [ABSTRACT FROM AUTHOR]

Pomegranate peels and seeds are industrial residues considered interesting sources of punicalagin (PU) and punicic acid (PA), respectively. To optimise their extraction process and protect them against environmental factors, pomegranate residues were extracted with supercritical CO2 (SC-CO2) using a Box-Behnken design and then optimal extracts encapsulated by spray-drying applying a 22 central composite design. Peel extracts showed a PU content of 0.4-9.5% with optimal extraction conditions of 400 bar, 43 °C and 20% ethanol. On the other hand, SC-CO2 seed extracts showed a PA content of 65.1-78.4% with 450 bar, 48 °C and 10% ethanol as optimal extraction parameters. Otherwise, the encapsulation efficiency of SC-CO2 extracts was significantly affected by core/wall material ratio and its quadratic effect. This parameter ranged from 35.1% to 72.4% for peel extracts and from 68.2% to 92.7% for seed extracts. Results showed that the proposed technologies are a feasible approach to the integral utilisation of residues from the pomegranate industry. [ABSTRACT FROM AUTHOR]

Pomegranate peel powders were prepared by superfine grinding, whose effects were investigated on the composition, functional and antioxidant properties of the pomegranate peel products. Fluidised bed jet milling technology was used to process superfine pomegranate peel powder. The physical-chemical properties of coarse powder A (D50 = 413.4 μm) and B (D50 = 197.1 μm), fine powder C (D50 = 142.6 μm) and D (D50 = 41.2 μm), superfine powder E (D50 = 7.68 μm) and raw material powder (RMP) (D50 = 352.2 μm) were investigated in this study. SEM images revealed the shape and surface morphology of six pomegranate peel powders. The physical determinations showed that the smaller the powder particle size was, the greater the surface area (from 0.214 to 1.597 m2 g-1) and bulk density (from 0.653 to 0.751 g mL-1) were, the smaller the angles of repose (from 51.69° to 38.74°) and slide (from 48.32° to 34.18°) were. The water holding capacity (WHC), water-solubility index (WSI), polyphenols and flavonoids release were significantly improved as the size of pomegranate peel particle decreased. The results of FTIR and UV indicated that grinding process would not influence chemical composition of pomegranate peel. Vitamin C (VC) and butylated hydroxytoluene (BHT) were used in DPPH scavenging activity determination, and DPPH scavenging activity was A < RMP < BHT < B < C < D < E < VC. [ABSTRACT FROM AUTHOR]