Evaluation of Bioactive Compounds in Pomegranate Fruit Parts as an Attempt for Their Application as an Active Edible Film

Pomegranate fruit contains high content of phytochemical constituents which have many health benefits. Peel and rind are wastes of pomegranate fruit processing, represent up to 50% of its weight. This study aimed to evaluate the ethanolic extract of pomegranate fruit parts: arils, rind and peel as sources of bioactive compounds as well as their antioxidant and antimicrobial activities for their application as an active edible film. Results clearly demonstrated that peel extract (PE) had the highest content of total phenolics and flavonoids (342 mg GAE /g and 82.33mg catechol /g, respectively ) followed by rind extract (RE) containing 213.00 mg GAE/g and 70.50 mg catechol /g, respectively, and finally arils extract (AE) ( 108.22 mg GAE /g and 55.58 mg catechol/g), respectively. Results indicated that total anthocyanins content was concentrated in PE (15.24mg Cynidian-3-glycoside/g) and AE (11.04 mg Cynidian-3-glycoside/g), while RE (6.51 mg Cynidian-3-glycoside/g) had the lowest value. Peel extract exhibited the highest antioxidant activity followed by RE and were significantly higher than that of AE. These results were confirmed with the DPPH and ABTS+ assays. Consequently, PE followed by RE had higher antimicrobial activity against several pathogenic strains than AE and can be used as natural preservative for food. Peel extract and RE were incorporated into pectin film at concentration of 15 mg/ml to develop an active edible film. Pectin film without the tested fruit parts extract was used as the control film. The obtained results revealed that the film prepared from pectin with PE and RE was successfully developed and considers as an active edible film with antioxidant and antimicrobial properties.