Effects of aqueous and ethanol extracts of pomegranate peel (Punica granatum) on the growth of inoculated Escherichia coli in (Cyprinus carpio) minced meat

Synthetic preservatives have been used as food additives to extend shelf life of foods, but they are strictly regulated due to toxicological concerns and some health problems. So, it is increasingly attractive to find out effective and nontoxic measures (e.g. use of natural antimicrobial agent) to delay microbial spoilage. Considering the high probability of Escherichia coli contamination of local fish, the present study aimed at investigating the effects of aqueous and ethanol extracts of pomegranate peel (Punica granatum) on the growth of Escherichia coli in minced common carp during refrigerator storage. The minced meat treated with different concentrations of water and ethanol extracts of pomegranate peel, and the sensory evaluation were performed. After determining the optimum concentration, the treated minced meat inoculated with 1×103cfu/g Escherichia coli. The treated samples packaged separately into sterilized bags and stored at (4±1) °C, then Counting the bacteria was performed at days 0, 1, 3, 6, 9 and 12 after storage in refrigerator. The results showed that treatment containing 20% ethanol extract significantly could eliminate the bacteria after the 24- hour period, then followed by 10, 12/5 and 15%. The aqueous extract antimicrobial activities showed a very weak role and the number of bacteria had a rising trend. The results of this study indicated that the aqueous and ethanol extracts of pomegranate peel at high concentrations, because of antibacterial, antioxidant and preservative properties, could play an important role in ensuring food safety and consumer play.