Investigation on Pomegranate (Punica granatum) Skin as a Potentially Effective Natural Food Preservative

Abstract

The study is aimed at estimating the possibility of using pomegranate peel extracts as a natural food preservative which was investigated in fish samples. All the extracts (cold water, hot water, and 70% methanol) have been tested against five bacteria (Escherichia coli, Staphylococcus aureus, Salmonella Typhi, Bacillus megaterium, and Bacillus subtilis) using the agar disc diffusion method. Hot water extract showed the best result against B. megaterium. The zone of inhibition (ZOI) for hot water extract as crude was taken 20 μl/disc was 25 mm. Total antioxidant activity and total phenolic content (TPC) were determined for different extracts. The results of a test for TPC showed that 70% methanolic extract (MeOH) and cold water extract, respectively, comprised 263.59 mg gallic acid equivalent (GAE)/g and 197.99 mg GAE/g of total phenolics. In addition, MeOH had a total antioxidant activity of $67.55\pm 5.58$  mg ascorbic acid equivalent (AAE)/g while hot water extract had a total antioxidant activity of $66.86\pm 3.55$  mg AAE/g. The extracts were applied to Ompok pabda fish, and the fish were preserved in prepared extracts for 24 hours in the open air. Total volatile nitrogen (TVN) and sensory parameters were evaluated at regular intervals of 0, 4, 12, 18, and 24 hours. The TVN value of the prepared extracts was found in order of hot water> MeOH> cold water. Fish preserved in hot water extract was in the acceptable range even after 24 hours. Methanol extract and hot water yielded superior outcomes in preserving the fish.