Comparative evaluation of proximate composition and biological activities of peel extracts of three commonly consumed fruits

Abstract

For the proper utilization of the fruits peel, investigation on their biological potential is needed. The present study was designed to determine the proximate composition and biological activities of the fruit peel extracts of three common fruits namely Citrullus lanatus, Punica protopunica and Pyrus pashia. The methanolic fruit peel extracts (FPEs) were analyzed for phytochemical composition and antioxidant activity in terms of free radical scavenging capacity (FRSC), antibacterial activity against Escherichia coli and Staphylococcus aureus and antifungal activity against Aspergillus niger and Fusarium oxysporum. The fruit peels were found to be statistically different (p < 0.05) in ash, moisture, crude protein, crude fiber content. A statistically significant difference (p < 0.05) was observed in ascorbic acid and total phenolic content, and antioxidant, antibacterial and antifungal activates of the selected FPEs. Each of the FPE showed a concentration-dependent significant linear increase in FRSC. However, the antibacterial and antifungal activity of the FPEs against each of the selected bacterial and fungal strains was found to be a logarithmic function of the extract concentration. The FPE of P. pashia was found to be the best among the selected plants due to comparatively higher values of carbohydrate, crude fiber and ascorbic acid content, FRSC, antibacterial and antifungal activity.

Keywords:
antibacterial activity; antifungal activity; free radical scavenging capacity; Punica protopunica, Pyrus pashia, Citrullus lanatus