Comparative Study between Extracts of Different Pomegranate Parts Issued from Five Tunisian Cultivars (Punica granatum L.): Phytochemical Content, Volatile Composition and Biological Activity

Very few studies are interested to the volatile compounds of pomegranate and evoking their potentials, especially, their antibacterial activity. In the present study, edible (arils) and non-edible (peels) parts of five pomegranate varieties (Tounsi, Kalai, Zahri, Chelfi and Garci) were compared for their phenolic contents, antioxidant activity, aroma profile and antibacterial propriety of their volatile compounds. Results showed that peel of the five varieties contained higher content in phenolics, flavonoids, tannins, anthocyanins and carotenoids additionally to higher antioxidant power. Considerable correlations have been highlighted between polyphenols, o-diphenols and flavonoids of peel extracts and the DPPH scavenging activity as well as reducing power. Concerning volatile compounds, Chelfi is quantitatively the richest cultivar. However, the Tounsi seems to be quantitatively the richest for both peels and arils. Gram positive bacteria were more sensitive to volatiles extract than gram negative with a substantial activity of both peel and seed extracts of Tounsi variety. It’s therefore tempting to speculate that the non-edible part (peel) has a therapeutic and nutritional potential that must be valorised.