Lipids, proteins, phenolic composition, antioxidant and antibacterial activities of seeds of peanuts (Arachis hypogaea l) cultivated in Tunisia.

Fatty acid composition of peanut seed oil in four varieties cultivated in Tunisia showed that linoleic (C18:2), oleic (C18:1) and palmitic (C16) acids account for more than 84% for Chounfakhi and Massriya and for more than 85% of the total fatty acids of Trabilsia and Sinya seed oil respectively. Seed oil contents were significantly different (P ≤ 0.05) and did not exceed 48%. The study of total phenolics revealed that Chounfakhi contained more total phenolics (2.1 mg GAE/g DW), followed by the Massriya and Sinya cultivars (1.35 mg GAE/g DW for each); Trabilsia presented the lowest total phenolic content with 1 mg GAE/g DW. Considerable antiradical ability was found, especially in the Trabilsia peanut seed cultivar (IC50 = 1550 μg/ml), the Massriya and Sinya cultivars had, respectively, 720 and 820 mg/ml IC50. In the Massriya variety the sterol fraction showed antibacterial activity against Listeria ivanovii, Listeria inocua, Pseudomonas aeruginosa, Staphylococus aureus, Enterococcus hirae and Bacillus cereus.