Antioxidant activity of Berberis integerrima seed oil as a natural antioxidant on the oxidative stability of soybean oil

Abstract

The barberry fruits are used as food flavoring. Berberis integerrima seeds are used as waste product in barberry’s processes. This study describes the potential use of B. integerrima seed oil (BSO) as a natural antioxidant. 2,2-diphenyl-1-picryl hydrazyl scavenging activity and ferric-reducing antioxidant power of the oil alcoholic extract were determined. Protective effect of BSO in stabilizing soybean oil was further evaluated based on the peroxide values, thiobarbituric acid values, conjugated dienes and trienes, and Rancimat test during storage. Results of gas chromatography (GC-FID) showed that more than 90% of the fatty acids were linolenic (ω-3), linoleic (ω-6), and oleic (ω-9) acids. Total phenolic compounds were 323.0 mg Gallic acid/kg oil. Chromatographic separation of their sterols and tocopherols (HPLC) demonstrated that β-sitosterol, campesterol, stigmasterol cholesterol, sitostanol, ∆5-avenasterol, ∆7-avenasterol, clerosterol, and α-tocopherol and γ-tocopherol were present in the BSO, respectively. The IC50 of the oil alcoholic extract was less than the commercial antioxidants, including butylated hydroxyanisole and butylated hydroxytoluene. The statistical results indicated that BSO has significant effects on soybean oil stability on most days.