Utilization of Jujube Fruit (Ziziphus mauritiana Lam.) Extracts as Natural Antioxidants in Stability of Frying Oil

摘要

The effects of ultrasound-assisted, supercritical CO_(2) and solvent extraction methods on antioxidant activity of Ziziphus mauritiana (Lam.) extracts were investigated using 2,2-diphenyl-1-picrylhydrazyl and β-carotene assays. Ethanol-water extract of the jujube that was obtained with ultrasound-assisted extraction had the highest antioxidant activity. Ultrasound-assisted extraction was the most effective method on extraction of phenolic compounds. The effect of ultrasound extract in stability of soybean oil was compared to synthetic antioxidants by measuring total polar compounds, carbonyl value, peroxide value, free fatty acids, oxidative stability index, and conjugated dienes and trienes values. Results showed that ultrasound ethanol-water extract at 600 ppm had a higher stabilization efficiency than commercial antioxidants butylated hydroxyanisole, butylated hydroxytoluene, and tertiary butylhydroquinone.