Effects of supercritical C02 extraction parameters on chemical composition and free radical-scavenging activity of pomegranate (Punica granatum L.) seed oil.

Pomegranate (Punica granatum L.) seed oil (PSO) was prepared by supercritical CO2 (SC-CO2) extraction technology. Changes in the yield, chemical composition and free radical-scavenging activity of PSO under different extraction parameters were investigated. The results of SC-CO2 extraction revealed that extraction pressure was the dominant factor to affect the oil yield. PSO was characterized by a high content of punicic acid (approximately 60%) and γ-tocopherol (more than 300mg/100g oil). A slight increase in the contents of punicic acid, arachidic acid and gadoleic acid was observed under higher extraction pressure and temperature. At lower pressure or shorter extraction time, PSO with high amount of total tocopherols was obtained. PSO extracted by SC-CO2 showed strong free radical-scavenging activity towards 2,2-diphenyl-l-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenz-thiazoline-6-sulfonic) diammonium salt (ABTS) radicals and its scavenging ability was correlated with the level of tocopherols in extracted oils. [ABSTRACT FROM AUTHOR]