Effects of supercritical carbon dioxide extracts of red pepper and pine needle on the oxidative stability of perilla oil

Abstract

The objective of this study was to determine the effects of supercritical carbon dioxide (SC-CO2) extracts from red pepper (RP) or pine needles (PN) on the physicochemical properties of perilla oil (PO). Subsequently, the physicochemical properties of the perilla oil containing SC-CO2 extract at 0.1% and PO without extract were compared. Oxidative stability was measured based on viscosity, acid value (AV), peroxide value (POV), antioxidant (2,2-diphenyl-1-picrahydrazyl) activity, p-anisidine value (p-AV), and fatty acid composition. All the samples were studied under medium temperature (65°C) accelerated oxidation conditions for 24 h. The viscosities of PO with PN extract and PO without extract significantly increased with increasing storage time, but that of PO added with RP extract was not significantly different (p<0.05). The oxidative stability properties, such as AV, POV, and p-AV, indicated that PO with RP or PN extracts exhibited superior oxidative stabilities than PO without extract. The antioxidant activities of all samples was significantly decreased with increasing the oxidation time (p<0.05). No significant differences in fatty acid composition between PO with and without extract were observed (p<0.05). Thus, the SC-CO2 extracts affect the lipid oxidative stability in perilla oil and may be used as natural antioxidant for food preservation.