Chemical properties and oxidative stability of perilla oils obtained from roasted perilla seeds as affected by extraction methods.

The chemical properties and oxidative stability of perilla oils obtained from roasted perilla seeds as affected by extraction methods (supercritical carbon dioxide [SC-CO(2)], mechanical press, and solvent extraction) were studied. The SC-CO(2) extraction at 420 bar and 50 °C and hexane extraction showed significantly higher oil yield than mechanical press extraction (P < 0.05). The fatty acid compositions in the oils were virtually identical regardless of the extraction methods. The contents of tocopherol, sterol, policosanol, and phosphorus in the perilla oils greatly varied with the extraction methods. The SC-CO(2) -extracted perilla oils contained significantly higher contents of tocopherols, sterols, and policosanols than the mechanical press-extracted and hexane-extracted oils (P < 0.05). The SC-CO(2) -extracted oil showed the greatly lower oxidative stability than press-extracted and hexane-extracted oils during the storage in the oven under dark at 60 °C. However, the photooxidative stabilities of the oils were not considerably different with extraction methods.