Contribution of minor compounds to the singlet oxygen-related photooxidation of olive and perilla oil blend

This study evaluated contribution of natural minor compounds including carotenoids, tocopherols, polyphenols, and phosphatidylcholine (PC) to the stability of chlorophyll sensitized oxidation of olive and perilla oil blend under 2,500 lx light at 25A degrees C for 48 h. The oxidation of the oil blend was evaluated by headspace oxygen consumption and peroxide values (POV). Minor compounds were also monitored. The headspace oxygen consumption and POV of the oil blend were increased with oxidation time; however, fatty acid composition was not significantly changed. Carotenoids, tocopherols, polyphenols, and PC were degraded during the oil oxidation, which was closely related with their singlet oxygen quenching. Correlations of the oil oxidation were higher with contents of carotenoids and PC (r (2)> 0.93) than with those of tocopherols or polyphenols, suggesting high contribution of carotenoids and PC to decreasing singlet oxygen-related photooxidation of olive and perilla oil blend.