Effects of plasma treatment on the oxidative stability of vegetable oil containing antioxidants

Abstract

Plasma, the fourth stage of matter, is a partially or wholly ionized state of gas. Degree of lipid oxidation and effects of antioxidants were evaluated in bulk oils at plasma treatment. Significant changes in the conjugated dienoic acid were induced after 10 min of plasma treatment, which corresponded to treatment for 2.5 h at 100 degrees C and 48 h at 60 degrees C. Tocopherol stability in the stripped corn oil was significantly higher than that in mediumchain triacylglycerol after the plasma treatment. The antioxidant capacities of 10 mu M of alpha-tocopherol and sesamol were higher than that of beta-carotene, and synergistic effects among alpha-tocopherol, sesamol, and beta-carotene were not observed. Added alpha-tocopherol and sesamol decreased CDA formation by 33 and 30% compared to control samples after plasma treatment. Moisture content in oils decreased significantly about 20% moisture after 6 min plasma treatment. Lipid oxidation could be an important issue in plasma-treated lipid-rich products.