Mechanisms and Factors for Edible Oil Oxidation

ABSTRACT: Edible oil is oxidized during processing and storage via autoxidation and photosensitized oxidation, in which triplet oxygen ( 3 O 2 ) and singlet oxygen ( 1 O 2 ) react with the oil, respectively. Autoxidation of oils requires radical forms of acylglycerols, whereas photosensitized oxidation does not require lipid radicals since 1 O 2 reacts directly with double bonds. Lipid hydroperoxides formed by 3 O 2 are conjugated dienes, whereas 1 O 2 produces both conjugated and nonconjugated dienes. The hydroperoxides are decomposed to produce off‐flavor compounds and the oil quality decreases. Autoxidation of oil is accelerated by the presence of free fatty acids, mono‐ and diacylglycerols, metals such as…