油脂氧化酸败研究进展

Research progress on the oxidative rancidity of oils and fats

油脂氧化酸败与风味劣变、营养丧失、生物学损害、组织老化紧密相关。该文概述油脂氧化研究以自动氧化自由基链式反应学说为核心发展历程;阐述自动氧化、光敏氧化、酶促氧化之间关联性与研究进展。自动氧化在油脂氧化中处主导地位,而光敏氧化和酶促氧化很可能在诱发氧化前期起关键作用;光敏氧化既可循II型单线态氧化途径,又可循I型自由基链式氧化途径,取决于激发态光敏剂是底物脱氢、还是直接攻击不饱和双键;酶促氧化在有氧条件下类似自由基链式反应,无氧条件下脂氧酶无活性。

Rancidity of oisl and fats is closely related to flavor deterioration, nutrient loss, biological damage and tissue aging. This article overviewed the evolution of lipid oxidation theory, with the theory of auto-oxidative free radical chain reaction as the focus. Besides, the research progress ＆ relationship among autoxidation, photosensitive oxidation and enzyme-catalyzed oxidation was elucidated. Auto-oxidation is in a dominant position in the lipid oxidation. Photosensitive oxidation and enzyme- catalyzed oxidation may play a key role in the initiation of the reaction. Photosensitive oxidation may follow either type II pathway of singlet oxidation or type I pathway of free radical chain oxidation, depending on whether the excited photosensitizer abstracts hydrogen with substrate, or directly attacks the unsaturated double bond. Enzyme-catalyzed oxidation acts similarly to free radical chain reaction under aerobic conditions, and lipoxygenase will have no activity under anaerobic conditions.