抗氧化肽延缓油脂氧化作用机制研究进展

油脂的氧化会引起食品质量劣变，影响其风味、色泽以及营养成分，寻找延缓油脂氧化的方法始终是产业发展的研究热点。抗氧化肽属于新型的抗氧化剂，然而其作用机制尚未完全了解。为推进肽在油脂体系中作用机制的认识，基于油脂氧化机理，系统梳理了抗氧化肽对油脂氧化各阶段诱因的抑制机制，主要归结于其多种功能的复杂相互作用，这些功能包括抑制活性氧生成，清除自由基，螯合促氧化金属离子，降低过氧化物的反应性。抗氧化肽清除自由基的抗氧化效果主要依赖其氨基酸残基组成，其中非极性氨基酸残基通过自由基加成作用，延缓油脂氧化起始期；极性不带电氨基酸残基通过将氢原子转移，形成抗氧化自由基来延迟油脂氧化的增长期；极性带正电荷氨基酸残基可以吸引负电荷自由基，如超氧阴离子自由基；相反地，极性带负电荷氨基酸残基可以通过排斥负电荷自由基从而减少金属离子促油脂氧化作用。

Progress on action mechanism of antioxidant peptides delaying lipid oxidation

The lipid oxidation will lead to the deterioration of food quality and the decline of flavor, color and nutrients, so it is always a hot issue of industrial development to find a way to delay it. Antioxidant peptides are new antioxidants, but their action mechanism has not been fully understood. In order to promote the understanding of the action mechanism of peptides in lipid system, based on the mechanism of lipid oxidation, the inhibition action of antioxidant peptides on the inducement of each stage of lipid oxidation was systematically summarized, which was mainly attributed to the complex interaction of their multiple functions, including inhibiting the generation of reactive oxygen, scavenging free radicals, chelating metal ions, and reducing the reactivity of peroxidation. The antioxidant effect of antioxidant peptides mainly depended on the composition of their amino acid residues, among which non-polar amino acid residues delayed the initial period of lipid oxidation by the radical adduct formation; polar uncharged amino acid residues delayed the growth period of lipid oxidation by hydrogen-atom transfer to form antioxidant free radicals; polar positively charged amino acid residues could attract negative free radicals, such as superoxide anion radical; polar negatively charged amino acid residues could repel the negative free radical to prevent lipid oxidation promoted by metal ions.