Abstract: Infant formula generally contains 25%–30% fat content. Unsaturated fatty acids, such as linoleic acid, linolenic acid, docosahexaenoic acid, arachidonic acid, and eicosapentaenoic acid, are often added to infant formula in order to ensure its nutritional adequacy. There is a membrane structure composed of whey protein-casein complexes on the surface of fat globules in infant formula, which leads to the accumulation of a fat layer on the surface of milk powder particles. This structure makes the oil in milk powder concentrate on the surface, which increases the chance of contact with oxygen and water, making the oil easier to oxidize and hydrolyze. During processing and storage, infant formula is susceptible to oxygen, metal ions and other fat oxidation reaction conditions, leading to the deterioration of product quality. In this paper, the fatty acid composition, the structural characteristics of fat globules, and the mechanism of fat redox reaction in infant formula are reviewed, and the different fat extraction methods and analytical methods used to determine the peroxide value of infant formula are summarized and evaluated. This review hopes to provide a theoretical basis for maintaining the quality and safety of infant formula milk powder during processing, storage, and marketing.

Key words: infant formula; oxidation reaction; mechanism; peroxide value determination

摘要： 婴幼儿配方乳粉脂肪质量分数通常在25%～30%，为保证营养充足，会添加不饱和脂肪酸，如亚油酸、亚麻酸、二十二碳六烯酸、二十碳四烯酸及二十碳五烯酸等。婴幼儿配方乳粉中的脂肪球表面有一层乳清蛋白和酪蛋白复合物的膜结构，导致乳粉颗粒表面积累形成脂肪层，该结构使乳粉中的油脂集中于表面，增加其与氧气和水分接触的机会，更易被氧化、水解。婴幼儿配方乳粉在加工及贮藏过程中，受到氧气、金属离子等影响，会发生脂肪氧化反应，导致产品品质劣变。本文综述婴幼儿配方乳粉中脂肪酸组成和脂肪球结构特点等产品的内在因素及油脂氧化还原反应的主要机理，并对目前婴幼儿配方乳粉过氧化值的不同油脂提取方法和检测方法进行汇总、分析，为婴幼儿配方乳粉加工、贮藏和销售过程中保证其质量安全提供理论参考。

关键词: 婴幼儿配方乳粉；氧化反应；机理；过氧化值检测