Abstract: Bovine milk contains 2%–5% lipids, secreted by breast epithelial cells and dispersed in the milk in the form of milk fat globules. Most of the milk fat (about 98%) exists in the milk fat globules in the form of glycerolipids, and the rest (about 2%) is polar lipids, including glycerophospholipids, sphingolipids, glycolipids, mainly distributed in the milk fat globule membrane surface. Despite their relative scarcity, milk polar lipids play an indispensable role in the growth and development of mammals. This review introduces readers to the types of polar lipids in milk, and compares the types and quantities of milk polar lipids from different milk sources including cows, buffalo, yak, sheep, goats, donkeys, camels, and humans. Next, this review summarizes the physiological functions of milk polar lipids including inhibition of neutral fat absorption, regulation of intestinal microbial community composition, prevention of cardiovascular disease, prevention of non-alcoholic fatty liver, promotion of cognitive function and nervous system development, and anti-inflammatory effects with a view to providing reference for the research and development of functional milk fat products.

Key words: milk polar lipids; glycerophospholipids; sphingolipids; saccharolipids; physiological functions

摘要： 乳中含有2%～5%的脂质，乳中的脂质由乳腺上皮细胞分泌并以乳脂肪球的形式分散在乳中。大部分乳脂（约98%）以甘油酯的形式存在于乳脂肪球内部，其余（约2%）包括甘油磷脂、鞘脂、糖脂等在内的少部分极性脂质则主要分布在乳脂肪球膜表面。乳极性脂质虽然在乳脂中占比较少，但却对哺乳动物的生长发育有着不可或缺的作用。本文首先介绍乳中极性脂质的种类，比较奶牛乳、水牛乳、牦牛乳、绵羊乳、山羊乳、驴乳、骆驼乳、人乳等不同乳源的乳极性脂质种类及含量差异，随后探讨乳极性脂质的生理功能，包括抑制中性脂肪吸收、调节肠道微生物群落组成、预防心血管疾病、预防非酒精性脂肪肝、促进认知功能与神经系统发育、抗炎作用等，以期为功能性乳脂产品的研发提供参考。

关键词: 乳极性脂质；甘油磷脂；鞘脂；糖脂；生理功能