Abstract: This study explored changes in the acidity of sheep milk across different lactation periods and the key factors affecting the acidity of sheep milk. The pH, titratable acidity, fat content, protein content and composition, total sugar content, mineral content, density, lactose content, fatty acid composition and content were analyzed, and the correlation between physicochemical indexes and acidity was investigated. The results indicated that the acidity of raw sheep milk was closely related to lactation stages. The highest acidity was observed in the early lactation period, which then gradually decreased as lactation progressed. Acidity changes were primarily associated with the protein content, fat content, fatty acid composition, total sugar content, lactose content, mineral content, and density of the milk. Among these, the protein content showed the strongest correlation with acidity changes, whereas fatty acid content had a relatively low correlation with acidity variations.

Key words: sheep milk; lactation period; acidity; physicochemical indicators; correlation

摘要： 探究绵羊乳在不同泌乳阶段的酸度变化规律，揭示影响绵羊乳酸度的关键因素。对不同泌乳阶段绵羊乳pH值、可滴定酸度、脂肪、蛋白质、总糖、矿物质含量、密度、乳糖含量、蛋白质组成、脂肪酸种类及含量进行分析，并通过相关性分析明确不同泌乳阶段绵羊乳理化指标与酸度变化之间的关系。结果表明：生鲜绵羊乳酸度变化与泌乳阶段密切相关，泌乳前期酸度最高，随着泌乳期延长，酸度逐渐降低；且酸度变化主要与乳中蛋白质含量、脂肪含量、脂肪酸构成、总糖、乳糖、矿物质含量及密度等因素有关；其中蛋白质含量与酸度变化关联度最大，而脂肪酸含量与酸度变化的关联度较小。

关键词: 绵羊乳；泌乳期；酸度；理化指标；关联度