奶及奶制品中酸度的比较研究

Comparison of acidity in milk and milk products

酸度是衡量牛奶新鲜度的重要指标,生乳中的酸度来源有两种:自然酸度和发酵酸度。自然酸度是指刚挤出来的生乳本身所具有的酸度,主要来源于生乳中的酪蛋白、白蛋白、柠檬酸盐、磷酸盐及二氧化碳等酸性物质。发酵酸度是指生乳在贮存运输的过程中,由细菌的侵入并在其中生长繁殖产生的酸性物质而升高的那部分酸度。为了保障牛奶质量和安全,部分国家和地区对牛奶中酸度进行了规定。本文对酸度与奶及奶制品质量安全的关系、影响酸度的因素和酸度的检测方法进行了综述,旨在为我国生乳酸度的研究提供一些基础资料。

Acidity is an important index to estimate the freshness of milk,there are two sources of acidity in raw milk:natural acidity and fer-mented acidity.Natural acidity refers to the acidity of the raw milk that has just been extruded.It is mainly derived from acidic substances such as casein,albumin,citrate,phosphate and carbon dioxide in raw milk.Fermentation acidity refers to the acidity of the raw milk which is raised by the intrusion of bacteria and the acidic substances produced by the growth and reproduction of the raw milk during storage and transportation.In order to ensure the quality and safety of milk,some countries and regions have regulations on acidity of milk.This paper re-viewed the relationship between milk acidity and milk quality and Safety,the influencing factors of milk acidity and corresponding determina-tion method,to provide some basic data for the research of milk in China.