酶法改性酪蛋白及婴儿配方乳粉的研究

Study on enzymatic modification of casein and process of formula milk powder

本文针对国内现有配方乳粉生产工艺中存在的弊病而提出的。通过参考国内外有关资料，研制出酶法改性酪蛋白婴儿配方乳粉新工艺，用固定化蛋白酶对牛乳中的酪蛋白预消化，使之转化为易被消化吸收的类乳清蛋白，通过控制蛋白质的水解度，使酪蛋白与类乳清蛋白的比例达到４０：６０，从而避免添加乳清粉的传统工艺。本文介绍了蛋白酶的选择、酶的固定化工艺、及新型婴儿配方乳粉的生产工艺，并研究了改性酪蛋白与乳清蛋白的有关性质，证明了酪蛋白经蛋白酶水解后变成了分子量较小的多肽，其许多相关性质完全可以与乳清蛋白相媲美，甚至优于乳清蛋白，通过调整脂肪酸含量及强化维生素和微量元素，使整个配方更接近母乳，并符合国家有关婴幼儿配方食品标准。

The research is conducted to solve the problems that exist in the present formula milk powder production. A new process is proposed to produce formula milk powder in which immobilized pancreatin are used to predigest the casein in milk to simulate more digestible whey protein . By controlling the new of hydrolysis the ratio of 40 to 60 is obtained between casein and whey protein which is similar to that breast's milk. So the addition of whey powder in traditional process is avoided. The research includes the selection of proteinases, the immobilization of enzymes and processing of formula milk powder. Chromatographic study shows that milk casein has been hydrolyzed into smaller peptides. The comparison between modified casein and whey protein reveals that they are similar in many aspects and in some cases the modified casein prove to be more suitable to be used in formula milk powder. The results lay a foundation for the development of hypoallergenic formula milk powder. The contents of fatty acids, trace elements and vitamins are adjusted according to breast milk profile. The whole formula is in keeping with national standard.