牛乳蛋白在人工瘤胃和小肠液中体外降解的动态变化

Dynamic degradation of bovine milk proteins by artificial ruminal fermentation system and small intestine fluid in vitro

研究了牛乳蛋白在人工瘤胃和小肠液中体外消化的动态过程.采用高效液相色谱分析消化液中的游离氨基酸含量,同时测定消化液中蛋白浓度和组成的变化.结果显示,脱脂乳在人工瘤胃中发酵24 h内,总游离氨基酸含量逐渐增加,其中Arg、Leu和Pro含量增加最明显;发酵30 min^7 h内,蛋白浓度迅速下降;发酵5 h后,大部分酪蛋白被降解,而β-乳球蛋白和α-乳清蛋白变化很小;脱脂乳在小肠液中进行体外消化,总游离氨基酸迅速增加,反应至7 h时,溶液中的总游离氨基酸增加约4倍,其中以Arg、Tyr、Phe、Leu、Lys和Pro含量增加最明显.

Bovine milk protein is fermented in an artificial ruminal fermentation system and digested in small intestine fluid in vitro.Free amino acid is measured by high performance liquid chromatography and protein concentration is determined in the digestion fluid to study the dynamic changes of milk protein degradation.The research reveals that during 24 h fermentation of skim milk in vitro system,the concentration of total free amino acid increases over time,especially Arg,Leu,and Pro.Protein concentration decre...