摘要
江米酒中的凝乳酶是引起我国传统乳制品米酒奶凝乳的原因。本实验对从江米酒中纯化得到的凝乳酶的酶学特性进行了研究。纯化凝乳酶的最适反应温度为45℃,酶活力在45～55℃之间比较稳定。纯化凝乳酶的最适反应pH为5.5,酶活力在pH值3.0～7.0之间比较稳定。Na^+、K^+、Ca^2+、Mg^2+、Zn^2+、Mn^2+、Fe^2+均对凝乳酶的凝乳活力有促进作用,其中Ca^2+对凝乳酶的凝乳活力有着显著地促进作用,Cu^2+对凝乳活力有抑制作用。凝乳酶特异性的水解酪蛋白,而对乳白蛋白和乳球蛋白不产生水解作用。凝乳酶的酶切主要位点在α-酪蛋白第95位M的N-端,同时还存在其他酶切位点。
The chymosin purified from glutinous rice wine is the reason why glutinous rice wine could coagulate Chinese royal cheese, one of traditional Chinese dairy produce. The coagulating characteristics of purified chymosin in glutinous rice wine were investigated systematically. The optimum coagulating temperature of purified chymosin was 45 ℃. The optimum coagulating pH was 5.5. Both the clotting activity and the proteolysis activity were stable between 45 -55 ℃, pH 3.0-7.0. Na^＋, K^＋, Ca^2＋, Mg^2＋, Zn^2＋, Mn^2＋ and Fe2＋ increased the clotting activity while Ca^2＋ showed the greatest effect. Cu^2＋inhibited the clotting activity. The purified chymosin specifically hydrolyzed casein while having no effect on α-lactoalbumin and β -lactoglobulin. The main enzymatic cleavage site is N-terminal of M95. There are other enzymatic cleavage sites as well.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2008年第4期259-262,共4页
Food Science
基金
天津市高等学校技术发展基金项目(20070911)
天津商业大学青年科研培育基金项目
关键词
凝乳酶
酶学特性
江米酒
chymosin
enzyme prooerties
glutinous rice wine
