摘要： 对羔羊皱胃酶的凝乳特性进行了研究。结果表明，皱胃酶的最适作用温度为50℃，低于40℃酶稳定性较好，60℃处理10 min，酶活完全丧失。在乳pH5.5~7.5之间，随乳pH的增大而降低，当pH达到7.5时酶活近乎完全丧失；酶液在pH2.0~7.0之间处理20h后，酶活还保持稳定。Al3+，CA2+和Na+对皱胃酶有较强的促凝乳作用，K+，Mg2+，Mn2+，Fe3+无较明显的促进和抑制凝乳作用，而Cu2+和Zn2+有明显的抑制酶活的作用。并研究了底物浓度对酶活的影响，得出羔羊皱胃酶催化反应的米氏常数Km为1.893g/L。
关键词:
羔羊皱胃酶,
凝乳活性
Abstract: The milk-clotting properties of kid rennet were investigated in the paper.The results showed that the optimum clotting temperature of kid rennet was 50℃.The milk-clotting activity of rennet was stable at less than 40℃,after 10 min treatment at 60℃,it would completely lose.The milk-clotting activity decreased with the increase of milk pHvalue between 5.5 and 7.5,at pH7.5 it almost losed completely.Treating kid rennet for 20 hours at the pHin the range of 2.0~7.0,the clotting activity maintained stable.Al3+,Ca2+and Na+ had obvious functions to accelerate milk coagulation.K+,Mg2+,Mn2+and Fe3+had no obvious functions to accelerate or inhibit milk coagulation.But Cu2+ and Zn2+ could keep milk from coagulating.The influence of milk concentration on enzymatic activity was also studied,obtaining the Km of kid rennet was 1.893g/L.
Key words:
Kid rennet,
Milk-clotting activity
中图分类号:
徐明生, 王毕妮, 张富新. 羔羊皱胃酶凝乳特性的研究[J]. 华北农学报, 2005, 20(6): 103-106. doi: 10.3321/j.issn:1000-7091.2005.06.026.
XU Ming-sheng, WANG Bi-ni, ZHANG Fu-xin. Investigation on the Milk-clotting Properties of Kid Rennet[J]. ACTA AGRICULTURAE BOREALI-SINICA, 2005, 20(6): 103-106. doi: 10.3321/j.issn:1000-7091.2005.06.026.