酵母乳糖酶对牛乳乳糖水解作用的研究

采用乳酸克鲁维酵母的乳糖酶(β-乳糖苷酶)对乳糖溶液、喷雾干燥脱脂奶以及全脂奶进行了试验,以确定将乳糖转化成单糖的最适条件。当牛奶中酶浓度为3u/ml时,于40℃反应2小时或4℃反应24小时,约60％的乳糖得以水解。随着乳糖浓度的增高,水解程度也有所提高。当酶浓度为10U/ml时,于40℃反应2小时,90％乳糖得以水解。用自制的乳酸克鲁维酵母的乳糖酶和加拿大lactaid Inc.生产的乳糖酶制剂lactaid水解乳糖无大的差异。

Lactose Hydrolysis of Milks By Kluyveromyces lactis Lactase

Lactase (β-galactosidase) from Kluyveromyces lactis was tested on lactose solution, spray-dried skim milks and whole milks to determine optimum conditions for converting loctose to monosugars. An enzyme concentration of 3 u/ml in milk incubated 2 hours at 40℃ or 24 hours at 4℃, hydrolyzed about 60% of the lactose. And with the increasing of lactase concentration, the extent of hydrolyzation is increased. An enzyme concentration, of 10u/ml in milk incubated 2 hours at 40℃, hydrolyzed 90% of lactose. There was no significant differnce in lactose hydrolysis between the lactis lactase and the Lactaid (produced by Lactaid Inc. in Canada)