摘要
通过流化床干燥法制备稳定化颗粒酶 ,提高酶的耐热性 .在制备过程中进风温度为 4 0℃ ,酶活回收率达到 90 %以上 .采用海藻酸钠 (SA)作包被剂 ,随着SA质量浓度的提高 ,酶的耐干热性先增加后降低 ,在 0 .4 g/dL最高 ,而其耐湿热性不断增强 .水分活度提高 ,固态酶的耐热性就随之降低 ,在Aw ≥ 0 .3时流化床干燥酶样品的耐热性都明显高于原酶粉 ,且SA质量浓度越高 ,酶对水分的耐受能力越高 .在流化床干燥酶制剂中添加硫酸铵、氯化钠、硫酸钠等盐类稳定剂 ,酶的耐干热性有的增强 ,有的减弱 ,而其耐湿热性都有所增强 ,其中硫酸铵的热稳定化效果最好 .酶在高温下的失活速度遵循一级动力学 ,即它的失活是由酶蛋白变性引起的 ,流化床干燥样品的失活常数低于原酶粉的失活常数 。
The fluid bed spraying and drying was used to prepare thermostabilized enzyme granules. During fluid bed drying, the activity recovery of all the enzymes investigated was more than 90%. The optimal inlet temperature was chosen as 40 ℃. Sodium alginate was used as a coating agent. As its concentration increased, the thermostability of enzymes treated in oven firstly increased and then decreased, but the thermostability of enzymes against steam treatment always increased. The heat resistance of fluid bed drying samples was about 10 times higher than that of control when water activity was higher than 0.3. Ammonium sulfate, sodium chloride or sodium sulfate was added as salt stabilizer. The effect on stabilizing enzymes was not equal and ammonium sulfate was a better stabilizer. The rate of enzyme inactivation followed first order dynamics. The inactivation constant of fluid bed drying sample was lower than that of controlled one. The enzyme inactivation rate at different temperature followed Arrenius' equation.
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2002年第1期27-32,共6页
Journal of Food Science and Biotechnology
