溶菌酶提取工艺及其在山核桃乳中的应用研究

Extraction of Lysozyme and Its Application in Chinese Walnut Milk

[目的]研究制备溶菌酶的最佳工艺条件及其在山核桃乳中的应用。[方法]以鸡蛋清为原料,通过阳离子交换树脂法提取溶菌酶,采用正交试验确定制备溶菌酶的最适工艺条件,并将溶菌酶与甘氨酸和NaCl复配后作为防腐剂应用于脱脂山核桃乳饮料中。[结果]通过正交试验确定的最佳工艺条件为:蛋清树脂比5:1、pH值7.0、搅拌吸附4h,用1.0mol/LNaCl洗脱,洗脱液经超滤、浓缩后冷冻干燥得到溶菌酶成品。该试验最终酶收率为89.78%,酶活力为14817U/mg。将0.05%溶菌酶与0.30%甘氨酸和0.40%NaCl进行复配用于生产脱脂山核桃乳,其抑菌效果较显著,降低了山核桃乳的杀菌强度,延长了产品货架期。[结论]该工艺操作方便,适合溶菌酶的工业化生产;溶菌酶用于生产脱脂山核桃乳效果好。

[ Objective ] The aim was to study the optimum technology condition for preparing the lysezyme and its application in Chinese walnut milk. [ Method] With the chicken egg white as the raw material, the lysozyme was extracted by the cation exchange resin method. The optimum technology condition for preparing the lysezyme was determined through the orthogonal experiment and the compound of lysezyme with glycin and NaCl was used as the preservative and was applied in beverage of Chinese walnut milk. [ Result] The optimum technology condition through the orthogonal experiment was follows： the ratios of chicken egg white to resin of 5： 1, pH value of 7.0, stirring adsorption for 4 h at room temperature, eluting by the solvent of 1.0 mol/L NaCl and the final product of lysezyme obtaining from this eluted solution that was made through the series processing of ultra-filtration, concentration and lyophilization. Under this technology condition the final enzyme yield was 89.78% and the enzyme activity was 14 817 U/mg. When the compound from 0.05% lysozyme, 0.30% glycin and 0.40% NaCl was used in the production of defatted Chinese walnut milk, its antibacterial effect was notable, which could reduce the sterilization intensity and prolong the shelf life of this product. [ Conclusion] This technology was convenience in operation and was suitable for industrial production of lysozyme which got good effect when being used in the production of Chinese walnut milk.