马铃薯酪氨酸酶评价美白产品测定体系的建立

Establishment of a Determination System for the Evaluation of Whitening Products of Potato Tyrosinase

从马铃薯中提取酪氨酸酶,以儿茶酚为底物,研究酪氨酸酶的动力学性质,用正交实验建立和优化一种酪氨酸酶活性抑制的测定体系,用此体系测定6种美白产品对酪氨酸酶活性的抑制率。结果表明,酪氨酸酶促反应产物的最大吸收波长为410nm,动力学参数为Km为0.486 mmol/L,Vmax为9.17 U/min,测定美白产品对酪氨酸酶抑制作用的最佳实验条件为:底物为0.3mL,酶为0.3mL,样品为1.5mL。用此体系测定8种美白产品对酪氨酸酶抑制率分别达到32.5%、36.7%、34.5%、31.0%、32.6%、28.6%、38.2%、35.6%。为美白产品功效提供了一种客观评价体系。

Vocational training has three characteristics:pertinence,flexibility and practicality.There are some problems that need to be improved in the promotion of vocational training in our government departments,vocational colleges,private vocational training institutions and enterprises.Vocational colleges for development.In order to improve the quality of vocational training,we should adhere to the three basic principles of employment oriented,skill based and quality-oriented,properly handle the relationship between vocational training and vocational skill training,school system education and vocational skill evaluation,and formulate the occupation standard of vocational training teachers to be sure,we should establish a system of evaluation,trial teaching,rewards and punishments,part-time teacher training,and a qualified team of vocational training teachers.