菠萝蛋白酶降解壳聚糖条件的研究

Study on the Degradation Condition of Chitosan by Bromelain

[目的]为菠萝蛋白酶降解壳聚糖制备壳寡糖提供工艺参数和科学依据。[方法]用DNS比色法测定还原糖的含量,探讨不同条件对菠萝蛋白酶降解壳聚糖的影响。用端基分析法测定壳寡糖的分子量,研究菠萝蛋白酶降解壳聚糖过程中壳聚糖分子量的变化。[结果]菠萝蛋白酶降解壳聚糖的最适pH为7.1,最适温度为53℃,最适酶浓度为0.30 g/L。在最适条件下,降解反应进行6 h以上,可以得到平均聚合度为8,平均分子量为1 306的壳寡糖。[结论]菠萝蛋白酶能有效降解壳聚糖,制备壳寡糖。

[ Objective ] The aim was to provide scientific basis and process parameters for bromelain degradation of chitosan. [ Method ] The reducing sugar content was measured by the DNS eolorimetric. The effects of different conditions on the degradation of chitosan were investiga- ted. The ehitooligosaccharides molecular weight was measured by End-group analysis method. The chitosan molecular weight change was stud- ied in bromelain degradation of chitosan process. [ Result] The optimum pH value for degrading chitosan by this enzyme was 7.1 and the opti- mum temperature was 53 ℃ and the optimum enzyme concentration was 0.30 g/L. After reaction for 6 hours, the chitooligosaccharides which the average degree of polymerization is 8, average molecular weight is 1 306 can be obtained under optimum conditions. [ Conclusion] Chi- tosan can be effectively degraded by bromelain under ootimum conditions.