不同水解酶组合对黄姜细胞壁降解和皂苷释放量的影响及其结构特征分析

The effects of polysaccharide hydrolase on cell wall degradation and saponin release in Dioscorea zingibiernsis and its structural characterizations

黄姜皂素产业面临的亟待解决的问题是生产工艺带来的环境问题及黄姜皂素收率低.为提高黄姜皂素的提取率,以纤维素酶(C)、果胶酶(P)和木聚糖酶(X)的不同组合作用次序为影响因素,确定酶添加量为150 U/g、反应温度50℃、pH=5.0,反应20 h.以黄姜还原糖和皂素含量为指标评价处理效果.结果表明:果胶酶是破坏细胞壁、促进皂素释放的关键酶,果胶酶处理样品的还原糖与皂素含量分别为12.558%、1.293%,分别是对照组的1.948倍、2.699倍;PC组合为最优组合,其还原糖和皂素提取率最高,分别为13.601%和1.574%,是对照组的2.110倍和3.286倍.由SEM图谱观察表明:P组和PC组处理黄姜淀粉颗粒更分散,纤维素和淀粉颗粒有明显的穿孔现象,对黄姜细胞壁的降解更充分.低温氮吸附比表面积分析表明,仅采用P处理后的黄姜样品比表面积比PC和PCX组合的更大.AFM结果显示,P比PCX处理后的黄姜颗粒表面更为不平.X线衍射分析表明,仅通过3种酶的不同组合和作用顺序处理不改变黄姜生物质的相对结晶度.

The environmental problems caused by the production process and the low yield of diosgenin are the main problems facing the diosgenin industry.In order to improve the extraction rate of diosgenin in this experiment,the different combinations of cellulase(C),pectinase(P)and xylanase(X)were taken as the influencing factors,and the added amount of the enzyme was determined to be 150 U/g,the reaction temperature was 50℃,and the pH value was 5.0.The reaction duration is 20 h.The results showed that pectinase was identified as the key enzyme to destroy cell wall and promote saponin release.The contents of reducing sugar and saponin treated by pectinase were 12.558%and 1.293%respectively,which were 1.948 times and 2.699 times than the control group.PC combination was the optimal combination,and the extraction rate of reducing sugar(13.601%)and diosgenin(1.574%)were the highest,2.110 times and 3.286 times than the control group,respectively.Through the results of SEM,it was found that compared with other treatments,starch granules in P and PC treatments were more dispersed,cellulose and starch granules had obvious perforation,and the degradation of cell wall of ginger was more complete.The analysis of BET showed that the specific surface area of DZW residues treated with P alone was larger than that of PC and PCX treatments.The AFM results showed that the surface of DZW residues treated with P was more rugged than that with PCX treatments.However,XRD analysis showed that the crystallinity of DZW residues was not changed only by different combinations and sequence of action of the three enzymes.