Flaschel E, Landert J P, Spiesser D, Renken A
Ann N Y Acad Sci. 1984;434:70-7. doi: 10.1111/j.1749-6632.1984.tb29802.x.
The maximum concentration of alpha-cyclodextrin for the enzymatic degradation of starch is limited to about 13.5 g X 1(-1). By addition of decanol, the equilibrium of the reaction system can be shifted towards an alpha-cyclodextrin yield of 50% even at high substrate concentrations. The main variables of the decanol process--pH, temperature, substrate quality, substrate, and enzyme concentration--have been studied. The cyclodextrin-glycosyltransferase from Klebsiella pneumoniae M5 al can preferentially be employed at pH 6 to 8, temperatures of 40 to 50 degrees C and a decanol concentration of 0.1 kg-1 starch. The dextrose equivalent of starch is important with respect to the maximum achievable starch concentration, but not with respect to the reaction. Under process conditions, the rate of alpha-cyclodextrin evolution is limited by the enzymatic reaction and not by mass transfer of decanol into the aqueous phase.
用于淀粉酶促降解的α-环糊精的最大浓度限制在约13.5 g·L⁻¹。通过添加癸醇，即使在高底物浓度下，反应体系的平衡也可向α-环糊精产率达50%的方向移动。已研究了癸醇法的主要变量——pH、温度、底物质量、底物和酶浓度。肺炎克雷伯菌M5a1的环糊精-糖基转移酶优先在pH 6至8、温度40至50℃以及癸醇浓度为0.1 kg·kg⁻¹淀粉的条件下使用。淀粉的葡萄糖当量对于可达到的最大淀粉浓度很重要，但对于反应而言并非如此。在工艺条件下，α-环糊精生成速率受酶促反应限制，而非癸醇向水相的传质限制。
