淀粉与碘的颜色反应与还原糖含量的关系  

On the Relationship between Color Reaction of Starch with I_2 and Content of Reducing Sugar

作　　者：江培翃[1] 陆红[1] 何正平[1] 吴忠良[1] 

机构地区：[1]复旦大学生物科学教学实验中心生物化学实验室,上海200433

出　　处：《实验室研究与探索》2005年第3期31-32,共2页Research and Exploration In Laboratory

摘　　要：将糖的定性实验和定量实验相结合,我们测定了淀粉遇碘呈不同颜色反应阶段还原糖的含量,给出定性实验一个量化的结果。当底物淀粉浓度为2g L,加入α 淀粉酶为0.5u mL时,0～2.5min呈蓝色,2.5～5.5min呈紫色,5.5～13.5min呈红色,13.5min后呈无色。对应颜色变化点还原糖的分解比率分别为45%(蓝色→紫色),66%(紫色→红色),76%(红色→无色)。An experiment was designed that combines both qualitative and quantitative experiment on sugar. The content of reducing sugar is measured when the different colors change during the reaction of starch with I_2, and a qualitative result corresponding to a quantitative experiment is reported. When the concentration of substrate starch is 2 g/L and that of α-amylase is 0.5u/mL, the solution shows blue, violet and red for the reaction time of 0～2.5 minu, 2.5～5.5min and 5.5～13.5 min respectively. Beyond 13.5 min, the solution turns to colorless. The decomposition rates of reducing sugar corresponding to the changing point of colors are 45% (blue to violet), 66%(violet to red) and 76%(red to colorless) respectively.

关 键 词：糖 颜色反应 还原糖含量 

分 类 号：Q53[生物学—生物化学]