双波长比色法测定马铃薯直链/支链淀粉含量

Dual-wavelength Colorimetric Method for Measuring Amylose and Amylopectin Contents of Potato Starch

摘要:

将新鲜马铃薯中的淀粉提出后，采用双波长比色法测定了直链/支链淀粉含量。淀粉经I2-KI溶液染色，直链淀粉呈蓝色，支链淀粉呈紫色。535和570 nm用于直链淀粉含量测定，555和760 nm用于支链淀粉含量测定。结果表明，样品溶解是检测的关键，淀粉与碘试剂的反应时间会对测定结果造成一定影响。同时通过本方法的检测，新大坪品种马铃薯的直链淀粉含量为21.20%，支链淀粉含量为78.80%。

Abstract:

Dual-wavelength colorimetry was developed to determine amylose and amylopectin contents after the starch was isolated from potato. By staining with I2-KI solution, amylose displayed a blue color, amylopectin displays a violet color. Absorbancies at 535 and 570nm were used for amylose content measurement, absorbancies at 555 and 760 nm are used for amylopectin content measurement. The XIN DAPING potato starch (from Dingxi, Gansu province) contained 21.20 % of amylase and 78.80 % of amylopectin. The detection results can be affected by the sample dissolution and the reaction time of starch and I2-KI solution.