双波长法分析测定汉中莲菜支链淀粉和直链淀粉的含量

Determination of amylopectin and amylose content in lotus root from Hanzhong by dual-wavelength spectrophotometry

用碘为显色剂,采用双波长紫外—可见法检测汉中莲菜中支链淀粉和直链淀粉的含量,并对汉中莲菜进行了评价。根据直链淀粉与碘形成蓝色复合物、支链淀粉与碘形成紫红色复合物的显色特征和双波长法测定结果,确定直链淀粉的测定波长和参比波长分别为511 nm和582 nm,y=0.046 43x+0.011 67(r2=0.998 7);支链淀粉的测定波长和参比波长分别为614 nm和549 nm,y=0.004 6x+0.002 55(r2=0.996 8)。测得汉中不同品种莲菜中的直链淀粉和支链淀粉各不相同,方法的回收率为98.07%~101.3%,稳定性的相对标准偏差(RSD)值分别为1.95%和1.85%,精密度RSD值分别为0.26%和0.11%,结果表明该方法可用于莲菜中淀粉的分析。

Dual-wavelength spectrophotometry was applied to determine the amylose and amylopectin content in lotus root from Hanzhong with iodine as coloring agent. According to the color characteristics of amylose mixed with iodine forming blue mixtures and amylopectin mixed with iodine forming amaranth mixtures, and the determination results of Dual- wavelength spectrophotometry, the determination and reference wavelength of amylose were 511 nm and 582 nm, respectively,Y =0.046 43x＋0.011 67 （r^2=0.998 7）; the determination and reference wavelength of amylopectin were 614 nm and 549 nm, respectively,Y=0.004 6x＋0.002 55（r^2=0.996 8）. The amylose and amylopectin content was different in different varieties of lotus root from Hanzhong, the recovery rate of both amylose and amylopectin ranged from 98.07% to 101.3%. The RSD of stability was 1.95% and 1.85%, and the RSD of precision is 0.26% and 0.11%,respectively. The results showed the method Could accurately analyze the starch in lotus root.