Comparison of Four Methods for the Determination of Amylose and Amylopectin

Four methods for the determination of commonly used linear and amylopectin were compared for better methods. The accuracy,recovery and sample test were performed on single standard single wavelength determination(method 1),single standard double wavelength determination(method 2),double standard single wavelength determination(method 3),double standard double wavelength determination(method 4). Results showed that:The measurement wavelength(638,536 nm)and the reference wavelength(430,768 nm)were determined based on the absorbance spectra of the amylose and amylopectin-iodine complexes respectively. The regression equation was established,and the Bill’s law was found within the range of concentration. Method 2,3,and 4 were more accurate in amylose determination,the relative standard deviation of Method 4 was 0.29%,the recovery rate was 103.25% to 103.48%. Method 2 and 3 of amylopectin determination were more accurate,the relative standard deviation of method 3 was the smallest(1.54%),the recovery rate was 94.52%~94.85%. In combination with the two methods,the mixed standard solution was selected,the measurement wavelength of amylose was 638,430 nm,and the measurement wavelength of amylopectin was 536 nm. The contents of straight and amylopectin was determined according to the regression equation.