| A new method for the determination of amylose and amylopectin in the commonly used raw materials was established based on dual-wavelength spectrophotometry. According to the principle of dual-wavelength spectrophotometry method, the contents of amylose and amylopectin in the common raw materials of starch were determined at the determination wavelength of 630 nm and 550 nm with the reference wavelength of 480 nm and 735 nm, respectively. The content of amylose and amylopectin could be figured out from two regressive equations. Beer law was obeyed in concentration of 0~36 μg/mL for amylose and 40~100 μg/mL for amylopectin, and both the exactitude and accuracy were very good. The total starch contents of the commonly used raw materials of starch ranged from 66.51% to 83.65%. The amylose contents of mung bean starch and pea starch were significantly higher than other starch raw materials. The amylopectin content of glutinous rice flour was the highest, and the amylose content was extremely low for its absorbance value too low to be detected. |
