Determination of Amylose and Amylopectin Content in Fresh Corn by Dual-wavelength Spectrophotometry

Dual-wavelength spectrophotometry was applied to the determination of amylose and amylopectin in the fresh corn through using iodine as coloring agent.According to the absorptive spectra of iodine-amylose and iodine-amylopectin,the wavelength of 629 nm and 463 nm were selected for the determination of amylose,wavelength of 553 nm and 738 nm were selected as the measuring wavelength for amylopectin.The content of amylose and amylopectin could be calculated based on the two regressive equations.Beer's law was obeyed in 10~60 mg/L for amylose and 60~200 mg/L for amylopectin.The results of amylose and amylopectin content in the fresh corn determined by the method were satisfactory.