On the Susceptibility of the Crystalline and Retrograded Forms of Amylose of Different Molecular Weights toward Black-koji Amylase System

Abstract

The crystalline and retrograded amylose preparations were digested by black-koji amylase system in the heterogeneous state such as in the case of raw starch digestion. It was found that the usual retrograded amylose should be fractionated into two parts—one easily digestible and the other resistant toward black-koji amylase system. The latter part, when recrystallized by n-butanol, however, turned highly susceptible toward the enzyme action. Its molecular weight, as determined by the light scattering method, was found to be 32,000, a value much smaller than that of the original amylose (140,000).