Enzymatic hydrolysis of amylopectins from lotus rhizome and kudzu starches

To elucidate the influence of chain distributions on enzymatic digestibility of lotus rhizome and kudzu amylopectins, the correlation between the chain length distribution and enzymatic hydrolysis of amylopectins was studied. The results indicated that lotus rhizome amylopectin was more susceptible to amylase hydrolysis than kudzu amylopectin since lotus rhizome amylopectin contained a higher proportion of short chains. Using alpha-amylase and glucoamylase, individually or in combination, the values of digestion rate constant k of kudzu amylopectin were lower than that of lotus rhizome amylopectin. A small amount of glucose was released from kudzu and lotus rhizome amylopectins with alpha-amylase alone, whereas the release of glucose remarkably increased with alpha-amylase and glucoamylase. It confirmed that the synergism existed between alpha-amylase and glucoamylase in glucose released from kudzu and lotus rhizome amylopectins. The chain length distribution of amylopectins significantly affected the hydrolysis of amylases and they were highly correlated with the digestibility properties of lotus rhizome and kudzu starches.