Preparation, Structure, and Properties of Enzymatically-Hydrolyzed Starch for Slowing Down the Retrogradation of High Starchy Foods

Amylase represents a green and healthy method that can be used to inhibit retrogradation of starch and high starchy foods. In this study, glutinous rice starch is hydrolyzed using alpha-amylase or beta-amylase at different dextrose equivalent (DE) values to investigate the effect of enzymatically-hydrolyzed glutinous rice starch (EGS) on the anti-retrogradation of rice cakes. The latter's hardness shows that EGS successfully slowed down the retrogradation of rice cakes with this effect being dependent on the type of amylase and DE value. The structure and physicochemical characteristics of different EGS are determined to identify the reasons for their different anti-retrogradation effects. It is found that with increasing DE values, molecular weight decreased but molecular structural differences increased, with both effects influencing the properties of EGS. Similarly, decreased swelling power and viscosity, and increased solubility affects the texture of rice cakes while decreased retrogradation enthalpy and crystallinity indicates that EGS can retard the retrogradation process. Overall, there are significant differences in structure and physicochemical properties of EGS that are hydrolyzed by alpha-amylase or beta-amylase. Since the production of enzymatically-hydrolyzed starch can be standardized, it is feasible for rice cake and other high starchy foods to become modern industrially-made convenience foods.

Automated summary

Amylase can be used to inhibit retrogradation of starch and high starchy foods. The study shows that enzymatically-hydrolyzed glutinous rice starch (EGS) slows down the retrogradation of rice cakes, with the effect depending on the type of amylase and DE value. Differences in structure and physicochemical properties of EGS hydrolyzed by different amylases influence their anti-retrogradation effects.