Impact of Enzyme Modification on Physicochemical Properties of Oat Flake and Starch

Abstract

AbstractOat flakes are modified with alpha (α)‐amylase and a combination of α‐amylase and cellulase (α‐amylase/cellulase) to determine the effect of enzyme modification on the quality of oat flakes and physicochemical properties of oat starch. Enzyme modification using α‐amylase and cellulase increases the water absorption capacity and decreases the hardness and adhesiveness of oat flakes by degrading long polysaccharide chains. The molecular weight of oat starch modified with α‐amylase and α‐amylase/cellulose is lower than that of native oat starch. Moreover, the depolymerization of starch molecules is more notable in starch modified with α‐amylase/cellulase than in starch modified with α‐amylase alone. α‐Amylase treatment during oat flake processing causes the loss of peak viscosity, while α‐amylase/cellulase treatment results in the loss of both peak and final viscosity of oat starch. In addition, enzyme modification with α‐amylase/cellulase reduces the content of amylose‐lipid complex. Solubility and swelling power are also significantly increased in α‐amylase/cellulase‐modified oat starch. These results indicate that the modification of oat flakes with α‐amylase and cellulase induces changes in starch structure, thereby affecting physicochemical properties of oat starch and quality of flakes.