Effects of enzymatic extrusion on the structure and physicochemical properties of oat flour and its application in oat milk production

Abstract

SummaryOat milk has received increasing attention because of its health benefits, however, the problems of easy sedimentation and deterioration of taste during storage are common problems faced by the industry. Enzymatic extrusion is a technology that combines high‐temperature, high‐pressure and high‐shear extrusion with enzymatic hydrolysis for rapid biological transformation of materials. To evaluate the feasibility of enzymatic extrusion to overcome these disadvantages, the effects of this technology on the physicochemical properties of oat flour and on the stability and sensory score of oat milk have been studied. The results showed that the water solubility index of the enzymatic extrusion sample (2‰ α‐amylase) increased by 37.64% (from 5.99% to 43.63%) and the reducing sugar content increased about 11 times (from 11.61 to 128.31 mg g−1) compared with original oat flour. The enzymatic extrusion samples were almost completely gelatinised and their viscosity and degree of order were significantly reduced. The rheological results indicated that the enzymatic extrusion samples exhibited greater viscous fluid characteristics. After enzymatic extrusion treatment, the stability of oat milk was significantly enhanced, sensory evaluation indicated a highest score of 7.29 on the 9‐point hedonic scale (2‰ α‐amylase). This study provides a new way to produce high‐quality oat milk.