Enhancing Functional Properties of Low Amylose Bengkoang (Pachyrhizus erosus) Starch Film by Ultrasonication

Abstract

Complete plasticization of starch granules plays an important role in maximizing the properties of a starch film. Ultrasonication treatment is one way to achieve this by breaking up insoluble starch grains. This study reports on the effects of ultrasonication on the characterization of bengkoang (Pachyrhizus erosus) starch films. Starch gel was sonicated using an ultrasonic probe at 66.9 W/cm² for 4 min. SEM of the fracture surface of the sonicated film showed a more compact structure than for the non-sonicated or control film. The sonicated films displayed a lower opacity than the control film. Opacity of the sonicated film was 6.82% lower than control film. The sonicated film also had lower hydrophilicity; moisture absorption of film was decreased about 10.28% after sonication. Furthermore, ultrasonication increased the tensile strength and decreased the fracture strain of films.