The effects of ball mill processing on the physicochemical properties of glutinous rice starch

Abstract

Glutinous rice starch (GRS) (Oryza sativa L.) is a product derived from a staple food that is commonly cultivated and consumed in Asia. This study investigates the effect of physical modification by planetary ball mill processing on some physicochemical properties of GRS to increase the value of GRS for further pharmaceutical application. Design of experiment: two-factor-three-level factorial design was utilized to design and interpret the results in this experiment. Speed (X1) (100-400 rpm) and time (X2) (30-120 minutes) of milling were two factors examined in this study. The relationship between the two parameters allowed individual examination of four properties; the swelling capacity (SwC) (0.71±0.037-3.42±0.084), percent cold water solubility (%CWS) (0.533±0.047%-26.708±1.598%), percent gelatinization (1.178±0.606%-25.314±0.957%), and particle size (47.131±2.899 µm-306.286±2.031 µm). Increasing the milling speed increased all four properties, whereas increasing the milling time only increased %CWS and particle size. The investigation demonstrated a positive effect on %CWS from the interaction of milling speed and time (X1X2). The quadratic of milling speed (X12) negatively affected SwC, while particle size was affected in a positive way. X-ray diffractogram and surface morphology analysis substantiated the milling response data.