Ultra-fine Pulverization of Rice: Effects on Hydration Properties and Enzymatic Hydrolysis

Abstract

We studied the hydration properties and enzymatic hydrolysis of micro-sized rice flour obtained by dry jet-pulverization to find new applications for the flour in the food industry. Ultra-fine rice flour (both white and brown) with a mean size of <5 μm was far more dispersible than coarser flours (15–120 μm). Dispersibility increased with finer mean particle size and higher starch damage. The ultra-fine flour also had the highest solubility, swelling power, water absorption index, and glucose release. Dry jet-pulverization to <5 μm mean size and consequent starch damage to (>30%) decreased enthalpy and gave very different hydration properties and enzymatic hydrolysis than in coarser flours.