Effects of Milling Methods on the Physicochemical Properties of Rice Flour from Indica, Japonica, and Glutinous Rice

This study evaluated the effects of three milling methods, which are dry, semi-dry, and wet milling, on the physicochemical, thermal, and rheological properties of three types of broken rice (indica, japonica, and glutinous rice). The aim was to evaluate how these milling methods affect key flour characteristics, including starch damage, particle size distribution, swelling power, solubility, and gelatinization behavior. Dry milling resulted in the highest degree of starch damage, leading to increased solubility and swelling power, but also a reduction in gelatinization temperature and paste viscosity. Semi-dry milling exhibited moderate starch damage, enhanced thermal stability, and superior functional properties in comparison to dry milling. Wet milling, while minimizing starch damage, produced finer particles but resulted in lower swelling power and solubility. The results also indicated that Japonica rice exhibited the least starch damage, followed by Indica and Glutinous rice. These findings provide important insights into optimizing milling techniques for high-quality rice flour production, particularly for gluten-free food products. Overall, milling method substantially modulates structure and function relations in rice flour, and semi-dry and wet milling preserve starch integrity better than dry milling. These results provide practical guidance for selecting milling strategies to tailor flour functionality for specific rice-based products.