Influence of particle size on the properties of rice flour and quality of gluten-free rice bread

Abstract

To investigate the influence of particle size on the quality of rice flour and rice bread, the rice flour with similarly low damaged starch content (4 g/100g) with different particle sizes (>200, 150–200, 100–150, 75–100, and <75 μm) were employed. With the reduction of particle size, the water hydration at high temperature and pasting viscosity of rice flour increased, while the gelatinization temperature (onset and peak temperature) slightly decreased. However, there was no significant difference in crystalline structure and enthalpy change of rice flour with different particle sizes. Further, the elastic and viscous modulus of rice batter increased as particle size decreased, except >200 μm. Moreover, rice bread made from rice flour with larger particle size had a significantly lower volume, rougher crumb structure and harder bread texture (p < 0.05) than that made from smaller particle size, leading to an undesirable rice bread quality. The results indicated that the rice flour with particle size 75–100 μm can exhibit preferable characteristics of rice flour, which could be used to produce similar desirable qualities of rice bread to the wet-ground rice flour.