Effect of the Partial Substitution of Rice Flour with Gelatinized Rice Flour on the Physical Properties of Rice Bread

Abstract

Rice bread has a low volume and hard texture compared with wheat bread because rice flour contains no gluten. We aimed to investigate whether partially replacing non-glutinous rice flour with extruded gelatinized rice flour could improve the textural characteristics of the batter and baked bread. In rice bread containing glutinous rice flour, partial substitution with gelatinized rice flour improved the Young’s modulus and bread volume. A substitution level of 15% gelatinized rice flour provided batter with the largest bubble and film thickness and rice bread with the most pleasant texture. In contrast, in rice bread containing rice gruel partially replaced with gelatinized rice flour, the volume and Young’s modulus were not affected so any improvements in the physical properties would not be expected. Changes in the dynamic viscoelasticity (G′ and G′′) of the batter containing glutinous rice flour and rice gruel corresponded with changes in sensory evaluation scores and the valu es of Young’s modulus in the baked bread. The partial replacement of non-glutinous rice flour with gelatinized rice flour has been shown to change the characteristics of rice batter, and consequently, the physical properties and texture of the baked rice bread.