Effect of amylose content in rice flour on batter rheology and bread baking quality

Abstract

The effect of amylose content in rice batter without wheat on the baking quality and rheological property of rice bread was assessed. Bread was made with waxy and non‐waxy rice flours of similar amylopectin structure at various mixing ratios. The quality of rice bread was evaluated by the expansion ratio. The use of rice flours with similar amylopectin structure controls for the effect of differences in amylopectin structure caused by mixing different rice types. The expansion ratio of bread increased in a rice flour amylose content‐dependent manner. Rheological data showed that high viscosity batters maintained the foam structure generated during proofing, which was related to the high amylose content of the rice flour. An iodine coloration experiment confirmed that the origin of the high viscosity of high amylose rice batters was the elution of amylose into the water surrounding the rice particles in the batter. PRACTICAL APPLICATIONS: In this study, rice bread was made without additives. The batter was made by mixing waxy and non‐waxy rice flours. Storage modulus of the batter was affected by alterations in the mixing ratio of rice flours. Storage modulus of the batter showed a tendency to increase as the ratio of non‐waxy rice increased. The use of high amylose rice flours allowed for the rice batter to be proofed and processed as bread. Practical application of this study is the development of various gluten‐free foods such as bread, pasta, and pizza using rice flour without wheat.