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.

Rheological behavior of batter and quality of gluten‐free bread based on nonglutinous rice flour and tartary buckwheat flour

“…The water absorption (Han et al., 2012), amylose content (Yano et al., 2020) and protein structure (Encina‐Zelada et al., 2018) would contribute considerably to batter stickiness. The higher water absorption resulted in fully contact between starch and water, so as to dissolve and release.…”

“…Yano et al. (2020) had proposed that batter containing RF of high amylose content resulted in increased batter viscosity. However, the AKRF batter is not consistent with the above conclusion.…”

“…As for RF/TBF mixture, the replacement amount of TBF below 10% increased the YF47RF/TBF and AKRF/TBF batter stickiness, while 10% replacement with TBF in LJ294RF decreased the batter stickiness when LJ294RF one was used. The higher amount of amylose eluted from rice particles increased batter stickiness (Yano et al., 2020). To sum up, the RF batter made by pure LJ294RF was the stickiest.…”

“…Han et al (2012) have reported that the stickiness of rice flour dough was related to the water absorption, and higher water absorption reduced stickiness and produced stiff dough. Yano et al (2020) had proposed that batter containing RF of high amylose content resulted in increased batter viscosity. However, the AKRF batter is not consistent with the above conclusion.…”

“…Based on previous studies, rice cultivars that have intermediate amylose (16.8%–23.3%) was preferable for breadmaking (Aoki et al., 2012). Additionally, the expansion ratio of rice bread increased with the increasing amylose content from 0%–20% (Yano et al., 2020). Therefore, rice type of appropriate amylose content can be useful for the development of high‐quality gluten‐free bread.…”