Summary Due to a lack of gluten, rice dough needed some additives to improve its properties. This study aimed to investigate effect of hydroxypropyl methylcellulose (HPMC), whey protein concentrate (WPC) and soy protein isolate (SPI) on rice dough and bread. HPMC increased water absorption of the rice dough (P ≤ 0.05). Adding SPI (2–4 g per 100 g flour) together with HPMC tended to increase stability time and reduce tolerance index. During fermentation, HPMC increased maximum dough height, while SPI increased final dough height (P ≤ 0.05). All addition improved tan δ (G″/G′) to be comparable to the wheat dough, but it could not improve gas production and retention. Therefore, specific volume, springiness, cohesiveness and chewiness of rice bread were lower than those of wheat bread (P ≤ 0.05). Percentage of small pores in rice bread was reduced to be comparable to wheat bread, by adding WPC. All addition could improve porosity of the rice bread.

Summary This study aimed to investigate effect of butter content (0–30 g/100 g flour) and baking conditions hot air baking (HA), microwave baking (MW) and hot air‐microwave baking (HA‐MW) on quality of the rice flour dough and bread. The increased butter (up to 15 g butter/100 g flour) enhanced elastic modulus (G′) and viscous modulus (G″) of dough and specific volume of bread. Additionally, the increased butter improved crust colour and reduced hardness of the bread. The HA‐MW and MW conditions were useful for the gluten‐free bread by reducing baking time and predicted glycemic index (GI), regardless of butter content. However, enthalpy of retrogradation and crystallinity in the HA‐MW and MW bread stored at 4 °C for 7 days were increased and higher than those of the HA bread, indicating a faster staling. The predicted GI of both MW and HA‐MW bread remained at a medium level during storage.

Due to the lack of gluten, hydroxypropyl methylcellulose (HPMC), whey protein concentrate (WPC) and soy protein isolate (SPI) were fortified (4 g/100 g flour) into gluten‐free bread made from rice flour. The heteropolymer structure of HPMC and protein covered starch granules, resulting in a decrease in predicted glycemic index (pGI) of bread from 84.08 to 67.20–71.04. Addition of butter reduced the pGI to 73.55. By changing the baking mode from hot air baking to microwave baking and microwave‐hot air baking, the pGI was reduced from 73.55 to 70.51–70.81 (p ≤ 0.05). With addition of HPMC or/ and protein, the gluten‐free bread exhibited stronger inhibition of 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radicals than the wheat bread. Therefore, starch digestibility of the gluten‐free bread was mainly reduced by mixture of HPMC, proteins and butter in the dough recipe. Addition of HPMC and WPC further benefited the improvement of antioxidant activity by DPPH assay. Practical applications The finding of this research was the technique to manipulate GI and antioxidant activity in the rice‐flour bread by microwave assisted baking process and addition of HPMC, WPC and butter. The outcome of this research could increase health benefit of gluten‐free bread from rice flour, in terms of slow starch digestion and high antioxidant activity.