The effects of infrared stabilized immature rice grain flour in gluten-free bread preparation

Immature rice grain, which is one of the by-products of paddy milling process, was used in gluten-free bread production at the levels of 0% (control) 30%, 50%, 70%, and 100% after being stabilized using infrared radiation (at 1,600W for 4min). The effects of the infrared stabilized immature rice grain flour (IRGF) substitution on proximate composition, cooking properties, crumb and crust color, mineral composition, B-1 and B-2 vitamins, tocopherols, gamma-oryzanol, texture, and sensory properties of the breads were evaluated. Insoluble dietary fiber, Mg, Mn, K, and Fe contents of the breads remarkably increased with IRGF incorporation (p<0.05). Tocopherol content of the breads substituted with IRGF at the level of 100% was 77% higher than that of the control bread, whereas no notable variation was observed for vitamin B-1 with regard to IRGF substitution (p>0.05). Gamma-oryzanol content of the breads made from IRGF (100%) was about three times higher than that of the tocopherol content. Hardness, adhesiveness, gumminess, and chewiness of the breads pronouncedly increased with the incorporation of IRGF at the level of 50% or higher. Gluten-free bread substituted with IRGF at the level of 30% was the most preferred bread with respect to consumers' overall acceptance.