Effect of heat treatment of sorghum flour on the functional properties of gluten-free bread and cake

Abstract

The effects of heat treatment on sorghum flour functionality in gluten-free bread and cake were investigated. The sorghum flour was subjected to dry-heat at two temperatures (95 °C and 125°) for 15, 30, and 45 min. The physicochemical and sensory properties of heat-treated, gluten-free bread and cake were studied and compared with control bread and cake. Flour heat treatment affects viscosity which has an important role in final cake and bread quality. Heating the flour at 125 °C for 30 min produced bread with the highest specific volume (3.08 mL/g) and the most cells per slice area (50.38 cells/cm2). This treatment also produced cakes with the highest volume (72.17 cc) and most cells per slice area (79.18 cells/cm2). The control sorghum flour produced breads and cakes with low volume, poor crumb properties, and dense textures. Additionally, cake and bread made from this heat treatment were more acceptable than the controls in consumer testing. The overall acceptability score for cake made with heat treated sorghum flour was 6.65 compared to 5.98 for control. The overall acceptability score for bread was 5.05 and 4.76 with heat treated and control flour respectively. These results can assist in advancing the quality of sorghum-based gluten-free foods for the celiac consumers.