Techno-functional and baking properties of optimised heat-moisture treated acha flour

Abstract

Hydrothermal processing of gluten-free flours has been shown to enhance their functional and baking properties. Process variables such as temperature, moisture and treatment time conditions were optimised in relation to quality characteristics of acha flour and using a three-variable Box–Behnken design based on response surface methodology. The derived optimal heat-moisture treatment conditions for acha flour were 80 °C, 25% moisture and 17 min, and their effect on proximate and functional properties of acha flour was studied. It was revealed that optimal heat-moisture treatment had minimal impact on the proximate compositions of acha flour but increase water and oil absorption capacities (135% and 90%), swelling power (32%), peak viscosity (8%), pasting temperature (6%) and decreased solubility (9%), breakdown viscosity (9%), setback viscosity (42%) and bulk density (22%). Optimal modified acha flour or was blended with wheat flour at ratios 10:90, 20:80 and 30:70 and utilised in production of bread, and their physical properties and sensory acceptability were studied in relation to their native counterparts and 100% wheat flour. It was revealed that acha flour-wheat flour breads containing optimal heat-moisture treated flours had higher specific volumes and consumer acceptability scores, and more open crumb structures than those of their native acha counterparts regardless of inclusion level. Ratio 10:90 of optimal heat-moisture treated flour and wheat flour produced bread with properties closest to 100% wheat flour bread. Thus, the derived optimal heat-moisture treatment conditions were successful in enhancing the functional and baking properties of acha. Findings from this study will be of relevance to the flour mills and the baking industry as well as will enhance knowledge on the baking prospects of hydrothermal treatment and acha flour properties.