Okara flours from chickpea and soy are thickeners: Increased dough viscosity and moisture content in gluten-free bread

Abstract

The by-product of plant-based beverages, okara, can be dried in a nutritious flour, but it generates dense bakery products due to high water absorption. Gluten-free bread often tastes dry, so the objective of this work was evaluating okara flour as thickener for mouthfeel enhancement. Proximate analysis revealed that chickpea okara contained more starch than soy (35.3 vs. 3.41 g/100 g), less insoluble fibre (43.3 vs. 57.0 g/100 g) and protein (9.51 vs. 18.1 g/100 g). Water absorption capacity was higher in okara than flour and for soy (8.29 vs. 6.01 g g⁻¹, respectively). When added to a gluten-free batter, both okara flours significantly increased viscosity. Upon addition of either okara to gluten-free bread (2% w/w) moisture content increased from 31.6 to 33.5 and 36.5 g/100 g, while crumb hardness increased by up to 45% and specific loaf volume decreased by up to 42%. Soy okara flour enhanced moistness of gluten-free bread.