Effect of cassava-banana flour composition and soy protein isolate addition on bread quality and antioxidant properties of gluten-free bread

Abstract

The effect of cassava-banana flour formulation and soy protein isolate (SPI) addition on gluten-free bread quality and antioxidant properties has been studied. The gluten-free flour composition was 25:75, 50:50, and 75:25 for cassava & banana flour with SPI levels ranged 0, 2.5, 5.0, and 7.5%. Wheat bread was used as control. Different gluten-free flour formulations and SPI addition affected the quality of gluten-free bread (height, specific volume, hardness, springiness, cohesiveness, and resilience) significantly. Banana flour gave a better specific volume compared to cassava flour, and the addition of SPI also increased the height and specific volume of gluten-free bread. Total phenolic content (TPC) and antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)) of gluten-free bread were altered by the type of flour composition and SPI addition. Banana flour composition increased TPC & antioxidant capacities. The SPI inclusion on the gluten-free bread also increased TPC and antioxidant activities. The highest DPPH and ABTS content were achieved from 25:75 cassava: banana flour with 5% and 0 % SPI addition (3.25 and 3.16 μmol Trolox equivalent (TE) respectively). These values were higher than the wheat bread control (2.04, and 2.92 μmol TE/100 g, respectively). It can be inferred that banana flour and SPI inclusion in the gluten-free bread gave a better gluten-free bread quality and enhanced antioxidant capacities.