Impact of dry sourdough based on a fermented chickpea starter on quality characteristics and shelf life of gluten-free bread

Abstract

The impact of drying of rice-chickpea flour sourdough (SD) made by a fermented chickpea extract (FCE) starter on rice flour-corn starch gluten-free (GF) batter and bread physicochemical properties were explored; FCE was prepared by submerged fermentation (37 °C × 15 h) of ground chickpeas. A liquid (freshly made) and two dried FCE-sourdoughs, dehydrated (air heating at 30 °C) or lyophilized, as well as a control formulation (without FCE-SD) were prepared at 80, 90, 100 and 110% (flour mixture basis) added water levels. Firmness, consistency, cohesiveness, and viscosity index of the batters, as evaluated by back extrusion testing, decreased by increasing the added water level in the formulation and increased by inclusion of the dehydrated sourdough preparation (p < 0.05). The lyophilized and liquid sourdough-containing breads exhibited the lowest pH and the highest specific volume, while dehydrated sourdough bread exhibited higher pH than the rest of the SD-containing breads and similar specific volume to that of control. Nevertheless, both dry FCE-SD preparations increased the crust redness and all FCE-SD breads had similar concentrations of butyric/isobutyric acids indicating a butyric fermentation during FCE preparation. Texture profile analysis revealed that both liquid and lyophilized sourdough improved crumb texture and retarded the bread staling process compared to control and dehydrated sourdough formulations (p < 0.05). The former products thus gained higher preference by a non-trained sensory evaluation panel. Overall, the lyophilized FCE-SD showed analogous potential with the liquid sourdough to improve quality attributes and shelf life of gluten-free breads, whereas the dehydrated FCE-SD (mild heating) did not fully retain its functionality.