Impact of yeast and fungi (1 → 3)(1 → 6)-β-glucan concentrates on viscoelastic behavior and bread making performance of gluten-free rice-based doughs

Abstract

The addition of bioactive β-glucan to gluten-free breads is of special interest to people suffering from celiac disease. Most of the studies found in literature involve cereal (1 → 3)(1 → 4)-β-glucan, while those from yeast and fungi are still nearly unexplored. This study focuses on the effect of fortifying gluten-free rice-based doughs and breads with (1 → 3)(1 → 6)-β-glucan concentrates derived from yeasts –soluble (SBG) and insoluble (IBG)– and fungi (Pleurotus Ostreatus) (FBG). SBG-enriched doughs were less firm and exhibited lower resistance to deformation than doughs with FBG or IBG. In contrast, FBG- and IBG-enriched doughs increased their resistance to deformation as the concentration increased. Doughs with a firmer consistency as determined by a forward extrusion test (FBG- and IBG-enriched doughs) corresponded to those with larger dynamic moduli and lower frequency dependence, lower elastic deformation and higher viscosity at steady state. The physical quality of breads was significantly improved by addition of all types of (1 → 3)(1 → 6)-β-glucan at optimized dough hydration. They caused an increase in the specific volume of the breads, a reduction in their hardness and longer shelf-life. Sensory evaluation also demonstrated an improvement in bread organoleptic attributes when SBG was added.