Impact of different S-cerevisiae yeast strains on gluten-free dough and bread quality parameters

Yeasts have been used for centuries for the leavening of bread. The main emphasis on the selection of yeast strains has been in relation to wheat products. This study is the first evaluation of different yeasts coming from the baking and brewing industry in a gluten-free system. Five different yeast strains (US-05, WB-06, T-58, S-23 and baker's yeast) of the species Saccharomyces cerevisiae were evaluated for their suitability to leaven gluten-free dough. A wide range of dough quality characteristics such as the time and temperature-dependent rising behaviour, the chemical composition of the dough and the pH were determined. In addition to this, the bread quality attributes like, volume, texture, structure, aroma and flavour were evaluated. Obtained results indicated different activity levels between the selected yeast strains. Doughs prepared with US-05 showed a slower dough rise during proofing and a decreased height, in comparison to the baker's yeast control. The application of WB-06 and T-58, however, resulted in a faster dough rise and increased dough height with greater gas cells (p < 0.05). These observations were also found in the baked breads, where these two yeasts reached a higher specific volume and a softer breadcrumb than the baker's yeast bread (p < 0.05). Statistical analysis revealed strong correlations (p < 0.05) between activity level, dough properties and bread properties. Results obtained showed that the selected yeast strains reached different level of activity due to diverse preferences in temperature, time and sugars. Yeast strains which originated from the brewing industry were found to be suitable for gluten-free bread making.