Abstract:
In this study changes during fermentation of spontaneously fermented modern and ancient (spelt, emmer, and
khorasan) wheat sourdoughs and their feasibility to act as leavening agents in breadmaking were evaluated.
During 6 h of fermentation, sourdough was characterized for lactic acid bacteria and yeasts counts, pH, total
titratable acidity (TTA), proteolytic activity, rheological and electrophoretic profiles. The effects of 25 and 50 g/
100g sourdough addition on physico-chemical and sensory properties of refined wheat flour bread were also
investigated. Although in all sourdoughs a pH drop, increase in proteolytic activity, gliadin and glutenin
degradation with fermentation were recorded, due to different flour composition and microbial activity, tested
sourdoughs significantly differed in rheological properties and breadmaking quality. Wheat sourdough being
characterized by the highest acidification, increase in proteolytic activity, and the most extensive hydrolysis of
gliadins, resulted in bread with the lowest specific volume and hardest crumb texture. Emmer sourdough, having the highest TTA, ash and wet gluten content, exhibited the highest extensibility, the least pronounced changes in proteolytic activity and the electrophoretic pattern which produced bread with the highest volume and softest texture. In general, ancient wheat varieties have shown great potential in sourdough breadmaking in comparison to modern wheat.
