Structural and Rheological Characterisation of Rye-Wheat Dough Fermented using Limosilactobacillus Fermentum

Author(s): Julia Nutter, Miriam O Iurlina, Amelia I Saiz

The acidification performance of Limosilactobacillus fermentum was studied in relation to the effect on the microstructure and rheology of sourdough. Scanning electron microscopy revealed a disruptive matrix of gluten without structures such as films or fibers that characterize a cohesive network of gluten. The production of lactic and acetic acids and ethanol was monitored by gaseous chromatography; the values obtained at the end of fermentation, 19 hours, were 5.86 g of lactic acid, 1.00 g of acetic acid, and 2.96 g of ethanol. Acidification profile of L. fermentum promoted the cleavage of disulphide linkages and was responsible for disordered protein structure and therefore a disrupted matrix of gluten. This observation was in line with viscoelastic performance of sourdough. G’ and G’’, determined by dynamic oscillatory assays, shown the same values to control dough and dough inoculate with L. fermentum. This event confirmed the absence of gluten network that account for sourdough elasticity.