A comparative analysis of the properties of doughs prepared by liquid and firm fermentation with a co-culture of Acetobacter tropicalis A3 and Saccharomyces cerevisiae Y10

Abstract

In view of the benefits of liquid dough fermentation and the positive impact of acetic acid bacteria (AAB) on the production of fermented goods, this study examined the properties of final doughs produced by liquid fermentation (FDL) using a mixture of Acetobacter tropicalis A3 and Saccharomyces cerevisiae Y10, and compared them with doughs produced by firm fermentation (FDF). The FDL dough had a higher microbial count, acidity level, reducing sugar content, protease and amylase activity, while a significantly altered gluten network and lower gluten index compared with FDF. The untargeted metabolomics analysis revealed that amino acids, peptides, and their analogues accounted for over 18% of the 179 differential metabolites found in the FDL and FDF doughs. Peptides accounted for more than 30% of the top 30 differential metabolites and were significantly positively associated with protease activity, but negatively correlated with gluten index and pH, suggesting a key role of protease for the gluten network and metabolomic profile between FDL and FDF dough. FDL exhibited increased peak and final viscosity, as well as decreased CO₂ production and bound water (T₂₁) relaxation time. These results enhance our understanding of the potential applications of A. tropicalis and S. cerevisiae in liquid dough fermentation.