Abstract:[Objective] The research on the synergistic use of lactic acid bacteria and yeast in sourdough is beneficial for meeting the industrial production demand of fermentation agents for baking food.[Method] This study investigated the acid tolerance, acid production, enzyme production, gas production, and alcohol production abilities of various strains during the fermentation process by measuring the microbial count, pH, stretching area, elongation, hardness, viscosity, storage modulus (G′), loss modulus (G″), etc. of bread dough. The effects of different fermentation agents on the total titratable acidity (TTA), stretching characteristics, texture characteristics, and rheological properties of bread dough were investigated. [Result] Lacticaseibacillus paracasei LG0260, Lactiplantibacillus plantarum LG1034, Lactococcus lactis LG0827, as well as Saccharomyces cerevisiae J2808 and S. cerevisiae J2815, maintained good acid production rates and abilities throughout the fermentation process. Especially, L. paracasei LG0260, Kluyveromyces marxianus J2828, and L. lactis LG0827 exhibited the highest phytase enzyme activity (23.21 mU/mL), amylase enzyme activity (0.82 U/mL), and protease enzyme activity (2.51 U/mL), respectively. In addition, the fermentation agent MY2L1 prepared by co-culture fermentation of S. cerevisiae J2808 and L. paracasei LG0260 effectively improved the stretching area and elongation of bread dough, with the highest values of 242 cm2 and 181 mm, respectively. [Conclusion] Liquid strains have greater impacts on the hardness and viscosity of sourdough than commercial Angel yeast. The mixed fermentation with liquid strains enhances the fluid properties of the dough. This study can provide technical reference for mining type Ⅱ sourdough fermentation agents and improving sourdough quality.
