Mixed fermentation of lactic acid bacteria and sourdough on quality and storage characteristics of steamed bun

The effect of mixed fermentation with sourdough and lactic acid bacteria (Lactobacillus plantarum and Streptococcus thermophilus), the physicochemical indexes, storage characteristics of dough and bun were investigated. Compared with sourdough-only dough and bun, the mixed fermentation significantly increase the total phenol, flavonoid and hydrolyzed amino acid content of the dough, the specific volume and height-diameter ratio of mixed fermentation bun increased significantly by 18.3 % and 7.9 %, respectively (P < 0.05), along with a significant improvement in sensory quality (P < 0.05), and exhibited enhanced skin whiteness (by 2.0 %), with an increase in stomatal density and porosity by 2.6 % and 16.5 %, respectively. During a nine-day storage period, the moisture content near the skin and bun core of steamed bun decreased by 3.9 %, and 1.6 %, respectively, and the aging enthalpy values of mixed fermentation bun were significantly lower than sourdough-only bun (P < 0.05). Mixed fermentation providing a theoretical basis for the development of novel steamed bun starters.