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 (<i>Lactobacillus plantarum</i> and <i>Streptococcus thermophilus</i>), 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 (<i>P</i> < 0.05), along with a significant improvement in sensory quality (<i>P</i> < 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 (<i>P</i> < 0.05). Mixed fermentation providing a theoretical basis for the development of novel steamed bun starters.