The effects of Trametes versicolor fermented Rosa roxburghii tratt and coix seed quild on the nutrition, sensory characteristics and physical and chemical parameters of yogurt

[Display omitted] •The polysaccharides and GABA content increased to 4.19 mg/mL, 2.27 mg/100 mL.•Fermentation of Trametes versicolor can make pH drop faster.•LB12, Q-1, and BLH1 can promote the content of GABA in yogurt. Trametes versicolor can produce aromatic flavor in growth and development, widely used in food fermentation. This study used a One-Factor-at-a-Time (OFAT) test and response surface analysis to study the optimum fermentation parameters of Rosa roxburghii tratt and coix seed yogurt by Trametes versicolor. The best fermentation process is as follows: skim milk powder 17 %, sucrose content 4 %, Rosa roxburghii tratt and coix seed liquid 36 %, fermentation temperature 39 °C, inoculum 2 %, strain ratio 2:1:1(LB12: BLH1: Q-1), fermentation time 9.5 h. Under this fermentation process, the sensory score was 82.11, the contents of vitamin C, GABA, and total live bacteria in this yogurt were 13.89, 2.58, and 1.02 times higher than in common yogurt. Correlation analyses showed a significant contribution of the leavening agent to the GABA content of yogurt. This study provides a foundation for producing Rosa roxburghii tratt and coix seed yogurt with high sensory and nutritional value.