Abstract:In this study, highland barley, a characteristic crop of the Qinghai-Tibet Plateau, was used as the raw material, and Tibetan mushrooms were used for liquid fermentation. Single-factor experiments and response surface tests were conducted on four fermentation parameters, including fermentation temperature, fermentation time, material-to-liquid ratio, and inoculum amount, to determine the contents of β-glucan and γ-aminobutyric acid in barley fermentation broth, and the effect of Tibetan mushroom fermentation on the quantities of nutrients in barley. The results showed that: the optimum material-to-liquid ratio for enriching β-glucan in highland barley with Tibetan mushroom fermentation was 1:25, the inoculum amount was 5% (m/m), the fermentation time was 36 h, and the fermentation temperature was 37 ℃; the optimum material-to-liquid ratio for enriching γ-aminobutyric in highland barley with Tibetan mushroom fermentation was 1:30, and the fermentation time was 8 h, with the inoculation amount and fermentation temperature being the same as those for enriching β-glucan. Under the optimized process conditions, the yield of β-glucan in highland barley fermented by Tibetan mushroom was 48.26%, 1.93 times higher than that before fermentation; the yield of γ-aminobutyric acid was 54.56%, 1.8 times higher than that before fermentation. In summary, the fermented highland barley with Tibetan mushroom can effectively increase its β-glucan and γ-aminobutyric acid contents, and realize the development and application of the nutrients in highland barley.
