Abstract:This study aims to improve the utilization rate of β-glucan in black highland barley.To be specific，unhulled black highland barley was fermented with each of six strains to screen the optimal strains，and then the highland barley was fermented with the mixture of optimal strains at different ratios to obtain the optimal ratio.With the yield of β-glucan as the evaluation index，the fermentation conditions of highland barley were optimized by single factor test and response surface methodology.For the β-glucan obtained under the optimal conditions，the in vitro antioxidant activity was tested.The results showed that the highest yield（[42.8±0.0）%]of β-glucan was achieved under the following conditions:mixture of highly-active dry yeast，alcohol-fermentation dry yeast，and Streptococcus thermophilus at the ratio of 2∶1∶1 （mass ratio），material-to-liquid ratio of 1∶12（g/mL），inoculum at 5% （mass fraction），temperature of 34 ℃，and fermentation for 26 h.The yield of β-glucan increased 63.01% after enrichment，indicating that it was feasible to enrich β-glucanin highland barley by fermentation.The yielded β-glucan had strong antioxidant activity and it can scavenge over 50% of the DPPH and ABTS+radical.