Abstract:Based on single factor experiments，the Box-Behnken response surface method was used to optimize enzymatic hydrolysis-based preparation of Ramulus mori oligosaccharides having the ability to inhibit the growth of Streptococcus mutans.The influence of enzyme addition，enzymolysis time，and enzymolysis temperature on the rate of S.mutans inhibition was investigated by using Ramulus mori polysaccharides as the raw material.The following parameters were used to optimize the preparation of Ramulus mori oligosaccharides using the enzymatic method:enzyme，β-glucanase；enzyme concentration，485 U/mL；enzymolysis time，3.6 h；enzymolysis temperature，44 ℃.Under these conditions，the S.mutans growth was inhibited at a rate of（68.30±3.96）%，which was consistent with the predicted value，indicating that this optimization process was feasible.The rate at which Ramulus mori oligosaccharides inhibited the growth of S.mutans was higher than that observed upon using Ramulus mori polysaccharides at the same mass concentration，indicating that the enzymatic hydrolysis step effectively improved the antibacterial activity of Ramulus mori oligosaccharides.Assessment of the antioxidant activity showed that Ramulus mori oligosaccharides prepared using the optimized method could scavenge DPPH，ABTS+free radicals and reduct Fe3+.The total antioxidant capacity increased with an increase in mass concentration.