Abstract:In order to effectively extract the aqueous extract of cinnamon with hypoglycemic activity，Guangxi cinnamon was used as the raw material，and the inhibitory effect of α‐glucosidase activity in vitro was employed as the index. The ultrasound‐assisted extraction process for the aqueous extract of cinnamon was optimized through single‐factor and orthogonal experiments. The effect of the aqueous extract of cinnamon on the diges‐tion and hydrolysis of rice starch was determined by a simulated digestion model in vitro. The results showed that the optimal extraction conditions for aqueous extract of cinnamon with hypoglycemic activity were as fol‐lows：solid‐liquid ratio of 1∶45（g/mL）and ultrasonic‐assisted extraction at 45 ℃and 480 W for 30 min. The yield of lyophilized powder of aqueous extract was 12.5%，with the proanthocyanidin content of 76.03% and the half‐inhibition concentration（IC50）on α‐glucosidase activity of 112μg/mL. During the in vitro digestion，the starch hydrolysis rate and starch hydrolysis kinetic rate of the samples by adding aqueous extract of cinnamon before and after rice starch gelatinization were significantly lower than those of gelatinized rice starch. It indi‐cated that the aqueous extract of cinnamon had a certain inhibitory effect on the digestion and hydrolysis of ge‐latinized rice starch，and the mechanism might be related to that the aqueous extract of cinnamon could not only act on digestive enzymes in the system but also interact with rice starch.