Abstract:Simulated gastrointestinal digestion combined with ultrafiltration was used to prepare peptides PMPa (Prinsepia utilis Royle meal peptide>5 ku) and PMPb (P. utilis Royle meal peptide<5 ku) with different molecular weights, and their hypoglycemic and antioxidant activities were analyzed. The added amounts of the studied peptides were 0%, 1.25%, 2.5%, 5.0%, and 7.5% biscuits. The color and texture of the biscuits simulate the rapidly digestible starch (RDS) content; chronically digestible starch (SDS) content; blood glucose load (GL); and 2 h postprandial blood glucose levels in type 2 diabetic mice after digestion. The α-amylase inhibition rates of PMPa and PMPb were 62.33% and 68.51%, respectively, which were significantly higher than those of acarbose. The albumin inhibition rate and 2,2-diphenyl-1-picrylhydrazyl free radical scavenging rate significantly higher for PMPb than PMPa and the positive control diclofenac sodium., vitamin E. As the amount of added peptide increased, the brightness, hardness, and chewiness of the biscuits gradually decreased, the RDS content decreased, and the SDS content increased after the biscuits were digested. Moreover, biscuits with 7.5% PMPa and PMPb added had the lowest glycemic loads of 15.57 and 13.79, respectively, which indicate that they are medium GL foods. The 2 h postprandial blood glucose concentration was significantly lower in type II diabetic mice fed biscuits with high proportions of PMP (5.0% and 7.5%) than in control mice. In summary, the addition of PMP can improve the in vitro digestion properties of wheat biscuits and regulate postprandial blood sugar levels to a certain extent. Owing to its dynamic attributes, PMP can be applied as a natural active food ingredient in nutritious biscuits.
