Inclusion of phenolic compounds from different medicinal plants to increase α-amylase inhibition activity and antioxidants in yogurt

Four types of yogurt (Y) were prepared in the presence of rosemary, dill, oregano, and ginger water extracts and refrigerated at 4°C. The effect on post-acidification, α-amylase inhibition activity, total phenolic content (TPC), and antioxidant activity was investigated during 0, 7, 14, & 21 days of storage. All herbal-yogurts showed ∼ 5 times higher α-amylase inhibition (74.45%-77.83%) than control (16%) on day 14 of storage. TPC of yogurt was increased significantly in the presence of rosemary and oregano after 14 days of storage. The presence of rosemary, dill, oregano, and ginger increased (p < 0.05) the radical scavenging activity, ferric reducing antioxidant potential (FRAP), and ferrous ion chelating (FIC) ability in yogurt during storage. There were no significant differences in the overall preference score for rosemary and ginger yogurts as compared to control. In conclusion, rosemary, dill, oregano, and ginger yogurts could be an effective treatment for postprandial hyperglycemia with antioxidant activity.