In vitro digestion nullified the differences triggered by roasting in phenolic composition and α-glucosidase inhibitory capacity of coffee

Coffee beans were roasted to medium, dark and very dark degrees, and respective brews were in vitro digested and tested for alpha-glucosidase inhibition, to explore their antidiabetic potential. Phenolic acids (PA) and Maillard reaction indices (MRI) were quantified before and after digestion. Molecular docking was carried out to investigate alpha-glucosidase inhibition mechanisms. In vitro digested coffee inhibited alpha-glucosidase more effectively, compared to undigested samples, but without differences between roasting degrees. The inhibitory effect may be attributed to chlorogenic acids (CGA), which were the most abundant PA in digested coffees. In fact, molecular docking predicted a high affinity of CGA for alpha glucosidase. Even though digestion nullified roasting-induced differences in alpha-glucosidase inhibition, CGA showed a decreasing trend upon digestion. Similarly, MRI did not differ among coffees upon digestion but decreased compared to undigested samples. Overall, the results reported in this study suggest that the presence of different compounds in coffee matrix may contribute to an antidiabetic effect.

Automated summary

This study investigated the potential antidiabetic effect of coffee beans roasted to different degrees. Through in vitro digestion and molecular docking, it was found that chlorogenic acids in digested coffee may play a key role in inhibiting alpha-glucosidase. Despite differences in roasting degrees, the inhibitory effect of coffee on alpha-glucosidase was not significantly affected, suggesting that the presence of different compounds in coffee matrix may contribute to its antidiabetic properties.