Changes in Antioxidant and α‐Glucosidase inhibitory activities of Coffee bean extracts by heat processing

Abstract

In the current study, we evaluated total soluble phenolics, phenolic profile and oxygen radical absorbance capacity (ORAC) of selected 4 coffee bean water extracts, with different roasting degree, such as mild (CEL), Midium (CEM), Med‐dark (CEMD), and dark (CED). We also investigated inhibitory activity of RCE against porcine α‐amylase and α‐glucosidase. CEMD had the highest α‐glucosidase inhibitory activity, ORAC value and total phenolic content. The α‐glucosidase inhibitory activity of the extracts was compared to selected specific phenolics detected in the RCE using HPLC. Chlorogenic acid and Caffeic acid, a major phenolic compound in RCE had high α‐glucosidase inhibitiory activity. The α‐glucosidase inhibitory activity of the RCE correlated to the phenolic content and antioxidant activity. These results suggest that selected RCE which has high Chlorogenic acid, Caffeic acid content with α‐glucosidase inhibitory activity and high antioxidant activity has the potential to contribute as a useful dietary supplement for controlling postprandial hyperglycemia and oxidative stress‐linked diabetes complications.