Antioxidant, anti-α-glucosidase and anti-glycation activities of coffee brew from Robusta coffee beans roasted at different levels

The aim of the present work was to evaluate the bioactive compound compositions of Robusta coffee brew and the antioxidant, anti-alpha-glucosidase and anti-glycation activities of these compounds, which are properties important for diabetes management. Robusta coffee beans were roasted at the first and second crack levels, followed by grinding and brewing. The DPPH activities of 5 geq/100 mL coffee brew of the first and second crack coffee beans were 1,694 mu mol/L and 1,702 mu mol/L, respectively, whereas the H-ORAC activities were 67,551 mu mol/L and 51,964 mu mol/L, respectively. The coffee brew from first crack coffee beans (12.5 geq/100 mL) inhibited the alpha-glucosidase activity up to 69% as compared to 60% by the brew from the second crack coffee beans. The IC50 values of the samples as anti-glycation agents were approximately 0.5 geq/100 mL and 0.6 geq/100 mL in the brews from the first and second crack coffee beans, respectively. Using NMR and LC-MS approaches, the first crack coffee brew was found to contain abundant phenolic acids, which are likely responsible for the antioxidant, anti-alpha-glucosidase and anti-glycation activities. Interestingly, the bioactive compounds in the second crack sample responsible for similar activities were neither phenolic acids nor melanoidins. Further study is therefore needed to evaluate the effectiveness of both Robusta coffee brews for the management of diabetes. (C) All Rights Reserved