Roasting process affects differently the bioactive compounds and the antioxidant activity of arabica and robusta coffees

- The AA of a roasted coffee results from the contribution of different compounds.
- Robusta coffee shows greater AA than arabica coffees because of the caffeine content.
- Phenolic compounds and melanoidins contribute to AA of roasted coffee.
- In dark roasting, phenolic losses may not be compensated by melanoidins formation.

The influence of different roasting degrees on the content of bioactive compounds and the antioxidant activity (AA) of arabica and robusta coffees was evaluated. AA was estimated by Folin-Ciocalteau, FRAP and ABTS methods. The results were analyzed by principal components analysis. While the levels of 5-CQA (5-caffeoylquinic acid), trigonelline, furfural and HMF (hydroxymethylfurfural) decreased with the degree of roasting, the level of melanoidins increased. Changes in the levels of the bioactive compounds were more intense that those observed for AA. PC 1 (principal component 1) was mainly correlated with the levels of, furfural, HMF, 5-CQA, trigonelline, and melanoidins. PC2 was mainly correlated with AA and caffeine content. Different compounds contribute to the AA of the coffee and the final result for AA is dependent on the balance of the compounds formed and degraded during the roasting process.