Antioxidant activity in green and roasted coffee: a critical review

Abstract

The pleasant taste and aroma coffee make it one of the most popular and widely consumed beverages worldwide. A number of studies have been performed to elucidate the possible beneficial effects of coffee consumption on human health and have shown that coffee exhibits potent antioxidant activity, which may be attributed mainly to its polyphenolic content. However, there is also evidence to suggest that coffee roasting (the procedure which turns green coffee beans to the dark, roasted ones from which the beverage derives) may alter the polyphenolic profile of the beans (e.g., via the Maillard reaction) and, concomitantly, their antioxidant activity. In the present study, the main findings on difference of antioxidant effect of green coffee and roasted coffee in vitro, cell-free and cell-based assays, animal and human studies is reviewed and summarized.