| Abstract
| - The iron-reducing activity of coffee beverages was determined by the ferric reducing antioxidant power(FRAP) assay. The influence on FRAP due to the degree of roasting (light, medium, and dark), species(Coffea arabica and Coffea robusta), and caffeine content (regular and decaffeinated) was investigatedusing ground and soluble coffee samples. The concentration of specific chlorogenic acids and caffeinein the beverages was determined by high-performance liquid chromatography and related to FRAPusing Pearson correlation coefficients. All measurements were expressed per unit of soluble solids.Beverages prepared with ground coffee had, on average, 27% higher FRAP values than thoseprepared with soluble coffee (p< 0.05). In the former beverages, FRAP of C. robusta samples wassignificantly higher (on average, 50.3%) when compared to that of C. arabica samples, and FRAPvalues decreased with increasing degree of roasting (p< 0.05). A strong correlation (r> 0.91) wasfound between FRAP and the total content of chlorogenic acids, particularly that of the caffeoylquinicacid isomers. The iron-reducing activity of coffee beverages was not influenced by caffeine. Keywords: Coffee; iron-reducing activity; FRAP; chlorogenic acids; caffeine
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