Contribution of chlorogenic acids to the iron-reducing activity of coffee beverages.
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 investigated using ground and soluble coffee samples. The concentration of specific chlorogenic acids and caffeine in the beverages was determined by high-performance liquid chromatography and related to FRAP using 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 those prepared with soluble coffee (p < 0.05). In the former beverages, FRAP of C. robusta samples was significantly higher (on average, 50.3%) when compared to that of C. arabica samples, and FRAP values decreased with increasing degree of roasting (p < 0.05). A strong correlation (r > 0.91) was found between FRAP and the total content of chlorogenic acids, particularly that of the caffeoylquinic acid isomers. The iron-reducing activity of coffee beverages was not influenced by caffeine.
Moreira
Daniel P
DP
Laboratório de Bioquímica Nutricional e de Alimentos, Instituto de Química, Departamento de Bioquímica, Ilha do Fundão, Universidade Federal do Rio de Janeiro, CT bloco A, 21949-900 Rio de Janeiro, RJ, Brazil.
Monteiro
Mariana C
MC
Ribeiro-Alves
Mirna
M
Donangelo
Carmen M
CM
Trugo
Luiz C
LC
D000975:Antioxidants / Q000032:analysis / Q000737:chemistry; D002110:Caffeine / Q000032:analysis; D002726:Chlorogenic Acid / Q000032:analysis* / Q000737:chemistry; D040503:Coffea / Q000737:chemistry*; D003069:Coffee / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry; D005511:Food Handling / Q000379:methods; D006358:Hot Temperature; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D012639:Seeds / Q000737:chemistry
D000975:Antioxidants; D003069:Coffee; D005290:Ferric Compounds; D002726:Chlorogenic Acid; D002110:Caffeine; D007501:Iron