RESUMO
In the present study a simple and highly sensitive RP-HPLC method has been established for simultaneous determination of chlorogenic acid, caffeic acid, vanillic acid and caffeine in coffee samples. The method has been applied to eight different coffees available on the Romanian market which were previously analysed concerning the total polyphenols content and antioxidant capacity. Reduction of the DPPH radical was used to determine the antioxidant capacity of the coffee extracts while the total polyphenols content was determined by spectrophotometry (Folin Ciocalteu's method). The total polyphenols content ranged from 1.98 g GAE/100 g to 4.19 g GAE/100 g while the caffeine content ranged from 1.89 g/100 g to 3.05 g/100 g. A large variability was observed in chlorogenic acid content of the investigated coffee samples which ranged between 0.6 and 2.32 g/100 g.
Assuntos
Antioxidantes/análise , Cafeína/análise , Café/química , Hidroxibenzoatos/análise , Cromatografia Líquida de Alta Pressão , Sequestradores de Radicais Livres/análise , RomêniaRESUMO
In the present study a simple and highly sensitive RP-HPLC method has been established for simultaneous determination of chlorogenic acid, caffeic acid, vanillic acid and caffeine in coffee samples. The method has been applied to eight different coffees available on the Romanian market which were previously analysed concerning the total polyphenols content and antioxidant capacity. Reduction of the DPPH radical was used to determine the antioxidant capacity of the coffee extracts while the total polyphenols content was determined by spectrophotometry (Folin Ciocalteu's method). The total polyphenols content ranged from 1.98 g GAE/100 g to 4.19 g GAE/100 g while the caffeine content ranged from 1.89 g/100 g to 3.05 g/100 g. A large variability was observed in chlorogenic acid content of the investigated coffee samples which ranged between 0.6 and 2.32 g/100 g.
En este trabajo, un método sensible RPHPLC fue desarrollado para la determinación simultánea del ácido clorogénico, del ácido cafeico, del ácido vanílico y de la cafeína en las pruebas de café. El método fue aplicado para analizar ocho tipos de café disponibles en el mercado de Rumania, que fueron analizados también en cuanto al contenido total de polifenoles y la capacidad antioxidante. La reducción del radical DPPH fue utilizada para determinar la capacidad antioxidante de los extractos de café mientras que el contenido total de polifenoles fue determinado por la espectrofotometría (método Folin Ciocalteu). El contenido total de polifenoles se situó entre 1,98 g GAE/100 g y 4.19 g GAE/100 g mientras que el contenido de cafeína se situó entre 1.89 g/100 g y 3.05 g/100 g. Una gran variabilidad se observó con respecto al contenido de ácido clorogénico en las pruebas de café analizadas, contenido que se situó entre 0.6 y 2.32 g/100 g.