Phenolic Profiles, Tyrosinase Inhibitory, and Antioxidant Effects of Green Coffee, and Turkish Traditional Coffee

Abstract

Coffee has been drunk for millennia due to its taste and health benefits. High levels of polyphenols, and especially flavonoids and phenolic acids, are found in coffee and contribute significantly to its flavor and health-giving properties. In this study the total phenolic contents, antioxidant, and tyrosinase inhibition of green coffee, and Turkish traditional coffee extracts were evaluated. Antioxidant activities of the coffees were examined by two different methods, radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP). Total phenolic contents were estimated by using Folin-Ciocalteu reagent as the gallic acid equivalent. The phenolic profiles were investigated by means of reverse phase-high performance liquid chromatography (RP-HPLC). At the same time, tyrosinase enzyme inhibition of extracts has also been worked. The extracts exhibited high levels of antioxidant activities associated with significant antioxidant compound contents. It was determined that the samples contain chlorogenic acid and benzoic acid in the RP-HPLC analysis. It was determined that green coffee extract exhibited tyrosinase enzyme inhibition as effective as kojic acid. The results show that green coffee especially from coffees can be regarded as a potential source of antioxidant compounds and tyrosinase inhibitors of significance in both the pharmaceutical and food industries.