PHENOLIC PROFILES, TYROSINASE INHIBITORY, AND ANTIOXIDANT EFFECTS OF GREEN COFFEE, AND TURKISH TRADITIONAL COFFEE

Coffee is the most widely consumed beverages worldwide. Coffee has been drunk for millennia due to their taste and health benefits. High levels of polyphenols, and especially flavonoids and phenolic acids, are found in coffee and contribute significantly to their flavor and health-giving properties. This study evaluated, the total phenolic contents, antioxidant, and tyrosinase inhibitor activities of green coffee, and Turkish traditional coffee extracts. 
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 gallic acid equivalent. The phenolic profiles were investigated by means of reverse phase-high performance liquid chromatography (RP-HPLC). This study investigated tyrosinase enzyme inhibitions against diphenolase (DOPA), using kojic acid as a positive control. 
The extracts exhibited high levels of antioxidant activities associated with significant antioxidant compound contents. The extracts exhibited high levels of tyrosinase inhibititory activity. 
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.