Recovery of Natural Bioactive Extract with Antioxidants and Anti-Tyrosinase from Coffee Silver Skin (CSS)

Abstract

Coffee silver skin (CSS) is a thin tegument of the outer layer of coffee bean, CSS is a by-product of the coffee, appearing during the roasting step. Although this is produced in large amounts as an agricultural waste, the chemical components and biological activity have never been explored. In this study, CSS was extracted using three different polarity solvents and three extracts were evaluated for antioxidant and anti-tyrosinase activity. The ethyl acetate extract showed the most potent inhibition against DPPH (2,2-Diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) with IC50 values of 0.31 ± 0.06 and 0.49 ± 0.03 (mg/mL), respectively. In addition, ethyl acetate extract also revealed the most potent inhibition (25%) against tyrosinase at the concentration of 0.25 mg/mL. This finding suggested that CSS would be developed as a prolific source of antiaging agents such as cosmetics.