Extraction of antioxidative compounds from wine lees using supercritical fluids and associated anti-tyrosinase activity

This study examines a co-solvent-modified supercritical carbon dioxide (m-SCCO2) extraction of polyphenols from rice wine lees. Chemical antioxidative activity, inhibitive melanoma tyrosinase and melanin that had been treated by the extracts were studied. Experimental results indicate that the Soxhlet 95% ethanol extract was effective in α,α-diphenyl-β-picryl-hydrazyl (DPPH) radical scavenging (86%), ferrous ion chelating (91%), reducing ability (1.877 optical density value; OD) and tyrosinase inhibition (57%). Among the m-SCCO2 extracts, the best antioxidative capacity was DPPH radical scavenging (31%), ferrous ion chelating (74%) and reducing ability (0.2373 OD). The amount of polyphenols in the extracts increased with the addition of ethanol in the m-SCCO2 extraction, enhancing the antioxidative activity and tyrosinase inhibition in cells tests. The tyrosinase inhibition in an agar-plate that was treated by m-SCCO2 extract is more effective than that of Soxhlet 95% ethanol extract, indicating that the polyphenols contents in the extracts are important in the suppression of tyrosinase and melanin.