This study examines a co-solvent-modified supercritical carbon dioxide (m-SC CO2) 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 ,-diphenyl--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-SC CO2 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-SC CO2 extraction, enhancing the antioxidative activity
and tyrosinase inhibition in cells tests. The tyrosinase inhibition in an agar-plate that was treated by mSC
CO2 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.
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