Notice of Retraction Research on Extraction Technology of Melanin from Black Rice

The extraction technology of melanins from black rice with ethanol was investigated to maximize the amount of melanins. Based on a preliminary study, such factors as concentration of ethanol, extracting temperature, extracting time, and liquid to solid ratio were identified as significant factors, which were subsequently optimized using response surface methodology. At the optimal condition, which was extracting time 92.42min, extracting temperature 69.26°C, concentration of ethanol 77.17% (pH=2), and liquid to solid ratio 4.24, the estimated absorbance of a melanin solution could be reached at 0.4539. The practical condition was modified as follows: extracting time 95min, extracting temperature 69°C, concentration of ethanol 79% (pH=2), and liquid to solid ratio 4.5. Experimental verification gave the value of 0.449.