Physicochemical Properties And Stability Of Melanin From Auricularia Auricula Fermentation Broths

Physicochemical properties and stability of melanin from Auricularia auricula fermentation broths were studied. The result showed that A. auricula fermentation broths melanin powder was dark with a little red and yellow colored (L*= 38.88, a*= 0.36, b*= -0.13). A. auricula fermentation broths melanin was insoluble in both water and common organic solvents. It dissolved only in alkali aqueous solution and precipitated in acidic aqueous solution (pH< 3). A. auricula fermentation broths melanin was gradually oxidative bleached by oxidant and was stable to reducer. It exhibited strong optical absorbance in a wide UV-VIS spectral range. Furthermore, A. auricula fermentation broths melanin was relatively stable in the range of 20-100 degrees C and under nature light. Result of present study indicated that A. auricula fermentation broths melanin could potentially be used in the food industry as a natural colorant.