Extraction Method of Pigments in Black Rice

This experiment was conducted to estabilish the efficient extraction condition for pigments in black rice. Efficiency of the pigments extraction was maximal when the content ratio of mixed solvent of methanol (3): ethanol (7) was 70%. In black rice pigment, 70%-80% ethanol containing 0.5% malic acid showed the best extraction efficiency and stability with a maximum absorbance wavelength at 538nm. The relative optical density of the pigments increased until the solvent temperature was reached at 70℃.The higher amount of the pigment was extracted from the longer stirring time of the solvent 10min was enough for the grindingtime of rice. Supernatant of the pigment extractives after one day storage at 4℃ in refrigerator revealed higher optical density.