A method of extracting black bran pigments of rice by extracting black rice bran as a by-product of milling of black brown rice with aqueous ethanol solutions and treating with micro-fine bubbles is provided to increase the extraction yield and give high quality pigments. Black rice bran is mixed with 50% aqueous ethanol solutions in a weight ratio of 1:3 and extracted at room temperature for 12hr in a first extraction step and treated with fine oxygen bubbles for 1 to 3hr and 1 to 3 times in a second extraction step to increase an amount of dissolved oxygen in the solutions. During the treatment process, the black rice bran is treated with micro-fine bubbles from a micro-bubble generator with an intensity of 30m/sec.
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