Extraction technique of pigment from black rice hulls by ultrasonic

A new technology of extracting pigment from black rice hulls by ultrasonic was studied.Based on the extraction rate of pigment,the single factor method and orthogonal design method were used for the optimization of ultrasonic extraction.The results showed that the optimal extraction conditions were: 80%vol ethanol with pH value 1.5,the ratio of material to liquid 40 ml/g,ultrasonic power 128W,extraction temperature 50℃ and extraction time 60 min.The extraction was conducted 3 times under above conditions.Then,the extraction rate of pigment reached 98.8%,which 18.3% higher than that of the water-bath extraction under the same conditions.