Studies on the microwave extraction of the yellow pigment from Rabdosia serra (Maxim.) Hara.

A new method of microwave extraction was used to extract the yellow pigment from Rabdosia serra (Maxim.) Hara. The extraction processes were investigated and the optimal conditions were determined as follows: raw material is 2. 0000 g dry powder, the extraction agent is 95% alcohol, the ratio of raw material to extraction agent is 1:60 (g:ml) , microwave power is 464 W, extraction time is 350 s, extraction times is 3. Under the optimal conditions, extraction rate is 90.6%, productive rate is 12.7%, colority E (1%, 330 nm) is 53.3 and pH value of the extractive is 6.0. Compared with solvent extraction, microwave extraction reduces extraction time from 6 h to 350 s and increases extraction rate from 90.4% to 90.6%.