Optimization for ultrasonic wave extraction of water-soluble pigment in red kojic rice by response surface method

The extraction technology of water-soluble pigment from red kojic rice was studied.On the basis of single-factor experiment,the response surface methodology was used to study the effects of ultrasonic time,material solvent ratio and ultrasonic wave power on the water-soluble pigment extraction.A quadric regression model for the water-soluble monascus pigment concentration was established,and the optimum extraction conditions were obtained.It showed that all the three factors played important roles to water-soluble pigment extraction.The optimum extraction conditions were as follows: ultrasonic time 20.6 min,material to solvent ratio 32.2 ∶ 1,ultrasonic wave power 730 W.Under such conditions,the water-soluble pigment concentration of the extract reached the theoretical maximum 570.5 U/g.