Optimization of extraction conditions of purple- red pigment from “Heijingang” potato based on Plackett- Burman and response surface method

In order to investigate on best extraction conditions of purple- red pigment from Heijingang potato,the yield of purple- red pigment was used as an indicator.The key and optimum conditions for extraction pigment were found by Plackett- Burman( PB) and the steepest ascent experiment on the basis of single factor tests.Then,the critical conditions( acid concentration,extraction time,extraction times) were reoptimized by using response surface method( RSM). The results demonstrated that acid concentration of 0.31 mol / L,solid- liquid ratio of1∶ 60 g / m L,extracting temperature of 70 ℃,extracting time of 87 min,extracting times of 3 times. Under those conditions,the yield could arrive to 3.43 mg / g.