Study on Extraction Technology of Red Pigment from Purple-heart Turnip and Its Stability

In this study,purple-heart turnip was used to extract red pigment.The extraction technology was optimized by using single factor test and orthogonal test,and the stability of the red pigment was studied.Results showed that the optimal extraction conditions are as follows:using distilled water as extraction solvent,ratio of raw material and extraction solvent 1:9,extraction temperature 70 ℃,extraction time 100 min,pH 7 and extraction times 2.pH value can greatly affect the stability of the red pigment,as well as Fe3+ and Cu2+,but heat and light as well as Na+ and Ca2+ have little effects.