The study of the extraction and stability of sweet potato leaf pigments

The paper explores purple sweet potato pigment extraction.Optimum conditions and stability were studied.The best extracting conditions were:95% ethanol at 50℃ for 30h.pH has a major influence:the pigment was more stable under acidic conditions and very sensitive to the light.Ca2+、Mg2+、Zn2+、Cu2+、Na+had no effect on the pigment stability while Fe3+and Sn4+caused the pigment color to change.