Studies on Stability of Deodorized Anthocyanins from Purple Sweet Potato

The effects of p H-value,metal ions and organic acids on the color characteristics and stability of anthocyanins off-flavor from purple sweet potato were studied in this manuscript. The results showed that the anthocyanins was most stable when p H lower 3.0;Fe3+in lower concentration could increase the color intense most largely. But it could accelerate anthocyanins to degrade and brown in high concentration over extended time.Fe2 +led to degradation.Ca2 +,Mn2 +and Cu2 +in low concentration had good copigmentation effects. Oxalic acid,malonic acid,and L-malic acid could enhanced the absorbance values and improved the thermal stability,which showed an increased tendency with organic acids concentration. Among the three organic acids,oxalic acid showed the best copigmentation effects,followed by L-malic acid and malonic acid.However,ferulic acid and citric acid had no significant copigmentation effect. Ascorbic acid was subtractive.