Extraction Technology and Antibacterial Activity of Anthocyanin in Purple Sweet Potato

The extraction efficiency of anthocyanin in purple sweet potato was compared under different conditions in this paper.The results showed that the optimal extraction conditions were 15% acetic acid as extraction solution,40℃ as extraction temperature,60 minutes as extraction time,1:25(g/ml) as solid to liquid ratio.Under such extraction conditions,the anthocyanin content in crude extractive was 2.20 mg/g and the extraction efficiency was 1.03 mg/g by colorimetric method.The superoxide anion radical scavenging ability of anthocyanin was worse than ascorbic acid at lower concentration(0.7 mg/ml),but better at higher concentration(0.7 mg/ml).The hydroxyl radical scavenging ability of anthocyanin was far greater than that of ascorbic acid,and was close to 100% at the concentration of 0.5 mg/ml.The preliminary determination by spread plate method showed that anthocyanin inhibited the growth of E.coli significantly.