紫甘薯花青素提取工艺及抑菌活性的研究

利用不同提取方法对紫甘薯中花青素的提取效率进行了比较,分别用5种不同溶液,选择15%乙酸作为最适宜提取液,并在不同温度、时间和固液比下对紫甘薯中花青素进行提取,选取最适宜提取温度40℃、时间60 min、固液比1∶25(g/ml),用pH比色法测定所提取物质中花青素的含量为2.20 mg/g,花青素提取率为1.03 mg/g。对超氧阴离子自由基清除能力研究发现,在低浓度条件下(0.7 mg/ml)花青素不如抗坏血酸,在高浓度条件下(0.7 mg/ml)超过抗坏血酸,对羟基自由基的清除能力研究发现,花青素对羟基自由基清除能力远远大于抗坏血酸,在0.5 mg/ml时花青素对羟基自由基的清除能力接近100%。用涂布涂板法对花青素抑菌活性进行初步测定,发现花青素对大肠杆菌的生长有明显的抑制作用。

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.