紫薯的抗氧化及活性成分研究

Study on composition analysis and antioxidant activity of purple sweet potato

以紫薯为原料,对其水分、脂肪、总灰分和矿质元素含量以及主要活性成分进行了测定,并对紫薯的体外抗氧化活性进行了评价。结果表明,紫薯中水分含量为69.10±0.64 g/100g鲜重、脂肪含量为0.21±0.02 g/100g鲜重、总灰分为1.23±0.02 g/100g鲜重。紫薯中矿质元素Ca的含量最高为137.8±1.4 mg/g干重,而硒元素的含量为0.3±0.1 mg/g干重。紫薯中总酚、总花色苷、总黄酮的含量分别为7.69±0.03 mg GA/g干重、1.80±0.02 mg/g干重、1.48±0.00 mg QU/g干重。通过UPLC–ESI–MS鉴定出7种紫薯花色苷和3种其他酚类物质,其中花色苷主要以peonidin 3–sophoroside–5–glucoside和cyanidin 3–sophoroside–5–glucoside为母核,同时带有一个或两个酰基化基团,主要为咖啡酸、阿魏酸和对羟基苯甲酸;其他酚类物质主要是绿原酸,含量为67.40±0.024 mg/g干重。紫薯对铁离子的还原能力为4.45±0.00μmol TE/g干重,对氧自由基的清除能力为38.7±1.90μmol TE/g干重。

Purple sweet potato as raw material,the moisture content,fat content,total ash and mineral elements were determined. The main active compounds and antioxidant activity of fresh purple sweet potato were investigated. The results showed that the moisture content was 69.10±0.64 g/100 g fresh weight,fat content was 0.21±0.02 g/100 g fresh weight,total ash was1.23±0.02 g/100 g fresh weight,Among all the metallic elements,Ca covered the largest amount of 137.8±1.4 mg dry weight and Se had a content of 0.3±0.1 mg/g dry weight. The total phenol,total anthocyanins and total flavonoid were 7.69±0.03 mg GA/g dry weight,1.80±0.02 mg/g dry weight and 1.48±0.00 mg QU/g dry weight,respectively. The seven anthocyanins and three other phenolic compounds were identified by UPLC–ESI–MS. The anthocyanins were mainly peonidin 3–sophoroside–5–glucoside and cyanidin 3–sophoroside–5–glucoside as a nuclear parent,meanwhile acyled with one or two acyl groups,which were mainly caffeic acid,ferulic acid and hydroxybenzoic acid. The other three phenolic compounds were mainly chlorogenic acid（67.40±0.024 mg/g dry weight）. The ferric reducing antioxidant power was 4.45±0.00μmol TE/g dry weight,and the ORAC was 38.7±1.90 μmol TE/g dry weight.