煮制加工对不同绿豆中黄酮含量的影响及抗氧化活性研究

在绿豆加工过程中,煮制对黄酮类物质相对含量影响较大,所以本实验分别考察了乙醇浓度、煮制温度、煮制时间和pH对绿丰2号和5号两种绿豆煮制液中黄酮含量的影响,在单因素试验基础上通过正交试验对影响黄酮含量的因素进行了优化研究,并对提取出的两种黄酮进行抗氧化活性测定。结果表明:乙醇浓度和pH对煮制液黄酮含量影响显著。最佳的煮制工艺参数为:pH为7.5,煮制温度80℃,煮制时间1.6 h,乙醇浓度为70%。在此提取参数下,绿丰2号绿豆的黄酮类化合物提取量为1.82 mg/g,绿丰5号绿豆的黄酮类化合物提取量为1.77 mg/g;而两种绿豆黄酮类化合物对DPPH自由基、羟基自由基、超氧阴离子自由基均有清除能力,同时,该研究也将为下一步绿豆饮料的开发中黄酮类物质的抗氧化活性提供数据依据。

Effect of cooking process on flavonoids content in different kind of mung beans and their antioxidant activity

Cooking method has a great influence on the relative content of mug bean flavonoids. Ethanol concentration, cooking temperature, cooking time and pH value for two kinds of green beans Lvfeng No.2 and No.5 were studied. The flavonoids extraction process was optimized by orthogonal test on the basis of single factor experiments. The antioxidant activities of two flavonoids were determined. The results showed that the ethanol concentration and pH value had significant effects on the flavonoid content. The optimum extraction parameters are : pH 7.5, cooking temperature 80?C, cooking time 1.6 h, and ethanol concentration 70%.Under the above extraction conditions, the content of flavonoids was 1.82 mg/g in Lvfeng No.2 mung bean, and 1.77 mg/g in Lvfeng No.5 mung bean. Both mung bean flavonoids showed scavenging ability to DPPH, hydroxyl radical, and superoxide anion radicals. The study also provides a reference for the study of antioxidant activity of flavonoids in mung bean beverages.