底圩茶多糖的超声波辅助提取及其抗氧化活性

为综合利用底圩茶资源,研究超声波辅助法提取底圩茶多糖工艺及体外抗氧化活性。考察颗粒度、超声时间、料液比、提取温度、超声功率5个因素对多糖得率的影响,通过正交试验确定其最佳提取工艺,并考察其抗氧化性。结果表明:最佳提取工艺为:颗粒度40目、料液比1:40 g/mL、超声时间110 min、提取温度60 ℃、超声功率750 W,在此条件下底圩茶多糖得率为11.28%±0.49%。抗氧化活性试验结果显示在浓度为2.0 mg/mL时,底圩茶多糖对O₂^-·、·OH、DPPH·、ABTS⁺·清除率分别为66.55%±2.67%、85.17%±1.70%、66.48%±2.99%、82.37%±1.00%,表明底圩茶多糖抗氧化能力较强,具有作为天然抗氧化剂的潜力。

Ultrasonic Extraction and Antioxidant Activity of Polysaccharide from Dixu Tea

In order to comprehensively utilize Dixu tea resources,ultrasonic assisted extraction technology and in vitro antioxidant activity of Dixu tea polysaccharide were studied. The effects of particle size,ultrasonic time,solid-liquid ratio,extraction temperature and ultrasonic power on the yield of polysaccharide were investigated. The optimal extraction process was determined by orthogonal test and its antioxidant activity was investigated.The results showed that the optimum extraction process was as follows:Particle size 40 mesh,liquid-material ratio 1:40 g/mL,ultrasonic time 110 min,ultrasonic temperature 60 ℃,ultrasonic power 750 W,under these conditions,the average extraction yield ofpolysaccharide was 11.28%±0.49%. The results of antioxidant activity in vitro indicated that the polysaccharide had a certain scavenging ability to the superoxide free radicals,hydroxyl radical,DPPH and ABTS free radicals,the rates were respectively 66.55%±2.67%,85.17%±1.70%,66.48%±2.99%,82.37%±1.00% at 2.0 mg/mL.The polysaccharide obtained under optimum extraction conditions exhibited strong antioxidant activities,which could be effectively used in making natural antioxidants.