桂花果实多酚的超声波提取及抗氧化活性研究

Ultrasonic Extraction and Antioxidant Activity of Polyphenols from Osmanthus fragrans Fruits

以多酚得率为考察指标,利用超声波处理,通过单因素和正交试验优化桂花鲜果多酚的最佳提取工艺条件,并对桂花果实多酚的抗氧化活性进行初步研究。结果表明:桂花果实多酚的最佳提取工艺条件为70%乙醇作溶剂、料液比1:8(g/mL)、以固定频率超声波提取2次、每次40min,桂花果实多酚的得率为0.283%(即2.83mg/g);在相同质量浓度条件下,桂花果实多酚溶液还原力明显高于VC溶液,对羟自由基、亚硝酸根离子的最大清除率分别为96.3%和65.4%,并对猪油有较好的抗氧化作用。本研究为桂花资源的综合开发利用提供了一定的依据。

The ultrasonic extraction of polyphenols from Osmanthus fragrans fruits was optimized by one-factor-at-a-time combined with orthogonal array design method to maximize extraction efficiency.The optimal extraction conditions were found to be 70% aqueous ethanol as extraction solvent at a solid-to-liquid ratio of 1：8（g/mL） for twice repeated extraction for 40 min each time.Under these conditions,the yield of polyphenols was 2.83 mg/g.The reducing power of the obtained extract was distinctly higher than that of vitamin C at the same concentrations.Its maximum scavenging rates against hydroxyl free radicals and nitrite ions were 96.3% and 65.4%,respectively.In addition,the extract revealed stronger antioxidant effect on lard.This study could provide references for the comprehensive exploitation of Osmanthus fragrans fruits.