神秘果种子多酚超声双水相复合提取工艺及其抗氧化活性

Ultrasonic-assisted two-phase aqueous extraction and antioxidant activity of polyphenols from the seed of Synespalum dulcificum

利用超声波与双水相体系复合提取神秘果种子多酚,研究不同条件下提取的多酚的抗氧化能力。分别考察丙酮浓度、硫酸铵用量、超声波温度、超声波时间、料液比对神秘果种子多酚提取率的影响;采用单因素试验及响应面设计,优化神秘果种子多酚提取工艺。结果表明,最佳提取工艺条件为:丙酮浓度50%、硫酸铵用量0.22g、超声波温度60℃、超声波时间100min、液料比1∶20(m∶V),多酚理论提取率为11.54%。该条件下神秘果种子多酚的平均提取率为11.56%。该体系提取的多酚纯度为87.85%,优于单独采用超声波提取,可实现初步纯化。抗氧化性试验结果表明,神秘果种子多酚提取物对DPPH·的清除能力和还原能力较强,且还原力和DPPH·清除率与总多酚含量呈正比关系;其抗氧化活性强于抗坏血酸。

The seed of Synespalum dulcificum was untrasonified in the acetone-（NH_4）_2SO_4aqueous two-phase syetem to extract total polyphenils and different conditions for extraction of polyphenols antioxidant activity was investigated.Acetone was chosen as the best extraction solvent for this research.The acetone concentration,amount of the（NH_4）_2SO_4,the ultrasonic time,extraction temperature,ratio of water to solid were discussed by the single factor experiment.The optimal extraction conditions were found to be：the concentration of acetone solution 50%,ultrasonic time 100 min and extraction temperature 60 ℃,ratio of water to solid 20∶1（V ∶m）.The maximum extraction yield of total polyphenils was 11.54% in the optimum conditions.Under the optimum conditions,through duplicated experiment the yield of polyphenols was 11.56%,it indicated that the extraction rate of polyphenols was extremely stable.The purity of polyphenols extracted with this system is 87.85%,superior to only use ultrasonic,preliminary purification can be realized.The results of the experiment on different conditions for extraction of polyphenols antioxidant activity showed that it has strong ability of removing DPPH free radical and reducing power and to the polyphenol content.The maximum DPPH scavenging rate by polyphenols was up to 62%,higher then that by ascorbic acid.