烟叶多肽的提取工艺优化及其抗氧化活性研究

Study on the Optimization of Extraction Process of Tobacco Polypeptide and Its Antioxidant Activity

[目的]以烟叶为原料,进行烟叶多肽的提取及其抗氧化活性研究。[方法]采用酶法辅助水提醇沉法提取烟叶多肽,应用单因素试验考察加酶量、酶解pH、酶解时间、浸提温度、底物浓度5个单因素对烟叶多肽提取量的影响,采用响应面法确定烟叶多肽的最佳提取工艺,并分析烟叶多肽对DPPH自由基和羟基自由基的清除作用,研究烟叶多肽的抗氧化活性。[结果]以处理样品质量1 g为基准,烟叶多肽的最佳提取工艺为加酶量4 200 U、酶解pH 8.2、酶解时间2.5 h、浸提温度49℃、底物浓度4.2%,烟叶多肽提取量为88.23 mg/g。按照该条件所提取的烟叶多肽对DPPH自由基和羟基自由基的清除率分别为83.09%和73.84%,表明烟叶多肽具有一定的抗氧化能力。[结论]该研究为烟叶的药用价值和烟叶多肽的药物开发提供一定的理论基础和技术指导。

[Objective]Taking tobacco as experiment material,extraction process of tobacco polypeptide and its antioxidant activity was studied in this research.[Method]Tobacco polypeptide was extracted by enzyme-assisted water extraction and alcohol precipitation.Single factor test was used to investigate the effects of enzyme addition,enzymolysis pH,enzymolysis time,extraction temperature and substrate concentration on the extraction rate of tobacco polypeptide.The optimal extraction process of tobacco polypeptide was determined by response surface method.The scavenging activity of tobacco polypeptide on DPPH and hydroxyl radicals was detected.[Result]The optimal extraction process for tobacco polypeptide was as follows(based on 1 g tobacco sample):enzyme addition 4200 U,enzymolysis pH 8.2,enzymolysis time 2.5 h,extraction temperature 49℃and the substrate concentration 4.2%.Under the optimized extraction process,the extraction rate of tobacco polypeptide was 88.23 mg/g.The scavenging rates of DPPH and hydroxyl radicals of the tobacco polypeptide were 83.09%and 73.84%,respectively.Tobacco polypeptide was of a certain antioxidant capacity.[Conclusion]This study provides a certain theoretical basis and technical guidance for the medicinal value of tobacco leaves and the drug development of tobacco peptides.