金丝小枣多酚的提取及抗氧化性和抑菌活性研究

选用金丝小枣(Ziziphus jujuba)为材料,采用超声波辅助法提取金丝小枣中的多酚。在单因素试验基础上进行正交试验,确定金丝小枣多酚的最佳提取工艺。试验结果表明:超声波辅助法提取金丝小枣多酚的最佳提取工艺为超声时间30 min、乙醇浓度50%、料液比1∶15、超声功率210 W、超声温度50℃,此条件下金丝小枣多酚提取量为12.45 mg/g。抗氧化性研究结果表明:金丝小枣多酚对亚硝酸根、羟自由基和超氧自由基有清除作用。金丝小枣多酚对枯草芽孢杆菌、大肠杆菌、曲霉、根霉4种菌有不同程度的抑制作用,可作为天然食品添加剂应用于食品保鲜。

Study on the Extraction of Polyphenols from Ziziphus jujuba and Its Antioxidation and Antibacterial Activity

Using Ziziphus jujuba as the raw material,polyphenols are extracted by ultrasonic assisted method.On the basis of single factor test,orthogonal test is carried out to determine the best extraction technology of polyphenols from Ziziphus jujuba.The experimental results show that the best extraction technique of polyphenols from Ziziphus jujuba is ultrasonic time of 30 min,ethanol concentration of 50%,solid-liquid ratio of 1∶15,ultrasonic power of 210 W,and ultrasonic temperature of 50℃.Under such conditions,the amount of polyphenols extracted from Ziziphus jujuba is 12.45 mg/g.The results of antioxidant studies show that polyphenols of Ziziphus jujuba have scavenging effects on nitrite,hydroxyl free radicals and superoxide free radicals.The polyphenols of Ziziphus jujuba have different inhibitory effects on Bacillus subtilis,Escherichia coli,Aspergillus,Rhizopus and can be used as natural food additive for food preservation.