橘黄酮的提取及其抑菌特性

Extraction of flavonoids from Citrus reticulate and their antimicrobial characteristics

采用乙醇浸提法从橘子皮中提取黄酮,通过正交试验确定提取的最佳条件为:70%乙醇为提取剂,固液比为1︰20(g/m L),提取温度是70℃,提取时间2h,在510nm处测定橘黄酮质量浓度为0.205g/L,从橘子皮中提取的黄酮干重得率为2.938mg/g。本实验探究橘黄酮的抑菌活性,采用牛津杯法测抑菌作用,结果表明,橘黄酮对金黄色葡萄球菌、大肠杆菌、黑曲霉、灰葡萄孢菌和黄枝孢菌均有抑制作用,铜和镁离子可分别增强橘黄酮对细菌和真菌的抑菌作用,低p H和低温可提高抑菌效果,且优化p H和温度的橘黄酮剂型降低了最小抑菌浓度(MIC)20%,对金黄色葡萄球菌、大肠杆菌、黑曲霉、灰葡萄孢菌和黄枝孢菌的抑菌作用分别提高了17%、27%、25%、28%、19%,高于对氯间二甲苯酚和甲基托布津的抑菌作用,特别是高于对细菌的抑菌作用。

The flavone compounds were extracted from citruspeels with a modified ethanol extraction method. The optimum extraction conditions were determined by orthogonal tests as：70% ethanol as extractant with solid to liquid ratio 1︰20（g/mL） at 70℃ for 2 hours. The concentration of the flavone compounds were determined with a spectrophotometer atλ=510nm. The results showed that the yield of flavone compounds to the raw materials reached 2.938mg/g,and the ethanol recovery could be up to 94%. The antimicrobial features were also studied. The inhibition of the extracted flavonoids against the growth ofStaphylococcus aureus,E.coli,Botrytis cinere,and Cladosporiumfulvumwas found,and copper and magnesium ions could enhance the inhibition function on bacteria and fungus respectively. In addition,pH and temperature of the flavonoids could affect the inhibition efficiency. The minimum inhibition concentration（MIC）was reduced by 20% with the ideal formulation of the extracted flavonoids,and the inhibition capabilities againstStaphylococcus aureus,E.coli,Aspergillus niger, Botrytis cinere,andCladosporiumfulvumwere increased by 17%,27%,25%,28%,19% respectively under acidic pH and suitable temperature. The inhibition capabilities of the extracted flavonoids against bacteria and fungus,particularly against bacteria,were higher than those of chloro 3,5-dimethylphenol p-chloro-m-xylenol and thiophanate-methyl at the equivalent concentration.