超声辅助乙醇回流提取冬凌草抑菌活性成分的工艺优化

Extraction of antimicrobial active ingredients from Rabdosia rubescens by using ultrasound-assisted ethanol reflux

冬凌草具有显著的抗菌活性,是一种能够抑制食品有害菌的良好资源,从其中提取天然食品防腐剂具有广阔的应用前景。对超声辅助乙醇回流提取冬凌草抑菌活性成分的工艺进行研究,以金黄色葡萄球菌为供试菌,考察了乙醇体积分数、超声功率、提取温度、料液比和提取时间对冬凌草抑菌活性物质提取的影响。在此基础上,选取超声功率、提取温度和提取时间3个因素进行响应面优化,获得的最优提取工艺条件为:乙醇体积分数为95%、超声功率200W、提取温度62℃、提取时间44 min、料液比1:25 g/mL。在此优化条件下,冬凌草提取物对金黄色葡萄球菌的抑菌圈直径达到28.89 mm。对5种食品致腐致病菌抑菌试验结果显示,冬凌草提取物显示出较好抑菌效果。

Rabdosia rubescens,which possesses significant antimicrobial activity,is a good resource to inhibit foodborne pathogens.So,natural food preservative extracted from R.rubescens has broad application prospects.In this paper,the extraction process of antimicrobial active ingredients from R.rubescens by using ultrasound-assisted ethanol reflux was studied.Staphylococcus aureus was used as test bacteria and the effect of ethanol concentration,ultrasonic power,extraction temperature,solidliquid ratio and extraction time on the extraction of antimicrobial active ingredients from R.rubescens was observed.On this basis,ultrasonic power,extraction temperature and extraction time were optimized by using response surface methodology（RSM）.The optimum extraction conditions were determined as follows： ethanol concentration of 95%,ultrasonic power of 200 W,extraction temperature of 62 ℃,extraction time of 44 min and solid liquid ratio of 1：25 g/mL.Under optimal conditions,the extracts of R.rubescens inhibited the growth of S.aureus with inhibition zone diameter of 28.89 mm.The antimicrobial test results for 5 foodbore pathogens and spoilage bacteria demonstrated that the extracts of R.rubescens showed better antibacterial activity.