中草药黄连抑菌物质的提取工艺条件及用于桑椹保鲜的效果

Process Optimization for Antifungal Substance Extraction from Coptis chinensis and Its Fresh-keeping Effect on Mulberry Fruit

为了开发用于桑椹保鲜的天然植物源生物保鲜剂,以传统中草药黄连为原料,采用超声波辅助乙醇的方法提取黄连抑菌物质并进行桑椹的保鲜效果试验。以提取液的抑菌圈直径为考核指标,在单因素试验的基础上,应用响应面法优化黄连抑菌物质的提取工艺条件为料液质量浓度1.5 g/L、提取溶剂乙醇体积分数50%、超声波功率400 W、提取时间72 min,在此条件下预测黄连提取液的抑菌圈直径为16.20 mm,实际验证值为15.98 mm。新鲜桑椹室温下用质量浓度为0.7 g/m L的黄连提取液处理后储存8 d,桑椹的失重率、霉变率和丙二醛含量分别较对照组桑椹降低了26.25%、58.62%和47.47%,可滴定酸含量提高了83.55%,可以延长保鲜时间3 d左右。采用优化工艺条件提取的黄连抑菌物质,具有良好抑菌活性,可作为天然保鲜剂应用于桑椹保鲜。

In order to develop natural plant agents for fresh-keeping of mulberry fruit, the antifungal substance from Cop- tis chinensis, a traditional Chinese herb, was extracted by ethanol and ultrasound-assisted method and used to conduct fresh-keeping test. Based on single-factor experiment, antifungal circle diameter was taken as the evaluation indicator for extraction process optimization of antifungal substance from C. chinensis using response surface methodology. The opti- mum extraction condition was found to be C. chinensis concentration of 1.5 g/L, ethanol concentration of 50%, ultrason- ic extraction power of 400 W, and ultrasonic extraction time of 72 min. Under the optimized condition, the C. chinensis extract was predicted to have an antifungal circle diameter of 16.20 mm and the actual value was 15.98 mm. On the 8th day after 0.7 g/L C. chinensis extract was used to treat fresh mulberry fruits, weight loss rate, decay rate and malondial- dehyde content of mulberry fruits at room temperature decreased by 26.25%, 58.62% and 47.47% respectively com- pared to the control group, and the titratable acid content increased by 83.55%. Shelf-life of the treated mulberry fruits could be prolonged by 3 days. The antifungal substance extracted from C. chinensis under optimum condition shows ef- fective antifungal activity, being a potential natural preservative of mulberry fruit.