Study On Extraction Process And Antibacterial Activity Of Flavonoids From Purslane

In recent years, with the development of science & technology and the improvement of people’s living standards, people increasingly focus on all kinds of hazards caused by food safety problems, especially the food spoilage caused by microorganism and chemical additives. Natural preservatives can effectively inhibit and avoid such phenomenon, therefore, the extraction of natural antimicrobial substances from plants, and the development of food preservative will have great social significance and broad prospects. In this paper, the portulaca flavonoids extraction and purification process, component analysis, antibacterial mechanism, antibacterial properties, its stability and its application were studied, the main research contents and results are as follows:(1) Through the optimization and comparison of solvent extraction, ultrasonic assisted extraction and microwave assisted extraction, the ultrasonic assisted extraction method was used in this paper, which has high withdrawal rate(21.3517 mg/g), low pollution, low energy consumption, the bad effects on active ingredients were also can be avoided.(2) The optimum conditions of HPD600 resin were determined: the concentration of sample was15mg/m L, the sample volume was 2BV, the p H value was 4, the elution solvent was 80% ethanol, the volume was 3BV. Under this condition, the purity of total flavonoids was 81.87%, about four times that of the previous total 20.35%.(3) The changes of reducing sugar, protein content, electric conductivity in the bacteria solution were detected. The growth of E.coli, S.aureus, Saccharomyces cerevisiae and Aspergillus niger were inhibited by the flavonoids from purslane.The effects on S.aureus is the most obvious. In conclusion, The antibacterial mechanism of purslane flavonoids mainly results from cell membrane damage, the contents of cell was leaked.(4) Under these conditions that the p H was 7, the ultraviolet radiation time was 30 min, the 80℃ last for 30 min, the antibacterial effects on S.aureus, E.coli, Saccharomyces cerevisiae and Aspergillus niger were optimum.(5) When the best bacteriostasis effect of portulaca flavonoids was applied to food preservation. Sensory evaluation displayed that flavonoids from purslane had no impact on the color and flavor of food, and they had the function to prolong food preservation time.