Extraction Of Plant Natural Food Preservatives

This thesis aimed at looking for natural food preservatives against two halotolerant yeasts: Debaryomyces hansenii and Zygosaccharomyces rouxii. The antimicrobial activity of more than twenty plants and Propolis was studied by disc diffusion method. The effective compounds of the cinnamon were seperated and identified by GC-MS, which offers theoretical basis for anticorrosion of sauce and pickles. The main content of the thesis list as following:(1) The first part elaborates the necessity of exploitation of natural food preservatives, the research development and the action mechanism of the plant source natural food preservatives is summarized, too. The second part introduces the Cinnamon research development, as well as the application in food and medicine aspect.(2) In order to obtain the optimize cultivation conditions, L9(34) orthogonal experiment has been applied in this research. The experiment took the fungus growth condition as the evaluating indicator, inspected the different culure medium, the fungus density, the raise time and the salt content, which influences halotolerant yeasts growth.(3) The inhibition function of twenty four plants and Propolis against halotolerant yeasts was studied by disc diffusion method, which screens the plants that have strong and steady antimicrobial activity, four plants'minimal inhibitory content was studied.(4) In order to seeking for its effective active components, Cinnamon,Fructus Foeniculi,Propolis were separated into several poler portions by Column chromatography and studied by disc diffusion method. The experiment builds the foundation for obtaining the effective active constituent.(5) After several rounds of separation of Cinnamon extrcation by Column chromatography,Vacuum Liquid Chromatography (VLC) and Thin Layer Chromatography (TLC), active components were determined by microbiological test and detected by GC-MS.