The Antibacterial Effect Of Spices On Moldy Bacteria In Cigarettes And The Establishment Of Mold Growth Prediction Model

Solutions to tobacco mildew are always in badly need for tobacco industries.The aroma of mildewed tobacco will fade,and taste of tobacco will be destroyed by mildew,which will descend value in use of tobacco.Most of the mold that cause mildew will secrete mycotoxin,which is carcinogenic,teratogenic and mutagenic,posing a serious threat to environmental safety and human health.China is rich in plant resources,of which many could restrain the growth of breeding of fungus.The essay focuses on exploration of screening botanical antiseptic that could restrain fungus on basis of indicator bacteria of tobacco mildew,and building the elementary model of aspergillus versicolor in extract in different concentration of restraining fungus.The cigarette Purple Nanjing was selected as the experimental subject.The author had sifted four mold that cause mildew through methods of fungus screening and named them as Fungus A,M,P and S.Through observing the morphology of bacterial colony and thallospore of the four,the author had initially identified the Fungus A as aspergillus,and Fungus M,P,and S as blue mold.Molecular methods were used to extract 18SrDNA from the fungus.After gene sequence and comparative analysis were performed,the author had identified the Fungus A as Aspergillus versicolor,Fungus M as Apple Penicillium,Fungus P as Cladosporium and Fungus S as E.javanicum.Through great number of critical review of literatures,the author selected 28 different kinds of Chinese herbal medicine and spices that could restrain fungus.Aspergillus niger,rhizopus nigricans,aspergillus fumigatus and penicillium expansum were set as indicator culture.Cinnamon,ginger oleoresins and litsea cubeba oil were sifted as bacterial antiseptic since they were tested as the most effective and have thin taste.As the experimental result has shown,when cinnamon,ginger oleoresins and litsea cubeba oil were compounded as the proportion 3:2:1,it will come into play the function of restraining fungus to the most,which was much better than using a single antiseptic.As shown in results,compound liquid(MIC)at its minimum concentration of 7.5mg/mL could restrain the growth of most of fungus,mixed,that cause mildew in cigarettes.Besides,the author compared the growth curve of aspergillus versicolor in condition of different temperature and relative moisture,and analyzed the influence of temperature and relative moisture to aspergillus versicolor.As shown in results,when the water activity of culture medium is less than 0.85,the growth speed of aspergillus versicolor will be descended.The author had also compared the influence to aspergillus versicolor by different concentration of compound liquid,using curve fitting by three elementary models and analyzed and compared these three models.Model modGompertz was shown as the most proper one.