| Tobacco is an important economic plant which has been badly destroyed by tobacco disease and mildew. The quality decreasing and breakage of tobacco caused by tobacco mildew is a crucial problem which must be attached importance to. Mildew controlling is an important part of general treatment of stored tobacco. In this dissertation, Dimethyl Fumarate was synthesized to be used as the fungicide on stored tobacco mildew which was proved to be highly effective.The synthesis condition and analysis method were studied first in this dissertation. The condition of synthesis of Dimethyl Fumarate was optimized. Sodium bisulfate was picked as the catalyst in the condensation reaction of fumaric acid and methanol. Using calcium oxide as the desiccant was an effective method of removing water from the methanol esterification. The molar ratio between fumaric acid and methanol was 1:10, usage of catalyst was 15% of fumaric acid, the reaction was carried out at 75℃as the churning rate was 136 r·min-1, refluxing for 5h, the yield was up to 74.9%. The product was analyzed by UV and IR right after purification. A peak was found at 210nm, comparing the IR spectra to the one of pure DMF, DMF was identified. High performance liquid chromatography (HPLC) was used to analyze the quantity of DMF. Chromatogram with high resolution was obtained using the column of Zorbax SB-C18(5μm,250mm×4.6mm i.d) with a UV detector and the mobile phase of ethanol: water 90:10v/v at a flow rate of 0.6 mL·min-1 at 30°C and 210nm of detecting wavelength.The fungi separated from stored tobacco were identified as species of Aspergillus, Penicillium, Rhizopus, Mucor. They were M. racemosus Fres, P.stoloniferum Thom, R.oryzae Went et Pr.Geerlings, A.niger, A.restrictus and P.expansum respectively.The results of mildew-preventing experiment showed that the inhibition effect of DMF against P.expansum was optimal while to R.oryzae Went et Pr.Geerlings it was worse. DMF could inhibit the growth of all fungi at a certain concentration. Its effect could be affected by temperature, pH and the votality itself. At the moisture content of 18%, DMF was effective in mildew-preventing at the concentration of 500 mg·kg-1, it also had favorable moth-preventing effect at a certain concentration. So DMF could be used as an effective fungicide and mothproofer in tobacco storage.Affect of addition of DMF on the sensory characteristics of cigarette were tested by 12 experts. The results showed that when the amount was at the range of 500-1500mg·kg-1, the addition of DMF had no effect on the sensory quality of cigarette. From the GC-MS results of mainstream smoke analysis, no DMF was detected either in the cigarette which were added DMF or not, so it was thought that no DMF was released. The residual DMF on stored tobacco were detected by gas chromatography. The results showed that there was no DMF left in the tobacco which had been treated using the general process when the addition amount was 500mg·kg-1.When the amount went to 1500mg·kg-1, the residual DMF was only 2.21mg·kg-1 , most of which had been volatilized.Above all, using DMF as the fungicide was safe and there was no influence both on the sensory charactertics and the general index of cigarettes.
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