Research On The Degradation Of Hazardous Compound Precursors In Paper-process Reconstituted Tobacco By Mcrobial Strain Fermention

The paper-process reconstituted tobacco, using tobacco wastes as raw materials, can beregards as a resource recycling products. It has the following and main characteristics: lowyields of tars and small releasing amounts of harmful compounds. The high content ofhazardous compound precursors, including cellulose, pectin andproteins in tobacco stem willlead to increasing the evolution of harmful compounds.Therefore, it was important todegradethe hazardous compound precursors of paper-process reconstituted tobacco to regulate thecomponent and yield of harmful compounds.According to the chemical composition characteristics of the paper of paper-processreconstituted tobacco, thisstudy focused on the separation of strains from the raw material,which has high capacity of degrading cellulose, pectin, protein and starch, then using thesemicrobial strains fermentation regulating the components of tar from paper-processreconstituted tobacco and raw materials. Meanwhile, the influences of fermentation processon the evolution mechanism of main harmful and chiefly fragrant compounds were studied byTG-FTIR and TG-MS.Based on the degradation capacity of cellulose, pectin, protein and starch, thepredominant bacterium were separated by theplate separation technology, and thenpurification and population identification.The research results show that the strain GX5hashighest pectinase activity, the value up to295.79U/mL, protease activity of the strainGX5was also higher; the strain GX6has highest amylase activity, the value up to31.74U/mL;the strain GX8has highest celluloseactivity, the value up to435.52U/mL. The threepredominant strains were identified as Bacillus subtilis (GX5), Bacillus cereus (GX6) andBrevibacillus brevis (GX8), respectively.Ingredients and the best fermentation process:2%ofthe corn flour,3.0%of soybean meal,2.0%of starch,1.5%of the orange peel powder,cultured24h, incubation temperature30°C, and initial pH value was7.0, the solids content of7.5%. The optimal proportion of GX5: GX6: GX8was1:2:2identified by the orthogonalexperimental design.Study on the effect of high enzyme activity strains on the chemical composition ofpaper-process reconstituted tobacco and raw materials. Meanwhile, thermal pyrolysis wasused to simulatethe reaction of tobacco burning suction process, the evolution tars during thisreaction were analyzed by GC/MS. Experimental results show that the fermentation processwill reduce the content of cellulose, pectin, protein and starch, however, total increase thecontent of total sugar and reducing sugar.From the regulation of the chemical composition of raw materials, the fermentation of reconstituted tobacco pulp is superior to the fermentation ofraw material. Mixed strains fermentation inhibit the formation of hybrid generationcompounds and PAHs, promote the generation of ketones, and the effect capacity of mixedstrains fermentation were better than the other single strain. The inhibition capacity of COduring the strain GX8and the mixed strain fermentation process are better than the strainsGX5and GX6. The formation of CO is directly related to the cellulose content.The effect of high enzyme activity strains and mixed strains fermentation on thecomponent and yield of reducing sugar, volatile components, and pyrolysis tars were studied.This study found that the fermentation process promote the formation of2,6-dimethylpyrazine, Malaysiaone and neophytadiene. The improve effect of volatile components andfragrant compounds during the mixed strains fermentation process are superior to single strainfermentation process.The fermentation time has significant effect on the releasing of pyrazine,pyridine and pyrrole.The composition characteristics of pyrolysis tar werenot only affectsbythe volatile components of tobacco stem extracts, but also affect by the Maillard reaction inthe heating process.The releasing laws of harmful and fragrant compounds from paper-process reconstitutedtobacco pyrolysis were studied by TG-FTIR and TG-MS. This study found that mixedfermentation process will lead to the thermal stability of reconstituted tobacco and tobaccostem extract reduce. Anew release peak of phenols appearsaround300℃during mixed strainfermentation process. Meanwhile, the mixed strain fermentation lead to the releasetemperature of ketones and phenols shift to low temperature zone, avoiding the formation ofaromaticsin high temperature zone, finally, reducing the formation of harmfulcomponents.Mixed strain fermentation will not only result in the reduction of furfural, indeneand naphthalene releasing, but also lead to the releasing temperature more focused. Aftermixed strain fermentation process, furfural release temperature range mainly in the400to650℃; the releasing temperature range of indene and naphthalene is concentrated in the500to800℃. The release temperature range of Phenols is mainly concentrated in the400to600℃. Mixed strain fermentation has nosignificant effect on the releasing temperature ofpyrrole and3–vinylpyridine, but will reduce the formation of3–vinylpyridine. Meanwhile,the releasing temperature range of2,6-dimethyl pyrazine will be extended, and the releasing amount of2,6-dimethyl pyrazine will be increased during the mixed strain fermentationprocess.