【作者】 施林燕；

【导师】 许赣荣；

【作者基本信息】 江南大学 ， 生物化工， 2012， 硕士

【摘要】 烟梗物料在烟草行业中的利用率不高,普遍认为是因为烟梗物料中以果胶质为主的细胞壁物质、淀粉和蛋白质等会对卷烟的吸食品质产生不利影响。降低烟梗中的果胶质、纤维素、蛋白质、淀粉等物质的含量,将会提升烟梗物料的利用空间,达到资源充分利用的目的。本课题以烟梗及梗丝为原料分别进行黑曲霉菌发酵和外加酶处理,部分降低烟梗物料中的果胶质、纤维素和淀粉等物质的含量,改善烟梗物料的内在品质,从而有效提高烟梗及梗丝在卷烟配方中的适用性。将重量法和高效液相色谱法相结合,建立了适合于发酵及酶解后烟草样品中果胶质含量的检测方法。研究结果表明,采用该方法可使果胶质提取更充分,酶解后烟梗及梗丝中各种形态的果胶质都能得到检测,检测结果更准确,且操作简单。优化了黑曲霉液态发酵烟梗降解果胶质的工艺条件,优化后的发酵条件为:装料量20 g(干基)/500 mL三角瓶,接种量15%(v/v),料水比1∶1 2,发酵温度30℃,摇床转速180 r/min,发酵时间72 h,在此条件下得到烟梗收率为40.89%。发酵后烟梗中的果胶质的降解率为83.99%。比较了不同类型的烟梗物料的酶解效果,酶解效果从高到低依次为:烟梗丝>烟梗粉末>完整烟梗。利用单一酶酶解烟梗丝,确定了在酶解梗丝中所需的酶种类,结果表明,有些酶的加入并无效果;采用果胶酶、淀粉酶、糖化酶和纤维素酶酶解烟梗物料即符合要求。优化了单一酶酶解烟梗丝的处理条件和酶用量,优化后的结果为:果胶酶用量为300 U/g烟梗丝,酶解时间为5 h,酶解温度为50℃。优化后纤维素酶的用量为200 U/g烟梗丝,淀粉酶的用量为200 U/g烟梗丝,糖化酶的用量为1000 U/g烟梗丝。将果胶酶、淀粉酶、糖化酶和纤维素酶复配成复合酶,并优化了复合酶用量及酶解条件,优化后的结果显示:以复合酶配方1酶解烟梗丝时,吸食品质最佳。复合酶配方1的酶用量如下:果胶酶200 U/g烟梗丝,淀粉酶133 U/g烟梗丝,糖化酶667 U/g烟梗丝,纤维素酶133 U/g烟梗丝。复合酶酶解时间为4 h,料水比为3∶4,酶解温度为47.5℃。与空白相比,在此条件下酶解烟梗丝,酶解后烟梗丝中果胶质的降解率为13.08%,淀粉的降解率为37.59%,还原糖含量增加了76.71%,水溶性总糖含量增加了68.48%。感官评吸结果表明:外源酶制剂在改善烟梗丝吸食品质方面有较显著的效果。鉴于处理烟梗物料需操作简单、高效、设备投入少等因素,选择外加商品酶酶解的方式处理烟梗物料。更多还原

【Abstract】 The utilization of tobacco stems in the tobacco industry was not used effectively. Some substances, such as the main cell wall materials, especially the pectin, starch and protein had adverse effects on the quality of smoke. Obviously, decreasing these substances could raise the utilization rate of tobacco stems and reduce the loss of resource.Microbial fermentation and enzyme hydrolysis of tobacco stems and cut-stems were investigated in this study. The contents of pectin, cellulose, starch and the like in the tobacco stems and cut-stems were degraded partially. Thus the quality and the applicability of tobacco stems in the cigarette will be improved.A new analysis method for various pectin substances in enzyme-hydrolysed tobacco samples was established by combining the gravimetric method with HPLC method. Using this new method, the coefficient of variation of the content of the total pectin acid was lower than traditional gravimetric method. The pectin substances would be fully extracted. The new method is comprehensive and with good reproducibility, and easy operations.In order to degrade pectins, submerged fermentation of tobacco stems by Aspergillus niger was carried out. The optimized fermentation conditions were as follows: adding 20 g tobacco stems in a 500 mL Erlenmeyer flask; inoculum volume:15%(v/v); solid to liquid ratio: 1∶12; fermentation temperature: 30℃; fermentation time: 72 h.The recovery yield of tobacco stems was 40.89%. The degradation rates of the total pectin were 83.99%.The effects of the enzyme hydrolysis on various kinds of tobacco stem substances were compared. The results were described as follows: cut-stem> stem powders> tobacco stem.The enzymes suitable for enzyme hydrolysis of tobacco stems were tested. Some enzymes are useless, and some enzymes, such as pectinase, amylase, saccharifying enzyme and cellulase were appropriate for the treatment of tobacco stems.The enzyme hydrolysis conditions of cut-stems by single enzyme and the dosages of enzyme were investigated. The optimized results were as follows: for 1 gram of tobacco cut-stems, the dosage of pectinase is 300 U; enzymolysis time: 5 h; digesting temparature: 50℃; the dosage of amylase is 200 U; the dosage of cellulose is 200 U; and the dosage of saccharifying enzyme is 1000 U.The formula of compound enzymes were established. The dosage of compound enzymes and the condition of enzymolysis were as follows: for 1 gram of cut-stem, the dosage of pectinase is 200 U; the dosage of amylase is 133 U; the dosage of cellulose is 133 U; and the dosage of saccharifying enzyme is 667 U. The optimized results were as follows: enzyme hydrolysis time: 4 h; digesting temparature: 47.5℃.When the intact cut-stems were hydrolyzed by the compound enzymes, the degradation rates of the pectin were 13.08%; and the degradation rates of starch were 37.59%; and the reducing sugar was increased by 76.71%; and the soluble sugar was increased by 68.48%, respectively. Sensory assessment results showed that the quality of cut-stems in the cigarette can be improved.As the requirements of simple operation, high efficiency, lower investment and other factors, the method of enzyme hydrolysis was selected.更多还原