【作者】 魏涛；

【导师】 刘慧霞；

【作者基本信息】 广西大学 ， 制糖工程， 2008， 硕士

【摘要】 21世纪是资源与环境的时代,合理利用资源,保护环境是国民经济持续发展的必然要求。本课题以综合利用为指导思想,首次提出从酒精生产源头上改变工艺,回收醪液中的酒精酵母实现酒精和酵母高附加值产品的联产,将酒精废酵母变废为宝,增加经济效益。既可提高废液回用率,又可减少废水污染负荷,减少排污治理费用,为制糖行业产品结构调整和副产物综合利用开拓新的有效途径,为工业化生产提供了切实可行的依据。项目研究了基础理论及各环节工艺条件,简要归纳以下:1.确定成熟醪离心的工艺条件以及酵母泥化学洗涤的工艺条件:洗涤水量30%,洗涤次数3次,离心转数3000r/min,离心时间10min;酵母泥化学洗涤先经过1.75%酒石酸洗涤30min,再用0.1%的碳酸氢钠洗涤。在此条件下酒精酵母得率达1.5%,成熟醪酒精损失3%。所得酒精酵母的总糖含量高于鲜酵母。2.检测比较了常规工艺与新工艺的废液技术指标的差异,并试验了废液代替清水的回用率。新工艺酒精废液SS下降了53.3%,COD下降了34%,BOD下降了56.9%,大大减轻了废液治理难度。新工艺酒精废液代替清水回用率可达20%,比常规工艺废液回用率提高了4倍,酵母洗涤废液①的回用率达70%。3.以酒精酵母为原料,研究确定了自溶-超声波-酶解-碱溶氧化法优化β-1,3-葡聚糖的制备工艺,实现β-1,3-葡聚糖与酵母抽提物的联产。利用单因素实验和正交实验确定了影响多糖纯度最重要的影响因素,然后利用响应面分析法得出酶添加量A、碱溶温度B、碱溶浓度C三个因素与多糖纯度（Y）之间的回归方程为:Y=-1174.3175+0.1755×A+27.3212×B+59.3075×C-6.75×10^-4×AB-4.5×10^-3×AC-0.253×BC-1.1267×10^-4×A²-0.1606×B²-5.6467×C²确定了最佳工艺条件为:酶添加量为470U/g,碱溶浓度3.2%,碱溶温度81.5℃。在最佳工艺条件下,酵母抽提物得率达69.92%,多糖得率达15.02%,β-1,3-葡聚糖含量76.21%、蛋白质含量1.52%。4.以啤酒酵母、活性干酵母为原料与酒精酵母比较进行多糖提取实验,通过比较产品的组分得知:本研究的提取工艺也适用于啤酒酵母和活性干酵母;酒精酵母中β-1,3-葡聚糖的总量高于啤酒酵母和活性干酵母,证明了酒精酵母提取β-1,3-葡聚糖具有较大的开发潜力。5.对酵母多糖样品进行了理化性质分析、初步纯度鉴定、单糖组分分析和分子结构分析,研究结果表明:酵母多糖样品难溶于水及多种有机溶剂,能在二甲基亚砜中形成稳定的悬浮液,产品由单一组分葡萄糖组成,β-葡聚糖分枝度约为21%,表明本实验制备的β-1,3-葡聚糖具有较高的生物活性。更多还原

【Abstract】 The 21 st century is resources and the environment time,Using the resources, protecting the environment is inevitable request of the national economy sustained development.This topic take the comprehensive utilization as the guiding principle,proposed the technical changes during alcohol production for the first time,recycled the alcohol yeast from fermented mash in order to achieve the co-production of high additional value products,such as alcohol and the yeast,recycled waste alcohol yeast to increase the economic efficiency.This experiment aims to increase reuse rate of waste liquid,reduce the pollution load of waste water,and cut down the expenses of pollution treatment,develop a new efficient path for the production structure adjustment of sugar manufacturing industry and comprehensive utilization of by-products,and provide the practical and feasible basis for the industrialization production.The project has studied the basic theory and technological conditions of various aspects,induces briefly as below:1.Determined the centrifugal conditions of mature fermented mash and technical conditions of yeast putty chemical washing:the volume of wash water is 30%,the number of wash time is 3,the centrifugal rotation is 3000r/min,centrifugal time is 10m;The yeast putty chemical washing uses 1.75%tartaric acid to wash 30 min first,then uses 0.1%sodium bicarbonate to wash.Under this conditions,The yield of distillery yeast reaches 1.5%,the mature fermented mash alcohol loses 3%,the total sugar content of obtained distillery yeast is higher than fresh yeast.2.The examination has compared the technical index differences between conventional craft and the new craft waste liquid,and experimented the reuse rate of using waste liquid to replace clear water.The study show that the SS of new craft alcohol waste liquid dropped 53.3%,COD decreased 34%,BOD dropped 56.9%,this added to reduce the difficulty of waste liquid treatment greatly.The reuse rate of using waste liquid to replace clear water has reached to 20%,enhanced four times compared to the conventional craft,and the reuse rate of yeast washing waste liquid reached 70%.3.The study taked the distillery yeast as raw material,has determined the autolysis-ultrasonic-enzymolysis-alkali dissolved-oxidation process to optimize the preparation craft ofβ-1,3-glucan,and achieved the co-production ofβ-1,3-glucan and yeast extracts.The experiment has used the single factor experiment and the orthogonal experiment to determine the most influencing factors of polysaccharide purity,and has used the surface analytic method to obtain the regression equation between three factors of the addition of enzyme A,the alkali dissolution temperature B,the alkali dissolution concentration C,and the polysaccharide purity（Y）is:Y=-1174.3175+0.1755×A+27.3212×B+59.3075×C -6.75×10^-4×AB-4.5×10^-3×AC-0.253×BC -1.1267×10^-4×A²-0.1606×B²-5.6467×C²This study has determined the best technological conditions are:the addition of enzyme is 470U/g,the alkali dissolution concentration is 3.2%,the alkali dissolution temperature is 81.5℃.Under the best technological conditions,the yield of yeast extracts and polysaccharide reached 69.92%,15.02 %,respectively;the content ofβ-1,3-glucan and protein are 76.21%,1.52%.4.The study has taken the beer yeast、the active dry yeast as raw material on the polysaccharide extraction experiment to compare with the distillery yeast.Through the component comparison,we has acquired:the extraction process of this research is also suitable for the beer yeast and the active dry yeast;the distillery yeast contain moreβ-1,3-glucan than beer yeast and active dry yeast,this has proven the extraction ofβ-1,3-glucan from distillery yeast has the big development potential.5.This study has carry on the chemical property analysis of the yeast polysaccharide sample,the preliminary purity appraisal,the monosaccharide proximate analysis and the molecular structure analysis.The findings indicated:The yeast polysaccharide sample difficult to dissolve in the water and many kinds of organic solvents,can form the stable suspending liquid in the dimethylsulfoxide.The product is composed of glucose as the sole component,the branching degree ofβ-glucan is 21%,the results shows that theβ-1,3-glucan prepared in the experiment proved to have the the high biological activity.更多还原