Study On Extraction Of β-1, 3-Glucan From Alcohol Yeast In Mature Fermented Molasses Mash

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.