The Studies Of Hydrolysis And Ferment Preparation Of Alcohol From Polysaccharide Of Soybean Dregs

Soybean dregs are the main byproduct of soybean processing industry. It’s protein content is about15.22%,62.06%polysaccharides content. Polysaccharides include non-soluble carbohydrate, soluble carbohydrate. In this experiment, bean dregs as raw materials, we explore the optimum conditions soybean dregs hydrolysis and then fermentation Ethanol optimum conditions. Before fermentation, making hydrolysis on Soybean dregs, so that the non-reducing sugars in the bean dregs will turn into reducing sugars, and reducing sugars under appropriate conditions, will produce ethanol.The pretreatment method is Alkali-soluble and acid precipitation to remove protein. Soybean dregs with no pretreatment Hydrolysis methods can be divided into two main conventional acid hydrolysis and subcritical water hydrolysis. The test made a comparison between direct hydrolysis of the conventional hydrolysis methods and subcritical hydrolysis methods on raw materials, and the methods were optimized and compared.After protein removed from soybean dregs, the liquid part is mainly soluble carbohydrate and the solid part is mainly non-soluble carbohydrate. Liquid part used to hydrolysis by conventional acid method and optimize. Solid part used to hydrolysis by subcritical water method and optimize. Add the best result of the two methods. Comparing all of the above hydrolysis method, the optimal hydrolysis scheme is selected for fermentation. Meanwhile fermentation conditions are optimized and get the optimized method to soybean dregs hydrolysis and fermentation to make ethanol.Conventional acid hydrolysis method is adopted on the bean dregs hydrolysis. The optimal hydrolysis conditions are determined by single factor and orthogonal experiments:reaction time being4h, the consistency of hydrochloride being0.51mol/L, the mass consistency of soybean residue being0.028g/mL, hydrolysis temperature being100℃. After hydrolysis, The yield of reducing sugar is41.62%。Soybean dregs are hydrolyzed by subcritical water method. The optimal hydrolysis conditions are determined by single factor and orthogonal experiments:reaction time being5min, hydrolysis temperature being150℃, the catalyst being FeSO4-7H2O, liquid ratio being200:1. After hydrolysis, The yield of reducing sugar is50.73%. Soybean dregs protein are removed by Alkali-soluble and acid precipitation method. Under the condition of solid-liquid ratio is1:9,0.1mol/L of sodium hydroxide use the method of alkali dissolution. After filtration, it can get soybean dregs of solid non-soluble carbohydrate. The solution is adjusted to PH4.6to make acid precipitation, filtration. Then it can get part of the protein, the soybean dregs of soluble carbohydrate.Conventional acid hydrolysis method is adopted on removal of part of the protein and non-soluble carbohydrate in soybean dregs. The optimal hydrolysis conditions are determined by single factor and orthogonal experiments:hydrolysis being4h, ph0.6, hydrolysis temperature being80℃. The yield of reducing sugar is3.69%.The non-soluble carbohydrate of soybean dregs is hydrolyzed by subcritical water method. The optimal hydrolysis conditions are determined by single factor and orthogonal experiments: hydrolysis temperature being210℃, reaction time being5min, liquid ratio being160:1. After hydrolysis, The yield of reducing sugar is38.47%.The Hyperactivity Saccharomyces Siccum was the fermentation yeast of soybean dregs. Addition nutrition content was:(NH4)2SO4was0.5g/L, MgSO4was2.5g/L. The optimal fermentation conditions are determined by single factor and orthogonal experiments:fermentation time was4d, inoculum size was10g/L, fermentation temperature was29℃, Incipient pH value was5.1. Surplus of reducing sugar is10.33%.Ferment the concentration of sub-critical water; the concentration adding cellulose enzymes and surplus of soybean dregs, after the fermentation complete, Using GC analysis the content of ethanol. The content of ethanol in turn were:the concentration of sub-critical water17.41%、the concentration adding cellulose enzymes and surplus of soybean dregs19.41%. After fermentation, the surplus content of reducing sugar was9.89%, pH value was4.42. Take the content of ethanol as index to appraise which was the better method.