The Resource Utilization Of The By-product In The Erythritol Production

Erythritol is a four-carbon sugar alcohol with special physiological functions andphysical and chemical properties. It is widely used in the area of food, pharmaceuticaland other chemical industries. Much by-product was got in the productive process oferythritol. The byproducts mainly include mother liquor and waste yeast. Withincreasing expansion of production scale, the by-product of production has not beencommonly good use. That was a waste of resources and serious pollution to theenvironment. In the study the waste-yeast and the crystallization mother liquor oferythritol were investigated in order to realize the resource utilization of theby-product. The research results are as follows:(1)The main ingredients of the mother liquor were analyzed. The results showedthat the solids contents of mother liquor was approximately70%. The erythritol of drymatter was about30%, and the ash content of the dry matter was20%. There was noglucose existence. In addition, there was other sugar alcohol composition, accountsfor about50%of the dry matter.(2)The mother liquor was purified. D315and001*7were screened based on theexchange capacity and adsorption characteristics of the erythritol. The seriesconnection of double pillar was employed to treat the erythritol waste mother liquor.The desalting rate could reach98.5%. Finally, after the vacuum distillation andcrystallization of the mother liquor, the yield achieved47.3%and the purity couldreach more than99%.(3)The unknown components of mother liquor were been identified by HPLCand LC-MS. The results showed that the main components of the mother liquor wereerythritol, arabitol, mannitol and a small amount of ribitol. Then the separation effectof the component in the mother liquid was been researched. The results showed thatUBK-555exhibits good separation effect to erythritol and arabitol. The high aspectratio, the flow velocity and sample quantity had great influence on the separationeffect.(4)The main ingredients of the waste yeast were analyzed. Then in order to getthe yeast extract two methods were used as follows alkali process and yeast autolysis.According to the results, the most optimum conditions of alkali process was theconcentration of NaOH8g/L, the yeast slurry concentration10%and in this condition the yield of yeast extract could above40%and the dissolution rate of protein53%.Themost optimum conditions of autolysis were as following: NaCl addition amount was4%; extraction temperature was50℃; pH5, the yeast slurry concentration was10%.The the yield of yeast extract was above31%and the dissolution rate of protein was52%.(5)Last, alkali burn was applied to extract the polysaccharides in the residue ofAutolysed-Yeast. According to the results the protein content of the products achievedby alkali burn was very low. And the extraction yield and purity of the products wasvery high.