Study On The Separation Techniques Of Sucrose Esters

Sucrose ester is a new type of polyol and non-ionic surfactant,and has wide applications in the field of food,medicine,cosmetics,and etc.At present,solvent-free process is a method used by most domestic companies to produce sucrose esters which has the advantages of simple operation and environment-friendly.However,this method has the problem that the impurities in the product could not be easily removed,resulting in the lower quality of the products which could not meet the market demand and thus affect the economic benefits.In view of this,the thesis focuses on the following study.Firstly the separation and purification of sucrose esters were studied.The method of a single solvent was tried to purify the crude sucrose esters synthesized by solvent-free process.HPLC-ELSD was applied for analysis of the products.We found that the purification effect of ethyl acetate is better,and the impurities content is 1.08%.The purification effect was improved obviously under mixed solvent of ethyl acetate and water volume ratio of 7:1 by adjusting the pH valve,and the impurity contents were decreased to 0.2% below.Secondly we studied the separation of high mono-ester of sucrose esters.The method of recrystallization was used to study the separation effect of mono-ester of sucrose esters,which found the separation efficiency of ethanol is better.Then the conditions for the separation of ethanol were optimized,and temperature,dosage,and the concentrationof ethanol on the separation effect of mono-ester was thoroughly surveyed.The orthogonal experiment showed that the concentration of ethanol was 55%(V/V),the amount of ethanol was 115 mL,the cooling temperature is 0?,and the content of mono-ester could reach 98.6%.Thirdly the separation of sucrose esters in enlarge pilot batch was carried out.Under the pilot scale,mixed solvent of ethyl acetate and water was used to purify crude sucrose esters.The results showed that the impurities content could reach 0.68% below,which is far lower than the current content of impurities purified by n-butyl alcohol.