Separation Research Of Fructose And Mannose

Mannose is a six-carbon sugar which has broad application prospects.It can be applied in the field of pharmaceutical industry,food industry,feed industry and life science research.Currently,industrial production of mannose is based on extraction method,but the raw material is limited and the extract is difficult to separate.As a result,the transformation of fructose by enzymatic conversion of glucose to mannose is considered to be the preferred manufacturing process.However,the product obtained by enzymatic conversion method is a mixture of fructose and mannose which causes a major problem of separation.In this study,chromatography separation method was used to explore the optimum separation conditions of fructose and mannose.First,eleven resins was investigated in this study,including DTF-01,PCR642,UBK510,UBK555 and so on.Calcium-based UBK555 cation exchange resin was found to be the best resin as the separation medium of fructose and mannose.Then,we explored different operating parameters,such as temperature,sample flow rate,elution flow rate,sample volume,sample concentration and other parameters on separation were studied.When the sample volume was 0.05 BV,the sample elution rate was 0.5 BV·h-1 and the sample concentration was 40%,the resolution could reach to 0.48 and mannose yield was 54.5%.Finally,in order to apply this technology to industrially produce fructose and mannose,this paper used simulated moving bed(SMB)to enlarge the single column experiment.At first,we established the mathematical model of SMB separation of fructose and mannose based on the true moving bed(TMB)transfer diffusion theory model and triangle law unifies,assuming the purity,yield and eluent consumption as the evaluation to optimize the operating parameters.Then,according to the model and optimization results,the operation parameter was set:feed rate 500 ml·h-1',eluent flow rate of 430 ml·h-1,switching time 275 s,1.05 Mpa BD outlet pressure,AD outlet pressure opening valve 23%.Under this conditions,we can obtain with 78%mannose at AD outlet and more than 90%fructose at BD outlet.