The Effectively Simultaneous Production Of Cello-oligosaccharide And Glucose Mono-decanoate From Lignocellulose By Enzymatic Esterification

Oligosaccharides as nutritional components of dietary supplements have attracted increasing attention.However,in the process of oligosaccharide production,monosaccharide as an important by-product affects the physiological activity of oligosaccharides,and it is difficult to separate because of its similar properties to oligosaccharides.Therefore,efficient separation of monosaccharides from oligosaccharides is great significance for the production of oligosaccharides.In this paper,it is difficult to separate monosaccharides from oligosaccharides because of their similar properties.By lipase substrate specificity,monosaccharides are selectively esterified without esterification of cello-oligosaccharides.A process route for the separation of monosaccharides from cello-oligosaccharides was developed using filter paper as a model.In this process,a great number of glucose in cello-oligosaccharides is converted to glucose mono-decanoate,which has important research value in the application of biodegradable nonionic surfactants,and has realized the efficient purification of cello-oligosaccharides.Firstly,the effects of ionic liquid,dilute sulfuric acid and cellulase hydrolyzing cellulose to produce cello-oligosaccharides were investigated using filter paper as cellulose model.The results showed that the hydrolysis effect of cellulase was better.The effects of cellulase addition,reaction temperature and reactor speed on the yield of cello-oligosaccharides were investigated.Under the optimal conditions of adding 0.6 wt%cellulase,50? and 200 rpm,the yield of cello-oligosaccharides reached 33%.Secondly,the cellulase hydrolysate was freeze-dried,and the dried hydrolysate and decanoic acid were used as substrates.In organic solvents,the monosaccharides were esterified into sugar ester with lipase as catalyst and the structure of the cello-oligosaccharides was identified.The lipase,solvents,temperature and substrate molar ratio were investigated and optimized respectively.Finally,the preparation of oligosaccharides and glucose mono-decanoate by bio-enzyme esterification was developed from lignocellulose.Three natural lignocellulose(switchgrass,corn straw and reed)were used to verify,after pretreatment,cellulase hydrolysis and two esterification,the cello-oligosaccharides of 36.3%(switchgrass),33.1%(reed)and 31.4%(corn straw)and about 22%sugar esters were finally obtained.The results show that the process also has good applicability to natural lignocellulose.