Enzymatic Synthesis Of Sorbitol Fatty Acid Ester By Lipase Fromcandida Sp.99-125

Sugar ester is widely used non-ionic surfactants, which can be usedin food, cosmetic and medicine area. Enzymatic synthesis is anenvironment friendly method for the calm reaction condition, harmless toenvironment and pure products. This research is based on Candidasp.99-125lipase made by ourselves and the aim product is similar tobusiness Span serial product.By using reactant surface method, optimized reaction conditionswere chose. The main influence factors are temperature, enzyme amountand molecular rate. A three level three factor reactant surface was thendesigned and the optimized reaction conditions were:10ml t-butanol,0.1mol sorbitol,0.5mol fatty acid,39.3℃,0.42g lipase, molecular rate1:5.After24h, reaction conversion was39%and the finale yield was0.01mol/L.A purification method was also designed in order to get pureproduct, and some white powder product were get through this way. AfterMS analysis, these products meet the characteristic of target products. In order to improve the reaction conversion and yield, a method wasdesigned to improve the solvability of sorbitol in t-butanol. In60℃,0.1mol sorbitol could dissolved in t-butanol. In optimized condition0.04mol/L sorbitol solvent, the conversion was80%. High consistent ofsorbitol would increase the system viscosity and then reduce the enzymeactivity. Moreover, this lipase calls for optimized water content in system.There should be1%water content to maintain the lipase structure. Toomuch or too less water content would reduce the conversion. Then a feedbatch experiment was designed in order to improve reaction yield.2ml0.1mol/L sorbitol solvent was added at6h and12h. The yield was thenimproved from0.03mol/L to0.04mol/L.After pure products were got, the non-ionic surfactants perimeterswere tested and then compared with business Span serial product. HLB ofour products were among4to10and CMC were among0to7, HLBdecrease with the chain length of fatty acid and CMC increase with that.The foamability of these products was among56-20and the emulsifyingproperty was among29to17, stability decrease with increase of theseproperties. After test, no big difference was found between business Spanserial products and our product, which means our products could bealternative to business Span serial products. Moreover, our products werepure product other than mixture, which means they can be used in medicine area.