Investigation Of Synthesis Of Triglycerides Rich In EPA And DHA

This paper summarizes a systematical study and a model of Enzyme Syntheticismfor concentrated EPA (Eicosapentaenoic acid) and DHA (Docosahexaenoic acid)Triglycerides. For this study a packed bed reactor was used and filled withimmobilized lipase Lipozyme RMIM as the catalytic agent to alcoholize the refinedmarine fish oil (as raw material, with EPA18.1%and DHA12.3%) and concentratethe EPA and DHA. After reaction EPA&DHA concentrated Glycerides (EPA31.3%,DHA22.4%) was separated from the reaction products with Triple grade moleculardistillation, which also helps retrieving Ethyl Ester (EE) as reaction by-product andconcentrating the EPA&DHA in EE. After distillation an Urea Treatment uponretrieved Ethyl Ester was carried to acquire concentrated EE with EPA41.8%andDHA31.1%. As there is a fine intersolubility between Fatty Acids Ethyl Ester andMixed Glyceride (Triglycerides mixed with large portion of Monoglycerides andDialycerides), this study can be used as a method to produce EPA&DHA concentratedTriglyceride by interesterification between concentrated EE and Mixed Glyceride,with immobilized lipase as the Catalytic agent. Proper process parameters are alsodetermined through single-factor experiments: when the Substrate mole ratio(Concentrated EE/Free Oxhydryl of Triglyceride) is1:1, using2%immobilizedlipase Novozym435as the catalytic agent under60℃, then separate theinteresterification products with molecular distillation. With such parameters we canacquire Mixed Glycerides with82.3%Triglyceride and basically no Monoglyceride(0.2%); and with EPA40.4%&DHA28.6%. After separating the mixed glyceridesfrom EE, the mono-and diacylglycerol lipase Lipase G50was used to selectivelyhydrolyze the Dialycerides, to purify the triglycerides. In aspect of single factoranalysis, the hydrolysis reaction could happen in any condition between moisture20%~100%, pH4-6.5and temperature20℃~45℃; and the best condition forhydrolysis should be pH6.0, under40℃and with moisture60%. Based on singlefactor analysis, when synthesizing all the effects that moisture, temperature and pHvalue could have made to hydrolysis, a Hydrolysis Model was achieved by usingsurface response analysis. The test results show that optimal condition for hydrolysisis when moisture57.64%, under temperature30.27℃and pH5.81. During thehydrolysis there are strong interactions between triglyceride concentration andmoisture&pH, as well as between triglyceride concentration and moisture&temperature. The hydrolysis model is on a level of significance and can be used to analyze/predict the hydrolysis reaction under different conditions. After moleculardistilling the hydrolysate, a Glyceride product with EPA42.14%and DHA29.6%which mainly consist of Triglyceride is achieved. This model is simple to process andwith reaction products (which mainly consist triglyceride) easy for separation, itcould be applied to industrial production.