Enzymatic Acidolysis Synthesis Of Human Milk Fat Substitute By Lipase

Oil is one of the important part of people's food composition, which are areserve source of energy to maintain life activities and bring the body ofcertain essential fatty acids and vitamin. With the improvement of people'sliving, more and more people are choosing to eat high-quality fat for healthy,so the concept of the structured ester aroused more attention. Human milk fatis one of them whose the special structure decides its nutritional function, andplays a vital role in the production of infant formula food.This paper studys the synthesis process of enzymatic acidolysis of naturalfats with the preparation of human milksubstitutes--1,3-Dioleoyl-2-palmitoylglycerol (OPO) for the purpose. Thespecific contents are as follows:1．Raw materials selection of synthesis. First of all, relevant informationis consulted to understand the common natural oils, mainly the fatty acidcomposition and distribution. Secondly, some natural animal and vegetablefats are bought, through some biochemical analysis, to understand the fattyacid composition, distribution, and certain physical and chemical properties.As the analysis result kown, lard has palmitic acid (C16:0) content of54.00%in the glycerol backbone Sn-2position which of the total palmitic acid(C16:0)content is73.08%. This approximate natural human milk fat.2．Study of the synthesis reaction conditions for enzyme acidolysis oflard by lipase. Candida sp.99-125lipase is the Beijing University of Chemicalindustrial production which catalyze an efficient esterification andtransesterification and is mainly used in this study. Enzyme acidolysis of lardand vegetable oil is catalyzed for synthesis of OPO by this lipase. Throughsingle factor experiments, the effect and the range of various factors areunderstand on the reaction. Through orthogonal test, both of the impact ofvarious factors and the interaction between the various factors on the reactionare investigated with getting the acidolysis synthesis reaction conditions.Through simple optimization and confirmatory experiment, the reactionconditions is confirmed which has stability and repeatability. The conditions are: the substrate mass ratio,1:2.0(the lard/oleic acid); enzyme load,7-10%(of total the substrate); reaction temperature,43℃(±3℃); and reaction time,3-4h. Under the condition of the reaction, the Sn-2C16:0content is59.82%and the OPO content is39.89%. Than to reduce costs the further optimizationof the conditions is carried out. With reaction temperature43℃, thesubstrate mass ratio1:2.0(the lard/oleic acid), water yield1%(of totalsubstrate mass) and cyclodextrin mass equal to enzyme load, enzymeacidolysis of lard is catalyzed by lipase of enzyme load1%(of lard mass) for24h. Under these conditions OPO content of products is more than40%,which meet the standard requirements.3．The preliminary amplification test of the process. Amplification test iscarried out under simply optimized reaction conditions. The reaction system isenlarged to20L, and the product of the synthesis reaction is analysis by gaschromatography and liquid chromatography, the results of which is similarwith the experiment results. The amplification test of products separationconditions, the effect of separation result is compared between centrifugalextraction and static extraction, and the analysis result showed little difference.Respectively the extrusion rate is71.56%and74.89%. By static extraction,the loss of triglycerides is lower than centrifugal extraction. The advantage ofcentrifugal extraction method is continuous processing and large capacity, sothe centrifugal rotate speed and two-phase flow rate should be controlled toachieve a better extraction efficiency. The advantage of static extractionmethod is simple operation, but it need suitable space and equipment toachieve large quantities of the processing.