Preparation and Characterization of Human Milk Fat Substitutes Based on Triacylglycerol Profiles

Human milk fat substitutes (HMFS) having similarity in (TAG) composition to human milk fat (HMF) were prepared by Lipozyme RM IM‐catalyzed interesterification of lard blending with selected oils in a packed bed reactor. Four oil blends with high similarity in fatty acid profiles to HMF were first obtained based on the blending model and then the blending ratios were screened based on TAG composition similarity by enzymatic interesterification in a batch reactor. The optimal ratio was determined as lard:sunflower oil:canola oil:palm kernel oil:palm oil:algal oil:microbial oil = 1.00:0.10:0.50:0.13:0.12:0.02:0.02. This blending ratio was used for a packed bed reactor and the conditions were then optimized as residence time, 1.5 h; reaction temperature, 50 °C. Under these conditions, the obtained product showed high degrees of similarity in fatty acid profile with 39.2 % palmitic acid at the sn‐2 position, 0.5 % arachidonic acid (n‐6) and 0.3 % docosahexaenoic acid (n‐3) and the scores for the degree of similarity in TAG composition was increased from 58.4 (the oil blend) to 72.3 (the final product). The packed bed reactor could be operated for 7 days without significant decrease in activity. The final product presented similar melting and crystallization profiles to those of HMF. However, due to the loss of tocopherols during deacidification process, the oxidative stability was lower than that of the oil blend. This process for the preparation of HMFS from lard with high similarity in TAG composition by physical blending and enzymatic interesterification, as optimized by mathematical models in a packed bed reactor, has a great potential for industrialization.