Immobilised Aspergillus niger lipase synthesises sn-1,3-dioleoyl-2-palmitoylglycerol

sn-1,3-Dioleoyl-2-palmitoylglycerol (OPO) is a structural triglyceride with a specific distribution of fatty acids, which is an important component of breast milk fat and which can better promote the absorption of minerals and energy in infants. In this study, a lab-made immobilised Aspergillus niger lipase (IM-ANL), which is more economical than a commercial lipase, was used for hydrolysis to produce free fatty acids (FFA) and acidolysis interesterification to produce OPO. The enzyme was used for multiple purposes, reducing the cost of enzymatic production. The optimum conditions for hydrolysis were determined by experiments: the amount of IM-ANL enzyme dosage was 3%, the reaction temperature was 45 °C, and the reaction time was 48 h. The optimum conditions for acidolysis interesterification were as follows: the amount of IM-ANL enzyme dosage was 4%, the molar ratio of tripalmitin to oleic acid was 1 : 8, the reaction temperature was 55 °C, and the reaction time was 3 h. In this study, economical palm stearin and high oleic acid sunflower seed oil were selected as reaction raw materials, and the reaction temperature was moderate, the safety risk was low, the energy consumption was reduced, the process was more economical, and the economic value of high oleic acid vegetable oil was improved, which was conducive to the further promotion of OPO production.