Chemical transesterification of flaxseed oil and medium‐chain triacylglycerols: MLCT yield, DAG content, physicochemical properties, minor compounds and oxidation stability

Summary A type of medium‐ and long‐chain triacylglycerols (MLCT) rich in α‐linolenic acid (ALA) was produced by chemical transesterification of medium‐chain triacylglycerols (MCT) and flaxseed oils. Under the optimal substrate conditions of 60%, catalyst loading of 0.3% at 60 °C for 15 min, the product contained MLCT (74.06%), ALA (37.26%) and diacylglycerol (DAG) (11.25%). After that, changes in fatty acid (FA) composition, physicochemical properties and minor compounds after chemical transesterification (CTE) were investigated. The correlations analysis results of these factors on oxidative stability showed these factors could be divided into positive and negative groups. Although DAG appears to be beneficial in slowing down oil oxidation, it is critical to avoid its mass production because it would decrease MLCT. MLCTs are desirable as health‐care products which can enhance overall health. In this work, the MLCT rich in ALA was produced by a sodium methoxide catalyzed chemical transesterification of flaxseed oil and MCTs. Considering oxidative stability is essential to lipid products, factors related to changes in oxidative stability of MLCT product prepared under the optimal conditions were analyzed.