Lipase-Catalyzed Interesterification of Schizochytrium sp. Oil and Medium-Chain Triacylglycerols for Preparation of DHA-Rich Medium and Long-Chain Structured Lipids

DHA-rich medium and long-chain structured lipids (MLSL) were successfully synthesized by lipase-catalyzed interesterification of microbial oil from Schizochytrium sp. with medium-chain triacylglycerols (MCT) containing 99% of caprylic acid. Parameters that affected the reaction process were investigated and the conditions were selected as follows: lipase from Aspergillus oryzae, NS40086; reaction time, 8 hours; substrate molar ratio (MCT/microbial oil), 1:1; lipase load, 8 wt%; reaction temperature, 60 °C. Under these conditions, the proportions of MCT, MLSL, and long-chain triacylglycerols (TAG) in the final products were 12.5%, 62.8%, and 24.6%, respectively. The final product was then subjected to UPLC-MS/MS. Eighty-three types of TAG were identified, in which 54 types contained MCFA and MLSL species with relatively high contents were 22:6–8:0–8:0 (6.8%), 8:0–8:0–16:0 (7.5%), and 16:0–16:0–8:0 (7.5%). This product rich in MLSL with DHA and MCFA in the same TAG molecule is beneficial for fat digestion and absorption in infant and thus can increase the bioavailability of DHA at the molecular level.