Synthesis, Purification, and Characterization of a Structured Lipid Based on Soybean Oil and Coconut Oil and Its Applications in Curcumin‐Loaded Nanoemulsions

Abstract Single natural vegetable oils may have some drawbacks in terms of structure and function. Enzymatic interesterification can greatly improve the quality of natural vegetable oils. In this study, soybean oil (SO) and coconut oil (CO) are combined to synthesize structured lipids (SLs) using Lipozyme RM IM as a catalyst to modify the structure of coconut oil, which can make coconut oil have better physicochemical properties. A total of 55.73% structured lipids of total triacylglycerols are synthesized under the optimum reaction conditions. The main fatty acids of SL‐SOCO are linoleic (C18:2, 37.11%), oleic (C18:1, 21.73%), and lauric (C12:0, 14.05%). The most abundant TAG species in SL‐SOCO are (14:0‐18:1‐18:3), (12:0‐14:0‐18:3), and (14:0‐14:0‐18:3) with the relative content of 10.56%, 7.13%, and 5.52%, respectively. Compared to the crystallization curves of SOCO, SL‐SOCO showed a delayed crystallization and a decreased enthalpy. Moreover, the curcumin nanocarrier prepared by SL‐SOCO as the oil phase has good stability, encapsulation efficiency (91.12%), and improved bioavailability (54.02%). To conclude, SL‐SOCO with monounsaturated fatty acid, polyunsaturated fatty acids, and medium‐chain fatty acids has good structural composition and SL‐SOCO nanoparticles have excellent applications in drug delivery system. Practical Applications : The prepared SLs can be used as one kind of functional lipids, which has the potential to improve lipid metabolism. In addition, it can be used as an oil phase to prepare carriers for encapsulating active substances, which have good stability, improved encapsulation efficiency, and bioavailability.