Submitted to: Chromatographia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2003
Publication Date: 11/1/2003
Citation: Lee, K., Jones, K.C., Lee, J., Kim, M., Foglia, T.A. 2003. High performance liquid chromatographic separation of structured lipids produced by interesterification of macadamia oil with tributyrin and tricaprylin. Chromatographia. 58(9/10):653-658. Interpretive Summary: One way to address the nutritional needs of the ill and aged is to provide liquid food supplements of high caloric density, which are readily metabolized and utilized by the individual. Such formulations also are popular as high-energy drinks for individuals during periods of extended physical activity. Typically, such supplements are fortified with oils or fats that contain essential long-chain (LC) fatty acid triglycerides and medium-chain (MC) fatty acid triglycerides. This is done to obtain the benefits of the MC fatty acids, such as faster clearance from the blood stream, while retaining the higher caloric content and the essentially important LC fatty acids. An alternative to using mixed MC and LC fatty acid triglycerides in nutritional supplements is to use structured lipids (SLs) that are designed to contain both LC and MC fatty acids within the same triglyceride molecule. Studies have shown that such structured lipids have clinical advantages over MC-LC triglyceride mixtures. The problem is that newly enacted food labeling regulations necessitate that methods be available for detecting and measuring these types of fat mixtures. In this paper we describe rapid analytical liquid chromatographic methods that can easily detect and accurately measure such high-energy fat supplements. This technology will allow manufacturers to provide the consumer with the information required by current and future regulations on food composition.
Technical Abstract: Short- and medium-chain triacylglycerols, namely tributyrin (1,2,3-tributyrylglycerol) and tricaprylin (1,2,3-trioctanoylglycerol), were interesterified with macadamia oil using an immobilized lipase as biocatalyst. Both normal phase (silica column; NPsil) and reverse phase (ODS column) high performance liquid chromatography accompanied with evaporative light scattering or mass spectrometric detection were used to separate and/or identify the newly synthesized structured lipid products. The normal phase method separated the structured lipid triacylglycerols on the basis of their regioisomeric-structures. Analysis of the structured triacylglycerols by the non-aqueous reverse phase method separated the regioisomeric triacylglycerols based on their total carbon number. From these analyses, it was found that of the triacylglycerol species produced by interesterification of macadamia nut oil with tributyrin or tricaprylin 77.6 and 94.1%, respectively, were structured lipid products.