Separation of Triacylglycerol Species from Interesterified Oils by High Performance Liquid Chromatography

Authors: LEE, JEUNG-HEE - CHUNGNAM NATIONAL UNIV; Jones, Kerby; Foglia, Thomas; Nunez, Alberto; LEE, JONG HO - YONSEI UNIVERSITY; KIM, NAM SOOK - CHUNGNAM NATIONAL UNIV; VU, PHUONG-LAN - CHUNGNAM NATIONAL UNIV; LEE, KI-TEAK - CHUNGNAM NATIONAL UNIV

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2006
Publication Date: 3/1/2007
Citation: Lee, J., Jones, K.C., Foglia, T.A., Nunez, A., Lee, J., Kim, N., Vu, P., Lee, K. 2007. Separation of Triacylglycerol Species from Interesterified Oils by High Performance Liquid Chromatography. Journal of the American Oil Chemists' Society. 84(3):211-217.

Interpretive Summary: One-way to address the nutritional needs of the ill and aged is to provide liquid food supplements of high caloric density. Such formulations also are popular as high-energy drinks for individuals during periods of extended physical activity. Typically, such supplements are fortified with a mixture of oils and fats whose triglycerides contain either essential long-chain (LC) fatty acids or medium-chain (MC) fatty acids. 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 nutritional benefits of the LC fatty acids. An alternative to using mixed MC and LC fatty acid oils and fats in nutritional supplements is to use structured lipids (SLs). SLs 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 the MC-LC triglyceride mixtures. One problem with such lipid supplements, however, is that food labeling regulations necessitate that methods be available for detecting and measuring these types of nutritional supplements. In this paper we describe rapid analytical liquid chromatographic methods that can easily detect and accurately measure these lipid supplements. This technology will allow manufacturers to provide the consumer with the information required by current and future regulations on food composition.

Technical Abstract: Using a 1, 3-regioselective lipase as catalyst, the short-chain triacylglycerol, tributyrin [1, 2, 3-tributyrylglycerol, (C4)], was interesterified with soybean oil and olive oil to produce mixtures of structured triacylglycerol (SL-TAG) isomers. After isolation and purification the structured lipids were analyzed by both normal phase (silica column; NPSIL) and/or reverse phase (ODS column) high performance liquid chromatography (HPLC) to separate the SL-TAG isomers. Individual triacylglycerol molecular species were detected and quantified by evaporative light-scattering detection and characterized by mass spectrometry. The NPSIL method successfully separated SL-TAG stereoisomers having butyryl groups and long chain fatty acids (from soybean or olive oil). The newly synthesized SL-TAG isomers were further analyzed on the ODS column, showing that non-aqueous reverse phase HPLC successfully separated each isomer.