Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2001
Publication Date: 6/20/2002
Citation: LEE, K., FOGLIA, T.A., OH, M.J. 2002. MEDIUM-LONG-MEDIUM AND MEDIUM-LONG-LONG CHAIN ACYL GLYCEROLS FROM BEEF TALLOW AND CAPRYLIC ACID. JOURNAL OF FOOD SCIENCE. 67(3):1016-1020. Interpretive Summary: In general, animal fats contain a higher proportion of saturated fatty acids (SFA) than do vegetable oils, which is of concern to health-conscious consumers. Tallow, however, contains a high proportion of a monounsaturated fatty acid (MUFA), namely oleic acid, which is viewed as being beneficial in the diet. Because the long-chain SFA and oleic acid in tallow are located at different sites on the fat molecules, it is possible to selectively replace the long-chain saturated fatty acids with a more nutritionally desirable fatty acid, such as a medium-chain (MC) fatty acid. Modified fats designed to contain both MUFA and MC fatty acids within the same fat molecule are commonly referred to as structured lipids. In this study, such structured lipids were prepared by exchanging the SFA in tallow with an MC fatty acid using an enzyme catalyst. This was done to obtain the benefits of the MC fatty acid, such as faster clearance from the blood stream, while retaining the health benefits of tallow's high oleic acid content. Studies have shown that such structured lipids have clinical advantages over common natural fats and oils. With this technology, food processors can tailor the caloric content of nutritional supplements by changing the structure of natural fats and oils used in their formulation.
Technical Abstract: Beef tallow was fractionated either without or with solvent to obtain a highly enriched unsaturated fatty acid (USFA) fraction. Solvent fractionation at low temperature (-18º C) successfully fractionated USFA-enriched triacylglycerols (TAG) from the tallow. The higher the solute to solvent ratio used for fractionation, the greater the weight yield of the USFA-enriched TAG from the liquid fractions was recovered from the fractionation. USFA-enriched fractions subsequently were interesterified with a medium-chain fatty acid (caprylic acid) using a I,3-selective lipase as the biocatalyst. Through this 2nd-step transesterification process, a MLM (1,3-dimedium-2-long chain TAG) type of structured lipid (SL) was produced in volume. The isolated SL was characterized by reverse phase HPLC, GC, and DSC. The SL synthesized in this study would be considered as a value-added product from a renewable animal fat that may be nutritionally beneficial in selected food applications.