Seminars in Food Analysis 1, 14.5-I 62 (1996) Determination of fat content in foods by analytical SFE I FRED J. ELLER* and JERRY W. KING Food Quaiin and Safep Research, National Center for Agriculruml Vrili:ation Research. Agricuhural Research Service/US bepartment of Agriculture,,t 1815 North University Street. Peoria, IL 61604 USA Analytical supercritical fluid extraction (WE) is finding widespread application in the analysis of food- stuffs, agriculturally derived materials, and natural products. The high efficacy that SE demonstrates toward the removal of oils and fats from such matrices makes it a natural technique for the determination of their fat and oil content. In this review, we have highlighted what is essential experimentally to optimize the SFE of fat and other lipid moieties from meats, oilseeds, snack foods, and cereal products. The role of extraction pressure/temperature and sample preparation before SFE is particularly emphasized as well as the inclusion of sorbenrs into the extraction process for controlling the molecular specificity of the extraction or the coextraction of water. Application of analytical SFE for total and speciated fat determi- nation is cited for both home-built as well as both manual and automated commercial instrumentation. Finally, an appraisal of the future of the technique is made with respect to its acceptance as an official analytical method and the crucial interface between the end-user and the instrumentation companies that produce the analysis modules. Keywords: SF& fat; lipid; analysis; food Introduction Fat: definition and determination Interest in dietary fat is widespread. Consumers, industrial food processors, and governmental agencies all have an intense interest in fat, although for very different reasons. Consumers are concerned with the reduction in the intake of total fat, saturated fat, and cholesterol for im- proving human health (Chao et al, 1991). Fat control is necessary for food processors who must strive to meet consumer demands for products containing less fat (i.e. “fat-free” or “low-fat” foods) as well as to maintain costs and to comply with labeling requirements. Governmental agencies must have suitable methods for fat determination to assure accurate labeling of food products. Although the determination of fat content is one of the most common analyses performed in a foodstuffs laboratory, the quantitative extraction and analysis of fat is far from straightforward (Lumley and Colwell, 1991). With the ever-increasing range of processed, composite, and novel foods available, the analyst faces an increasingly difficult task of selecting an appropriate method for fat determination. Impact of NLEA As a result of the Nutritional Labeling Act (NLEA) of 1990, total fat is currently defined as the sum of all fatty acids obtained from total lipid extract expressed as triglycerides (Federal *To whom correspondence should be addressed. *Names are necessary to report factually on availabledata, however, the USDA neither guarantees nor’ warrantsthe standard of the product. and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable. 1084-2071 0 1996 Chapman& Hall