A COMPARISON OF OIL AND FAT-CONTENT IN OILSEEDS AND GROUND-BEEF - USING SUPERCRITICAL-FLUID EXTRACTION AND RELATED ANALYTICAL TECHNIQUES

A supercritical fluid extraction (SFE) has been applied for the determ ination of total fat content of five different oilseed matrices (soybe ans, sunflower, safflower, cottonseed and rapeseed) and ground beef sa mples containing approximately 10, 20 and 30% fat by weight. Lipid con tent was determined using both gravimetric analysis as well as the sum of all fatty acids, expressed as triglycerides, from the gas chromato graphy (GC) profiles of the fatty acid methyl esters (FAMEs). The latt er analysis is required by the Nutritional Labeling and Education Act of 1990 which redefined the determination of fat for nutritional label ing purposes. The oilseed results are compared to data from a collabor ative study by the American Oil Chemists Society (AOCS) and the Associ ation of Official Analytical Chemists International (AOAC). The collab orative study data were determined by both AOCS Official Methods and b y SFE. All of our data yielded higher oil recoveries than the collabor ative study data obtained via AOCS official methods and SFE with neat carbon dioxide (CO2). However, our results are in excellent agreement with the collaborative study data obtained by SFE with ethanol-modifie d CO2 and the Federation of Oil, Seeds and Fats Association Internatio nal method. The ground beef results are compared to previously publish ed reports from our laboratory. They show that fat determination using CC-FAME analysis is equivalent to the gravimetric analysis results an d has the additional benefit that different types of fat (i.e. saturat ed and monounsaturated) can also be determined in addition to total fa t. Hence, the results from this study advocate the use of SFE as a sui table replacement for traditional organic solvent extraction in the de termination of fat/oil content in agriculturally-derived products. Pub lished by Elsevier Science Ltd.