Abstract
The commercially available Foss-let fat analyzer was evaluated for the determination of fat in meat and meat products by comparison with AOAC method 24.005(a). With the Foss-let procedure, mechanical and instrumental equipment is used to determine fat in 7–10 min. A sample is extracted with tetrachloroethylene in a mechanical orbital shaker for 2 min and the specific gravity of the extract is measured in a magnetic float cell controlled by a digital potentiometer. During extraction, anhydrous calcium sulfate absorbs moisture droplets originating from the sample. The variations of comparative determinations on 67 meat samples containing 1.1–95.4% fat and 17 frankfurter samples containing 17.3–37.3% fat were analyzed statistically by grouping the data according to meat type (beef or pork) or frankfurters and into 6 ranges of fat content, and by treating the entire set of data. Error analysis of the differences and standard deviation of each grouping of paired determinations by the Fosslet and AOAC methods indicated that meat type and fat content >7.5% were not significant (P = 0.05) sources of variation as determined by t-tests on the statistics from the blocks of data. Determinations on samples containing ≤7.5% fat were consistently low and an additive correction of 0.25% was indicated. From the overall results, the accuracy and precision of the method were characterized as follows: the mean Foss-let method determination was high by 0.08% fat relative to that by the AOAC method; repeatability of ± 0.31% fat between duplicate determinations compared favorably with ±0.38% obtained with the AOAC method; and precision between paired determinations by the 2 methods was ±0.44%. Both a t-test for significance (P = 0.05) and the linear regression of the 84 comparative determinations indicated that the Foss-let method was equivalent to the AOAC method for determining fat.
