A precise method to measure the total fat content of spreadable fats

A simple gravimetric solvent-extraction method was developed to determine the total fat content of a wide range of spreadable fats having fat contents in the range 23-82 g 100g(-1). Operating parameters affecting the yield of lipid were optimised. The available evidence indicated that full recovery of mono- and diglycerides and sterols was obtained. The method was compared with the Schmid-Bondzynski-Ratzlaff (SBR) method, which was shown to have a much poorer repeatability and to co-extract non-lipid matter. Precision estimates obtained from a pilot collaborative study, involving six laboratories and 10 different spreadable fats, were 0.27 g 100 g(-1) and 0.44 g 100 g(-1) for repeatability (2.83s(r)) and reproducibility (2.83s(R)) respectively. These estimates were constant over the fat range tested and thus did not depend on the composition of the products. The relative repeatability standard deviations (RSDr) and the relative reproducibility standard deviations (RSD,) for total fat were very low with ranges of 0.10-0.32% and 0.15-0.95%, respectively. The method has fewer health and safety risks than the Rose Gottlieb and SBR methods and is deemed sufficiently precise to be used for checking the fat content of spreadable fats against legislative specifications. (C) 2001 Elsevier Science Ltd. All rights reserved.