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

A simple gravimetric solvent-extraction method was developed to determine t he 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 e stimates obtained from a pilot collaborative study, involving six laborator ies 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)) respectiv ely. These estimates were constant over the fat range tested and thus did n ot depend on the composition of the products. The relative repeatability st andard deviations (RSDr) and the relative reproducibility standard deviatio ns (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 Ro se Gottlieb and SBR methods and is deemed sufficiently precise to be used f or checking the fat content of spreadable fats against legislative specific ations. (C) 2001 Elsevier Science Ltd. All rights reserved.