Reference measurement procedure for the determination of mass fraction of fat content in food

This article develops the reference measurement procedure (RMP), including acid hydrolysis, Randall extraction, evaporation of solvent, and weighing of dry residue in the determination of mass fraction of fat content. This paper’s RMP applies to dairy, meat, and egg products, and to baby food. In order to develop this RMP, selection and optimization of hydrolysis and extraction parameters were carried out. The paper takes into consideration the components of measurement uncertainty arising from the contributions of equipment and reagents. It also evaluates measurement equations and methodological factors. This article also presents the results of an inter-laboratory comparison of the determination of mass fraction of fat in Russian enterprises’ dairy products. These results demonstrate that the RMP developed by this research had the highest level of accuracy and the absence of bias in the measurement results as compared to other routine methods. Experiments carried out during the participation of UNIIM in an inter-laboratory comparison organized by MUVA Kempten GmbH (Germany) confirmed the equivalence of the RMP developed by this research with similar foreign measurement methods. The results of the work will ensure coherence of the results of determining the fat content in food products and food raw materials in the Russian Federation, and their conformity with the results obtained in other countries.