Improvement of the State Primary Reference Measurement Procedure for the Determination of Mass Fraction of Fat Content in Food Products and Food Raw Materials

In order to ensure metrological traceability of fat mass fraction measurements, the State Primary Reference Measurement Procedure (SPRMP) for the Determination of Mass Fraction of Fat in Food Products and Food Raw Materials was developed, certified and approved in 2018. The SPRMP applies to samples of milk powder, sour cream, cottage cheese, cheese, meat and meat products, dry egg products, milk mixtures, grain porridge, grain-milk mixtures, canned baby food and establishes requirements for the procedure for measuring the mass fraction of fat using the Randall extractiongravimetric method. In the process of applying the SPRMP, the need to expand the scope of its application was identified. The purpose of the research is to improve the SPRMP of the mass fraction of fat in food products and food raw materials. An analysis of regulatory documents defining requirements for new measurement objects, measurement ranges and accuracy indicators has been completed. The measurement parameters and their permissible variation limits for new objects have been established. As a result of improvement, the scope of application of the SPRMP includes drinking milk and cream, condensed milk and cream, fish fillet, fish meat, including minced meat, bakery products, f lour confectionery, pasta, cocoa powder, chocolate, flour from cereals, nuts, nut paste, including peanut. An assessment of the accuracy indicators of the SPRMP was carried out using certified reference materials, food products and food raw materials. The developed measurement procedure made it possible to ensure a margin of accuracy of the measurement results using the SPRMP in comparison with standardized measurement procedures from 2 to 25 times, depending on the object and the measurement range. As part of the interlaboratory comparison tests, the procedure for using the SPRMP to assess the correctness of measurement results obtained using standardized measurement procedures was tested. During the COOMET pilot comparisons, as well as the analysis of foreign reference materials, the equivalence of the SPRMP to similar measurement methods of foreign countries was demonstrated. The applicability of the SPRMP for determining the certified value of the mass fraction of fat during the characterization of reference materials was demonstrated.

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