DETERMINATION OF TOTAL FAT IN MEAT AND MEAT-PRODUCTS BY SOLVENT-EXTRACTION AFTER HYDROCHLORIC-ACID HYDROLYSIS - NMKL INTERLABORATORY STUDY

A gravimetric method including acid hydrolysis and solvent extraction according to SBR (Schmid, Bondzynski, and Ratzlaff) for the determination of total fat in meat and meat products was collaboratively studied in 12 laboratories. The study aimed at investigating whether an older SBR method for the determination of fat in meat and meat products, published by the Nordic Committee on Food Analysis in 1974, could be simplified without significant losses in precision. The study samples consisted of 12 materials in the form of 6 matched pairs of meat types: ham, beef trimmings, pork loin, black pudding, sausage, and liver pate. The fat contents of the samples varied between 2.6 and 44.4 g fat per 100 g. The participating laboratories were asked to analyze the samples by both the old and the new methods. The results indicated that there was no significant difference between the results obtained by the 2 methods. The precision of the revised method in most respects meets the U.S. Department of Agriculture, Food Safety and Inspection Service requirements on methods for the analysis of meat and meat products. The relative standard deviation for repeatability of the method varied from 0.93% for the 44.5 g/100 g level of fat to 4.5% for the 2.5 g/100 g level. The relative standard deviation for reproducibility varied correspondingly between 1.2 and 6.1%. For samples with a fat content <5 g/100 g, the revised method gave somewhat lower fat concentrations than the older method. However, the mean differences were small and did not exceed the precision (repeatability and reproducibility) of the method. Ten of the 12 participating laboratories found the revised method easier to work with than the original method.