Preparation and characterization of control materials for the analysis of conjugated linoleic acid and trans-vaccenic acid in beef

Beef and beef fat control composites (CC) were prepared for a large multi-year study of conjugated linoleic acid (CLA) and trans-vaccenic acid (TVA) in beef. Raw ground beef and beef suet were each frozen in liquid nitrogen, ground to a fine powder, dispensed into subsamples, and stored at − 60 °C under nitrogen. The CCs, reference materials (beef/pork fat; meat homogenate), and standards prepared at two concentrations of CLA and TVA added to a total lipid extract of beef (differing by 0.27 g/100 g CLA and 1.2432 g/100 g TVA) were analyzed via alkaline saponification of lipids, derivatization to fatty acid methyl esters, and GC. CLA and TVA recoveries from the standards were 95–113% (CLA) and 103–106% (TVA). Fatty acids quantified in the reference materials were within the certified ranges. Relative standard deviations (n = 3 in each of 5 assay batches) were < 5% (TVA) and < 10% (CLA) for both CCs, at both laboratories.