Heat-stable peptide markers for bovine heart, kidney, liver, lung, and spleen for authenticity testing of minced beef products

Due to the high market value of beef, the beef supply chain is susceptible to economically motivated food fraud. Focusing on the particular risk of offal as an adulterant, a bottom-up proteomics approach was used to identify tryptic, heat-stable peptide markers for the detection, identification, and differentiation of bovine offal in minced beef products. The workflow, which included extensive selectivity testing to rule out cross-selectivities with meat of six other meat-producing animal species (chicken, goat, horse, pig, sheep, turkey) as well as 25 other food ingredients, resulted in the discovery of 17 new peptide markers and the confirmation of five additional peptide markers from the literature: heart (6), kidney (1), kidney/liver (2), liver (3), lung (6), spleen/lung (2), spleen (2). All evaluated peptide markers were heat-stable and detectable in a highly processed model beef matrix, confirming their suitability for use in the development of analytical methods for food authenticity testing.