The circular economy is one of the main building blocks of the European Green Deal. In this context, the use of former foodstuffs containing ruminant gelatin was recently authorized in nonruminant feed. This minor modification makes it more challenging, if not impossible, to interpret the analytical results of the official control for animal proteins. The presence of ruminant DNA from authorized byproducts (i.e., milk and/or gelatin) may hide the use of prohibited byproducts. The objective of this work was to evaluate the use of sedimentation to increase the sensitivity and specificity of bovine-processed animal proteins (PAPs) detection by mass spectrometry-based proteomics. Both approaches (standard versus optimized method) were evaluated by UHPLC-MS/MS on various animal feeds and samples from an interlaboratory study. The optimized method was able to achieve the adulteration level below the level of 0.1% PAPs required by the European Commission. This approach presents a simple and economical solution to improve the method without the need for new equipment or expertise since it is already in place in the control laboratories.
Keywords: MS; PAPs; animal byproducts; collagen; feed safety; hemoglobin; proteomics; sedimentation.