An accurate and simple Computed Tomography approach for measuring the lean meat percentage of pig cuts (une approche précise et simple de la mesure du taux de viande maigre des découpes de porc par tomodensitométrie)

The global challenge was to develop a robust, unbiased, accurate and simple reference method for measuring the lean meat weight and percentage (in live animals, carcasses, cuts and meat pieces). The principal aim of this study was first to develop such a method on pig cuts. Sixty-three left sides, were taken as a representative sample of the French pig slaughtering, were jointed into the four primal cuts. These cuts were scanned by spiral Computed Tomography (CT) using a 3 mm slice thickness. Muscle volume was automatically measured as the voxels in the Hounsfield range 0-120. LMP (Lean Meat percentage) was calculated applying a constant muscle density. The four cuts were fully dissected and LMP was calculated according to the EU definition. Correlations between CT and dissection were all higher than 0.98. Biases between dissection and CT were not significant. The regression of dissection on CT for muscle weight gave an RSD in the range 45-51 g for loin, shoulder and ham, 80 g for belly and 186 g for the whole. For LMP the RSD was 0.54 %. This CT procedure is presently the simplest and most accurate method to measure the lean meat percentage of the main pig cuts. It will be used in France for calibrating the classification methods and for composition studies. Variability in muscle density is under investigation in order to assess the robustness of this approach. The detection of the different tissues, especially in the belly, could merit further improvement.