The aim of this study was to investigate the relationship between the abundances of Bov-SERPINA3 inhibitors (able to form pseudo-irreversible complexes with their target enzymes) and meat tenderness in Rectus abdominis muscle from PDO Maine-Anjou cows. The experiment included 4 tender (TE) and 4 tough (TO) samples from 20 animals, based on Warner-Bratzler shear force measurements (WBSF) and sensory tenderness scores at 14 days post mortem (d p-m), taken at 24 h p-m. Western blotting revealed three Bov-SERPINA3 forms with MW of 114 (not yet identified), 75 and 45 kDa. The intensities of 75 and 45 kDa Bov-SERPINA3 bands were significantly lower in TE than TO group whereas no difference was observed for the 114 kDa band. The 45 and 75 kDa Bov-SERPINA3 were strongly correlated with both WB shear force (r=0.81 and r=0.75, respectively) and the 45 kDa was further significantly correlated with tenderness scores (r=-0.74).