. Bovine biceps femoris is resistant to tenderization by lower-salt moisture enhancement or enzyme addition. Can. J. Anim. Sci. 90: 495Á503. Unacceptable toughness in retail beef cuts prepared from round muscles is not uncommon. The biceps femoris (BF) muscle is a particular challenge due to its high connective tissue content. Disruption of connective tissue by proteolytic enzyme injection has been demonstrated to improve tenderness in some muscles. Moisture enhancement can also be effective; however, concern over sodium content in processed foods is rising. The single and combined effects of lower-salt moisture enhancement (ME; 0.25% sodium chloride/0.25% sodium phosphate) and injection of enzymes from different sources (fungal aspartyl protease, bacterial protease, porcine pancreatin, plant-derived papain) on tenderness characteristics of the BF was examined. The enzyme and ME treatments were not interactive. Moisture enhancement had no impact on peak shear force or sensory tenderness, although juiciness and saltiness perception was enhanced, even at the relatively low salt level. Each enzyme treatment reduced the shear force associated with the myofibrillar component of the BF, but did not influence the connective tissue component. No off flavour development or other sensory defects resulted from enzyme treatment. The ineffectiveness of the treatments may have been due to the low salt level, lack of enzyme specificity for collagen, or the relatively intractable nature of the BF to tenderization treatments.Key words: Beef, tenderization, lower salt, moisture enhancement, enzyme injection, tenderness Pietrasik, Z. et Shand, P. J. 2010. Le biceps femoris des bovins re´siste a`l'attendrissement quand on accroıˆt la teneur en eau tout en re´duisant la concentration de sel ou quand on ajoute des enzymes. Can. J. Anim. Sci. 90: 495Á503. Il n'est pas rare que les pie`ces de boeuf venant de la ronde soient trop coriaces. Le muscle biceps femoris (BF) soule`ve des difficulte´s particulie`res parce qu'il renferme beaucoup de tissu conjonctif. L'injection d'enzymes prote´olytiques pour dissocier ce dernier accroıˆt la tendrete´de certains muscles. On peut aussi augmenter la teneur en eau, mais la concentration de sodium dans les aliments transforme´s est de plus en plus pre´occupante. Les auteurs ont examine´l'incidence d'une hausse de la teneur en eau avec plus faible concentration de sel (ME; 0,25% de chlorure de sodium/0,25% de phosphate de sodium) et de l'injection d'enzymes d'origines varie´es (aspartyl prote´ase fongique, prote´ase bacte´rienne, pancre´atine porcine, papaı¨ne ve´ge´tale), se´pare´ment ou ensemble, sur la tendrete´du BF. Les traitements ME et enzymatiques ne sont pas interactifs. Le traitement ME n'influe pas sur la re´sistance maximale au cisaillement ni sur la tendrete´perc¸ue, bien que la viande semble plus juteuse et sale´e, en de´pit de la quantite´relativement faible de sel employe´e. Chaque enzyme re´duit la re´sistance au cisaillement associe´e aux myofibrilles du BF, sans agir sur le tissu ...