Effects of mechanical treatments and moisture enhancement on the processing characteristics and tenderness of beef semimembranosus roasts.

The combined effect of blade tenderization (TD,NTD), pre-massaging (0 and 30min), moisture enhancement and post-injection tumbling (2h) on the chemical, binding and textural characteristics of pre-cooked roasts made from beef top round was investigated. Properties of the beef roasts were determined by measuring processing (i.e., cooking yield, expressible moisture (EM)) and textural characteristics (Warner-Bratzler shear, Kramer shear (KS), texture profile analysis). Brine injection helped to improve the cook yield and had the largest effect on tenderness of semimembranosus muscles. Post-injection tumbling did not significantly improve yield and textural properties of roasts; however, combined with the tenderization, it had beneficial effects on water holding and moisture retention. Pre-tumbling and blade tenderization treatments prior to injection generally were found to be beneficial for textural characteristics; pre-tumbling also tended to improve cook yield, but did not influence EM. However, no synergistic effect between these two variables was observed. An interaction between injection/tumbling and pre-tumbling was observed for KS. There was a significant improvement of KS values of roasts due to pre-tumbling observed for either non-injected roasts or those injected but without tumbling. However, no additional reduction in shear force was observed with pre-tumbling when roasts were tumbled after injection. This suggests that pre-tumbling may not be necessary to ensure more tender roasts when post-injection tumbling is applied, but would be beneficial for non-injected roasts or when tumbling is not applied after injection.