Early post mortem muscle shortening and tension in relation to tenderness in beef M. longissimus

Summary

Muscle tension and shortening were continuously registered in temperature controlled rigormeters (Rigotech) 1.5-20.5 h post mortem in M. longissimus dorsi from 30 young bull exposed to two different chilling rates. To ensure reproducible rigormeter measurements a polyacrylamid gel was initially manufactured and tested in the six rigormeters employed in the study. Moreover, sarcomere length in fresh beef and Warner-Bratzler (WB) shear force in cooked beef were measured and correlated to muscle tension and shortening. Shortening correlated to neither WB shear force nor sarcomere length, whereas tension explained 61% of the variation in WB shear force, however with no obvious connection to sarcomere length. An inverse relationship between tension and WB shear force was observed.