Effects of blast chilling and postmortem calcium chloride injection on tenderness of pork longissimus muscle.

Two studies were conducted to evaluate the effects of blast chilling of carcasses and injection with calcium chloride (CaCl2) at 24 h postmortem on Warner-Bratzler shear values (WBS) and moisture losses of pork longissimus muscles (LM). In a preliminary study, Exp. 1 was conducted to determine whether the injection procedure using 100% water had an influence on WBS of pork LM. Injecting pork LM with water at 24 h postmortem had no effect on WBS (P = .64). In Exp. 2, 27 carcass sides were assigned to 1) blast chilling for 1 h at 25 degrees C and then chilling for 23 h at 1 degree C or 2) standard chilling for 24 h at 1 degree C. At 24 h postmortem, the LM was removed from each side and divided into anterior (AL) and posterior (PL) halves. For each LM, the CaCl2 treatment was assigned randomly to either the AL or PL. Those receiving CaCl2 were injected with a .3 M solution at 10% by weight. Muscles then were stored for 3 d at 1 degree C before 2.54-cm chops were removed, cooked to an internal temperature of 70 degrees C, and allowed to cool for 2 h, then six 1.27-cm cores were taken and sheared. No differences (P > .05) in purge or cooking loss were observed, but rapid chilling reduced (P < .05) the combination of purge and cooking loss without influencing WBS (P = .77). The injection of CaCl2 at 24 h postmortem lowered (P < .05) WBS of pork LM muscle. Therefore, the tenderness of pork can be enhanced by injection of CaCl2.