THE EFFECTS OF CALCIUM-CHLORIDES, SODIUM-CHLORIDES AND ZINC-CHLORIDESTREATMENT ON THE QUALITY OF BEEF

The effects of pre-, post-rigor and CaCl2, NaCl and ZnCl2 treatment of bovine longissimus muscle on meat quality traits, degradation of myofi brillar proteins, and calpain and calpastatin activities were investig ated in three experiments. Pre-rigor treatment with CaCl2 induced extr eme muscle contraction and increased drip loss. NaCl and post-rigor Ca Cl2 treatment resulted in an increasedwaterholding capacity. Pre- and post-rigor CaCl2 and NaCl treatmentimproved tenderness at 2 d post mor tem. Yet, only CaCl2 treatment resulted in clearly reduced calpain and calpastatin activities and increased degradation of myofibrillar prot eins at 2 d post mortem. After 14 d ageing, only pre-rigor NaCl-treate d samples were more tender than the controls. Both CaCl2 and NaCl trea tment reduced colour stability, but this effect was most pronounced in the CaCl2-treated muscles. Incubation of muscle samples in CaCl2 and NaCl solutions resulted in progressive swelling of the samples with an increase in salt concentration. In contrast, incubation in ZnCl2 resu lted in shrinkage of the samples. CaCl2 injection at 14 d post mortem resulted in a decreased shear force, whereas ZnCl2 treatment resulted in an increased shear force in combination with an increase in cooking loss. The effects of ZnCl2 are likely explained by a decrease of the muscle pH due to binding of Zn2+ to imidazole groups.