Table 1. pH and activities of endogenous enzymes (cathepsin B and H) in 6 h post-mortem hot boned beef brisket (control) and subsequent storage at either 4°C or −20°C for 4 d

	6 h post-mortem meat (Control)	4 d post-mortem meat stored at 4°C	4 d post-mortem meat stored at −20°C
pH	5.78±0.07	5.67±0.04	5.84±0.05
Cathepsin B¹⁾	13,004±2,837^C	36,965±3,294^A	27,748±2,331^AB
Cathepsin H¹⁾	25,066±4,508	16,910±4,652	14,770±1,335

All values are mean±SE of mean for three replicates.
The units for the enzyme activities are expressed as increase in FU per min per g of muscle for cathepsin activities.
Different letters in each row are significantly different (p<0.05).