Color Stability of Hot and Cold Boned Longissimus and Psoas Major Muscle.

From eight cows, following electrical stimulation, the righthand-side longissimus and psoas major muscles were hot boned within 1 1/2 h post mortem, vacuum packaged and chilled at 1±1°C. The lefthand longissimus and psoas major muscles were cold boned and vacuum packaged after the carcasses had been chilled for 24 h (i.e. 1 1/2 h at -1 to -4°C, 3 m.s immediately after slaughter followed by chilled storage at 1 ± 1°C). After 12 d of storage at 1 ± 1°C all primals were unpacked and cut into steaks which were subsequently displayed at 3±1°C under continuous illumination with a 300-400 Lux lamp. At days 0, 2, and 4 the color of the steaks was measured both instrumentally (Hunter L*, a*, b* and spectrum analysis) and visually (6-member butcher-panel). After 4 d of display steaks from hot boned psoas major muscles had a more stable color (higher a*- and chroma-values) than steaks from cold boned counterparts (P<0.05) which coincided with slightly, though not significantly, better color scores (P<0.10). The color stability of the longissimus muscle was not affected by time of boning. It is concluded that the color-stabilizing effect of hot boning is fairly small and probably of marginal significance to the retailer when electrical stimulation is included in the slaughtering process.