Effects of electrical stimulation, boning-temperature and conditioning mode on display colour of beef meat

The effects of electrical stimulation of hot-boned (ESHB) bovine longissimus dorsi muscle, followed by vacuum packaging with different temperature/time regimes and storage in aerobic conditions, compared with cold-boned treatment (CB), on colour characteristics was assessed. No significant difference in haeminic iron content was noted between ESHB and CB meat. The opacity was more pronounced in ESHB meat vacuum packaged and incubated at 37°C. This treatment (37° C/4 h) allowed a lighter and brighter red meat colour with a higher level of contamination which was always acceptable. The worst results for colour characteristics were obtained with ESHB meat conditioned rapidly at 2°C. No differences were noted between ESHB meat conditioned at 25°C and CB meat. To explain these discrepancies between treatments about colour characteristics, where muscle translucency is largely involved, differences in enzymic reducing activity and denaturation of sarcoplasmic proteins during glycolysis must be implicated.