The effects of spray-chilling carcasses on the shrinkage and quality of beef.

After slaughter, alternate beef carcass sides (left, right) were allocated to an intermittent spray-chilling cooling treatment using water (4 cycles per hour; 60 s/cycle) and conventional air chilling (1-2°C; air velocity 0·5 m/s), or conventional air chilling only. Experiments 1, 2, and 3 (n = 19, 26 and 16 carcasses) involved spray-chilling for 4, 8, 12 h in shrouded sides, whereas experiment 4 (n = 16 carcasses) involved 8 h of spray-chilling in unshrouded sides. At 24 h post-slaughter all sides were ribbed (12 13 th ribs ), and assessed for meat and fat colour. Half the treatment and control sides in each experiment were aged for 6 days, while the boneless ribs and inside rounds were removed from the remaining sides, vacuum packaged and held for 6 days. After 6 days of storage, retail packs of rib steaks and round roasts were prepared and assessed for colour and drip losses over a 4-day period. Spray-chilling significantly reduced carcass shrinkage at 24 h post slaughter in experiments 1-4 by 0·48, 0·69, 0·89 and 1·48%, respectively. After 6 days of cooler storage, spray-chilling significantly reduced carcass shrinkage in experiments 3 and 4 only (0·47 and 0·94%). Weight and drip losses for vacuum packaged ribs and inside rounds were not influenced by spray-chilling over 6 days of storage. Spray-chilling had no influence on rate of pH decline, but reduced loin and round muscle temperatures by 1-2°C. Loin eye muscle colour and shear force were not affected by treatment, but in experiments 2, 3 and 4, fat colour was significantly lighter in spray-chilled compared to conventionally chilled sides. Colour changes and drip losses in retail packs over 4 days for rib steaks and round roasts were not related to spray-chilling. It was concluded that spray-chilling could provide a moderate reduction in carcass shrinkage during cooling without having a detrimental influence on muscle quality.