Very fast chilling of beef: effects on meat quality.

The effect of very fast chilling (VFC) of beef on several meat quality parameters was studied in semitendinous samples of three young bulls of the Belgian Blue breed. Left carcass sides were chilled conventionally. The semitendinosus of the right carcass sides were hot boned at approximately 50 min post mortem and cut longitudinally in two equal pieces. Packed in plastic bags, one piece was chilled very fast using a brine solution (3.4% NaCl, -2°C), whereas the other was chilled in a freezer (-20/-25°C, 3 m/s). The very fast chilling treatments lasted until 5 h post mortem. Samples were further chilled in a refrigerator (2°C) until 24 h post mortem. Sub-samples for meat quality measurements were taken and frozen at -18°C after an ageing period of 1, 4 and 11 days at 2°C. In three of the six cases, a core temperature of 0°C was achieved within 5 h post mortem [VFC condition; In the other cases, the VFC condition was nearly met. The brine chilling treatment in this study resulted in a higher cooling rate compared with the freezer treatment, and concomitantly in more pronounced effects. VFC resulted in increased concentrations of water extractable calcium and higher pH values at 5 h post mortem. These factors could be expected to activate the calpains and to accelerate proteolysis. This could not be confirmed by our results. Cold shortening occurred and sarcomere lengths were reduced by more than 30% in the VFC treatment compared with conventional chilling. This was reflected in much higher shear force values for the VFC samples.