Evaluation of spray chilling at a meat processing site

The chilling process uses circulating cold air to cool hot carcasses.  The cooling process results from cold air evaporating carcass surface moisture.  As the cooling process continues and surface moisture has been evaporated, deeper tissue is cooled as moisture is drawn to the surface.  The evaporation is rapid in the initial stages as there is a large difference between the hot carcass temperature and the chiller air temperature.  Evaporation rate declines as the temperature gap reduces.

The evaporation, termed carcass shrinkage is the moisture/weight lost by the carcass due to the chilling process.  This is a significant cost to the processing facility.  Spray chilling uses sprays of water to offset the evaporative loss of carcass chilling.  Sprayed water is then evaporated from the carcass and moisture is not drawn from deeper in the tissue.  Timing of sprays and amount of water sprayed is key to get the shrinkage as close to zero as possible.  Shrinkage and carcass chilling are also influenced by other variables; including but not restricted to: chiller design, operating conditions, carcass size and carcass fat cover.

Further information on spray chilling is available.

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