Cooling, chilling and cold stabilization in meat production
Meat in slaughterhouses should be cooled as fast as possible to a uniform temperature to reduce the growth rate of microorganisms that may be present on carcass surfaces, and thus minimize spoilage. The right level of temperature, humidity, and air motion should be selected to prevent excessive shrinkage, toughening, and discoloration.
The deep body temperature of an animal is about 39oC, but this temperature tends to raise a couple of degrees in the midsections after slaughter as a result of the heat generated during the biological reactions that occur in the cells. The temperature of the exposed surfaces, on the other hand, tends to drop as a result of heat losses. The thickest part of the carcass is the round, and the centre of the round is the last place to cool during chilling. Therefore, the cooling of the carcass can best be monitored by inserting a thermometer deep into the central part of the round. Refrigeration depends on removing heat from meat and then maintaining it at a lower temperature than its surroundings Applications It is used in the information about meat processing
Typical parameters of the process
The EC legislation does not define a chilling time, only a maximum final meat temperature of 7°C before transport or cutting. Typical chilling times are 24 – 48 hours for beef sides, 12 hours for lamb and 12 – 24 hours for pig carcases.
Table 1: Specific energy required (MJ/t) to chill, freeze and process (cutting and deboning) meat (Ramirez et al., 2006).
|Product||Whole and chilled||Whole and frozen||Cut, debones and frozen|
|Beef, veal anf sheep||1390||2110||2866|
|Poultry||3096||4258 - 5518||5014 - 6274|
Figure 1: Flow chart Inputs and Outputs for cooling systems
Source: Cleaner Production Assessment in Meat Processing; prepared by COWI Denmark for UNEP (United States Environment Programs) and Danish Environmental Protection Agency, 2000 Denmark