After the slaughter of animals the carcasses or parts of the carcasses are cooled in a short space of time to values generally lying below 7°C. For this purpose the objects for cooling (carcasses or carcass parts which have been pre-treated to a greater or lesser extent, including removed organs) are placed in a freezer. The temperature in such a freezer usually lies between-20 and-10°C. After about one to two hours the cooled objects are removed from the freezer and then transferred to a cooling area which has a temperature of a few degrees above 0°C. From the viewpoint of an effective quality control, it is important to bring the carcasses and carcass parts as quickly as possible to a temperature below 7°C. A drawback of the existing method of cooling is that very considerable freezing capacity is required for this purpose (it must be borne in mind here that existing slaughterhouses for large livestock can often process several thousands of animals per hour, wherein the carcasses must be cooled down from a starting temperature of about 40°C). Research by applicant has also shown that, after the standard period of time in the freezer, the temperature on the outside of the carcass can increase once again to above 7°C in the cooling due to egress of heat enclosed in the core of the carcass (part). A further drawback of the existing method of cooling is that the weight of the carcasses (carcass parts) decreases by several percent during the cooling process.

The present invention has for its object to provide a method and apparatus for cooling carcasses (and carcass parts) of slaughtered animals in a quicker and more readily controllable manner, with less energy and less weight loss.

The invention provides for this purpose a method for cooling carcasses and carcass parts of slaughtered animals by applying a liquid mist to the object for cooling and carrying the mist-covered object into a gas flow. By applying a liquid mist and then causing the applied liquid to (at least partly) evaporate, a considerable amount of energy is extracted from the object for cooling, which means that the first phase of the cooling route in

particular can be speeded up considerably compared to the prior art. A more rapid cooling results in an improved hygienic control (inter alia a limited bacteria growth) of the cooling process and less discolouring of chopped bone parts.

The gas flow preferably has a lower temperature than the object for cooling. It has however been found possible to achieve good cooling results (at least comparable to the cooling results according to the prior art) with a gas flow, the temperature of which at the start of the cooling lies between 15 and 35°C, preferably between 20 and 30°C, such as for instance 25°C. This is very surprising since such a temperature of the gas flow is considerably higher than the temperature of the freezers applied according to the prior art. It will be apparent that this has a significant effect on the energy required for cooling of the carcasses or carcass parts. The present invention therefore enables a very significant reduction in the energy required for cooling. This is extremely advantageous from a commercial and environmental viewpoint. In addition, the cooling installations and processing areas (the freezer area respectively the processing area required according to the present invention) can also take a considerably lighter, simpler and less expensive form. Examples hereof are lighter floors, less insulating material, fewer cooling compressors and so on. Account must also be taken here of the reduction in the capacity for holding carcasses and carcass parts when passage through the cooling route is more rapid. It is expected that a desired cooling result can be obtained within 15 to 18 hours using the method according to the invention. It is further noted that excessively large temperature differences between the carcass (carcass part) for cooling and the gas flow must be avoided. Tests have shown that the advantages of the present invention are hereby partly nullified. The required cooling time thus increases for instance when a colder gas flow (for instance-10°C) is used immediately. Air will normally be used as cooling gas.

Yet another advantage of the present invention deemed particularly relevant is that the carcasses and carcass parts for cooling display considerably less weight reduction (weight loss) during the cooling. A weight reduction of carcasses from the initial weight of about 2%, and up to more than 3. 5% in specific conditions, is usual during the first 24 hours of cooling. With the present invention weight reduction can be decreased to anticipated values lying between 0.7 and 1.0% of the initial weight. This is also of great importance commercially.

Owing to the method of cooling according to the invention the quality of the meat is also enhanced. Not placing the carcass (carcass part) in the freezing cold prevents the muscles in the carcass from contracting (thought to be a reaction in particular of the unburnt blood sugars in the case of excessively rapid cooling), which enhances the tenderness of the meat. This can be compared to slaughtering and cooling in traditional manner in atmospheric conditions wherein the meat also remained more tender than in present-day slaughtering techniques. Tests have also shown that the heat is extracted more uniformly from the whole carcass instead of the relatively warm core and a cold outer layer which occur in cooling according to the described prior art. Another advantage of the proposed cooling method is that the colour of the carcass (carcass part) is hereby better preserved than heretofore.

In order to apply the liquid mist to the carcass (carcass part) it is desirable that, during application of the liquid mist to the object for cooling, the object is situated in an environment with a small gas flow. As liquid use can be made of water, for instance softened water. It is however also conceivable for additives to be added to the water or for another liquid to be used for atomizing.

Since the cooling process requires that the atomizing and subsequent placing of the. carcass (carcass part) in a gas flow is repeated many times, the objects for cooling can be carried through a plurality of successive compartments substantially separated from each other, in which a similar treatment of the carcass takes place each time. Cooling can thus take place in a continuous product flow, which makes it easier to mechanize the cooling method according to the present invention on a large scale. It is herein found to be advantageous that the objects for cooling are treated in successive cooling phases with gas flows which become increasingly colder.

Favourable results can be achieved using gas flows which lie at the start of cooling between 15 and 35°C, preferably between 20 and 30°C (for instance 25°C) and which decrease to about 0°C at the end of the cooling process. At the start of cooling the speed of the gas flow lies between 5 and 10 m/s (for instance 8 m/s) and may decrease in a later phase of cooling preferably to between 3 and 7 m/s (for instance 5 m/s).

The invention also provides an apparatus for cooling of carcasses and carcass parts of slaughtered animals, comprising: holders for carrying the objects for cooling, mist- generating means and gas flow-generating means. Such an apparatus can be manufactured relatively easily and can connect without great problems onto the transporting systems for carcasses and carcass parts already present in slaughterhouses.

The holders can thus be formed by existing spreaders which are displaceable along a guide and from which carcasses and carcass parts can be suspended.

The transport path is preferably enclosed by a housing and the transport route preferably passes through a plurality of cooling compartments substantially separated from each other, so that the local processing conditions can be optimized. The mist-generating means can be realized in simple manner by applying spray nozzles connected to a water supply. Particularly when a liquid supply is combined with blow air (or optionally even compressed air), good results are achieved in practice with atomizing. Another additional advantage of a combination of liquid supply and blow air (compressed air) is that a low-pressure liquid supply can suffice, so that special measures for this purpose become unnecessary; a normal water conduit can suffice. The gas flow-generating means can be formed by fans and preferably comprise a cooling for cooling the gas flow to be generated. For further advantages of the apparatus according to the invention reference is made to the foregoing description of the present method.

It is stated explicitly that the cooling device excluding the holders for carrying the objects for cooling (including the transporting means for such holders) individually also forms part of the present invention.

The invention will be further elucidated on the basis of the non-limitative embodiments shown in the following figures. Herein: Figure 1 shows a view of a cross-section through a cooling tunnel in which the cooling means according to the present invention are disposed, and Figure 2 shows a view of a detail of cooling means according to the present invention.

Figure 1 shows a cooling tunnel 1 in which are arranged four parallel guides 2 for carcasses 3 of slaughtered animals. These are here carcasses 3 of pigs but they could also be carcasses of for instance other large livestock such as cattle or poultry. Tunnel 1

can of course also be embodied with a single guide 2 or with other than four guides 2. In order to realize a sufficiently long cooling route, the tunnel will usually have a length of several hundreds of metres and, due to the generally limited availability of space, can be constructed as a winding configuration.

Spreaders 4 are displaceable along guides 2 (by means of transporting chains which are not shown). The carcasses 3 (in this case in opened state) are suspended from spreaders 4. Through a network of pipes 5 liquid is supplied to atomizers (or spray nozzles) 6. The atomized liquid is carried to carcasses 3 by means of spraying patterns 7, shown schematically by broken lines, such that mist is applied to the carcasses on all sides. The atomizers 6 at lower positions make a particular contribution here toward atomizing the inside of carcasses 3.

Above guides 2 are disposed cooling means 8 as well as a fan 9 for generating air flow.

Although this is not apparent from the view in this figure, it is recommended that cooling means 8 and fan 9 lie at a distance from (in the direction of transport for instance behind) atomizers 6. This is to prevent the mist not reaching carcasses 3 but already being blown away before the mist reaches carcass 3. This will be further discussed with reference to figure 2. It is also noted that groups of atomizers 6 are disposed at a number of locations (in practice usually dozens of positions) in the transporting direction, these atomizers being alternated with cooling means 8 and fans 9 for successively atomizing carcasses 3 and causing the produced mist to evaporate.

For guiding of the gas flow along carcasses 3 a vertical partition 10 is placed between the two middle carcasses 3, so that the gas flow is urged below the partition 10 as according to arrow Pl, whereafter the gas flow returns as according to arrow P2 through cooling means 8 to fan 9 (see also arrow P3) for renewed circulation. The heat discharged by means of cooling means 8 can optionally be employed elsewhere for heating purposes.

Adjacently of fan 9 is also arranged a walkway 11 for the purpose of supporting for instance maintenance staff.

The pipe network 5 and atomizers 6 are shown in more detail in figure 2. This figure is appended in particular to show partitions 12 with which more or less mutually separated compartments are created in the transporting direction. The compartments limit the gas flow in the transporting direction, whereby both atomizing and evaporation of the applied mist can take place in more controlled manner. Successive atomizing and gas flow compartments can thus for instance be created, or successive combined compartments in which both atomizing and gas flow take place (in general substantially at a distance from each other).