The present invention relates to a method for cooling of foodstuffs, especially fish, where a cooling medium is brought into contact with the foodstuff.

The invention also relates to a means for carrying out the method.

Fish which is to be sold fresh must be kept refrigerated for the quality to be retained as much as possible. The most usual is to employ ice for the chilling.

The fish is placed together with ice in more or less insulating packaging. Boxes of expanded plastic, for example of"Isopor"are extensively employed as packaging.

It is also possible to place ice loosely in the abdominal cavity of the fish after gutting, as is known for example from GB 2 232 575A.

Something which creates a significant problem with the afore-mentioned solution is that the ice melts to a greater or lesser degree during transportation, depending on the ambient temperature, the distance of transportation, the insulating ability of the packaging etc.. Considerable quantities of melting water can be formed thereby. The result is that packaging of water-resistant material must be employed, usually of plastic as mentioned above. The

melting water will readily mix with blood from the fish and form a fluid which contaminates the packaging and makes it difficult to reuse the latter. Moreover this blood- containing melting water can have a negative influence on the quality of the fish.

There is thus a need for solutions which should at best eliminate, but at least reduce, the afore-mentioned problems, and the object of the present invention is to provide a method and a means for achieving the object.

The object is achieved by means of the characterising features of claim 1 and claim 5 respectively.

Preferred embodiments are evident from the dependent method and means claims.

Various solids and liquids can be employed as cooling mediums according to the invention. By way of the means running away of the solid, after melting, or the liquid is prevented.

However for various reasons ice will be the preferred cooling medium. It is relatively non-expensive, and its melting point is favourable for cooling foodstuffs, both when it is produced from fresh water and when it is produced from salt water. By employing salt water the freezing point becomes lower and the fish is chilled to a lower temperature, something which causes less growth of bacteria.

The invention will require less cooling medium than in the known solution where the cooling medium is placed between the individual fishes. In that way the transportation can be more reasonable or there is space for more fish.

To date the invention is considered to be most prominent for the cooling of fish. However one sees that also poultry, such as fowls and chicken, can be cooled according to the invention. The invention is however not limited to these foodstuffs since the most important thing

is that the cooling medium is placed in a means which prevents it from flowing away in liquid form.

In what follows mention of the invention will be concentrated on the cooling of fish.

On cooling fish the means is placed in the form of an ice-containing bag in the abdominal cavity of the fish after gutting. The bag is preferably made of plastic material. Water can be poured into the bag which thereafter is refrigerated so that the water freezes to ice. It is thereby important that the bag has a form and size which fits as well as possible into the abdomen and conforms to the flesh of the fish so that the cooling will be as effective as possible.

It is important on cooling fish that the fish flesh is not chilled to such low temperatures that the cells of the fish flesh are split and the quality of the fish is diminished. Freezing of the water in the bag shall therefore not take place at too low a temperature.

When water is frozen in the means in the form of a bag there is thus obtained an oblong"ice block"which is placed in the abdomen of the fish. This way of doing it brings about the advantage that the whole bag is filled with ice. It has however the disadvantage that the block is shapeless and therefore does not always conform totally to the abdomen of the fish.

It is therefore also of interest to put pieces of ice or spheres of ice into the bag which is thereafter placed in the fish abdomen. The pieces of ice will to a greater or lesser degree be moveable relative to each other, and the bag will therefore conform more easily to the fish.

When the means is placed in the abdomen of the ready gutted fish which is placed in one or other form of box the ice will melt, and melting water is formed. This is present in the bag and consequently does not flow out of the box which the fish lies in. This will make it possible to employ boxes of other material than that which is usual to-

day, for example boxes of pasteboard or cardboard, which are easier to recover/destroy than boxes of expanded plastic.

It is important that the ice cools the fish as effectively as possible. The bag shall therefore insulate the fish flesh as little as possible. On the other hand it is desirable that melting which does not contribute to the cooling of the fish is reduced. The bag can therefore be equipped with insulation around portions of its surface, which face towards the abdomen side of the fish whereby there is obtained a controlling of the cooling effect in the desired direction, that is to say towards the flesh side of the fish. Such a design of the bag will be the most usual and be especially important on transportation over long distances and in regions with higher ambient tempera- tures.

If there is space in the box it could also be of interest to place such bags between the individual fishes.

Both for fish and poultry it could be of interest to vacuum pack each carcass individually after the cooling means is placed in the carcass. On vacuum packing there can be employed if desired a modified atmosphere. The vacuum packing can contribute to maintaining the cooling means in place and make the handling of the fish more hygienic.

The invention will be explained further in what follows having with reference to the accompanying drawing, wherein: Fig. 1 shows a schematic view of a gutted fish and the introduction of a means according to the invention.

Fig. 2 shows a cross-section through a fish with the means according to the invention introduced.

Fig. 1 shows a fish 1. This is head cut off and gutted, and the tail removed. A bag 2 of plastic filled with ice, either in the form of a block or pieces or spheres, is in the act of being introduced into the

abdominal cavity of the fish 1 where it will bring about cooling of the fish.

Fig. 2 shows a cross-section through the fish 1 with the bag 2 placed in the abdominal cavity. Towards the flesh of the fish, that is to say upwards in Fig. 2, the bag consists of relatively thin plastic material, which is water-tight, but relatively inferior as a heat insulator and thereby cools the fish flesh. Towards the abdominal side of the fish the bag 2 has however an insulation 3.

This causes especially the portions of the bag where the cooling effect is of less significance, but where it is important that the ice melts the least possible, to be insulated towards the surroundings and thereby maintains the ice to a lesser or greater degree intact without melting.