The invention relates to a food packaging tray. The food of concern may be, fresh or frozen, meat, poultry, fish, fruit and vegetables.

It is already known, for extending the shelf life, to package perishable food in a modified gaseous environment, in taking the air out of the tray, prior to injecting the modified atmosphere and closing the tray hermetically. This is of a particular interest for fluid-exuding and oxygen sensitive food.

Accordingly, trays are known, which are divided into a food chamber, where the food is received on a support, and

a liquid chamber, where the exuding fluid is received.

Preferably, the food support is a partition wall dividing the tray into the two chambers and it is perforated so that the modified atmosphere may diffuse in both chambers and, hence, circulate around the food, envelop the food. The gas mixture can come into direct contact with the underside of the food product. EP 2 540 634 teaches such a tray.

In the tray of this prior art reference, the perforated partition support is surrounded by a circular opening through which the fluid exuding from the food may flow into the fluid chamber. For that reason, it has been often proposed to cover the bottom of the fluid chamber with an absorbing layer (absorbent), as taught for instance in US 6152295.

However, the absorbent material is full of air (or gas) and, little by little, this air is coming out of the absorbing layer and modifies the modified atmosphere which is thus polluted, with the drawback of reducing the shelf life of the product.

The invention of the instant case aims at obviating such a drawback. To this end, the invention relates to a closed food packaging tray, for fluid-exuding and oxygen sensitive food, comprising

• a food chamber,

• a liquid chamber,

• a perforated partition between the two chambers, arranged for supporting the food,

• the tray, for extending the shelf life of the food, being filled up with modified atmosphere enveloping the food thanks to the perforations of the perforated partition,

characterized in that

• the perforated food supporting partition obturates both chambers, and

• the liquid chamber is empty of gas releasing material.

The liquid chamber of the tray of the instant case may even be empty of solid material. The tray of the instant case has two major advantages.

The first one is the fact that there is no absorbent in the liquid chamber and, therefore, the modified atmosphere will not be modified or polluted by air. Furthermore, since there is no absorbent, there is no risk that the absorbing layer and the perforated food supporting partition come in direct contact with each other, thus no risk that i) the absorbing layer, through the perforations of the partition, sucks out liquid from the food product and ii) the modified atmosphere does not circulate around the food product anymore.

The second advantage is the fact that the exuding fluid cannot flow around the perforated partition but only through its perforations. The flow is very slow and in both ways either from the food chamber to the fluid chamber or, after having inadvertently turned the tray upside down, from the liquid chamber back to the food chamber. In the preferred embodiment of the invention, the perforated partition is a permeable film, advantageously a moisture permeable film. The permeable film has a liquid communication between the two food and liquid chambers and may also have micro- perforations used for gas circulation only and too small for liquid circulation. The bottom of the liquid chamber may have a capillary honeycomb structure.

Advantageously, in the tray of the instant application, the food supporting partition is supported by a shelf provided on the inner wall of the tray and, more advantageously, also on pillars having an height, from the bottom of the liquid chamber, such that their free ends and the top surface of the shelf lay in a common plane parallel to the bottom of the liquid chamber. By top surface of the shelf is meant the surface supporting the supporting partition.

The invention shall be better understood upon reading the following description while reverting to the attached drawing in which - figure 1 is a perspective top view of the tray of the invention;

figure 2 is a simplified cross-sectional view of the tray of figure 1;

figure 3 is a top view, at a larger scale, of a portion of the bottom of the liquid chamber of the tray of figure 1 and

figure 4 is a simplified view of the perforated food supporting partition of the tray of figure 1.

Referring to figures 1, 2, the packaging tray of the instant case has a generally parallelepipedic shape with an outer side wall 1, and a bottom 2. In a plane generally parallel to the bottom 2, the side wall 1 is extended by a rather thin top border 3, except that the four corners where it is slightly larger. A transparent plastic sheet 4 is secured onto the border 3 for covering and closing the tray. The inner surface 5 of the sidewall 1 is provided with a shelf 6 for supporting a perforated food supporting partition 7, dividing the tray into a food chamber 8 and a liquid chamber 9 (figure 2).

The height of the partition 7 above the bottom 2 is small, compared to the height of the closing sheet 4 above the partition 7.

The perforated food supporting partition 7 obturates both chambers 8, 9.

The liquid chamber 9 is empty of absorbant material. Actually, the chamber is empty of gas releasing material; it could be just empty of air or oxygen releasing material.

The bottom 2 of the tray has here a capillary structure 10, here a honeycomb structure, as shown on figure 3, with, here, hexagonal recesses 16.

Pillars 11 are provided on the bottom 2, of an height such that their free ends 12 lie here in the same plane as the top annular surface 13 of the shelf 6 forming a shoulder supporting the partition 7.

In the instant case, the perforated partition is a permeable film 7, which could be preferably a moisture permeable film.

The tray as described above will be used as follows.

The permeable film 7 having been secured onto the annular shoulder 13 of the shelf 6 and a food product 14 - here a piece of meat - having been put on the film 7, the air is taken out of the tray and a modified atmosphere is injected therein prior to closing the tray on top of the food chamber 8 by the plastic sheet 4 secured onto the top boarder 3. Thanks to the invention and particularly to the perforations of the film 7, the modified atmosphere may diffuse in both chambers 8, 9 and circulate around the piece of meat 14. The fluid chamber 9 being empty of solid material, the modified atmosphere is not polluted.

The film 7 obturating both chambers 8, 9, in case of the piece of meat exuding fluid (blood) which can thus flow through the perforations of the film 7, exclusively, the flow is very slow and there is very little liquid which can flow to the liquid chamber. And if the tray has been turned upside down, the fluid in the liquid chamber 9 can hardly return to the food chamber 8.

In the instant case, the perforations 15 of the film 7 are designed for liquid circulation. Some of the perforations could be micro-perforations used for gas circulation only and too small for liquid circulation. In any case, the film 7 should be designed for the modified atmosphere to be able to envelop the piece of food 14 and be in contact with the underside of the food product.