Method for packaging non-liquid food products, in particular those sensitive to oxygen, in a container with a low oxygen content

A method for packaging non-liquid food products, particularly those sensitive to oxygen, such as vegetables, in a container with a low oxygen content, the container including an opening. The method includes the following steps: the container is filled with the products, in a non-controlled atmosphere; the air is removed from the container by filling same to capacity with a liquid; the full container is placed in a non-oxidizing atmosphere formed by at least one non-oxidizing gas; the liquid is fully or partially emptied from the container in a non-oxidizing atmosphere while the food products are kept in the container, such that the at least one non-oxidizing gas replaces the liquid in the container; and the above-mentioned container opening is closed in a gas-tight manner in a non-oxidizing atmosphere. A unit for carrying out the method is also described.

FIELD OF THE INVENTION

This invention relates to a method for packaging non-liquid food products, such as in particular vegetables, in particular those sensitive to oxygen, in a container with a low oxygen content.

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

BACKGROUND OF THE INVENTION

In order to preserve non-liquid food products (i.e.; vegetables or pieces of meat), sensitive to oxygen, it is known to package said food products in a packaging with a low oxygen content.

In the case of packaging that is substantially dimensionally stable, such as for example metal tins filled in limited juice, the reduction in the oxygen content is obtained primarily by placing the metal tin in a vacuum. Possibly, a non-oxidising gas (i.e. N2) sweeps the products in order to remove the residual oxygen.

The tin is then closed with a lid which is crimped in a vacuum. In order to substantially reduce the quantity of oxygen, this method requires machine speeds that are relatively low, much less than conventional industrial speeds (400 cpm).

Another disadvantage of this method resides in the fact that the packaging must be sufficiently resistant to mechanically resist a vacuum. In the case of metal tins, it is as such required to provide tin thicknesses at least equal to 0.18 mm in order to prevent said tin from imploding. Another disadvantage of this method is the difficulty in obtaining residual oxygen contents that can be reproduced.

For the case of a packaging (metal tin) with limited headspace, i.e. comprising a low volume of air in the vicinity of the opening because it is practically entirely filled with a juice, another method of inerting consists in blowing a non-oxidising gas (i.e. N2) on said headspace, and simultaneously closing and crimping the lid. This method however consumes a substantial amount of non-oxidising gas and is therefore expensive.

SUMMARY OF THE INVENTION

The purpose of this invention is to overcome these aforementioned disadvantages by proposing a method for packaging products, in particular non-liquid food products, such as for example vegetables, in particular those sensitive to oxygen, in a container with a low oxygen content, which allows for high production speeds and which does not require expensive packaging in order to be carried out.

Another purpose of the invention is to propose a method making it possible to obtain a substantial reduction in the oxygen content in the packaging.

Another purpose of the invention is to propose a method that can be carried out in a unit by limiting industrial investments, and/or which results in the production of a thinner container.

As such, the invention relates to a method for packaging products, such as for example food products, in particular those sensitive to oxygen, non-liquid, such as for example vegetables or meat in pieces, in a container with a low oxygen content, said container having an opening.

According to the invention, the method comprises the following steps:the container is filled with the products, in a non-controlled atmosphere (ambient atmosphere),the air is removed from the container by filling same to capacity with a liquid,the full container is placed in a non-oxidising atmosphere formed by at least one non-oxidising gas,the liquid is fully or partially emptied from the container in a non-oxidising atmosphere while said products are kept in said container is such a way that said at least one non-oxidising gas replaces said liquid in said container.said opening of the container is closed in a gas-tight manner in a non-oxidising atmosphere.

According to an embodiment, said filling liquid is degassed, prior to said step of filling of the container with said liquid.

According to an embodiment, the method comprises the following steps:the container is filled with the products in a non-controlled atmosphere,the air is removed from the container by filling same to capacity with a liquid,the full container is placed in a non-oxidising atmosphere formed by at least one non-oxidising gas.the liquid is fully or partially emptied from the container in a non-oxidising atmosphere while said food products are kept in said container in such a way that said at least one non-oxidising gas replaces said liquid in said container,said container is filled with a final liquid, in particular food juice, in a non-oxidising atmosphere, partially,said opening of the container is closed in a gas-tight manner in a non-oxidising atmosphere.

According to an embodiment, the method can be carried out on a continuous production line comprising a chamber, in particular a tunnel in a non-oxidising atmosphere, filled with at least one non-oxidising gas, said chamber provided with conveying allowing for the forward motion of said containers continuously. The step of emptying of said liquid is carried out by means of a container turnover device, internal to the chamber provided with means, such as a punched wall, making it possible to keep the non-liquid food products in said container during the turning over.

According to an embodiment, the containers are metal tins.

According to an embodiment, metal tins have a wall thickness less than or equal to 0.15 mm, for example 0.12 mm.

According to an embodiment, the step of closing the container can be carried out at least by the placing of a lid. The method can further provide a step wherein the lid of the metal tin is crimped (in a non-oxidising atmosphere, or in a non-controlled atmosphere).

According to an embodiment, the products to be packaged are food products (i.e. pieces of vegetables, meat). In this case, said final liquid is a food juice (salted water, sauce, etc.).

The invention also relates to a unit for the packaging of products, non-liquid food products in particular, in particular sensitive to oxygen, in a container with a low oxygen content, on a continuous production line, said container having an opening, said unit comprising, according to the direction of forward movement of the containers, successively:means for filling said containers to capacity with a liquid in a non-controlled atmosphere,a chamber in a non-oxidising atmosphere, filled with a non-oxidising gas, said chamber being provided with means of conveying that allow for the forward movement of the containers continuously, receiving a container turnover device, internal to said chamber making it possible to empty the liquid from said containers, provided with means making it possible to keep the non-liquid products in said container during the turning over,a device for closing in a gas-tight manner the opening of said container.

The method and the unit in accordance with the invention will find particular application for the packaging of food products such as vegetables, meat or others, in dimensionally stable tins, in particular made of metal.

The invention is not limited to the packaging of food products and can have an application for the packaging of any other product that is sensitive to oxygen.

DETAILED DESCRIPTION OF THE INVENTION

As such, the invention relates to a method for packaging in particular non-liquid food products, such as for example pieces of vegetables; pieces of meat, or others, in particular those sensitive to oxygen in a container with a low oxygen content. The method can make it possible to obtain a concentration of oxygen in the packaging less than or equal to 12 ppm, even less than 6 ppm.

The container1has an opening2for its filling.

The method, in accordance with the invention, comprises the following steps:the container1is filled with the products, in particular food products in a non-controlled atmosphere (not shown),the air is removed from the container by filling same to capacity with a liquid3,the full container1is placed in a non-oxidising atmosphere4, formed by at least one non-oxidising gas5,the liquid3is fully or partially emptied from the container1in a non-oxidising atmosphere4while said products in particular food products are kept in said container in such a way that said at least one non-oxidising gas5replaces said liquid3in said container,said opening2of the container1is closed in a gas-tight manner in a non-oxidising atmosphere4.

“Filling to capacity” means the complete or almost complete filling of the internal volume of said container with said products and said liquid. This is in opposition to filling “in limited juice”, wherein the internal volume of said container filled with said products is not fully filled with liquid, with interstices remaining between the products.

According to an embodiment, the containers1can be metal tins that can have a wall thickness less than or equal to 0.15 mm, for example 0.12 mm.

The non-oxidising atmosphere can be N2, CO2or another non-oxidising gas, or a mixture of these gases.

According to an embodiment, the filling liquid3utilised to remove the air from the container, via filling to capacity, can be degassed beforehand. The liquid3can be, for example, water.

According to an embodiment, the method can further have an additional step wherein the container is filled with a final liquid, in particular food juice in a non-oxidising atmosphere; the method then comprises the following steps:the container is filled with the products, in particular food products in a non-controlled atmosphere,the air is removed from the container1by filling same to capacity with a liquid3,the full container1is placed in a non-oxidising atmosphere4, formed by at least one non-oxidising gas,the liquid is fully or partially emptied from the container in a non-oxidising atmosphere, while said products in particular food products are kept in said container, in such a way that said at least one non-oxidising gas replaces the liquid in said container1,said container is filled with a final liquid6in particular a food juice such as a sauce, in a non-oxidising atmosphere, partially,said opening of the container is closed in a gas-tight manner in a non-oxidising atmosphere.

Advantageously, the method, in accordance with the invention, can be carried out on a continuous production line, comprising a chamber11, such as a tunnel, in a non-oxidising atmosphere4, filled with said at least one non-oxidising gas5. This chamber11is provided with means of conveying allowing for the forward movement of the containers continuously.

The step of emptying the liquid3can be advantageously carried out continuously, by means of a container turnover device12, internal to the tunnel11. The device12can include according to an embodiment guides intended to engage with said containers1, during the forward movement of said containers, in such a way as to turn said container around a traverse axis of said container by imposing a spiral trajectory of said containers. Furthermore, means make it possible to keep the non-liquid food products in the container1during the turning over.

Such a device for turning over12is known per se in prior art, usually referred to as a “tippling belt conveyor” by those skilled in the art. Document EP-0.070.195 is an example of this.

The means14making it possible to maintain the products, in particular non-liquid food products, during the turning over in said container1, can be comprised of a punched wall of the device whereon will be thrust the opening2of the container when it is turned over. Alternatively, these means can be comprised of a punched lid44, temporary, placed upstream of the device for turning over12, then removed downstream of this device for turning over12(seeFIG. 1).

Other devices for turning over can be considered. For example, the device for turning over can include individual container holders70, each intended to maintain one container.

A mechanism including in particular a cam and a cam follower or an actuator can make it possible to control the turning over of each of the container holders70, then to reposition each of the containers with the opening upwards.

For example, each container holder70can, according to the examples inFIGS. 3 and 4, include a clamp with a first jaw71and a second jaw72.

The container holder70grasps a container by bringing the jaws71,72close to one another, while the container is resting on the lower jaw (second jaw72such as shown inFIG. 3).

The upper jaw (first jaw71) then comes to but against the container1, covering the opening2of the container1.

Once grasped, a mechanism allows for the joint turning over of the holder70and of its container1, in particular around a pivoting axis73of the holder70, in order to empty the liquid from the container.

Advantageously, the first jaw71comprises a punched wall, covering the opening2which makes it possible to keep the non-liquid products in the container (FIG. 4).

The step of closing the opening2of the container1can be carried out at least by the setting into place of a lid15; in a non-oxidising atmosphere. The method can further provide a step wherein the lid15is crimped to said metal tin. This step of crimping can be carried out either in a non-oxidising atmosphere, or in a non-controlled atmosphere.

The invention also relates to a unit10for the packaging of non-liquid food products, in particular those sensitive to oxygen in a container1with a low oxygen content, on a continuous production line.

The container1has an opening2and can be a metal tin, such as described hereinabove.

Said unit10comprises, according to the direction of forward movement of the containers1, successively:means for filling20said containers to capacity with a liquid3in a non-controlled atmosphere,a chamber, such as a tunnel, in a non-oxidising atmosphere, filled with a non-oxidising gas5,a device50,60for closing in a gas-tight manner the opening2of said container1(not shown).

Said chamber11is provided with means of conveying allowing for the forward movement of said containers1, continuously, and receives a container turnover device12, internal to said tunnel making it possible to empty the liquid3from said containers, and means making it possible to keep the non-liquid food products in said container during the turning over. The device12can include guides intended to mesh with said containers during the forward movement in such a way as to turn the container around a traverse axis of said container by imposing a spiral trajectory of said containers. Alternatively, the device can implement the previously described container holders70.

Such as shown according to the example inFIG. 1, the containers1, in particular metal tins, can be conveyed on the production line one right after the other, in line. The forward movement of the containers is obtained by the containers coming to abut against one another, with one upstream container pushing one downstream container.

The means for filling20can be comprised of a ramp for the supply of liquid provided with several nozzles supplying the containers with liquid. In this zone, the containers2are positioned upright, the opening of the container at the upper portion.

After filling, the containers enter into one of the ends21of the chamber11(tunnel) which can include an airlock which provides a certain degree of tightness between the non-oxidising atmosphere inside the tunnel and the outside atmosphere (ambient air). The containers1exit this tunnel at the other end30of the chamber11by the intermediary in particular of an airlock intended to provide a certain degree of tightness between the internal atmosphere of the tunnel and the outside atmosphere.

The interior volume of the chamber is kept in a non-oxidising atmosphere4kept in a slight overpressure by the intermediary of means of nozzles40, with non-oxidising gas5.

The container turnover device12is provided internal to the chamber11. This device12comprises, according to the example inFIG. 1, guides intended to engage with the container during the forward movement of said containers in such a way as to turn said container around a traverse axis of said container by imposing a spiral trajectory of said containers as such making it possible to empty said container.

Such as shown, the containers1enter one end of the device12(shown as a dotted line) upright, with the opening of the container oriented upwards (indicated by the arrow), then are turned over in order to empty the container fully or partially.

They are reoriented by the device12so that the opening2of the container is oriented upwards at the exit. Possibly, container1can pass through an intermediary position, turned to 180°, such as is shown inFIG. 1.

The means making it possible to keep the non-liquid food products in the container1, during the turning over, can be comprised of a punched lid14, which is placed on the opening of the container2, before it enters the device12, then removed at the exit of the device12such as shown inFIG. 1.

Alternatively, these means can be comprised of a punched wall of the device12whereon will be thrust the opening2of the container when it is turned over.

A drain17can be provided, in alignment, under the device12for the recovery and the drainage of liquids escaping from said device12.

The unit10can further have, such as is shown inFIG. 1, means for supplying16a final liquid6, such as a food juice inside the chamber11. These means of supplying16include means for metering and make it possible to partially fill the containers with a food juice6, such as for example a sauce.

Finally, a device60can allow for the placing of a lid15on the opening2of the container1, in order to keep the non-oxidising gas in place in the container1. An atmospheric crimping50, even a crimping machine under pressure of a non-oxidising gas internal to the chamber11, can make it possible to successively attach the lid to said tin.

Note that the applicant filed on the same day a patent application for a method of packaging products in particular food sensitive to oxygen, specially intended for liquid products and which also comprises for general principle to fill to capacity the container in order to remove the air from the container, to place the container in a non-oxidising atmosphere, and to empty the liquid from the container, partially, before closing the container in gas-tight manner.

Naturally, other embodiments could have been considered par those skilled in the art, without however leaving the scope of the invention defined by the claims hereinafter.