MXPA97003262A - Method and apparatus for desoxigenating food products and packaging for food desoxigen - Google Patents

Abstract

The present invention relates to a method for deoxygenating a food product and packaging it, comprising: providing one or more products capable of being packaged individually or in groups as non-flowing products, supplying one or more products to an evacuation chamber, applying vacuum to the chamber to deoxygenate the chamber and the product or products, inject protective gas into the chamber to replace at least part of the oxygen evacuated from the product and the chamber with a protective gas, and transfer the product to a separate packing unit. the evacuation chamber and pack it into a substantial flexible package

Description

METHOD AND APPARATUS FOR DESOXIGENATING FOODSTUFFS AND PACKAGING FOR DEXIOGENATED FOOD DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for deoxygenating a food product and packaging it. The apparatus and method according to the invention are particularly suitable for deoxygenating and wrapping, through flow, oxygen sensitive products such as bulk products, bent food products or products of complex structure wrapped with air. The invention also relates to a package for a deoxygenated food. For the storage of food products sealed in packages, the oxygen level in the package can be determinant for the life of the product. This is especially the case for oxygen sensitive products, such as uncooked or fresh dough products, meat products, etc. Therefore, the release of oxygen in the package reduces the life of the product. Oxygen release can usually be observed through package inflation. To reduce oxygen within a package, it is known to flood the package with gas containing the product before sealing it. When packaging powdered products it is known to flood the product with gas immediately before packing. In this way, the atmosphere in the upper space above and around the product is replaced with a suitable gas such as nitrogen and carbon dioxide. This type of replacement of the atmosphere in a food package containing a product, however, has the disadvantage that the oxygen in the product will develop a few hours after the packaging of the product with the undesirable effect of oxygen, as discussed below. previous. This problem is substantial when mass-based products are packaged as a result of the level of oxygen content in the product and the release thereof. Foodstuffs of complicated structure or bent products that encapsulate air cavities also give additional oxygen in the package. The prior art packing machines are intended to reduce the level of oxygen in the package by subjecting the package containing the product to a vacuum possibly followed by subsequent flooding of the package and the product with a suitable gas. For example, the evacuation of the atmosphere from bags containing products can be presented in a wrapping machine by flow before sealing the bags. In a wrapping machine by means of flow, the bags are configured around a mandrel from a sheet rail and welded to bags. Due to the evacuation of the atmosphere, the bag is sucked close to the product and creates a "vacuum" package of the product. The evacuation of each package reduces the packing capacity of the machine, considerably, and therefore, it is only used for larger items, for example, steaks. This packing method has therefore been considered unsuitable for many purposes, due to the relatively low capacity of a maximum of 8 to 10 packing cycles / minute. The evacuation principle is also used in thermoconfiguration packing machines, such as a Multivac ™, where trays are formed from a lower plastic sheet. The trays are filled with food products and then the atmosphere is evacuated around the tray with the product therein. Immediately after the evacuation, the tray and the food product are flooded with a gas and an upper plastic sheet seals the tray. The type of Multivac ™ packaging requires large amounts of packaging material. For example, the thickness of the packaging base material of the Multivac ™ is approximately 500 μm, while the sheet used for the wrapping packaging by flow is approximately 80 μm. Accordingly, it is an object of the present invention to provide a high speed method and an apparatus for packaging food products., especially food products sensitive to oxygen and food products with a high oxygen content. In this way, one embodiment of the present invention relates to a method of wrapping by flow and an apparatus, which can be operated at an average speed of 80 packing cycles / minute. The method and apparatus provide packages with a low oxygen content and allow a reduction in the amount of packaging material used. Advantageously, the method and the apparatus according to the invention can also be used for products of a complex structure or folded or rolled products, which can encapsulate air pockets. In addition, the present invention provides a deoxygenated food package, which can be easily opened. Accordingly, the present invention relates to a method for deoxygenating a food product and packaging it, which comprises: supplying one or more products to an evacuation chamber, evacuating oxygen from the chamber to deoxygenate the chamber and the product or products, injecting protective gas in the chamber to replace at least part of the oxygen evacuated from the product and the chamber with protective gas, and transfer the products to a packing unit and seal them in a package. The present invention provides a method for packaging food products, which makes the capacity of the packing unit independent of the capacity of the deoxygenation process. Accordingly, it is possible, according to the invention, to supply deoxygenated products to the baler unit at a speed that matches the speed of the packing cycles of the baler unit. This separate deoxygenation process allows oxygen-sensitive products to be packaged in high-speed packing machines such as a flow wrapper packing machine which generally has about 80 packing cycles / minute. Consequently, it is preferable that the products are delivered to the evacuation chamber in batches of products, and the batch is transferred to the packing unit, while the products are packed individually or in groups, while the remaining part of the batch is left out. of the packing unit. This can be done conveniently, so that the transfer of products to the packing unit is such that the introduction of the products individually or in groups, coincides with the packing cycles of the packing unit. In the context of the present, a protective gas is an inert gas, nitrogen and carbon dioxide, being the most common. The proper evacuation will depend on the product structure that is going to be packed. For mass products, evacuation or vacuum treatment from 70 to 80% (evacuation to 100% being vacuum) is appropriate, preferably approximately 75%. For meat products, such as sliced ham, an evacuation of 90% or more may be desirable. The evacuation of the chamber is conveniently done through a vacuum pump. Furthermore, according to the invention, it has been surprisingly obtained that by deoxygenating the product, removing air from it, and subsequently replacing the evacuated oxygen with a protective gas, it is possible to subject such a modified product to a normal atmosphere for a limited period without diffusion of gas and the oxygen level substantially increasing. For example, for fresh or uncooked mass products, a pause time, in the normal atmosphere, may be, for example, from 1 to 4 minutes. Therefore, it is possible to transfer the products in the batch to a packing unit by feeding one or more of the products individually or in groups to the packing unit, while leaving the remaining part of the batch outside the packing unit. For products that have good gas retention capabilities, such as mass-based products, see example below, products can wait while it is their turn to be packed or transferred to the packing unit in the normal atmosphere. For food products where the protective gas tends to diffuse from the product after the final exposure of gas, in order to again leave the place for oxygen at such a high speed that the speed of the packing unit is not sufficient to retain a desired level of deoxygenation of the product, it may be desirable to protect the products with a modified atmosphere while they wait in front of the packing unit or during the transition. Such precautions can be obtained, for example, by passing the products through a funnel with a modified atmosphere. This may be appropriate for products such as compact meat products. In this method, it is preferred that the products, individually or in groups, be inserted into packages having one or more openings, through which protective gas is injected or flooded through the package before it is sealed. Advantageously, this is done in order to substantially replace all the air in the package. In one embodiment of the invention, the product or products are / are packaged in packages having an opening or mouth to receive both the product or products and the protective gas, and through which air can escape into the package. The protective gas can be injected while the product or products is / are introduced to the package. However, it may be advantageous to allow the protective gas to flood through the package until it is sealed. Conveniently, the products are introduced individually or in groups to a tube closed at one end and configured from a reel of sheet material, for example, flexible plastic sheet, which is welded or sealed together along a length of longitudinal seam running in the processing direction. Such packages can be produced in a conventional flow wrapping machine. In such a machine, the products are normally introduced through a mandrel around which the tube is configured. See below for further discussion regarding the apparatus according to the invention. Another method according to the invention relates to the deoxygenation of a food product for packaging.

Such method comprises supplying one or more products to an evacuation chamber, evacuating oxygen from the chamber to deoxygenate and the product or products, injecting protective gas into the chamber to replace at least part of the oxygen evacuated from the product and from the chamber, with protective gas. The products treated according to this method can be stored, for example, in a modified atmosphere in batches and then packaged. In a second aspect, the invention relates to an apparatus for deoxygenating a food product comprising: an evacuation chamber comprising means for evacuating oxygen from the chamber to deoxygenate the chamber and the product or products therein, injection means for injecting protective gas into the chamber to replace at least part of the oxygen evacuated from the chamber and the product or products, conveyor means for transporting the product or products to and from an evacuation chamber, and transferring the products to a packing unit. In a preferred embodiment of the invention, the conveyor means are adapted to advance the batches of product or products to and from the evacuation chamber and transfer the products individually or in groups to the packing unit, while allowing the remaining part of a batch of treated product wait outside the packing machine. This allows a continuous input feed and a high speed packaging of the products, as discussed in the above. The conveyor means and the evacuation chamber can be separate units. However, it is preferred that the apparatus also comprises the packing unit. In a further aspect, the invention relates to a deoxygenated food package comprising a flexible bag comprising a deoxygenated product, wherein at least part of the oxygen in the product has been replaced by protective gas and an upper space comprising a protective gas and where the flexible bag is not sucked into the product. This food packaging overcomes the known difficulties in relation to the opening of products packaged in vacuum due to the packing material that clashes hermetically with the product. The food packaging of the invention allows it to be easily opened and to have access to the food product by simply piercing the bag. As mentioned above, packaging is also desirable from the point of view of cost and environmental considerations. The food package can be manufactured according to the method and apparatus of the invention.

It should be understood that the present invention is not limited to reducing the oxygen level in food packages. The method and apparatus of the invention can also be adapted to delimit the effect of other undesirable gases in food packages. Now, the invention will be described with reference to the accompanying drawings which illustrate a preferred embodiment of the apparatus and method of the invention by way of example only, and wherein: Figure 1 is a schematic illustration of an apparatus according to the invention to perform the method according to the invention, Figure 2 is a schematic illustration of a packing unit by flow. Figure 1 shows an apparatus 10 for deoxygenating a food product and packaging it. The apparatus 10 comprises conveyor means in the form of an inlet feed conveyor 11 for feeding a batch of rolled products 13 into an evacuation chamber 12. In the chamber 12, the air is expelled from the chamber through a source of water. vacuum, not shown in the drawings, which reduces the pressure in the chamber and deoxygenates the chamber 12 and the products 13. The apparatus 10 also comprises injection means for injecting protective gas into the chamber 12. A second conveyor 14 transfers the products coiled 13 from the chamber 12 to a standby position 15, where the products 13 wait until they are transferred to the packing unit. The evacuation of the chamber 12 and the number of products therein, preferably are adjusted so that the products are fed in a continuous flow to the packing unit. A suitable packing unit may be a wrapping unit for flow wrapping as discussed above, such as a unit illustrated in Figure 2. Such packing unit 16 for wrapping by flow may be of the conventional type. At present, a horizontal type machine is illustrated, but vertical packing machines can also be used, if appropriate for the product to be packed. The packing unit 16 for wrapping by flow individually wraps the products supplied by a conveyor 28. The packing unit 16 comprises a mandrel 17, around which a tubular pack 18 having a longitudinal seam 19 is formed, through rotary sealing tools 27 , from a sheet material 21, which is supplied from a spool 20. The tubular pack 18 is closed at both ends 22 and 23 through sealing tools 29 creating seams 24 and 25 running transverse to the seam longitudinal 19.

To flood the package with an appropriate gas before, during or after the "introduction of the product or products therein, the unit for wrapping by means of flow comprises injection means comprising an injection shuttle 26, which injects the protective gas into the packaging 18. The shuttle is projected towards the film tube, above the product and thus, during use, blows gas towards the package 16 and forces the air out in a direction opposite to the injection.An illustration of the invention is given. as a test: A batch of rolled pizza dough products were evacuated to 75%, and then flooded with protective gas: CO2 and N2 50/50, then the products were transferred to the wrapper unit through flow , where they waited outside in the normal atmosphere, one after the other, the rolled-up mass products were packed and sealed while they were flooded with gas with the same protective gas mentioned above. After 24 hours, the upper space in the packages was analyzed. The remaining oxygen value was 0.2%. Similar to rolled, packaged bulk products, which were not subjected to evacuation, comprised oxygen up to 1%. As a comparison, a package comprising fresh dough should not comprise an oxygen value greater than 0.5%, if the package is to be stored and refrigerated for 4 to 5 weeks. It is said that the samples not evacuated provide an unsatisfactory result for the purposes of the present.

Claims (17)

1. A method for deoxygenating a food product and packaging it, characterized in that it comprises: supplying one or more products to an evacuation chamber, evacuating oxygen from the chamber to deoxygenate the chamber and the product or products, injecting a protective gas into the chamber to replace at least part of the oxygen evacuated from the product and the chamber with a protective gas, and transfer the products to a packing unit and seal them in a package.

2. The method in accordance with the claim 1, characterized in that the products are supplied to an evacuation chamber in batches of products, and the batch is transferred to the packing unit, while the products are packed individually or in groups while the remaining part of the batch is allowed to wait outside the packing unit.

3. The method according to claims 1 and 2, characterized in that the transfer of products to the packing unit is such that the introduction of the products individually or in groups coincides with the packing cycles of the packing unit.

4. The method according to any of claims 1 to 3, characterized in that the product or products, during the transfer of the evacuation chamber is / are subjected to the normal atmosphere.

5. The method according to claims 1 and 3, characterized in that the product or products, when transferred from the evacuation chamber, is / are transferred through a modified atmosphere.

6. The method according to any of claims 1 to 5, characterized in that the products, individually or in groups, are inserted into packages having one or more openings through which protective gas is injected before the package is sealed.

7. The method according to claim 6, characterized in that the protective gas replaces substantially all the air in the package.

8. The method according to any of claims 6 and 7, characterized in that the protective gas and the product or products are / are introduced through the same opening in the package.

9. The method according to any of claims 6 to 8, characterized in that the protective gas is injected as the product or products are introduced into the package.

10. The method according to any of claims 1 to 9, characterized in that the products individually or in groups are introduced to a tube closed at one end and configured from a reel of sheet material.

11. A method for deoxygenating a food product for packaging, which comprises supplying one or more products to an evacuation chamber, evacuating oxygen from the chamber to deoxygenate the chamber and the product or products, injecting protective gas into the chamber to replace at least part of the oxygen evacuated from the product and from the chamber with protective gas.

12. An apparatus for deoxygenating a food product characterized in that it comprises: an evacuation chamber comprising means for evacuating oxygen from the chamber to deoxygenate the chamber and the product or products therein, injection means for injecting protective gas to the chamber to replace at least part of the oxygen evacuated from the chamber and the product or products, conveyor means for transporting the product or products to and from an evacuation chamber, and transferring the products to a packing unit.

13. An apparatus according to claim 12, characterized in that the apparatus comprises the packing unit.

14. The apparatus according to claims 12 and 13, characterized in that the conveyor means are adapted to advance the batches of products to and from the evacuation chamber and transfer the products individually or in groups to the packing unit, while allowing the remaining part of a batch of treated product wait outside the packing machine.

15. The apparatus according to claims 13 and 14, characterized in that the packing unit is a unit for wrapping by means of flow to pack the products individually or in groups, the packing unit comprises a mandrel, around which packets or tubular bags are formed from of a sheet material.

16. The apparatus according to any of claims 13 to 15, characterized in that the packing unit is provided with injection means for injecting gas into the package.

17. A package for deoxygenated foods comprising a flexible bag, which comprises a deoxygenated product, characterized in that at least part of the oxygen in the product has been replaced by protective gas, and an upper space comprising a protective gas, and wherein the Flexible bag is not sucked into the product.