WO1998012937A1

WO1998012937A1 - Frozen meal

Info

Publication number: WO1998012937A1
Application number: PCT/EP1997/004879
Authority: WO
Inventors: Alfred Morand; Jérôme LAFFONT; Thu-Thao Mariaud
Original assignee: Societe des Produits Nestle SA; Nestle SA
Current assignee: Societe des Produits Nestle SA; Nestle SA
Priority date: 1996-09-26
Filing date: 1997-09-04
Publication date: 1998-04-02
Anticipated expiration: 1999-03-26
Also published as: IL128248A0; CA2262512A1; NO991417D0; AU4701197A; NO991417L; EP0929239A1

Abstract

A process for the preparation of a frozen meal by putting the components of the meal into moulds, subjecting the thus filled moulds to a freezing step, demoulding the frozen meal, and packaging the deep frozen meal.

Description

Froze" meal

This invention pertains to a process for preparing a frozen meal .

Traditionally, frozen culinary products have two packages, an inner package such as an aluminium tray or a boiling bag containing the food product and a box around the tray or the bag. Usually, there is a dead space between inner and outer package so that the end product becomes unnecessarily voluminous and requires much space on the shelves, in the storage room and during transport. It would therefore be desirable to put frozen culinary products on the market which are characterized by a less voluminous package.

A reduction in packaging material would not only be advantageous from a financial standpoint, but would also be in line with recent environmental requirements.

The Applicants have surprisingly found that by introducing a food preparation into moulds and freezing or prefreezing it there to rectangular bricks it is possible to directly put the thus obtained frozen bricks into cardboard boxes or flow packs without having to resort to additional packaging material .

Freezing foodstuff to brick-shaped forms is known in the prior art .

Thus, DE-C-1003021 discloses a process of wrapping poultry into a transparent sheet . The package is then placed in a mould and pressed into the shape of a brick. The mould with the packages is then frozen. After that the frozen packages are put into an outer package such as a cardboard box. However, there is no disclosure in this document of placing the foodstuff directly into the moulds in order to obtain a final product with only a single package.

GB-A-1041155 relates to a process of packaging fish by placing fish pieces into a cardboard box and then pressing the box into shape. Thereafter, the box is frozen. Again, there is no disclosure of placing the foodstuff directly into moulds and freezing it there. In addition, in order to permit the air which is entrapped during the compression step to escape and thus avoid air void formation, the interior surface of the cardboard boxes used in this process is specially structured in that depressions are embossed into the paperboard before the package is formed; normal cardboard boxes are not suitable.

WO 95/21541 refers to a process for producing pet food consisting of lumplike meat pieces and a liquid sauce, whereby frozen raw meat is cut into pieces and packed with equally frozen sauce granules into a press where the mixture is pressformed to a form corresponding to the lower section of the container into which the thus obtained form is subsequently emptied. The container, usually a tray or a tin, is then sealed on the upper side with a foil. By freezing the liquid constituents of the foodstuff, the problem of accidentally spilling sauce on the rim of the container during the filling step is circumvented. If said rim is contaminated with food traces, the foil will not tightly adhere to the container and thus an airtight sealing is prevented which, of course, has a negative effect on the shelf-life of the product. This document does not disclose the suitability of normal cardboard boxes or flow packs as the only package nor does it relate to freezing the foodstuff when being enclosed in moulds. Furthermore, the process as disclosed in this document requires the additional step of formpressing which is not necessary in the process of the present invention. In view of the fact that formpressing is performed with hard frozen pieces it would appear that the frozen product does not have a perfectly smooth surface. Finally, the process as disclosed in this document is not suitable for the preparation of meals with a topping or multilayered food such as lasagna.

It is therefore an object of this invention to provide for a process for preparing a frozen meal which can be packaged into a single package such as a normal cardboard box or a flow pack.

It is a further object of this invention to provide for a process for preparing a frozen meal which can be packaged into a less voluminous package.

It is a still further object of this invention to provide for a process which does not require a formpressing step as disclosed in WO 95/21541.

It is a further object of this invention to prepare a meal having the shape of frozen bricks, which require a minimum of space on the shelves.

It is a still further object of this invention to prepare a frozen meal having a smooth surface which is appealing to the customer.

It is a still further object of this invention to provide for the preparation of frozen meals having a topping or of multilayered meals such as lasagna.

Surprisingly, the above objectives can be realized by a process for the preparation of a frozen meal comprising the following steps: a) putting the components of the meal into moulds; b) subjecting the thus filled moulds to a freezing step; c) demoulding the frozen product; and d) packaging the deep frozen product.

The process of the present invention can be carried out in conventional moulds such as plastic or metallic moulds. Plastic moulds have the advantage of being less rigid and less adhesive than metallic moulds so that demoulding is facilitated by simply knocking or twisting the moulds. Basically, both vertical and horizontal moulding is feasible, horizontal moulding is preferred, however, as a wider variety of products can be obtained with this technique. Thus, with this technique it is possible to process both viscous and liquid products, no matter whether large pieces are contained in the meal or not. It is equally possible to produce meals having a topping or even multi-layered meals.

The frozen meal of this invention is preferably formed to a rectangular shape such as a brick. With such a shape, the volume of the package as well as the dead space can be kept at a minimum, in addition, multi-packs can be easily formed. This form of packaging would meet the needs of catering services and would also be in line with the eating habits of families where the different members do not have the same eating hours. Alternatively, the product can also be offered as a single portion.

The size of the individual portion is not particularly limited and can be adjusted to the individual needs.

Preferably, the weight of a frozen brick is in the range of from about 50 g to 1 kg. The bricks are most preferably portioned to 150 g each. Such an amount of food roughly corresponds to a complete meal for a child and for an elderly person, while adults would be expected to consume 2 portions per meal. The portions are most preferably sized to bricks of about 110 x 75 x 20 mm each.

The process as claimed in this application is not limited to particular food, basically any meal can be prepared. The frozen bricks may contain all the constituents of a complete meal such as meat, pasta, vegetables, rice, sauce etc. Neither is the process limited to a particular consistency of the food: meals comprising lump-like pieces of meat can equally well be processed as more liquid or saucy meals. "Chili con came" , "riz cantonais" , "moussaka" or multi-layered meals such as "lasagna" are most preferably prepared with the claimed process.

The freezing step may be performed by any suitable technology and may include e.g. cryogenic freezing or crusting, i.e. passing the meal through a liquid nitrogen tunnel, air blast freezing or contact freezing in a mechanically refrigerated tunnel. The meal may be deep frozen in one step or frozen at the surface, demoulded and deep frozen with cold air. Alternatively, the meal can be frozen by liquid freezing, i.e. by dipping the moulded meal into a brine bath at low temperature.

In a preferred first embodiment of the freezing step including cryogenic freezing, the meal is filled in plastic or in metallic moulds and then partially frozen (= crusted) in a liquid nitrogen tunnel. After demoulding, the bricks are deep frozen in an air blast tunnel and subsequently packaged. The empty moulds are washed (if necessary) and conveyed back to the filling station for the next cycle.

In a preferred second embodiment of the freezing step including liquid freezing in a brine bath, the moulds are filled with the meal and dipped into a cold brine. Maximum heat transfer efficiency is achieved when all the brine is recirculated with high speed through the brine distribution piping. In order to accelerate the freezing of the upper surface, cold air is blown over the moulds. The frozen bricks are demoulded and transferred to the packaging units. The empty moulds are washed and conveyed back to the filling station.

Demoulding can be facilitated by blowing warm air on the moulds, or, in case of the brine process, by defrosting with warm brine.

The process of this invention is not limited to a particular packaging material. Preferably, plastic films, paperboard, or coated paperboard are used. With regard to environmental considerations, the paperboard and coated paperboard materials are the most preferred packaging materials .

Both individual portions and multi -packs are packaged in flow packs or reclosable paperboards with multipacks contained in reclosable paperboards being the most preferred product .

The present invention also pertains to the frozen meals obtained by the process as described above. The concept of freezing a complete meal to a bricklike structure and packaging said brick directly into a simple flow pack or cardboard box, realized by freezing or crusting said meal while being contained in moulds, is unknown in the prior art. Therefore, the meals of this invention can be distinguished from those of the prior art by a much simpler packaging. In addition, the frozen meals of this invention are characterized by a very smooth surface, in particular as far as the lateral and the bottom sides of the brick are concerned which are in direct contact with the inner surfaces of the moulds. Smooth surfaces are appealing to the customer on the one hand. On the other hand, they are mandatory for reducing the aforementioned dead space and, as a consequence, the volume of the packaging to a minimum. Again, such smooth surfaces are only feasible with the process as described above, they cannot be obtained with the method as disclosed in WO 95/21541 wherein already frozen particles are pressformed to a particular shape.

Within the scope of the present invention it is also possible to provide for an embodiment where the surface of the product is irregular. This product conception consists in the piling up of sauces (several dosing may be performed) , garnish (vegetables, noodles or rice, for example) and finally at the top a piece of fish or meat.

The main advantage of this concept is to gain an appealing product when looked at from above, either in or out of the package. The latter should keep the visual aspect intact and could be a flow-pack or the darfesh system for refrigerated products (plastic film wrapped around the portion to make a skin), for example.

The moulds used for this embodiment may still be of rectangular or brick shape, but any shape that can be made in thermoformable material (high density polyethylene, for example) can be provided for. The mould set up offers flexibility for having new shapes faster and at a lower cost, or for changing quickly the whole set of moulds.

The demoulding step can be carried out by spraying warm water (10 to 20°C, especially 13 to 15°C, for example) on the outside of the mould in order to unstick the product from the mould, and then by pushing the bottom of the mould so as to lead the product out of the mould, for example. Such an easy and efficient (no product left in the mould) way of demoulding the product is feasible because of the ability of plastic to stand deformation.

The moulds may then travel back to the start of the line. They may be washed both on the inside and the outside and dried. A dosing equipment may be provided for to put both a sauce and a solid garnish into the mould automatically, for example .

The freezing equipment may comprise a brine bath at a temperature of from -40 to -30°C approximately below a conveyor of moulds, and a freezing tunnel on top of the products, for example. A cold source for the freezing tunnel may be blasted air cooled with ammonia or freon or liquid nitrogen, or liquid nitrogen sprayed directly at the surface of the product .

The invention will now be described by way of the following examples :

Example 1 (cryogenic freezing)

The tests have been performed with meals of different textures. In particular, "riz cantonais" , "chili con carne" and "moussaka" have been used. Moulds yielding bricks of 110 x 75 x 20 mm, corresponding to a weight of 150 g were selected. The meal was filled in aluminium moulds and in thermoformed polycarbonate. The moulds were then introduced into a cryogenic air liquid tunnel (Zip Freeze, supplied by Air Liquid, France) . At a temperature of about -120°C, the crusting time (minimum time to permit demoulding and handling of the brick without sticking and deforming) is in the range of from 3 to 3.5 min for metallic moulds and from 3.5 to 4 min for the plastic moulds, respectively. The moulds are subsequently emptied. Demoulding can optionally be facilitated, particularly in case of the rigid metal moulds, by blowing warm air before the moulds are emptied. The prefrozen bricks are then subjected to deep freezing and directly packaged into cardboard boxes .

Example 2 (brine process)

The tests were again performed with "riz cantonais", "chili con came" and "moussaka" . Moulds having the dimensions as those described in Example 1 were used. The filled moulds were introduced into the brine bath. The lower and lateral parts of the moulds were in direct contact with the brine at a temperature of about -38°C. In order to reduce the freezing time, especially of the upper surface which is not in direct contact with the brine, an air blast cooling tunnel generating an air temperature of -20°C was installed on top of the brine bath. With this additional cooling equipment the freezing time is about 15 min. The bricks were then extracted from the moulds by means of suction cups after defrosting with warm brine and further processed.

Claims

1. A process for the preparation of a frozen meal comprising the following steps: a) putting the components of the meal into moulds; b) subjecting the thus filled moulds to a freezing step; c) demoulding the frozen meal; and d) packaging the deep frozen meal .

2. A process according to claim 1, wherein the deep frozen meal is directly packaged into a cardboard box or a flow pack .

3. A process according to any of claims 1 and 2, wherein the frozen meal comprises a complete meal such as "chili con carne" or "mousaka" .

4. A process according to any of claims 1 to 3, wherein the meal is moulded into a brick.

5. A process according to any of claims 1 to 4 , wherein the freezing step is performed by dipping the moulds into a cold brine .

6. A process according to claim 5, wherein the cold brine is kept at a temperature of between about -30 to -40°C.

7. A process according to claims 5 or 6 , wherein additionally cold air is blown over the moulds during the freezing step to accelerate the freezing, especially of the upper surface .

8. A process according to any of claims 1 to 4 , wherein the freezing step is performed in a cryogenic tunnel or in a mechanically refrigerated tunnel.

9. A process according to claim 8, which comprises introducing the filled moulds into a cryogenic tunnel and freezing the meal at the surface, emptying the moulds and deep freezing the demoulded bricks with cold air.

10. A frozen meal obtainable by a process as defined in any of claims 1 to 9.