WO2004069014A1

WO2004069014A1 - Method for cooking and conversion and means ofr carrying out said method

Info

Publication number: WO2004069014A1
Application number: PCT/FR2003/000050
Authority: WO
Inventors: Jacques Roquefere
Original assignee: Jacques Roquefere
Priority date: 2003-01-09
Filing date: 2003-01-09
Publication date: 2004-08-19
Also published as: AU2003216798A1

Abstract

The invention relates to method from cooking and/or conversion under steam pressure after which the product (2) is placed with an optional amount of additional solvent in a receptacle (1) or container defining a closed volume with a means for removal of solvent and the product is supplied with energy. Said method is characterized in that a cover or receptacle comprising a continuous non-micro-perforated membrane (4), permeable to the solvent in the vapour state and impermeable to the solvent in the liquid state, is provided and the energy supply is instantaneously limited and limited over time to a value which permits the solvent to pass into the vapour state under pressure and temperature conditions which permit the reheating and/or the cooking and/or the conversion by means of a thermal effect but which is less than the value required for rupturing said membrane.

Description

COOKING AND PROCESSING METHOD AND MEANS FOR CARRYING OUT THE METHOD

The invention relates to a cooking method.

It also relates to the means for implementing the method. The present invention relates more particularly to the techniques of setting and maintaining temperature in semi-enclosed space, among which appear in particular the cooking techniques which consist in bringing and / or maintaining a product in a state of temperature determined or not and optionally a pressure state, determined or not, and for a determined time in order to modify the state and make it reach an objective state defined by descriptive criteria possibly calling upon the different human senses.

By cooking, we will also understand the operation which consists in reheating an already cooked or semi-cooked product.

Various methods are known for cooking food. The most common method is to place food with or without additional water in an open container placed over a heat source.

The heat causes, among other things, heating of the additional water and / or that contained in the food, water which contributes to cooking.

This type of cooking requires, on the one hand, a significant amount of energy and, on the other hand, to monitor the food to prevent the water from evaporating completely and the material from drying out and then burning.

To accelerate cooking, it is known to use cooking under vapor pressure requiring a closed container comprising a pressure control valve.

These valves are mechanical and are designed to relieve the pressure from a value determined in advance. They also prevent excessive loss of vapor. Also known are micro-perforated films which can be used for microwave cooking. There are therefore different techniques among which, if we take the case of the individual but which is extrapolated in many cases to industry, the container (saucepan, frying pan, etc.), which is put on a heat source with or without lid, the containers hermetically closed with pressure relief valves, reheating and cooking in the microwave, although if this process is recognized in cooking for fish and vegetables, it is admitted that for meats, fruits and fried foods , the results are not as good.

Trays covered with a film can also be used in the microwave oven, but their use is limited because, in the case of completely waterproof films, when energy is brought in causing a rise in temperature, there is then an increase in pressure causing a deformation of the membrane then its rupture and the bursting of the film.

There is therefore no longer any heating and / or cooking and / or transformation under thermal effect of the products subjected to the energy supply and to the solvent vapors at the pressure level where they are found with different systems allowing communication. from the inside of the tray with the outside to prevent them from bursting under pressure.

In the case of perforated membrane FR 2674737, we find ourselves as with leaks in a waterproof membrane and we will not be able to build up pressure by continuous leakage.

Of course, this disadvantage could be overcome by reducing the size of the perforated membrane or by reducing the size of the perforations, but in this case and apart from the cost of micro-perforation, regulation becomes difficult and the risk of bursting is growing and that is probably why this solution does not appear in those envisaged by the manufacturers of trays intended for microwave cooking as a possible alternative to valves.

The first equipment or utensils have the disadvantage of ^" taking a long time to reheat and / or cook, the hermetically sealed containers have the disadvantage of being expensive because they are designed to be able to withstand significant pressure and risks overpressure.

We can obviously find smaller dimensions but as we have to buy several, we generally limit ourselves to one and we choose consequently an important dimension, but ill-suited for small quantities. Versatility is not easy.

Cooking in the microwave oven does not accommodate steam cooking because the containers used due to the nature of the constituent materials do not allow the pressure resistance and for the reasons previously mentioned risks of bursting watertight trays which cannot be used except in the case of trays with a communication valve, complex and in any event which cannot be put in place by the consumer but only by manufacturers, on ready-made preparations and whose grammages are therefore pre-established in portions.

^•• - - - Anyway, another disadvantage of valve systems, pressure cooker type, or microwaves is to either have to heat a volume of water which will generate the steam which must escape through the valve, either preheat the dish which will go to the microwave before putting it back there with the food to be cooked which takes a significant time to add to the time of reheating and / or cooking and / or transformation under thermal effect announced by itself , short.

Finally, there are many circumstances or failing to move with all your kitchen paraphernalia, you must resign yourself despite all that exists to reheat and / or cook as in the past in the basic container, the only acceptable solution .

Also known in other fields of application are various membranes having the particularity of being permeable to the vapor of a solvent.

Optionally, they can be impermeable to this solvent itself, this solvent possibly being in particular water. These membranes give rise to different applications allowing precisely and mainly when said membranes are impermeable to a solvent, to assign them two functions. ^"

The membrane delimiting alone or with other elements two distinct universes, a first function based on the impermeability to the solvent consists thanks to the membrane to preserve the solvent in one of the universes and to protect the universe being on the other side of a transfer of this solvent. A second function is to allow the vapor of this solvent and alone to pass through the membrane to pass from one of the universes to the other under variable conditions according to the applications.

Generally, these applications are intended to avoid the passage of water in one direction and to allow the transfer of water vapor in the same direction or the other direction.

So it is, membranes used in the field of clothing and thanks to which we will promote for the well-being, the elimination of sweat in one direction while protecting from the rain in the other direction or, in another field , that of under roofs where the interior of the house will be protected against rain, while allowing the evacuation of interior water vapors which would condense on a cold surface under the roof.

Another use of these membranes is known, which images the economic opposition that there is in these two separation phenomena. In this application, we will favor, for economic reasons, the dissipation of a purified solvent in vapor form, in one direction, while avoiding, in the same direction, its elimination in liquid form, insufficiently separating from other materials likely to be eliminated with him.

This type of membrane is used to dry material. This drying is done with little or no energy input.

It is therefore economical but requires a significant time of realization and therefore reducing the energy saving by generating other expenses even if comparatively they are less.

The downside of this very separative and economical process is therefore that it takes time and we will talk in the case of drying for example of days or tens or even hundreds of days.

Thus, to better meet the needs of industrialists but also of individuals, the invention relates to a process of reheating and / or cooking and / or transformation under vapor pressure according to which the product is placed with an additional quantity of solvent in a container or container delimiting a closed volume comprising a means for discharging the solvent according to which the product is subjected to an energy supply, this process being characterized in that:

- a container or container is provided, comprising at least locally a continuous non-micro-perforated membrane permeable to the solvent in the vapor state and impermeable to the solvent in the liquid state, and

- the energy supply is limited instantaneously and over time to a sufficient amount to allow the passage of the solvent in vapor form at pressure and temperature conditions allowing heating and / or cooking and / or transformation under thermal effect but to an amount less than that capable of producing the rupture of the aforementioned membrane.

The invention also relates to the means for implementing the method.

The invention will be better understood with the aid of the description below given by way of nonlimiting example with regard to the drawing which schematically represents an application of the method.

Referring to the drawing, a container 1 is seen for carrying out an operation of the heating or cooking or transformation type of a product 2, for example a food product.

Obviously, this process also applies to the transformation of any product requiring energy and in the presence of a solvent. Conventionally, the process of reheating and / or cooking and / or transformation under vapor pressure comprises a first step according to which the product is placed with incidentally an additional quantity of solvent in an envelope delimiting a closed volume comprising a means of controlled evacuation of the solvent and the product is subjected to an energy supply. According to the invention:

- a ^" casing or container comprising at least ^" locally is provided with a membrane 4 permeable to solvent in the vapor state and impermeable to the solvent in the liquid state, and - the energy supply is limited instantly and in time to an amount sufficient to allow the passage of the solvent in vapor form at pressure and temperature conditions allowing heating and / or cooking and / or transformation under thermal effect but at an amount less than that capable of producing the rupture of the aforementioned membrane 4.

In the particular case of a heat source of the electric hob or burner type, when the products do not contain a liquid component, the wettest components are placed in the lower part of the container so that the effect of the temperature difference between the heat source and the components.

Preferably, the temperature is adjusted to a value limiting the rate of transfer of the solvent through the membrane. The subject of the invention is a process which, to better meet the needs of manufacturers but also of individuals, consists in putting the product to be reheated and / or cooked under the effect of the temperature and the vapor pressure of a portion. of the solvent contained in the product itself or added to the product, and which has passed into the form of vapor, and in a time less than that which it takes to escape from the enclosure in which it is under the effect of a minimum energy input, allowing gentle cooking of the product with the vapor of its own solvent.

Thus, this process of reheating and / or cooking and / or transformation under a thermal effect, under vapor pressure, in a semi-enclosed space of wet or non-wet products is characterized in that it consists mainly in making an energy contribution at the minimum likely to ensure state transformations of the type of those, even if they may be a little different, that these said materials undergo, subjected to other modes of reheating and / or cooking and / or transformation under thermal effect, by enclosing hermetically said materials in a container, having a valve representing at least one wall zone possibly not adherent to said materials, in which said valve, ^~~ capable of withstanding with or without deformation to a level of pressure which would be applied to it on a only one of its faces and which is essentially constituted by a semi-permeable membrane made of a material selectively permeable to the vapor of d it solvent excluding said materials and excluding said solvent in the liquid state, operating under the effect of a differential pressure between the two faces of said membrane by migration of the gaseous molecules of said solvent within of said material which is ensured by virtue of the mobility of vacant intra-molecular sites of the polymeric material and therefore ensuring a time delay due to molecular inertia for the dispersion of solvent vapor on the scale of the time necessary for heating and / or the cooking and / or processing under thermal effect. It is necessary that the production of steam for the energy supply is greater than the loss of this steam through the membrane.

Membrane technology is used as a valve element, avoiding too high a pressure rise but promoting the lowest possible but continuous loss of solvent in vapor form, the role of valve with minimum effect of vapor loss based on molecular inertia inside the membrane.

Note that, in this case, the membrane is not used to remove the steam but to contain it enough to obtain pressure cooking.

Note when this cooking is done with the sole vapor of the product solvent, it preserves the product from tap water and is done with the water that nature has placed inside the product, protecting it thus pollution.

It should be noted that, compared to valve systems operating intermittently, this process has the advantage on a thermodynamic level of being continuous and therefore of avoiding energy losses as there may be at the time of variations in pressure temperature which occurs when the valves close, opening, creation of threshold and / or push effects to open the valves.

The energy to be supplied for heating and / or cooking and / or transformation under thermal effect will therefore be optimized since it will have to be limited to the only energy authorizing the loss of solvent not necessary for the final result. Note that in terms of safety, the containers used do not need to be designed as pressure cookers that must respond to any incident that may

^" cause an abnormal rise in pressure (by blocking the valve for example), since the film will present sufficient strength for the process but mechanically limited. To modify the result as little as possible, the objective will be to take advantage of the lack of speed the solvent vapor transfer phenomenon for having finished heating and / or baking and / or transforming under thermal effect before too much of vapor and therefore of solvent has not disappeared, so that these vapors being taken in the body itself, the reheating and / or the cooking and / or the transformation under thermal effect modifies as little as possible its objective state and the improvement objective will be, against drying, to go slower in the elimination of the solvent and for example to obtain thicker membranes to increase the time of passage through the membrane of the vapor molecules. solvent and decrease their rate of elimination, and to accentuate research on the regulation of pressure maintenance of the membrane so that it does not explode.

Another difference consists in the fact that concerning drying, it is in the interest of the process to use as much exchange surface as possible, concerning cooking it is to use as little as possible and of rather reduced dimensions for have less mechanical stress on the membrane.

The thoughts which governed the definition of the cooking process were therefore, and must be, to contribute to its improvement in a different order of reflection.

In all that follows, the term “vapor permeable membrane” is understood to mean a membrane which is let through by gaseous molecules.

Said materials to be reheated and / or cooked and / or transformed thermally targeted by the invention correspond either to materials containing a solvent, which must be used in part in order to maintain a saturated atmosphere of this solvent, or materials not containing the solvent, dry materials among others are possible and to which a little solvent will be added so that they can subsequently be placed in an atmosphere saturated with solvent vapor.

It should be specified that, depending on the applications, the solvent is not necessarily of an aqueous nature and that the vapor may be due to any solvent other than water.

The setting in cëϋvrè ^" di-F heating and / or cooking process ^" and / όîT transformation under thermal effect according to the invention is explained below by placing itself in the case where the materials to be reheated and / or cooked and / or transform under thermal effect are materials loaded with water, said water being used in part for cooking. The steam cooking process relies for its pressure limitation on a phenomenon comparable to that of osmosis. It exploits the fact that inside the container containing the materials to be cooked, an osmotic type overpressure is created due to the supply of energy serving to give the conditions of temperature and pressure, which activate the heating and / or cooking and / or processing under thermal effect and at the saturated vapor pressure of the humidification solvent. In such conditions, the laws of thermodynamics provide that the vapor pressures are balanced on either side of the wall of the valve. In the case of a waterproof but very elastic film, this equilibrium will occur by extension of the internal volume and reduction of the internal pressure until reaching the external pressure if the film resists the necessary expansion of its surface. However, in this case, it will no longer be possible to use the internal pressure to activate cooking.

To prevent the expansion from being too great, it is therefore possible to reinforce the film and slow down its expansion and to prevent the rise in pressure from causing the film to burst, it is possible, as appears in many embodiments, to put a valve.

The level at which the valve will be adjusted will characterize the robustness that the film must have. In the case of an unsealed film, equilibrium will occur by rapid transfer of the solvent in the vapor phase through the film, which will make heating and / or cooking and / or transformation under thermal effect impossible.

According to the invention, this significant difference in the pressure balances between the interior medium and the exterior medium of the container and valve assembly, is gradually established by evaporation of the solvent above the material to be heated and / or cooked and / or transform under thermal effect inside the container and valve assembly while a temporary equilibrium ^"is established during the transfer and diffusion of the vapor of the solvent through the wall of the membrane from which the The characteristic of the invention consisting in using the fact that this rate of diffusion or transfer of the vapor of the solvent through the wall of the valve, finds according to the invention a level which, varying with the energy supplied, East sufficiently low compared to the speed of cooking, to allow the solvent to remain at the right pressure until the end of cooking, and is strong enough to avoid too high internal pressure and too great an extension of the membrane, that would blow it up. In the case where the container is made of membrane, the entire container can thus become a valve.

It is clear that the gaseous molecules of the solvent diffuse by migration through the thickness of the membrane only in a unidirectional direction, namely, from the inside to the outside of the membrane until the thermodynamic equilibrium is established. In the case where the valve membrane constitutes the container and if the material to be reheated and / or cooked and / or transformed under thermal effect is wet and if the solvent only comes from said material, as the solvent must vaporize with inside the membrane, it is preferable that at least one wall zone of this membrane is not in contact with the wet material so that the phenomenon of saturated vapor pressure can occur properly, the evaporation of the solvent contained in the matter contained in the membrane obviously supposes that the said solvent to be put into vapor has a saturating vapor pressure which is not negligible at the conditions of external pressure temperature and relative humidity.

In the case of a material to be reheated and / or baked and / or transformed under thermal effect and in the absence of a membrane, as the solvent evaporates and the gaseous molecules of said solvent diffuse in the atmosphere, the material becomes depleted in liquid solvent and dries up and this is a reproach that is made of a certain number of materials to be heated and / or cooked and / or transformed under thermal effect passed in the microwave or which have to be reheated or baked for a long time or take a long time to transform under thermal effect.

In the case of the invention, if the overpressure is maintained inside, as long as the material is moist and contributes to the regulation by continuing to activate the elimination of the vapor, it should be said that this pressure can be considerably reduced, and if the valve membrane is flexible this regulation can be very thin because we will see the membrane swell and deflate depending on the energy intake made

Recognition of the state of reheating and / or cooking and / or transformation under thermal effect will result from what is already known and in particular from all that is already known concerning steam cooking and microwave cooking.

From what has been said above, it therefore appears that the heating and / or cooking and / or transformation under thermal effect of the material hermetically sealed in the container and valve assembly is governed by two thermodynamic phenomena: evaporation of the solvent above the product to be reheated and / or to be cooked and / or to be transformed under thermal effect, that is to say in the vicinity of the wall zone which is not adherent to the material to be reheated and / or to be cooked and / or to transform under thermal effect, on the one hand, and the diffusion of the vapor of the solvent through the thickness of the membrane on the other hand. Taking into account the phenomena involved, the heating and / or the cooking and / or the transformation under thermal effect is carried out without excessive drying only if the kinetics of diffusion of the solvent through the thickness of the membrane is comparatively slow compared to the kinetics of evaporation of the solvent in the container and valve assembly because there will be saturation, condensation and evaporation again very quickly, the condensed solvent being a priori easier to pass into vapor phase than the solvent still remaining in the material due to its natural composition.

It goes without saying that the gaseous molecules diffuse all the less quickly as the thickness of the membrane to be crossed is greater and its surface is less important. We therefore see here two ways of controlling the pressure prevailing inside the closed enclosure by controlling the rate of diffusion of the solvent through the thickness of the membrane by modifying the thickness of the ^" wall of ^" the membrane or by reduction of its surface, at least in the zone not adhering to the material to be reheated and / or to be cooked and / or to be transformed under thermal effect. The valve and the membrane wall are chosen and implemented to promote, compared to comparable methods, a minimum loss of the liquid solvent. In particular the membrane, constituting at least the wall zone which is not adherent to materials sensitive to humidification, is a membrane permeable to the vapors of the solvent to be eliminated and impermeable to the corresponding liquids, made of a material whose intrinsic characteristics allow the elimination solvent in the slowest possible vapor state, compatible with the admissible pressure inside the container and valve assembly.

Without wishing to be limiting of the reality of the phenomena in question, we can explain the functioning of the membrane and its selective permeability to vapors, by an exclusive transfer of these vapors through the membrane directly linked to the inherent structure of the molecular chains of the material. . It seems that the transfer of vapors takes place by migration of the vapors through the entire thickness of the membrane. This mode of operation can be analyzed in more detail as explained below.

Thus concerning polymer membranes, one can more precisely describe and quantify as indicated below.

The transfer by migration of the gaseous solvent molecules is made possible thanks to the existence within the polymer material itself and on the microscopic scale of vacant spaces or sites which globally constitute what is called free volume. In a polymer material, in fact, the total volume occupied by the polymer comprises a volume corresponding to the volume that the polymer would occupy if it were condensed into a second volume corresponding to the spaces occupied by the polymer and which is known as free volume.

In accordance with the invention, it has been observed that these vacant sites have an essential role in the diffusion of gaseous molecules through the thickness of the polymer material. It has also been noted that it is essential for diffusion to occur that the polymer of the membrane has a selective chemical affinity with the said T gas molecules of the solvent, which are preferably slightly congested in order to be able to migrate freely in the vacant sites of the material. .

The optimal implementation of the method according to the invention therefore requires that the membrane, which constitutes at least the wall zone of the valve intended to be traversed by the vapor diffusing molecules because separated from the materials to be heated and / or cooked and / or transform under thermal effect, can establish physicochemical interactions with said molecules and has an amount of free volume mobile enough to accommodate the vapor molecules which move over the entire thickness of the membrane.

It should be noted that the size of the vacant sites is advantageously of the order of an angstrom (10 ^"10 m), making it only possible to transfer gaseous molecules by migration through the thickness of the membrane. Liquid molecules being non-individualized, they cannot cross the membrane via vacant sites.

Advantageously, the polymeric material is a copolymer formed of rather crystalline rigid blocks ensuring the mechanical resistance of the material and of flexible blocks of rather-amorphous elastomers ensuring the permeability of the material to vapors by the mobility of vacant sites.

The chemical nature of the flexible sequences is chosen such that the said sequences have a selective affinity with respect to the gaseous solvent molecules, without the possibility of interaction with the other constituents of the material. The polymeric material can also be a polyester. The polymer membrane can be combined, by adhesion with or without the use of an adhesive, to a nonwoven, consisting of textile fibers entangled one inside the other, the nature of which is chosen so that it does not disturb the capacities. permeable from the membrane. Said nonwoven is for example based on polypropylene resins or polyester resin.

It plays the role of reinforcement or support layer which reinforces the mechanical strength of the membrane when, in particular, it consists of a membrane which is very weak in mechanical resistance due to the mass importance of the flexible sequences. It is not excluded to add several layers of nonwoven to the membrane.

It is also possible, to strengthen the mechanical strength of the polymer membrane, to fix said membrane on a woven fabric or on a micro-perforated plate. It is obviously advisable each time to choose a support layer which does not alter the permeable properties of the membrane and in particular, it is advantageous that the material constituting said support layer has an openwork structure.

It is also advisable to make sure, before fixing the membrane to the support layer, that the chemical composition of the materials of said support layer is compatible with that of the membrane so that the membrane / support layer adhesion is facilitated.

The adhesion is advantageously carried out by hot calendering, during which the thickness of the membrane is controlled.

As it is a copolymer-based membrane formed of rigid blocks and flexible blocks, the respective position of each of the links in the polymer material determines the degree of permeability of the membrane. -Seeing what has been said previously on the feasibility of the diffusion of gaseous molecules through the membrane, it appears obvious that an intrinsically hydrophilic polymer material, that is to say in which the flexible sequences are those of a hydrophilic oligomer and are in a preferential majority proportion with respect to the rigid sequences, essentially allows the transfer of water vapor.

However, the hydrophilic nature being a direct consequence of the presence of polar groups, the said oligomer can establish polar type relationships with a polar organic solvent and therefore the process according to the invention allows heating and / or cooking and / or the transformation under a thermal effect of materials moistened with water or any other polar organic solvent with similar behavior, such as methanol, ethanol, acetone which are frequently used in organic synthesis. For heating and / or cooking and / or processing under thermal effect material thus moistened, the applicant has found that the polymers of the poly (ether-block-at IDE) ^{'particularly} suitable to the implementation of consistent process to the invention. A poly (ether-blocks-amide) is a block copolymer, the macromolecular chains of which consist of successive sequences of polyether blocks representing the flexible sequences and of polyamide blocks representing the rigid sequences. Such a copolymer results from the polycondensation of polyamide oligomer chains and a single type of polyether block, in particular in the context of the present invention, polyamide blocks formed solely of polyamide 12 are used, denoted PA-12 (- (CH ₂ ) n- CO-NH), and polyether-diol sequences formed either of polyethylene glycol, denoted PEG (-O- (CH ₂ ) ₂ -), or of polytetramethylene glycol denoted PTMG (-O- (CH ₂ ) ₄ -).

The explanation given below to understand the properties of the selective permeability of the membrane with respect to a constituent of the product to be heated and / or cooked and / or transformed under thermal effect, namely the solvent, n is in no way limiting of other interpretations which could be made.

The PA-12 blocks of the poly (ether-block-amide) are crystalline and rather hydrophobic.

Inherently, they therefore tend to have a rather repulsive effect with respect to polar solvents. On the other hand, they provide the mechanical properties necessary for the membrane to resist certain industrial uses for which it is intended. The polyester blocks are on the contrary rather hydrophilic amorphous. They therefore exhibit, within the membrane selectively permeable to molecules in the gas phase, a selective affinity for molecules which lend themselves, by polar attraction, to specific physicochemical interactions with macromolecular chains.

It is then the polyether blocks which, because of their affinity with polar diffusing molecules, ensure the transfer of water vapor and polar solvent vapors via the available vacant sites.

The number-average molecular masses of the polyether sequences and of the PA-12 sequences are chosen so that they are not too high for the permeable capacities of the membrane to be optimal. In fact, the quantity of free volumes available increases when ^"the molecular mass decreases. The number-average molecular mass of sequence PA-12 is advantageously between 1500 and 5000 and that of the polyether sequences between 650 and 2000.

The proportions of each of the polyamide and polyether blocks are chosen so as to obtain an intrinsically hydrophilic material. Advantageously, the poly (ether-block-amide) used for implementing the process comprises from 30 to 60% of polyether blocks and from 70 to 40% by weight of polyamide blocks.

Whatever the chemical nature of the membrane used for implementing the method according to the invention, said membrane is chosen to be continuous, that is to say non-micro-perforated, preferably impermeable to bacteria and / or to microorganisms. and / or possibly sterilized.

Sterilization can be carried out by usual sterilization techniques such as sterilization by autoclave (120 ° C), by β or y ray or by ethylene oxide. The use of a previously sterilized membrane allows materials to be stored in a sterile environment.

The membrane is obviously chemically inert with respect to the solvent to be removed.

Its properties allow it to resist for a relatively short time, which last heating and / or cooking and / or processing under thermal effect, heat, which makes possible the possible introduction of the membrane containing the materials in a oven or microwave.

In this case, a significant advantage of the process is to avoid cleaning the oven which is no longer necessary after use. Another advantage being to trap for the time that heating and / or cooking and / or processing under thermal effect last, a significant part of the aromatic molecules and therefore of being able to cook, without the odors invading the house for those who do not don't like that and especially the smell of heated oil or grease. The thickness of the membrane is chosen so that the migration of the vapor is not too slow.

In the case of the cooking application for ^" a private individual, the thickness will often be less than 1000 μm in order to be within the orders of magnitude of a film. Preferably, the thickness is between 10 and 100 μm and advantageously between 10 and 60 μm. The membranes used advantageously have a permeability to water vapor of between 7,000 and 20,000 g / m ² : 24h (according to ASTM E 96 BW standard, at 38 ° C and 50% RH), an O ² permeability of 6,500 at 18,500 cm3: M ² / 24h / bar and a CO ² permeability of between 72,000 and 177,000 cm3 / m ² / 24h / bar. Said membranes have a density of 1.02 to 1.07 g / cm3 and a Shore hardness of 25 to 75 D.

The elongation at break is close to 365% and the load at break close to 3.9 daN / mm ² .

Advantageously, the membrane used as a valve in the case of the process applied to the materials to be heated and / or to be cooked and / or to be transformed under thermal effect is present:

- either in the form of a flat film closing a system, of the container or saucepan or frying pan or ramekin or any other usual or less usual container, resistant to the energy supply process used to heat and / or cook and / or transform under thermal effect, and which is obviously different depending on whether this contribution is made by microwave, direct flame with gas for example, or electric with plate or by induction or by oven or by any other existing system,

- Either in the form of a hermetically sealed bag, particularly suitable for enclosing dishes to be put in the microwave or in certain cases and under certain conditions, in the oven.

Hermetic sealing of the bags directly constituting the container is carried out by simple means such as twisting the film and making a knot or pinching it with suitable pliers or by adhesive, or even using elastic bands chosen to meet the temperature requirements. , dimension, resistance. In the case of industrial products in the form of a tray capable of being introduced into an oven or a microwave oven, the closure may be achieved by various suitable means such as the cover, as in the case of frozen products for which it could be in the form of a folded or unwrapped film and welded or glued. The method according to the invention is suitable for reheating and / or cooking and / or processing under thermal effect of solid or pasty products as well as of liquid products. According to a variant of the invention, the method can be used until the complete disappearance or almost of the solvent vapor under the effect of heat as long as this corresponds to a cooking and / or transformation process under thermal effect treated materials, such as for example for making jam, manufacture to which the present process applies.

According to a variant of the invention, the method is no longer used only for heating and / or baking and / or transforming under thermal effect under the effect of the vaporization of the solvent but for separation in such a process of the different components which may be in vapor form. This involves, for example, selectively separating vapors from materials contained in a mixture of different chemical natures.

This separation is based at the start on the same operating principle, namely evaporation not of a liquid solvent this time but of several solvents then diffusion of the corresponding vapors of only one of the solvents through a membrane having a selective affinity with respect to said solvent alone authorized to escape.

One of the liquids in the mixture is compatible with the chemical composition of the membrane while the other is less compatible or even incompatible. The membrane is selectively permeable to the vapors of the compatible solvent, with which it establishes chemical interactions facilitating diffusion.

The solvent said to be incompatible and which does not exhibit interactions with the material of the membrane which cannot be eliminated and possibly after condensation, returns to the vapor phase cyclically.

One can thus imagine developing a type of cuisine where one would decide to reheat and / or cook and / or transform under thermal effect under oily vapor and no longer bathing in oil, while letting escape only the vapors of ^" products to be reheated and / or cooked and / or transformed under thermal effect through the membrane, which leads to a lighter oil cooking. According to a variant of the invention, the process is used specifically for uncooked products and advantageously since, permeable to oxygen and CO ² , the membrane allows until they must be reheated and / or cooked and / or thermally transformed, the respiration of pretreated products enclosed in the container and membrane assembly without being denatured and at the same time their preservation by the addition under pressure of neutral gas such as nitrogen to which said membrane would not be not permeable. One will think there for example of raw vegetables peeled and cut into cubes or slices in the case where the storage time is sufficiently short, having regard to the thickness of the valve and its composition so that they retain their moisture of enough.

The benefits depend on the uses that can be made and that cover several families.

The process can be used to have similar effects or in place of steamed cooking to replace impractical or poorly sized equipment such as pressure cookers.

So to steam a portion for one person, it will suffice to stretch a film on a small pan. The solution will suit single people, the elderly, students.

Cooking will consume less energy per unit of time because it can be adjusted to the lowest necessary energy level and shorter, because first and generally cooking less long but also because it avoids the setting process. heats other processes.

Finally, it allows a more tasty cooking even than in a pressure cooker, because even less wet and softer in the cooking conditions. The solution will also be suitable for those who are more and more numerous who seek a balanced diet and the least energy consumption in everyday life or during the functioning of industrial processes.

The process can be used during cooking or the energy supplied is that of ^"" microwaves. Cooking in the microwave If it is fast, however, requires supervision because its effects are not all favorable. Note the baking of the edges before the center. The process allows you to enjoy cooking in the microwave and at the same time to steam, which promotes a different distribution of cooking, which makes the dishes softer. It also makes it possible to dispense with the reheating of the containers reheated by the steam itself.

The process can be used in all cases of trays intended to heat and / or cook and / or transform under thermal effect in particular in replacement of the multiple valve concepts.

Indeed, by playing on the different parameters (thickness, surface, composition, multiplicity of layers), it is possible to respond to the problems of the food industry for the general public and for communities in an economical and elegant manner, with more- taste value. The use of a grill which can also be compatible under certain conditions.

An advantage of the invention lies in the fact that the polymer-membrane protects the product which it contains from attacks by the external environment.

In particular, it prevents the risks of contamination from occurring and microorganisms from entering the container and membrane assembly, which makes it possible to reheat and / or cook and / or transform under thermal effect in a very aseptic fashion. expensive.

We can see the interest in foods intended for young children, or in the case of surrounding conditions naturally at risk (climates) or accidentally (cataclysm, war, etc.). But in the absence even of risk of pollution, this process is interesting because why indeed move in the hypothesis or it is conceivable, with a microwave oven or a self-cooker, when one could obtain the same results with bags like food bags or with sheets of transparent film with which to cover a dish or a pan before putting them on a baking sheet or even in the oven.

Another advantage is to be able to use this process at the industrial stage by marketing ^" prepared ^" dishes ^- to be reheated or raw elements directly packed in containers corresponding to the principles described and to reheat and / or cook and / or process thermally without the remove from their packaging. The process can be used to heat and / or transform under thermal effect in an accelerated way by using a solvent existing or not in the product and / or added taking into account the evaporation temperatures.

Another advantage of the present invention lies in the fact that the quality of reheating and / or cooking and / or transformation under thermal effect of fragile or difficult products is optimal.

Indeed, for products sensitive to high temperatures, such as chemicals with a low melting point, proteins or natural products and extracts, the process of reheating and / or cooking and / or transformation under thermal effect allows less denaturation. .

This list of advantages is obviously not limiting, other advantages having already appeared very clearly in the explanations of the preceding pages.

The invention will now be described in the context of specific examples of implementation and application of the method.

Example 1 - Cooking in a pan (enamel base), a set of vegetables and more exactly an onion, a potato and two carrots.

(Household film and industrial process market)

The potato is cut into cubes, the carrots into rings and the onion into strips.

The onion is placed at the bottom of the pan, then the carrots and then the potatoes.

Nothing is added, in particular, it is not put in water. It is not put oil either, nor any liquid matter. The pan is closed with a sheet of the polymer film according to the invention.

The useful surface of the sheet is that corresponding to the diameter of the pan which is T35 mm.

The contact surface with the surrounding atmosphere is therefore 143 cm ² .

The sheet is held in place with several thin elastic bands over the film around the pan.

It could have been held in place with a single wide elastic. In an industrial design, it can be held with a belt tightening and pinching the film.

The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 50% by weight of PEG sequences and 50% by weight of PA-12 sequence .

The thickness of the membrane wall is around 25 μm. The membrane is supported by a nonwoven. Is used as control ¹ without the same film configuration. Is used as a 2 ^nd control the same vegetable configuration placed in a pressure-cooker of 6 liters. We use as the 3 ^rd witness the same configuration without film but that we are trying to cook in the microwave.

The cooking time is twelve minutes for the test. Cooking is done on a SCHOLTES TL600 GEA2 hob, on the smallest fire known as an “auxiliary burner” giving a power of 861 mth / h for a flow of 98 l / h with G 20 gas - Natural 20 mbar , but the cooking is started and carried out in its entirety in the pilot position. The energy saving is considerable.

Although the cooking was done "dry", the pan is not marked. The potatoes are soft and more consistent in their center, slightly firm without giving the impression of a lack of cooking, the taste is well pronounced, rather better than in the case of cooking with water.

Carrots are very slightly firm and have a very pronounced taste. They are reminiscent of what is called modern cuisine. The onion strips while retaining a good hold and all their material remains flexible and tender.

The result is estimated to be very, very good. Comparatively:

We had to stop cooking in a pan without film, the food attached to the bottom.

Cooking in a pressure cooker took longer, consuming more energy and the results were estimated to be less tasty in terms of taste. Cooking in the microwave is more difficult (you are either cooked but a little too dry, or even wet but not fully cooked).

A new microwave test carried out with a film closing the dish as indicated in the case of the pan, gives results which, although not identical, are of the quality level of the test carried out in a pan with film.

Example 2 - Cooking in a pan (enamel base) with a clementine and banana jam.

(Household film and industrial process market)

This example is recorded because it corresponds to a slightly longer time than in the case of the previous examples and happens to be a step going further than the case of cooking the roast at 30 minutes. In addition, it includes a complementary aspect in the context of process control. Indeed, the energy conditions applying over a longer time, we arrive at the end of cooking with so little water that the membrane is no longer under conditions of temperature and partial solvent pressure, allowing it to be overpressure relative to the outside of the container. The membrane deflates and thus announces in a simple and very fine way the end of cooking.

Clementines cut in half and quartered and representing a weight of 460 grams are put in a pan with a banana cut into rings and representing a weight of 150 grams. The whole is sprinkled with 300 grams of powdered sugar and put on standby for 24 hours.

Then close the pan with a sheet of the membrane.

The useful surface of the sheet is that corresponding to the diameter of the pan which is 195 mm. The surface is therefore 298 cm ² .

The sheet is held in place by elastic bands on the outer rim of the pan.

The thickness of the membrane wall is 25 μm. A control test of the same configuration is not carried out, all of the preceding witnesses sufficient to validate the comparisons and the cooking of this product in the oven being also perfectly controlled.

The cooking is done on a SCHOLTES TL600 GEA2 hob, on the medium flow fire called "Semi-fast burner" giving a power of 1550 mth / h for a flow of 168 l / h with G 20 gas - Natural 20 mbar, but cooking is started and carried out in its entirety in the pilot position.

The cooking is stopped after exactly two hours while, the well-inflated membrane, begins to deflate, reflecting a drop in pressure inside the container compared to the outside, due, if we refer in the previous explanations to a virtual disappearance of the solvent in this case of cooking.

In this case cooking and disappearance of almost all of the corresponding solvent in terms of process, we see that there is an extremely interesting control element for the process. The jam is immediately potted. It has a beautiful color and a pleasant fragrance.

Nothing attaches to the pan (which is rare in this type of cooking), and the pan is absolutely unmarked.

The next day, a sample is tasted, the fragrance is still as pleasant. The taste is very pronounced and represents well the fruits of which the mandarin, which was the most difficult to preserve.

The texture of the fruit is also fairly well preserved and the small pieces of quarters, such as the slices, are recognizable.

In the opinion of the experimenter used to making jams it is one of the best if not the best he has ever made.

Example 3 - Cook the pot (stainless steel bottom), sliced mushrooms and garlic cloves en ^'shirt.

(Household film and industrial process market)

The minced mushrooms almost fill the pan, the garlic cloves are placed on the mushroom slices.

Nothing is added, in particular, it is not put in water. It is not put oil either, nor any liquid matter. The pan is closed with a sheet of polymer film. The useful surface of the sheet is that corresponding to the diameter of the pan which is 170 mm.

The contact surface with the surrounding atmosphere is therefore 227 cm ² . The sheet is held in place with several thin elastic bands over the film around the pan.

It could have been held in place with a single wide elastic. In an industrial design, it can be held with a tightening belt pinching the film. The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 40% by weight of PTMG sequences and 60% by weight of PA-12 sequence .

The thickness of the membrane wall is around 12 μm. Is used as control ¹ without the same film configuration. The cooking time is fifteen minutes for the test.

Cooking is done on a SCHOLTES TL600 GEA2 hob, on the smallest fire known as an “auxiliary burner” giving a power of 861 mth / h for a flow of 98 l / h with G 20 gas - Natural 20 mbar , but the cooking is started and carried out in its entirety in the pilot position. The energy saving is considerable.

Although the cooking was done "dry", the pan is not marked. Appearance, taste and texture are perfect. Comparatively:

It was necessary to stop cooking in a pan without film, the material attached to the bottom.

Example 4 - Cooking in a pan (enamel base), an apple. ^" (Household film and industrial process market) The fruit is hollowed out and put without water in the pan. The pan is closed with a membrane sheet. The useful surface of the sheet is that corresponding to the diameter of the pan which is 135 mm. The surface is therefore 143 cm ² .

The sheet is held in place by an adhesive on the outer rim of the pan.

The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 40% by weight of PEG sequences and 60% by weight of PA-12 sequence .

The thickness of the membrane wall is 12 μm.

Is used as control ¹ without the same film configuration.

Is used as ^2nd witness the same vegetable placed in the microwave configuration.

The cooking time is ten minutes for the test.

Cooking is done on a SCHOLTES TL600 GEA2 hob, on the smallest fire known as an “auxiliary burner” giving a power of 861 mth / h for a flow of 98 l / h with G 20 gas - Natural 20 mbar , but the cooking is started and carried out in its entirety in the pilot position.

The fruit holds well and when the spoon enters its flesh, you can slightly feel the pectin fibers. In the mouth, the apple is perfectly soft without being soft, it retains a light consistency before melting in the mouth. The witness in a pan without film had to be stopped, the cooking being done badly while the bottom was burning.

The fruit processed in the microwave did not have a pleasant shape and seemed rather shrunk in its skin. The pulp was rather burst, the result obviously less good. Example 5 - Cooking a pear and a banana in the pan.

(Household film and industrial process market)

This cooking was chosen to verify that it was possible to quickly make a dessert with cooked fresh fruit, rather than taking canned fruit or syrup.

The test was used to make a "Belle Hélène pear". The cut fruits are put without water in the pan.

We close the pan with a sheet of membrane. The useful surface of the sheet is that corresponding to the diameter of the pan which is 135 mm.

The surface is therefore 143 cm ² .

The thickness of the membrane wall is 12 μm.

Cooking is done in less than nine minutes.

It is made on a SCHOLTES TL600 GEA2 hob, on the smallest fire known as an “auxiliary burner” giving a power of 861 mth / h for a flow of 98 l / h with G 20 gas - Natural 20 mbar, but the cooking is started and carried out in its entirety in the pilot position, on the fire of smallest flow, the cooking is started and carried out in its entirety in the pilot position.

The results are perfect especially from the point of view of the texture of the pear. Example 6 - Cooking raspberries in a pan.

(Household film and industrial process market)

This cooking was chosen because of the particular fragility of the raspberry.

The whole fresh fruit is put without water in the pan.

The surface is therefore 143 cm ² .

The thickness of the membrane wall is 12 μm.

Cooking is done in less than two minutes.

It is made on a SCHOLTES TL600 GEA2 hob, on the smallest fire known as an “auxiliary burner” giving a power of 861 mth / h for a flow of 98 l / h with G 20 gas - Natural 20 mbar, but the cooking is started and carried out in its entirety in the pilot position; on the lowest flow fire, cooking is started and carried out in its entirety in the pilot position. After cooking, the hot raspberries and their cooking juices were poured over vanilla ice cream for an original dessert. Note that cooking has preserved all the water in the fruit which, mixing with the active products gives a nice red juice. The results are perfect, both in terms of the taste enhanced by the temperature, as well as that of the well-preserved fruit texture and the eye, which is important in cooking.

The speed of execution is fantastic.

Example 7 - Cooking in a casserole of a tournedos (enamel base), with shallots. (Household film and industrial process market)

The shallots are cut into rings and placed at the bottom of the pan, the tournedos is placed on the shallots.

The surface is therefore 143 cm ²

The sheet is held in place by elastic bands on the outer rim of the pan. The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 50% by weight of PEG sequences and 50% by weight of PA-12 sequence . The thickness of the membrane wall is 25 μm. Is used as control ¹ without the same film configuration. Is used as ^2nd witness the same configuration made in the microwave.

^" The cooking is done on a SCHOLTES TL600 GEA2 hob, on the medium flow fire called" Semi-rapid burner "giving a power of 1550 mth / h for a flow of 168 i / h with G 20 gas - Natural 20 mbar, but cooking is started and carried out in its entirety in the pilot position.

The cooking time is eight minutes for the test, the shallots are tasty and the meat is cooked quite well but surprisingly tender. Despite its non-grilled appearance, the meat looks more like seared or roasted meat than meat cooked in water

It was necessary to stop the test without film, the meat did not cook while the vegetables blackened and gave a burning smell. Meat in the microwave is far from achieving equivalent quality results.

Example 8 - Cooking in a pan (stainless steel bottom), a tournedos.

(Household film and industrial process market)

Under conditions substantially similar to those of Example 7, a 140 g tournedos is cooked placed directly at the bottom of a pan.

A sheet of membrane is placed on the pan. -

The useful surface of the sheet is that corresponding to the diameter of the pan which is 200 mm.

The surface is therefore 314cm ² The sheet is held in place by elastic bands on the outside rim of the pan.

The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 40% by weight of PTMG sequences and 60% by weight of PA-12 sequence . The thickness of the membrane wall is around 12 μm.

The membrane is supported by a nonwoven.

Cooking time is less than nine minutes.

Cooked meat barely ^~ point is surprisingly tender.

Example 9 - Cooking in a pan (stainless steel bottom), a fresh mullet on a background of various vegetables (endives, fennel). (Household film and industrial process market)

The vegetables are cut into strips and placed at the bottom of the pan. The mullet deposited on the vegetables. Nothing is added

A sheet of membrane is placed on the pan.

The useful surface of the sheet is that corresponding to the diameter of the pan which is 200 mm. The surface is therefore 314cm ² .

The sheet is held in place by elastic bands on the outer rim of the pan.

The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 40% by weight of PTMG sequences and 60% by weight of PA-12 sequence .

The thickness of the membrane wall is 25 μm.

The cooking time is twelve to thirteen minutes for the test, the fish is well cooked, soft but consistent, slightly firm, the taste is good.

The vegetables are tender and although, cooked without preparation, the endive has no unpleasant bitterness. The result is considered surprising in quality and the process surprising in simplicity.

Example 10 - Frozen cod fillet in the microwave.

(Household film and industrial process market)

In general, the microwave is only used to thaw frozen steak and poison which are then cooked in a pan. However, in certain cases, particularly for fish, cooking is also done in the microwave, passing from the defrosting power to the maximum power.

It is watched what happens when the fish is cooked according to the process, that is to say using at the same time microwave and steam. The frozen fish rack is placed on a small plate.

Nothing is added.

A sheet of membrane is placed on the plate. The useful surface of the sheet is that corresponding to the diameter of the plate which is 130 mm.

The surface is therefore 133 cm ² .

The sheet is held in place with an adhesive on the underside of the plate.

The thickness of the membrane wall is 25 μm. Is used as control ¹ without the same film configuration.

Is used as ^2nd witness the same configuration in a small pan on gas.

Is used as a ^3rd control the same configuration on the gas, being placed on the frozen vegetables. The cooking time is ten minutes, recommended time on the product packaging.

The result is correct in net. The fish rack keeps its shape and taste well, it is soft but consistent, the pieces come apart well according to the still well preserved structure of the fish flesh. Comparatively, we are better on this last point than fish cooked in the microwave using the ordinary process.

This is a common remark with meats and fish cooked in the microwave. Cooking is done from the outside from the perimeter to reach the center of the product. But when the process is used, the appearance of steam rebalances this situation by subjecting the center to heating at the same time as the perimeter, which can explain a slight saving in time.

^" Cooking in the same square is better, however, ^" and even better when cooked with vegetables.

In general, the process is particularly surprising and brings interest in conventional cooking, and has more added value in microwave cooking. On the other hand, it is very interesting in the microwave as soon as one is in a heating situation. Except for cooking raw vegetables, and other products that can be cooked directly in a tray.

But this is the lesson to be drawn from these examples, taken in large numbers to demonstrate through practice and experience, the value of the process, while showing that cooking must be rethought and for each product redefine rules, cooking powers and times specific to the process, such as cooking in a pressure cooker has its recipes, its heating powers and its times and like microwave cooking has its recipes, its heating powers and its times.

Example 11 - Reheating in special trays for microwaves. (Market for pre-cooked products in a neutral atmosphere or frozen in a tray)

This reheating was chosen to test the mechanical behavior of a microwave-polymer tray assembly in the reheating and / or transformation process under thermal effect, because this set opens up important market horizons.

For the test, a cooked dish prepared in a microwave tray was purchased. Here, the taste result is not directly attributable to the process.

The lid of the tray was removed and the polymer film which is the subject of the present process was put in its place and fixed by adhesive. The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 50% by weight of PEG sequences and 50% by weight of PA-12 sequence .

The thickness of the membrane wall is around 25 μm.

The membrane is supported by a nonwoven. The tray was then put in the microwave for a time slightly longer than that indicated on the packaging of the prepared dish. The film stretched but held on while a little water vapor escaped through the membrane ^" (the microwave wall revealed condensation).

The reheating went well without breaking the film or the tray. The object was not to analyze the taste of the tested kitchen which was in this case an industrial kitchen, but one can say that its taste was unchanged. The process can therefore be applied in reheating to microwave trays to avoid the complexity of film with valves.

Example 12 - Cooking fresh vegetables in microwave trays.

(Market for raw products in a neutral atmosphere or frozen in a tray) This cooking was chosen to test the mechanical behavior of a tray assembly for microwaves - polymer film in the cooking process and / or transformation under thermal effect, because this together opens up important fresh markets.

For the test, a cooked dish prepared in a microwave tray was purchased.

The lid of the tray has been removed, the tray emptied of its contents and the latter replaced by fresh vegetables (a potato cut into cubes and two carrots cut into rings).

The polymer film which is the subject of the present process has been put in its place and fixed by adhesive.

The thickness of the membrane wall is around 25 μm. The membrane is supported by a nonwoven.

The tray was then put in the microwave for a time equivalent to the times experienced for previous cooking trials of fresh vegetables. The film tightened but held while a little water vapor escaped by transfer through the membrane (the wall of the microwave revealed condensation).

The results in terms of appearance, taste and texture were considered very positive.

The process can therefore be applied during cooking and particularly when cooking fresh vegetables with microwave trays to avoid the complexity of film with flaps.

Example 13 - Cooking couscous semolina in a cooked vegetable broth in the microwave. (Market for precooked products in a neutral atmosphere or frozen in a pouch or in a metal box)

This reheating-cooking was chosen to test the process in the case of a dish or set comprising a large mass of liquid and / or water in order to test the vapor permeability and the impermeability to liquids thus opening up to the process a whole fields of application which today means buying in a so-called transport packaging that must be emptied and then reheated and / or cooked and / or processed thermally.

The present verification and the proper functioning of the process makes it possible to apply the process to cases where the product to be reheated and / or cooked is liquid. Sold directly in the bag that contains it, it can go directly to the microwave without having to open the container. The film will allow heating and / or cooking without breaking the sales package and breaking it only for serving. This test went further, however, since we operated in two stages.

1 - Reheating of the liquid product with good resistance of the film.

2 - Introduction of semolina and cooking thereof with still good film resistance.

In both cases, the film tightened but held while a little water vapor escaped by transfer through the membrane (the wall of the microwave revealed condensation). However, no leaks could be observed, which confirmed the good sealing of the film to liquids and opened up a new field of possibility for the process.

The description of the test is as follows: The liquid form includes tomatoes cut into pieces and cooked with zucchini and eggplant in a very liquid and abundant juice. ^~ This liquid form is placed in a polymer bag. The bag is approximately 200 by 200 mm.

The contact surface with the surrounding atmosphere is therefore 400 cm ² . The bag consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 50% by weight of PEG sequences AND 50% by weight of PA-12 sequence . The thickness of the membrane wall is around 25 μm.

The membrane is supported by a nonwoven.

After reheating on the order of three minutes, the bag, which is simply knotted, is untied and the couscous semolina introduced. Industrially it would be very possible to envisage a double bag or a bag with double compartments which would open at the end of the first phase.

A second phase follows, roughly of the same order of time in this case but without this being a general sign.

At the opening, one can appreciate a well impregnated semolina pleasant in texture and taste.

Example 14 - Reheating in a pan of goat cheese for a warm goat cheese salad.

(Household film and industrial process market)

This reheating is done without major technical reason, but simply because it is thus fast, economical and practical and allows pleasant entrees and salads.

We place at the bottom of the pan three rounds of fresh goat cheese, accompanied by walnuts.

The pan is closed with a sheet of polymer film. The useful surface of the sheet is that corresponding to the diameter of the pan which is 135 mm.

The contact surface with the surrounding atmosphere is therefore 143 cm ² .

The sheet is held in place with several thin elastic bands over the film around the pan. The film consists of a semi-permeable membrane formed of a polymer material based on poly (ether-block-amide) consisting of 50% by weight of PEG sequences and 50% eh ^"Weight sequence PA- 12.

The thickness of the membrane wall is around 25 μm.

The membrane is supported by a nonwoven. It is made on a SCHOLTES TL600 GEA2 hob, on the smallest fire known as an “auxiliary burner” giving a power of 861 mth / h for a flow of 98 l / h with G 20 gas - Natural 20 mbar, but cooking is started and carried out in its entirety in the pilot position, on the lowest flow fire, the cooking is started and carried out in its entirety in the pilot position.

The cooking time is less than four minutes for the test.

The energy saving is considerable. The cheeses are hot, slightly drier, they crumble pleasantly, their taste is pronounced and they seem lighter in the stomach.

Example 15 - Cooking so-called “fried” eggs, simply in a saucepan.

(Household film and industrial process market local authorities market and local suppliers)

Fried eggs are preferably cooked in scrambled egg or omelet-type kitchens, because the egg is in two non-homogeneous phases which makes cooking more complex.

The egg is broken directly in the container, without water, oil or fat whatsoever.

The pan is closed with a sheet of polymer film.

The useful surface of the sheet is that corresponding to the diameter of the pan which is 135 mm.

The contact surface with the surrounding atmosphere is therefore 143 cm ^2. The sheet is held by means of several fine elastic bands passed over the film around the pan.

The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 50% by weight of PEG sequences and 50% by weight of PA-12 sequence . The thickness of the membrane wall is around 25 μm.

The membrane is supported by a nonwoven.

Is used ^'as eή ¹ witness the same film without configuration.

Is used as ^2nd witness the same configuration without film microwaves. Is used as a ^3rd control the same configuration with film microwaves. The cooking is done on a SCHOLTES TL600 GEA2 hob, on the medium flow fire called "Semi-fast burner" giving a power of 1550 mth / h for a flow of 168 l / h with G 20 gas - Natural 20 mbar, but cooking is started and carried out in its entirety in the pilot position. The cooking time is less than four minutes for the test.

The energy saving is considerable.

Although the cooking was done "dry", the pan is not marked. The egg is peeled off with a wooden spatula without the yolk piercing. The appearance is very pleasant. Before even tasting you can feel that the egg will be light in the mouth. which is the case. The result is estimated to be very, very good.

Comparatively:

You have to stop cooking in a pan without a film, the egg begins to smell burnt without the upper surface of the egg appearing cooked. The microwave configuration without film does not work. White is too dense and heavy, yellow cooks at the same time and therefore it is overcooked. Cooking is done from the outside to the center, it is difficult to stop the process earlier. A solution might be to cook more slowly but in this case the duration would no longer be to the advantage of the microwave. The results are not as good as those of the pan when cooking with the film in the microwave.

This is not surprising when you know what it takes to cook eggs in the microwave.

Knowledge of the community food industry suggests that this application can provide interesting openings. We can also think of direct cooking in an individual dish that can pass over a flame.

It ^"is important to note that cooking without fat is particularly healthy and moreover light and tasty.

Example 16 - Cooking in a pan (enamel base) of a roast with potatoes.

(Household film and industrial process market) This example is recorded because all the experiments indicated mainly concern individual parts where the process is fast, practical and very economical. But it must be shown that the process is also valid for larger quantities and that it also gives very good results. A 500 g "roast" roast beef is placed in the bottom of a pan. It should be noted that it is not covered with any element of fat but that a spoon of oil is spread on its upper face so that the coarse salt and the herbs including the thyme with which it is sprinkled, hang better .

Some shallots are cut into rings and placed at the bottom of the pan with two potatoes cut into cubes of approx. Lxlx 2 cm.

We close the pan with a sheet of membrane.

The useful surface of the sheet is that corresponding to the diameter of the pan which is 195 mm.

The surface is therefore 298 cm ² . The sheet is held in place by elastic bands on the outer rim of the pan.

The sheet consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 50% by weight of PEG sequences and 50% by weight of PA-12 sequence . The thickness of the membrane wall is 25 μm.

A control test of the same configuration is not carried out, all of the preceding witnesses sufficient to validate the comparisons and the cooking of this product in the oven being also perfectly controlled.

The cooking time is thirty minutes for the test, the meat is cooked between rare and medium but could have been left shorter to be more rare.

As with the previous meat cooking tests, it is surprisingly tender. The potatoes are tender but slightly firm and otherwise impregnated with a red juice which remained in the cooking container; it is very tasty. In mixed cooking, the advantage over baking from this point of view is still evident. The shallots are also very tasty.

The result is considered excellent. Two other examples are presented under the same title because they correspond to the same market, that of frozen products sold in individual packages.

EXAMPLE 17 Microwave Frozen Products in the Membrane Serving as Individual Packages of the Portion or Ground Beef Type

(Market of frozen in individual portion or not) This example is recorded because the setting in film valve before the stage of freezing then the thawing, and the reheating and / or the cooking and / or the transformation under thermal effect constitute an application and a market in itself important and clean.

Products as indicated here are put directly in the microwave and thawed and cooked in the minimum position unlike the cooking mode indicated for these products and which are in the microwave in the maximum position, and this after defrosting times corresponding to the usual times .

In both cases, the packaging consists of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 50% by weight of PEG sequences and 50% by PA-12 sequence weight.

The thickness of the membrane wall is around 25 μm.

The membrane is supported by a nonwoven.

The results are quite convincing and documented with the results of the various tests mentioned above. Example 18 - French fries obtained in the microwave from fresh potatoes.

(Market for ^" household film and industrial processes)

We know that the fryer remains the only way to make fries with the drawbacks that we know. Fat product and energy consumer. We also know that the microwave is not everything and in particular fried food in the case of which we do not know how to control temperatures. But potatoes are a complex product to cook in some of its forms. Also in the case of fries, experiments are an approach that should be completed.

We take potatoes which we cut into strips like usually french fries.

At first, they are cooked as well.

In a second test, after the potato has been cut, the fries, still raw, are put in a container known under the brand "tupper-ware" with a few drops of oil and the whole is vigorously stirred. A minimum of oil is deposited in a thin film on the potato strips and we proceed to cooking.

In both cases, they were placed on a plate, in a dish branded "Arcopal" and finally directly in a film and in all cases, spread so as not to stick between them. The dish and the plate were covered with a sheet of the same polymer film.

The sheet of the pocket is made up of a semi-permeable membrane formed of a polymer material based on a poly (ether-block-amide) composed of 40% by weight of PTEG sequences and 60% by weight PA-12 sequence. The thickness of the membrane wall is around 12 μm.

The tests were also carried out with a sheet consisting of a semi-permeable membrane formed of a polymer material based on a poly (ether-blocks-amide) composed of 50% by weight of PEG sequences and 50% by PA-12 sequence weight. The thickness of the membrane wall is around 25 μm.

The membrane is supported by a nonwoven.

The cooking time in a 1350 W microwave oven at maximum power was 5 to 8 minutes.

The result is not bad but these fries are in one case a little dry and too crisp and in the other, they are soft inside while standing, but not crisp as made in an oil bath. Those made in the pocket seem the best and a way in this direction could be deepened. The trials did not go any further, but they made it possible to approach a pleasant consistency of French fries made from fresh potatoes in a very short time, little energy and practically no fat at all.

The time and energy savings are enormous if you realize that there is no preheating to do.

This very "technical" cooking remains to be improved.

Another advantage noted in the test, there was no noticeable smell of frying in the room.

It should be noted that this is a very practical way to make fries for one person, if in particular in a family, a child wants fries while the parents do not want them.

Naturally, and as already follows from all of the above, the invention is not limited to the conditions or quantities which have been specified with regard to examples chosen to illustrate the invention in its preferred embodiments.

In general, the very gentle cooking method results in good texture recognition, great tenderness, respect for cooking utensils, speed and practical ease, which are the strongest demands of the consumer. Generally always and in all cases, we were able to judge on the digestive level, the extreme lightness of this cuisine.

Claims

1- Cooking process and / or transformation under vapor pressure according to which the product is placed with an additional quantity of solvent in a container or container delimiting a closed volume comprising a means for discharging the solvent and the product is subjected to a energy supply, this process being characterized in that:

- we provide ourselves with an envelope or container comprising at least locally a continuous non-micro-perforated membrane permeable to the solvent in the vapor state and impermeable to the solvent in the liquid state and - the energy supply is instantly limited and in time to an amount sufficient to allow the passage in vapor form of the solvent at pressure and temperature conditions allowing heating and / or cooking and / or processing under thermal effect but at an amount less than that capable of producing rupture of the aforementioned membrane. 2- A method of cooking and / or transformation of state under thermal effect according to claim 1 characterized in that a valve is formed with a membrane permeable to solvent in the gaseous state and impermeable to the solvent in the liquid state.

3- A method of heating and / or cooking and / or transformation of state under thermal effect according to claim 2 characterized in that the container and the valve are chosen and implemented to promote the stabilization of the rise in pressure due to the presence of said vapor of solvent in the vicinity of the zone of wall of valve not adherent to said materials, by diffusion of said vapor through the wall of the valve.

4- A cooking method according to claim 1 characterized in that the diffusion of the vapor is ensured thanks to the mobility of the vacant sites of the membrane and to the chemical affinity of the gaseous molecules of the solvent with the components of the membrane.

5- Means for implementing the method according to any one of claims 1 to 4 characterized in that one uses a continuous non-micro-perforated membrane permeable to a solvent in the gaseous state and impermeable to said solvent to l liquid state. 6- Means according to claim 5 characterized in that the membrane is made from a copolymer of flexible polyether blocks and rigid polyamide blocks.

7- Means according to claim 5 characterized in that said membrane is a polyester.

8- Means according to claim 6 or 7 characterized in that the thickness of the membrane is less than 1000 microns and is preferably between 10 and 100 microns and preferably between 10 and 60 microns so as to form a film.

9- Means according to claim 5 or 6 or 7 characterized in that the membrane is fixed to a nonwoven or a woven.

10- Means according to claim 6 characterized in that the polymer membrane is a copolymer formed of rigid sequences ensuring the mechanical strength of said membrane and flexible sequences of elastomers ensuring the permeability of the membrane by the mobility of vacant sites. 11- Means according to claim 5 characterized in that they comprise a membrane, permeable to solvent in the vapor state and impermeable to said solvent in the liquid state, closing a container.

12- Means according to claim 11 characterized in that the container is a tray of material capable of being introduced into a microwave oven. 13- Means according to claim 11 characterized in that the container is a tray capable of being introduced into an oven.

14- Means according to claim 11 characterized in that the membrane alone constitutes the container.

15- Means according to claim 5 characterized in that the membrane is permeable to oxygen and / or carbon dioxide and impermeable to nitrogen.

16- Means according to claim 5 characterized in that the membrane is ^" sealed against bacteria and / or microorganisms