LT4908B - Continuous combined microwave and steam cooking - Google Patents

Abstract

The invention relates to a method of continuous production of a green dough product, characterized in that it consists of microwave cooking and steam cooking stages, microwave cooking essentially ensures rapid baking in the center of the baked product and formation of a sufficiently stable jelly structure, while steam cooking complements the microwave baking, preventing cooking. break down and dry

Description

The present invention relates to a method of preparing food products by combining microwave cooking and steam cooking, to an apparatus implementing this method and to a product prepared in this way.

The object of the invention is to prepare a baked product of stable structure by continuous fast cooking. This method is particularly applicable to the preparation of fish semi-finished products.

Methods of baking a continuous steam food preparation, such as fish-based, are already known. This method involves long cooking times and / or long oven lengths, for example from 10 to 20 meters, when the products move smoothly in the oven at 3 to 7 m / min. Such a problem is encountered, for example, in baking evenly moving fish dough larger than (1-2) centimeters thick, which is then subjected to mechanical processing, such as grating, slicing. This necessitates the use of a thinner tape to properly bake the product. This greatly reduces the rate of preparation.

In addition, much faster microwave cooking techniques are known. However, using such techniques makes it very difficult to obtain a product of the required stability, free from dry spots or deformation. For example, when molded fish dough pieces move smoothly in a (4-5) meter long microwave oven, the shape of the baked product at the outlet of the oven is strongly altered and its surface is dried.

In fact, microwave baking exhibits an effective increase in the temperature of the baked product from (0-10) ° C at the inlet of the oven to (65-75) ° C in the threshold temperature range. With such rapid baking, with typical (2-4) kW microwave power per oven block, the gelatinization begins very early in the product center, avoiding deformation of the product in the oven, especially if the dough has a green dough structure it is not stable for a long time, because the dough shrinkage changes the shape of the product before it stabilizes during baking.

In contrast, beyond this threshold area, continued microwave baking at higher temperatures (75 to 90 ° C) in the center of the product at high power levels would result in overheating of the product with excessive evaporation of water. This causes the product to swell undesirably, sometimes disintegrate, change its shape, and dry the surface of the product.

The present invention seeks to overcome these disadvantages by providing a method that allows the product to rapidly solidify and to prevent deformation of the baked product.

The purpose of the method is to enable rapid simultaneous baking of the product at its center and on the surface.

The invention also aims to greatly reduce the dimensions of the equipment and the required oven length for continuous cooking.

The invention also seeks to provide great applications ranging from small shapes of a few centimeters to wide strips of product which are baked and machined.

Moreover, the invention is applicable to a wide variety of baked product formulations. For example, the invention relates not only to fish dough, but also to a mixture of fish dough and fish fiber.

To this end, the present invention has the object of providing a process for the continuous preparation of a food product from a green paste comprising the steps of microwave cooking and steam cooking; microwave baking mainly ensures rapid baking in the center of the product, which produces a fairly stable jelly-like structure, while steam cooking complements the microwave baking without causing the baked product to dry or crack.

In one embodiment, the microwave baking stage precedes the steam cooking stage.

In another embodiment, microwave cooking and steam cooking take place simultaneously.

The method implements a microwave-type device comprising an inlet and an outlet, and comprising the steps of:

- inserting the baked product through the oven inlet;

- transferring the baked product from the oven inlet to its outlet, with microwave baking such that the microwaves are uniformly distributed in the baking chamber;

- removing the baked product from the oven and cooling it.

The method implements a microwave oven consisting of sequentially arranged baking modules and comprising the steps of:

- the first step of a microwave baking module at high microwave power, typically from 2 to 4 kW per module, to increase the temperature of the baked product to (65-75) ° C the instant microwave baking module or modules at the exit; fast baking prevents deformation of the molds;

- a second stage of medium steam boiling to bring the product in the center to a temperature of 75 ° C to 90 ° C, but slowly raising it to avoid splitting and completing the surface baking without drying.

In one embodiment, the method comprises a medium microwave baking step using a sufficiently reduced power, typically from 1 to 3 kW per module, to complete surface baking without changing the molds.

The method provides for a vapor stream which circulates in the modules in the same or opposite direction of movement of the products in the furnace.

In one embodiment, the baked product has an oven duration of from 30 to 120 seconds in combination with microwave and steam cooking, with the steam temperature in the cooking tunnel at 75 to 130 ° C with a total radiated microwave power of 3 to 12 kW distributed along oven with a cooking capacity of 50 to 140 kilograms per hour.

Incidentally, the method may include filling the molds prior to baking, presenting the baked product in the form of filled molds, typically 1 to 3 cm wide and 1 to 5 cm thick, and having a weight of 3 to 300 g, typically 3 to 20 g.

In one embodiment, the baked product is provided in strips having a width of more than 2 cm and a thickness of 1 cm, typically 30 cm to 1 m wide and 1 to 5 cm thick.

A process that may include a coloring step prior to baking, by spraying, coating or squeezing a viscous colored material.

In one embodiment, the material is fish dough, which contains more than 30% washed and refined gelatinized fish meat, particularly with stabilizing cryoprotectants preserving it during freezing and less than 80% moisture.

In another embodiment, the baked product is a mixture of fish dough and fiber; The fibrous material consists of a mechanical separation of fibers obtained by crushing of fiber from 1 gm to 1 mm or of fine fiber from 0,1 mm to 1 mm obtained by mincing of semi-finished fish or marine natural waste wastes in which the fiber content of the dough is between 5 and 60% by weight, depending on the product structure desired, usually between 5 and 30%.

Typically, the extruded fiber comprises 15 to 50% dry matter, especially 25 to 40% dry matter; this dry matter contains a total of at least 35% protein, fish and / or other seafood processing residues, mainly containing seafood protein in the form of minced meat, loin, pulp, crab sticks extracts and, where appropriate, seafood extracts such as fish oil , fishmeal, shellfish, chitosan, fish collagen.

Fish semi-finished products intended for the production of fine fiber shall contain more than 50% meat suitable for gelatinisation, after washing and refining, in particular with stabilizing cryoprotectants preserving it during freezing, and having a moisture content of less than 80%.

According to a second aspect, the invention relates to a device for implementing a method described above comprising a baking product preparation means, a baking chamber, a microwave oven, a steam cooker, and a conveyor.

Microwaves include:

- at least one module for high speed microwave cooking required for high speed microwave cooking;

- at least one steam cooking module required for medium steam cooking after high speed microwave cooking;

- microwave generator set-ups with total power from 3 to 12 kW, with at least one high speed microwave cooking module with one generator, with power from 2 to 4 kW per module;

- one steam generator for one or more slow cooker modules;

- a device for regulating the cooking intensity in each module.

In one embodiment, the microwaves comprise at least a medium microwave baking module, with or without a steam cooking module (s), a set of microwave generators delivering an average microwave power of 1 to 3 kW uniformly distributed in the average microwave baking module or modules.

The microwave generator emits microwaves on at least one side of the baking product, the generator itself is mounted on the oven wall or in a chamber separated from the oven, which is connected to the oven by waveguides.

According to a third aspect, the invention relates to a product using the above-described method, wherein a baking oven outlet provides a stable jelly structure, at least 1 cm thick and wide, in the form of casts or strips.

Other objects and advantages of the invention will become apparent upon consideration of the description relating to the drawings in which:

Figure 1 is a schematic representation of a baking apparatus implementing the method of embodiment 1;

- Figure 2 depicts a molded product at the exit of a baking oven;

- Figure 3 depicts a baked ribbon product.

We will first describe the method of simultaneous microwave cooking and steam cooking in a continuous operation oven.

The purpose of microwave baking is to rapidly provide the center of an insulated or strip-shaped piece of energy with a very short time to gelatinize the proteins and bake the other ingredients of the product.

The purpose of steam cooking is to supplement the baking to achieve the optimum baking temperature at the center and on the surface of the product.

According to the method described, additional but different microwave energy is supplied to complete the baking in the threshold zone (65-75) ° C to the desired temperature (75-90) ° C at the center of the product.

To carry out the method, a device 1 consisting of a bakery product means, which includes an oven 2, is used. The oven 2 has an entrance zone 3, a baking zone 4, an exit zone 5. The baking zone comprises a chamber 6 forming a baking tunnel.

The furnace 2 is equipped with an automatic conveyor type of belt conveyor 7 which holds the baked product 9 which moves in the D direction from the entrance of the oven to its exit, from which baked goods 9 are removed.

The baking product 9 passes through a supply funnel area into which a green dough from 0 to 10 ° C enters. The embodiment described relates to fish dough.

From the funnel 10, the dough enters the dough maker, which forms green dough into pieces (2-3) inches thick and wide.

These formed pieces of green dough are colored with a sprinkler 11 before continuously entering the oven inlet; on tape 7 they are arranged in parallel in the D direction.

After passing the baking tunnel 6, which is open at its inlet end 12 and outlet end 13, the pieces are baked; they retain their pre-bake shape but have a stable jelly-like texture before cooling and are suitable for subsequent stages of the process, such as conditioning or slicing.

The furnace consists of:

- a microwave generator 14;

- steam generator 15.

In a first embodiment, microwave baking is performed throughout the length of the tunnel 6. Tunnel 6 is made up of a first module starting at its entrance

16, second module 17, third module 18 having lengths L1, L2, L3 respectively.

The direction of movement in the D direction is equal to, for example, 3 m / min, where the baked product stays in the chamber for 3 to 120 seconds with microwave and / or steam, with a steam temperature of 75 to 130 ° C and a steam generator pressure of 5 up to 5.5 bar, and the total radiated microwave power from 3 to 12 kW is distributed over the entire length of the furnace.

Each module 16, 17, 18 has two microwave power generators 19 mounted on the oven wall 20.

The first module 16, with a Li length of 1 meter, is used for high speed microwave baking with a power of 2 to 4 kW and a temperature of 65 to 75 ° C at the center of the baking product upon reaching the module output.

The second module, with a length of L2 equal to 1 meter, is used for less rapid cooking than in the first module, using medium microwave and steam cooking simultaneously in this module.

The microwave power is 1 to 3 kW, lower than in the first module

16th

The third module 18, with a length L3 equal to 1 meter, is used for simultaneous medium microwave and steam cooking, as in the second module.

The microwave power is 1 to 3 kW, less than the second module

17th

. The steam boiling provided in the second module 17 and the third module 18 enables baking at the desired temperature (75-90) ° C, which is reached at the center of the product being transported.

Microwave cooking in reduced power modules 17 and 18 completes surface cooking.

This avoids crusting and water loss during dry baking.

The generators 19 of each module are connected to the main generator 14 by a main branched waveguide 21.

Steam boiling creates a stream of steam directed in the opposite direction of the baked goods. From the steam generator 15, steam passes into the inlet 23 in the wall 20 of the third module 18 at the level of its rear end 23a. The steam in the tunnel is distributed around the baked goods so that they are baked uniformly throughout the volume. From the tunnel, steam is directed through the outlet 24 in the wall of the second module 17 to the inlet of the second module 18 through the outlet pipe 25. The steam thus blows the second module 17 and the third module 18.

Thus, the furnace becomes more compact. The length of the furnace shown in Figure 1 is equal to 5 meters. Meanwhile, steam-only stoves are 15 to 20 meters long. Such a furnace is easy to install into classical production lines. Such a line may include a plurality of parallel-connected furnaces for products of different shapes and forms, such as one furnace for shaped pieces, one furnace for strip products which are baked and cut and cooled.

For a better coloring, predominantly color it with a sprinkler before baking.

From the description of this first embodiment, it can be seen that microwave devices are compatible with the length of time the products are in the oven and their linear density on the belt conveyor.

Other embodiments are also possible by varying the length and number of modules. The baking results were found to be satisfactory when the furnace is made up of at least two modules: the first module is high power, typically 3 to 4 kW, to rapidly increase the temperature and fix the shape of the product.

According to a second embodiment, the steam is directed in the same direction rather than in the opposite direction of movement of the product. It enters through the second module 17 and is removed through the third module 18. In one embodiment, steam is directed directly to the third module and to the second module using two different vapor pipes.

In a third embodiment, steam cooking is started in the first module simultaneously with high power microwave cooking.

In a fourth embodiment, microwave baking is provided in the first module when the temperature in the product center reaches (65-75) ° C. Slow microwave baking is not used here. The furnace has a second module, but a third module is not required. In this case, steam cooking completes the baking of the whole product at a temperature of (75-90) ° C in the center.

From the embodiments described, it will be appreciated that different ovens, especially with different types of microwave generators, steam generators, chamber materials, can be used to realize the desired baking. In most cases, depending on the apparatus used, it is possible to use a branched central generator connected to the modules or one or more autonomous generators installed in the modules. What's more, you can change the number according to your needs, for example from four to six modules. In addition, an apparatus having a total power of 3 to 12 kW is described; power can be increased and adjusted, for example, between 25 and 60 kW for industrial applications with a production capacity of 500 kg per hour.

The bakery products used are now described in more detail.

According to a first embodiment of this product, the product is green fish dough containing 30 to 60% fish meat, 25 to 40% water, 5 to 15% thickeners, such as starch or potato flour. In addition to these basic ingredients, gelling agents such as carrageenan, xanthan, gelatin or guar flour may be added.

According to a second embodiment of this product, the product is a mixture of a dough such as the fish dough described above and a fibrous material, if necessary textured by blowing air into the dough before mixing. This texturing can be done with one part of the air {blowing into one part fish dough or 0.5 part air into one part fish dough. The air content can vary from 0.5 to 1. This allows the dough to be more or less air filled with different structures. The mixture of air and fish dough gives you a new texture of dense, light, elastic, juicy dough.

According to the first embodiment of the second embodiment, the fiber is obtained by squeezing fish dough. The fibrous material is composed of:

ΙΟ fiber obtained by extrusion, having a diameter of between 0,1 and 1 mm and having a diameter of between 1 μίτι and 1 mm.

The mixture is mainly composed of fish and / or other seafood proteins: fish, fish meat, crab sticks, squid, crab, octopus, shrimp, molluscs and others. Fish proteins include fish and / or other marine products.

According to a second embodiment of the second embodiment, the fiber material is composed of fine fibers obtained by grinding a fish mixture.

For example, fine fiber is derived from fish dough consisting of 80% fish filling, 7% starch, 7% water, 3% salt, 3% flavoring. The dough is formed at a temperature of 1 to 4 ° C by placing it in an airtight shell which determines the shape, e.g., a hose (50-80) cm long and (10-15) cm in diameter, into a shrink bag, into a plastic shell or plastic mold. This dough is baked in its airtight container at (80-95) ° C (1-1.5) hour, then stored at -20 ° C until use. The product is finally stored at 0 ° C to -10 ° C until it shrinks to produce fibers less than 1 mm in diameter and (0.5 to 5) cm in length.

In another embodiment, the fine fiber is obtained by crushing a pressed fish dough consisting of, for example, 60% fish filling, 19% water, 10% vegetable fat, 1.5% salt, 1% flavoring, 7% starch and 1.5%. % of gelling agents.

According to a third embodiment of the second embodiment, the fiber is composed of natural fried or crude fibers such as small pieces of natural meat of fish, crab or other seafood obtained by mechanical separation of myotomes. The fibers are more or less fragmented, more or less long. The raw materials used to obtain these fibers are usually selected from the following categories:

- fish fillets or cuts and / or pieces of fresh meat or offal;

- Of fatty or lean fish:

- white or pink or blue fish (whiting, whiting, cod, salmon, trout, mackerel, etc.);

- fresh or frozen fish, whether natural or smoked.

Precise examples of seafood materials are described. Other applications may be chosen for the implementation of composite continuous microwave baking, in particular for cooking pasta, the structure of which must be stabilized by rapid heating but without drying. This is the case, for example, in the preparation of certain cheese or sausage semi-products, such as ham dough, small fish pies, poultry or fish pieces, cheeseburgers, mini sausages.

Claims (21)

1. A method of producing a continuous food product from green dough, characterized by the simultaneous use of microwave cooking and steam cooking; microwave baking essentially ensures rapid baking at the center of the product to form a fairly stable jelly-like structure, while steam cooking complements microwave baking, preventing the baked product from drying out and breaking down. 2. The method of claim 1, wherein the microwave cooking is preceded by steam cooking. 3. The method of claim 1, wherein the microwave and steam cooking are performed simultaneously. The method of claims 1-3, wherein a microwave-type device is provided having inlet and outlet openings, comprising the steps of: - inserting the baked product through the oven inlet; - moving the baked product from the oven inlet to its outlet, with microwave baking such that the microwaves are uniformly distributed in the baking chamber; - removing the baked product from the oven and cooling it. A method according to any one of claims 1 to 4, wherein a microwave oven is formed comprising a plurality of sequentially arranged baking modules, comprising the steps of: - the first step of a high speed microwave baking module at high microwave power, typically from 2 to 4 kW per module, to increase the temperature of the baked product to 65-75 ° C at the outlet of the high speed microwave baking module or modules, when deformation of the molds is avoided by rapid baking; - a second stage of medium steam boiling, aimed at raising the temperature in the center of the product from 75 ° C to 90 ° C, but slowly increasing it to avoid fractures and to add surface baking without drying. 6. A method according to claim 5, characterized in that it utilizes a medium microwave baking stage using a sufficiently reduced power, typically from 1 to 3 kW per module, to complete surface baking without changing the shape. 7. A method according to claim 5 or 6, characterized in that it generates a flow of steam circulating in the modules in the same or opposite direction to the direction of movement of the products in the furnace. 8. A method according to any one of claims 1 to 7, wherein the product is baked in an oven using a combination of microwave and steam cooking for 30 to 120 seconds at a temperature of 75 ° C to 130 ° C in a boiling tunnel, where the microwave power of 3 to 12 kW is distributed along the oven and the cooking capacity is 50 to 140 kilograms per hour. A process according to any one of claims 1 to 8, comprising the step of filling the molds, wherein the baked product is presented in the form of filled molds, typically 1 to 3 cm wide and 1 to 5 cm thick, and having a weight of 5 to 300 cm. g, typically 5 to 20 g. 10. A process as claimed in any one of claims 1 to 8, characterized in that it provides a baked product in the form of strips having a width of more than 2 cm and a thickness of 1 cm, typically 30 cm to 1 m wide and 1 to 5 cm thick. 11. A process according to claim 9 or 10, characterized in that prior to baking, a coloring step is carried out by spraying, coating or squeezing the viscous colored material. 12. A process according to any one of claims 9 to 11, wherein the dough contains fish dough containing more than 30% washed and refined gelatine fish meat, in particular with stabilizing cryoprotectants preserving it during freezing and less than 80% moisture. 13. A method according to any one of claims 9 to 11, wherein the mixture is a mixture of fish dough and fiber as a baked product; The fibrous material consists of a mechanical separation of fibers obtained by crushing of fiber from 1 gm to 1 mm or of fine fiber from 0,1 mm to 1 mm obtained by mincing of semi-finished fish or marine natural waste wastes having a fiber content of between 5 and 60% by weight, according to the composition of the product, generally between 5 and 30%. 14. The method of claim 13, wherein the fiber is extruded comprising 15 to 50% dry matter, in particular 25 to 40% dry matter; this dry matter contains at least 35% total protein, fish and / or other seafood processing residues, mainly containing seafood protein in the form of minced meat, loin, pulp, crab sticks extracts and, where appropriate, seafood extracts such as fish oil, fishmeal, shellfish, chitosan, fish collagen. 15. The method of claim 13, wherein the fish semis are prepared for use in the manufacture of fine fiber containing more than 50% gelatine washed and cleaned fish meat, in particular stabilizing cryoprotectants preserving it during freezing and less than 80%. moisture. Production apparatus for carrying out the process according to any one of claims 1 to 15, characterized in that it comprises bakery products, microwaves, steamers, conveyors. 17. The apparatus of claim 16, for the process of any one of claims 1 to 15, wherein the microwave oven comprises: - At least one module for high speed microwave cooking required for high speed microwave cooking: - at least one steam cooking module required for medium steam cooking after high speed microwave cooking; - microwave generator set-ups with a total power of 3 to 12 kW with at least one high-speed microwave cooking module with one generator with a power of 2 to 4 kW per module; - one steam generator for one or more slow cooker modules; - a device for adjusting the cooking intensity in each module. 18. The apparatus of claim 17, wherein said microwave cooking means comprises a medium microwave baking module, with or without a steam cooking module (s), a microwave generator assembly providing an average microwave power of 1 to 3 kW, uniformly distributed. in the Module or Modules for Medium Microwave Baking. 19. The apparatus of claim 17 or 18, further comprising a microwave generator emitting microwaves on at least one side of the baked product, the generator itself being mounted in a furnace wall or in a chamber separated from the furnace and connected to the furnace by waveguides. 20. The apparatus of any of claims 1-4, wherein the total microwave power is from 25 to 60 kW with a production capacity of 300 to 500 kilograms per hour. 21. The product of the process according to any one of claims 1 to 15, characterized in that it is formed at the exit of the baking oven in the form of stable jelly-shaped pieces or strips of at least 1 cm in width and thickness.