Method and installation for smoking a food product

Abstract

Method for preparing a food product, comprising the steps of: a. Injecting smoke into contact with the food product, in a tank (32) of a mixer cooled to a temperature leading to condensation of the smoke, b. Evacuating the smoke through a discharge circuit (7) connected to the tank.

Description

Method and installation for smoking a food product

[0001] The present invention relates to the preparation of smoked food products, particularly those based on meat or fish.

[0002] Patent application EP1321041 describes a method for smoking a food product, based on the use of a single-jacketed mixer and the injection of a smoking agent, which may be liquid or gaseous, into its rotating drum. The smoking operation may be preceded and / or followed by a drying operation.

[0003] When using a liquid smoking agent consisting of smoke condensate, it can be atomized in the tank by maintaining a negative pressure in the tank using a vacuum pump connected to the mixer, for example, at a pressure between 20 and 45 mbar. Steam can be injected into the tank simultaneously with the smoke condensate.

[0004] When using a gaseous fuming agent, it can be introduced at one axial end of the tank, while the circulation of this fuming agent is ensured by suction extraction at the opposite end, with the pressure in the tank during this phase being between 100 and 500 mbar. A subsequent drying operation is recommended to improve the fixation of the fumes on the treated products.

[0005] Application EP3695726A1 describes a smoking installation comprising a rotating tank into which smoke is injected through an inlet located substantially on the tank's axis. Smoke extraction is carried out via a duct connected to an extractor. A valve is located downstream of the extractor to regulate the smoke extraction rate to the outside; some of the smoke can be recycled back to the smoke generator. Steam injection can take place in a smoke supply duct upstream of the tank. After smoke extraction, a vacuum can be created in the tank.

[0006] There is a need to further improve smoking processes and facilities in order to benefit from a process that is simple to implement and leads to excellent results in terms of appearance and taste quality of the products.

[0007] The invention aims to address this need.

[0008] The invention thus relates to a process for preparing a food product, comprising the steps of: Injecting smoke in contact with the food product, into a tank of a mixer cooled to a temperature leading to condensation of the smoke, Preferably, injecting water into the tank, Evacuating the smoke by an evacuation circuit connected to the tank.

[0009] Step c) can take place continuously during step a) or intermittently. The same applies to step b).

[0010] Preferably, the mixer tank has a double jacket, and its cooling is achieved by circulating a refrigerant liquid through the double jacket.

[0011] The invention allows for good fixation of the smoke on the product, thanks to the cooling of the tank, and the injection of water is advantageous because it promotes the condensation of the smoke.

[0012] This results in smoked products that are particularly attractive to the consumer.

[0013] The term "smoke" refers to any smoking agent obtained from plant-based products, in the form of logs, chips, or sawdust, preferably from walnut, beech, oak, apple, fir, cherry, maple, or a mixture thereof. The smoke can be generated by friction. It is also possible to use smoke generated from liquids or smoke flavorings.

[0014] The products placed in the tank can be free to move around inside it, due to the rotation of the tank.

[0015] Preferably, the smoke is injected using a smoke delivery system with an accelerator located upstream of the tank. This accelerator can be located downstream of a smoke generator. It may include a rotating turbine or propeller.

[0016] The overpressure generated at the accelerator outlet is, for example, between 85 and 400 Pa. The gas flow rate at the accelerator outlet is, for example, between 140 and 275 m³ / s 3 / h.

[0017] Preferably, the intake and exhaust of smoke take place on the same side of the tank, preferably its front side, through which the loading and / or unloading of the food product to be treated can also be carried out.

[0018] Water is preferably injected into the tank by atomization, that is, in the form of a mist of fine water droplets. The water injection can be carried out approximately along the longitudinal axis of the tank. Water can be injected intermittently when the mixer is small and continuously when it is large. The temperature of the injected water can be controlled by means of a heat exchanger, either hot or cold. The process may include the injection of steam into the tank, particularly simultaneously with the water injection by atomization.

[0019] Preferably, the amount of water injected remains relatively small so as not to saturate the product and to preserve its attractive appearance. For example, the amount of water injected ranges from 0.2% to 1.5% of the mass of the product introduced into the tank. The water is sprayed at a rate of 0.5 l / h to 2 l / h in the case of continuous spraying.

[0020] The smoke circulates within the exhaust system advantageously without suction, except at the end of the cycle to facilitate the evacuation of smoke from the mixer tank. This avoids the drawbacks of smoke recirculation, namely the concentration of certain compounds that could lead to explosive conditions.

[0021] However, when smoking conditions permit, at least partial recirculation of smoke between the tank and the smoke generator can be planned, with detection of an accumulation of one or more predefined gaseous compounds likely to lead to explosive operating conditions, as detailed later.

[0022] The smoke exhaust system can vent directly into the atmosphere, but preferably includes a damper to control the smoke density in the tank during smoking. This damper can be, for example, a passive damper or a damper electrically controlled by the system's PLC. The damper can be controlled based on the return flow from a concentration probe of a predefined compound or from an explosimeter, particularly in cases of at least partial smoke recirculation.

[0023] The process may include, as mentioned above, at least partial recirculation of the flue gases between the flue gas generator and the vessel. In this case, preferably, the process includes monitoring using at least one gas explosimeter-type sensor for the recirculated gases. The concentration of certain critical compounds in the recirculated gases, such as CO, H2, CH4, and / or VOCs (organovolatile compounds), can be monitored.

[0024] In one example of implementing the process, the food product is subjected to a preliminary evaporative drying operation in the tank before smoking.

[0025] In the presence of a double jacket, this evaporative drying can be done with circulation of a hot fluid in the double jacket.

[0026] Drying the surface prepares it and facilitates the deposition and absorption of smoke, resulting in smoked products that are particularly attractive visually, in terms of taste and consistency.

[0027] Preferably, the cooling of the mixer during the smoking operation is chosen so as to maintain the food product during the smoking operation at a temperature between -10° and +12°C, better between -2°C and +10°C.

[0028] In the presence of a double jacket, the temperature of the fluid circulating in the jacket is set to a temperature adapted to the desired cooling.

[0029] The process can be implemented with the same tank closure cover, through which the injection of smoke, steam, evacuation of smoke, injection of water, and creation of vacuum are carried out.

[0030] In one variation, the process is implemented with two different lids: one used for creating a vacuum in the tank and injecting steam, and the other for smoking, with the injection of smoke and water and the evacuation of smoke. At least one of these lids, particularly the one used for smoking, can be hinged to a support structure, if necessary, to facilitate its installation and removal.

[0031] The process yields good results for pre-smoking raw meats, for example, to obtain a wood-fired flavor for a burger. Fresh meat, in whole or cut pieces, undergoes a smoking process in a kneading machine. The meat pieces can then be sold to be cooked into steaks to impart a wood-fired flavor. Another alternative is to grind the meats to obtain ground beef or ground meat preparations with a wood-fired flavor.

[0032] The food product can thus be fresh, unsalted meat; the process involves maintaining the product, during the injection of smoke in contact with it, at a temperature below 10°C, preferably below 4°C, and ideally below 2°C. Preferably, in this case in particular but not exclusively, a friction smoke generator is used, which makes it possible to obtain cold smoke.

[0033] In this case, but not exclusively, it is possible to repeat cycles of smoke injection and mixing of the food product in contact with the smoke in the mixer, without venting the smoke during mixing.

[0034] The food product may not be a solid but a liquid or semi-liquid. "Semi-liquid" refers to a product that takes the shape of its container but retains some cohesion, for example, a purée, a thick sauce, or a paste. This allows for the production of sauces with a wood-fired flavor, or even smoked water.The invention also relates, according to another of its aspects, to a food processing installation, in particular for the implementation of the smoking process as defined above, this installation comprising: A double-jacketed mixer tank, or a temperature-controlled enclosure in which the tank is placed, a cold fluid supply circuit for the double jacket during a smoking operation, or an air conditioning system for the enclosure allowing to generate a sufficient temperature difference with the tank to obtain the desired temperature for the tank, a smoke generator, a smoke supply circuit for the tank, preferably comprising an accelerator upstream of the tank, and preferably downstream of the smoke generator, a smoke evacuation circuit, preferably, a water atomization device in the tank.

[0035] The smoke extraction system can be designed so that smoke is evacuated by natural circulation, without suction. This allows the smoke to be concentrated in the tank. The installation may include a smoke recirculation circuit, if necessary, with one or more sensors to prevent the occurrence of dangerous operating conditions.

[0036] The smoke extraction system may include a smoke density control valve inside the tank. This allows the smoke extraction to be restricted to achieve the desired smoke accumulation in the tank.

[0037] The smoke supply circuit for the tank and the smoke evacuation circuit can both enter the tank from the same side.

[0038] The installation may include a steam supply to the tank.

[0039] The installation may include a duct connected to a vacuum source, allowing the tank to be subjected to evaporative drying or vacuum mixing.

[0040] The installation can be arranged to circulate a hot fluid in the aforementioned double jacket when needed, for example to ensure defrosting or during an evaporative drying operation.

[0041] The installation may include a single cover to which are connected the smoke supply circuit for the tank, the smoke evacuation circuit, the steam supply, the conduit connected to the vacuum source, and a water and air intake to the water atomization device.

[0042] Alternatively, the installation includes two lids, one being used for evaporative drying and the other for smoking.

[0043] The lid used during evaporative drying is connected to the vacuum source and the steam supply.

[0044] The lid used during smoking is connected to the smoke supply circuit, the smoke evacuation circuit, and the water and air intake.

[0045] At least one of these two lids, particularly the one used for smoking, may be hinged on a support structure. In this case, the smoke evacuation system may include a pivoting fitting that rotates with the lid.

[0046] The invention will be better understood upon reading the detailed description that follows, a non-limiting example of its implementation, and upon examination of the attached drawing, in which:

[0047] The schematic perspective drawing, with transparency to reveal certain details, represents a first example of a smoking installation according to the invention, with a single lid.

[0048] The diagram schematically represents, in perspective and with transparency to reveal certain details, a second example of a smoking installation according to the invention, with a double lid, when using the lid for evaporative drying.

[0049] lareprésentate the installation of lalors d'utilisation du Couvercle servis au fuming,

[0050] This illustrates a variant with a pivoting lid of the installation shown in figures 2 and 3.

[0051] illustrates steps of an example of a process according to the invention, and

[0052] is a view analogous to that of a variant of the process.

[0053] An example of a smoking installation 90 according to the invention is shown, comprising a mixer 2 having a double-walled tank 32, the front of which has a frustoconical wall closed in its center by a front cover 22 allowing the introduction and removal of food products. The tank can be emptied via the front cover 22. When the tank has an internal paddle, the tank can be rotated in the opposite direction to the direction of travel during emptying. The efficiency of the emptying can be improved by installing the rear legs on lifting jacks, if necessary.

[0054] The tank may include, as illustrated, an inspection hatch 31, which can be used to clean the inside of the tank, or even, in some cases, to load the tank. This loading can also be carried out using another inspection hatch (not shown) by means of a conveyor.

[0055] The double jacket 3 may include a coil or a corrugated sheet providing a helical conduit, in which a heat transfer fluid circulates.

[0056] The tank 32 is rotatable and can rotate in a cradle 33 around its longitudinal axis thanks to a set of rollers (not visible) carried by the cradle 33.

[0057] The installation 90 includes a smoke generator 1, known in itself, equipped in the upper part with an accelerator 4 connected to a primary pipe 11 which connects via a smoke circuit isolation valve 10 to a secondary pipe 12, itself connected to an injection / extraction system 35. The latter is supported by the front cover 22 by means of a rotating fitting 36, centered on the longitudinal axis of the tank.

[0058] The double jacket 3 is supplied from the rear of the tank with a heat transfer fluid whose temperature is chosen according to the operation to be carried out in the tank, smoking or evaporative drying, or simply to control the temperature of the product. This fluid is preferably glycol water.

[0059] A cold water and air intake pipe 19 connects to the injection system 35, which includes a water or air / water nozzle for atomizing the water, which can be sprayed according to a cone 14 with an axis substantially parallel to the longitudinal axis of the tank, as illustrated.

[0060] The installation may also include a steam supply pipe 20, connecting to the injection / extraction system 35, the latter being arranged for example to deliver steam along a cone 13 with an axis substantially parallel to the longitudinal axis of the tank.

[0061] The diffusion of smoke in the tank can take place along a cone 15 with an axis substantially parallel to the longitudinal axis of the tank.

[0062] The installation includes a smoke evacuation circuit 7, connected to the injection / extraction system 35 by a pipe 17.

[0063] The evacuation circuit 7 may include a valve 8 for isolating the smoking circuit, allowing, depending on its degree of opening, the regulation of the smoke density inside the tank.

[0064] The installation 90 may include a high-vacuum inlet circuit 6, connected to the injection / extraction system 35 via an isolation valve 16. A venting connection 21, connected to a primary vacuum line 18, allows pressure control in the tank, optionally via a solenoid valve (not shown).

[0065] The operation of installation 90 can be controlled by a programmable logic controller (PLC).

[0066] We will now describe, with reference to the different stages of an example of a smoking process according to the invention.

[0067] The food product to be smoked is introduced at step 100 into the mixer tank through the front cover 22 or otherwise. It can be a meat product or other.

[0068] The tank may have been pre-cooled by circulating the cooling fluid in the double jacket to a temperature between 0 and 2°C, especially if smoking takes place after brining and / or drying in a mixer. The setpoint temperature of the cooling fluid is for example -5°C.

[0069] Next, with cover 22 in place, the tank can be rotated while smoke is injected in step 101.

[0070] During this injection, gas circulation can take place in the tank, with the smoke being pushed into the tank by the accelerator 4 while the smoke-laden air escapes through the exhaust circuit 7, depending on the degree of opening of the valve 8.

[0071] Water can be atomized intermittently in the tank at step 103, during the smoking operation.

[0072] Steam can also be injected at step 105, at the same time as water is atomized.

[0073] The low temperature of the food product contained in the tank, as well as the presence of atomized water, promotes the condensation of smoke on the food product.

[0074] Once the smoking operation has been completed, the food product can be removed from the tank through the front cover 22 or otherwise, at step 106.

[0075] It can be advantageous, particularly for all products of animal origin, to subject the food product, before the smoking stage, to an evaporative drying operation in order to have a drier surface and therefore better adhesion of the smoke to the product.

[0076] In this case, the process may include, as illustrated in Figure 1, between the food product introduction and smoke injection steps, an evaporative drying step 110 during which a vacuum is generated in the tank while the double jacket 3 receives a hot fluid. In a variant, the tank does not have a double jacket, although this is preferred as a means of compensating for the endothermic nature of the evaporative drying reaction.

[0077] Evaporative drying involves, for example, creating a vacuum in the tank via pipe 6 so that the absolute pressure in it is between 0.1 and 20 mbar, better 0.1 and 15 mbar, the double jacket 3 of the tank being brought to a temperature between 5 and 60 °C, better 5 and 50 °C, by circulating a fluid at a suitable temperature through it.

[0078] In the variant of installation 90 illustrated in figures 2 and 3, two different covers are used respectively for evaporative drying and smoking.

[0079] On the, we have represented the installation 90 with a lid 24, in place, used during evaporative drying, and a lid 25, waiting, used during smoking.

[0080] Lid 25 is shown in place on the diagram, lid 24 being in standby position.

[0081] The cover 24 is connected to the high vacuum inlet pipe 6, the primary vacuum pipe 18 and the steam inlet pipe 20, and has its own swivel fitting.

[0082] The cover 25 is connected to the secondary smoke intake pipe 12, the smoke exhaust pipe 17 and the water and air intake pipe 19.

[0083] Assuming that evaporative drying and smoking are carried out successively, the lid 24 is first fixed to the tank, for example using three fasteners. The lid is connected to the vacuum system via the pipe 6.

[0084] After mixing, the inside of the tank is brought back to atmospheric pressure using the primary vacuum line 18, then the cover 24 is detached, for example by removing the three fasteners, and the cover 24 is slid on a guide bar and wedged at the end of the stroke.

[0085] Next, the smoking lid 25 is put in place of the lid 24. It is attached in the same way with the three fasteners. If the pipes 12 and 17 are not connected, they are connected, and then the smoking process is started.

[0086] One of the covers 24 and 25, for example cover 25 used for smoking, can be mounted in a hinged manner on a support structure 91, using a swivel fitting 92 connected to the evacuation circuit 7, as illustrated in the figure.

[0087] In the case of a minced beef or pork steak, smoking in a mixer for a period of between 45 minutes and 1 hour 15 minutes, especially one hour, is a good compromise between the lack of browning of the minced meat due to smoking and obtaining a light smoky flavor.

[0088] In one example, in the case of beef, the process includes the following steps: Smoking in a mixer for one hour (with a log-fired smoke generator) of beef short rib, Cutting into 5 cm pieces, Stiffening at -3°C, Stamping with a 5 mm plate, Shaping

[0089] Of course, the invention is not limited to the examples just described.

[0090] For example, it is possible to make the mixer differently, for example with mixing blades and a fixed tank.

[0091] It is particularly advantageous for the tank to have a double jacket. However, in one variation, the tank is cooled by installing it in a temperature-controlled chamber, at a temperature chosen to bring the tank to the desired temperature, for example, a cold room with an ambient temperature at least 5°C below the target cooling temperature for the tank at the start of the cooling cycle. The same method can be used for heating the tank, if the chamber's temperature control allows it to be heated.

Claims

A process for preparing a food product, comprising the steps of: Injecting smoke into contact with the food product, into a tank (32) of a mixer cooled to a temperature leading to condensation of the smoke, Evacuating the smoke through an evacuation circuit (7) connected to the tank. Method according to claim 1, the tank being double-jacketed (3) and the cooling of the tank being effected by circulation of a refrigerant liquid in the double jacket (3). A method according to one of the two preceding claims, the smoke being injected using a smoke delivery circuit comprising an accelerator (4) placed upstream of the tank (11). A method according to any one of the preceding claims, the admission of smoke and its evacuation taking place on the same side of the tank. A method according to any one of the preceding claims, comprising injecting water into the tank. A method according to claim 5, the water being injected at a predefined temperature. A method according to any one of claims 5 and 6, the water being injected into the tank by atomization. A process according to any one of claims 5 to 7, the quantity of water injected being between 0.2 and 1.5% of the mass of the product introduced into the tank. Method according to any one of the preceding claims, the smoke evacuation circuit comprising a shutter (8) allowing control of the smoke density in the tank during smoking. A method according to any one of the preceding claims, the circulation of smoke in the evacuation circuit taking place without suction. A method according to any one of the preceding claims, comprising at least partial recirculation of the smoke between the tank and a smoke generator, with detection of an accumulation of one or more predefined gaseous compounds likely to lead to explosive operating conditions. A process according to any one of the preceding claims, wherein the food product is subjected, prior to smoking, to a preliminary evaporative drying operation of the product in the vat. Method according to claim 12, the tank comprising a double jacket (3), the evaporative drying being carried out with a circulation of a hot fluid in the double jacket. A method according to any one of the preceding claims, with reference to claim 2, the temperature of the fluid circulating in the envelope (3) during the smoking operation being chosen so as to maintain the food product during the smoking operation at a temperature between -10°C and +12°C, preferably between -2°C and 10°C. A method according to any one of the preceding claims, comprising a steam injection, in particular simultaneously with a water injection into the tank by atomization. A process according to any one of the preceding claims, wherein the food product is fresh, unsalted meat, the process comprising maintaining the product, during the injection of smoke in contact with it, at a temperature below 10°C, preferably below 4°C and ideally below 2°C. A process according to any one of claims 1 to 15, wherein the food product is a liquid or semi-liquid. A method according to any one of the preceding claims, wherein a friction smoke generator is used. A method according to any one of the preceding claims, wherein cycles of smoke injection and mixing of the food product in contact with the smoke are repeated in the mixer, without evacuation of the smoke during mixing. Installation for processing a food product, comprising: A double-jacketed mixer tank (32), or a temperature-controlled chamber in which the tank is placed, a cold fluid supply circuit for the double jacket (3) during a smoking operation, or an air conditioning system for the chamber allowing to generate a sufficient temperature difference with the tank to obtain the desired temperature for the tank, a smoke generator (1), a smoke supply circuit (11, 10, 12) for the tank, a smoke evacuation circuit (7). Installation according to claim 21, the tank (32) comprising a double jacket (3). Installation according to one of claims 20 and 21, comprising a water atomization device in the tank. Installation according to any one of claims 20 to 22, the smoke extraction circuit being arranged so that the smoke is evacuated by natural circulation, without suction. Installation according to any one of claims 20 to 23, the smoke extraction circuit comprising a smoke density adjustment shutter (8) inside the tank. Installation according to any one of claims 20 to 24, the smoke supply circuit to the tank and the smoke evacuation circuit opening into the tank on the same side of it. Installation according to any one of claims 20 to 25, comprising a steam supply (20) to the tank. An installation according to any one of claims 20 to 26, comprising a conduit (6) connected to a vacuum source, allowing the tank to be subjected to evaporative drying. Installation according to claims 20 and 27, being arranged to circulate a hot fluid in the double jacket during an evaporative drying operation. Installation according to any one of claims 20 to 28, comprising an accelerator (4) upstream of the tank, and preferably downstream of the smoke generator (1). An installation according to any one of claims 20 to 29, comprising two covers (24; 25), one (24) being used for evaporative drying and the other (25) for smoking.

Images