METHOD FOR THE ASEPTIC PRODUCTION AND FINISHING OF FOOD

Abstract

The present invention relates generally to an improved method and device for the aseptic processing and packaging of liquid or, as appropriate, pumpable foods. There is a continued need for the development of improved methods for the aseptic processing of foods, particularly for processing foods with large particulate components and low acid content. The object of the present invention is achieved by a process consisting of: a) transforming consumable ingredients into a pumpable mass; b) indirectly heating the pumpable mass; c) treating the hot pumpable mass by direct steam injection; d) maintaining the food in an isolated area; e) cooling the food; and f) aseptically filling a food container with the cooled food. The invention also relates to the products thus obtained and a device for carrying out the process.

Description

In certain embodiments of the invention, the liquid phase of the pumpable mass (and / or food) comprises an emulsion of oil and / or fat in water. In certain embodiments of the invention, the liquid phase of the pumpable mass (and / or food) comprises one or more polysaccharides and / or one or more proteins, which function primarily as thickeners. In one embodiment, the liquid phase of the pumpable mass (and / or food) comprises one or more components selected from the group consisting of starches, gums, gelatin, pectin, alginate, etc., in an amount of at least 0.5% (w / w) based on the total weight of the pumpable mass. pumped, preferably of a minimum of 1.0% (W / W), more preferably of a minimum of 2.0% (W / W). In certain embodiments of the invention, the liquid phase of the pumpable mass (and / or food) comprises one or more aromatic herbs and / or spices. In certain embodiments of the invention, the liquid phase of the pumpable mass (and / or food) comprises salt (NaCl) in concentrations typical for this type of product. In one embodiment, the liquid phase of the pumpable mass is characterized by a given pH value, in particular by a pH value in the range of 4.5 to 8, preferably from 5 to 7.5, in particular from 5.25 to 7.25. In one embodiment of the invention, step a) comprises cutting and / or grinding ingredients, such as in particular, but not exclusively, the constituents discussed above, into a pumpable mass and the subsequent addition of one or more particulate constituents, such as in particular, but not exclusively, the particulate constituents discussed above. In embodiments of the invention, a certain amount of water may be added to the other ingredients during step a). As discussed in detail below, step a) will account for the further dilution of the product in subsequent steps of the process. More specifically, the water content in the pumpable mass produced in step a) will be lower than the target water content in the final food product. As defined above, step b) comprises the indirect heating of the pumpable mass produced in step a). In the context of the present invention, the term "indirect heating" refers to any heating process in which heat from an external source is transferred to the pumpable mass without this involving any transmission and / or a Mass exchange. These types of processes are generally known in specialized fields. Suitable systems for carrying out step b) include, for example, so-called tube-in-tube heat exchangers, which typically consist of an inner tube through which the feed mass is pumped, surrounded by an outer tube through which hot water, for example, water heated under pressure to approximately 120°C, is pumped. In such a system, the heating level can be regulated by adjusting the flow rates. In one embodiment of the invention, step b) includes the indirect heating of the pumpable mass produced in step a) to a temperature in the range of 75-90°C, preferably to a temperature in the range of 80-90°C. As defined above, step c) involves treating the pumpable mass by direct steam injection. This step generally follows directly from step b), i.e., without intermediate cooling of the pumpable mass. The term "direct steam injection," also abbreviated as 'DSI', refers to a technique generally known in the specialized field, in which a liquid or pumpable mass is brought into direct contact with steam. In this process, this results in an increase in the temperature of the pumpable mass as well as an increase in its water content. DSI is a technique that is well-known in the specialized field. Suitable DSI cartridges that could be applied in processes according to the present invention are commercially available. In one embodiment of the invention, step c) includes the treatment of the mass that can be pumped by DSI up to a temperature in the range of 120-150°C, preferably up to a temperature in the range of 125-145°C, particularly up to a temperature in the range of 130-150°C. To achieve this, steam is injected under high pressure. Excessive pressure is undesirable for the purposes of this invention because it causes deterioration of the particulate constituents. For optimal results, steam is preferably injected at a pressure in the range of 7 to 15 bar, preferably 8 to 12.5 bar, and more preferably 8.5 to 10 bar. In one embodiment of the invention, step c) is carried out in such a way that the target temperature is reached in a time period of 3-20 seconds, preferably in a time period of 3.5-15 seconds, particularly in a time period of 4-10 seconds. In one embodiment of the invention, step c) is carried out in such a way that the mass that can be pumped is diluted with water by a factor in the range of 2-12%, based on the total weight of the mass that can be pumped, preferably by a factor in the range of 3-10%, in particular by a factor in the range of 4-8%, for example by a factor of about 6%. In the production of the mass that can be pumped in step a), the dilution following treatment by DSI is taken into account, in that the amount of water which is added by DSI in step c) is deducted from the amount of water which should be added in step a) to achieve the target total water content of the final feed. In the process according to the invention, there is a direct relationship between the dilution of the pumpable mass during the DSI step and the heating level. In the present process, the general rule that applies is that each 5°C temperature increase is accompanied by a dilution of approximately 1%, based on the total weight of the pumpable mass, or by a dilution of approximately 6% for the DSI treatment in which the temperature is increased from approximately 108°C to approximately 140°C. This general rule assumes that the pumpable mass can be considered similar to water (i.e., a Newtonian liquid). The extent to which this assumption is justified depends heavily on the specific formulation. The average person skilled in the art will understand that the regulation of the Using this general rule can therefore lead to inaccuracies in the final water content. As a result of this inaccuracy, the product quality could fluctuate significantly. The present invention also provides a solution to this problem by applying a feedback coupling based on data relating to the flow velocity of the mass that can be pumped into the system (the aseptic part thereof). The term "aseptic part" is used in the description to refer to a part of the system where the mass to be pumped or the food intended is free from bacterial contamination, or after the DSI device of the system. In one embodiment of the invention, the flow velocity of the pumpable mass is therefore measured both upstream of the DSI device and downstream of the DSI device and / or the holding section of the system. The term "holding section" is used in the description to designate the part of the system where step d) is performed. Then, based on the difference in flow velocity, the deviation of the actual dilution from the calculated dilution is determined. Various measures can be implemented in the process to correct a deviation in water content. The present invention relates to an embodiment in which the process is carried out in continuous mode, with flow velocity data measured before and after the DSI device and / or the holding section being used via a feedback loop to adjust the amount of water added in step a). The present invention relates to an embodiment in which the process is carried out in such a way that data relating to the flow velocity measured before and after the DSI device and / or the holding part are used to adapt the quantity of water which is added in step a). In one embodiment of the invention, flow velocity data, measured before and after the DSI device and / or the holding section, are used to determine whether the batch of feed produced meets the specifications and is therefore accepted or rejected. These measurements are effective in optimizing product quality and reducing variability in product quality. As defined above, step d) involves holding the food in a specially designed holding section of the system, such that the elevated temperature following the DSI step remains maintained for a certain period. This procedure is generally known in the specialized field and is often referred to as 'holding'. For example, the procedure is carried out by pumping the food mass through an insulated holding section of the system, whereby the temperature of the mass during its passage through this section of the system does not decrease, or only minimally. Those skilled in the art will understand that step d) is performed in a closed system under aseptic conditions. In one embodiment of the invention, step d) is carried out such that the food is maintained at a temperature in the range of 120-150°C, preferably in the range of 125-145°C, particularly in the range of 130-150°C. In another embodiment of the invention, step d) is carried out such that the food is maintained at the target temperature for a period of 1-5 minutes, preferably for a period of 1.5-4.5 minutes, particularly for a period of 2-4 minutes. As defined above, step e) involves cooling the food. Suitable systems for carrying out step e) include, for example, an indirect system, such as a tube-in-tube heat exchanger. Those skilled in the art will understand that step e) is carried out in a closed system under aseptic conditions. In one embodiment of the invention, step e) includes cooling the food to a temperature in the range of 10-45°C, preferably to a temperature in the range of 15-40°C, particularly to a temperature in the range of 20-35°C. In one embodiment, the cooled food is then moved to an aseptic storage tank, where it can remain for a certain period before being dispensed into the food containers. Those skilled in the art will understand that such a storage tank forms part of the closed aseptic system, as described above. In preferred embodiments of the invention, pressure differences exist in this system, particularly between the DSI portion and the storage tank, and these pressure differences are used to regulate the feed flow rate through the system. These embodiments are particularly advantageous for application in the present invention, compared to known DSI systems in which static mixers or similar systems are used to prevent the deterioration of particulate constituents. In one embodiment, the storage tank is pressurized to create a back pressure that ensures the proper execution of the DSI step. This is particularly important when processing food containing one or more particulate components, especially large pieces. Therefore, one embodiment relates to a process in which the pressure in the storage tank is maintained above 1 bar, for example, in the range of 1.25–15 bar, preferably in the range of 1.5–10 bar, particularly in the range of 2–8 bar, to create a pressure drop between the DSI system and the aseptic storage tank, preferably a pressure drop of approximately 1–10 bar, preferably a pressure drop of approximately 2–7.5 bar, particularly approximately 2.5–5 bar. In one embodiment, no direct mechanical force is exerted on the food. As defined above, step f) involves the aseptic filling of food containers with the cooled food stored in the aseptic storage tank. A suitable system for carrying out step f) is, for example, a combined GIS system. Those skilled in the art will understand that step f) is carried out in a closed system under aseptic conditions. After filling and sealing the food container in step f), the finished product is ready for packaging and storage and / or distribution. One aspect of the invention relates to the food and the filled food container as obtained by applying the process described above. As will be understood from the description, the food in question is characterized by microbial stability and a relatively low content of components that are characteristically formed during food overheating. Another aspect of the invention relates to a device for carrying out the process as described above. One embodiment of the invention relates to such a device, this device, intended for the preparation of food, which comprises a continuous liquid phase and one or more particulate constituents, according to a process as described above, comprising: (i) a transformation device for transforming consumable ingredients into a pumpable mass comprising a liquid phase and a certain quantity of particulate constituents; ii) a heating device for the indirect heating of the pumpable mass obtained in the transformation device, preferably to a temperature in the range of 75-90°C; iii) a DSI ('direct steam injection') device for processing the hot mass that can be pumped by direct steam injection, after which the pumpable mass is diluted to obtain the feed targeted and following which the resulting food is further heated, preferably to a temperature in the range of 120-150°C; (iv) a holding part to maintain the food temperature, preferably for 1-5 minutes between 120-150°C; (v) a cooling device for cooling the food, preferably to a temperature in the range of 10-45°C; vi) an aseptic storage device which is suitable for the temporary storage of chilled food; vii) a filling device for the aseptic filling of a food container with chilled food. In a preferred embodiment of the device, the aseptic storage device is maintained at a pressure in the range of 1-15 bars. In a preferred embodiment of the device, a branch is located between the DSI device and the aseptic storage device, with one branch leading to the aseptic storage device and the other to a waste line. Preferably, this branch is located after the cooling device and before the aseptic storage device. The feed changeover process involves several steps. First, any remaining feed residue in the device is rinsed away. Next, the device is cleaned. Finally, the device is filled with the next batch of feed. The initial portion of the next batch is then discharged via the waste line, as it may still contain some cleaning residue. This waste line is used to remove the waste stream generated during the feed changeover. In a preferred embodiment of the device, a backpressure valve is located upstream of the bifurcation, designed to be active during the changeover of the feed to be produced and inactive when the product is being conveyed to the aseptic storage tank. Preferably, this backpressure valve is positioned after the cooling device and before the bifurcation. In this device, a pressure drop between the DSI device and the aseptic storage unit is used to move the food through the device. The inventors found that, thanks to the placement of the backpressure valve, the pressure difference between the DSI device and the subsequent components of the device—on the one hand, the aseptic storage unit, and on the other hand, the waste line—can be kept constant. As a result, everything passing through the DSI device and the holding section remains in the DSI device and the holding section for the same duration and, consequently, can be sufficiently sterilized.Similarly, during feed changeover, it is important that any leftover feed and cleaning water to be rinsed away are adequately sterilized before entering the waste line; otherwise, microbial contamination could occur in the aseptic section of the device, or even after the DSI device. The inventors found it advantageous for this backpressure valve not to be in operation during the production of feed containing particulate matter, since the backpressure valve could destroy the particulate matter. In one embodiment, a flow velocity measuring device is placed upstream and downstream of the DSI device. This achieves the advantages described above for the process. In one embodiment, the flow velocity upstream of the DSI device is regulated by a pump located within the device. Preferably, this pump is located after the transformation device and before the DSI device. The flow velocity measuring device upstream of the DSI device is preferably located between this pump and the DSI device. Indirect heating in the heating device is preferably carried out as already described above for step b) of the process. Direct steam injection into the DSI device is preferably carried out as already described above for step c) of the process. The temperature maintenance in the holding section is preferably carried out as already described above for step d) of the process. The cooling of the food in the cooling device is preferably carried out as already described above for step e) of the process. It should be clear that the above description is intended to illustrate the operation of preferred embodiments of the invention and not to limit the scope of the invention. Based on the above explanation, many variations will be obvious to a person skilled in the art that lie within the spirit and scope of the present invention.

Claims

Demands

1. A process for preparing a food comprising a continuous liquid phase and one or more particulate constituents, the process comprising the following steps: a) transforming consumable ingredients into a pumpable mass comprising a liquid phase and a certain amount of particulate constituents; b) indirectly heating the pumpable mass obtained in step a) to a temperature in the range of 75-90°C; c) treating the hot pumpable mass by direct steam injection, whereby the pumpable mass is diluted to obtain the intended food and the resulting food is further heated to a temperature in the range of 120-150°C; d) holding the food in such a manner that the temperature of the food is maintained for 1-5 minutes in the range of 120-150°C; e) cooling the food to a temperature in the range of 10-40°C;and f) aseptically fill a food container with the cooled food.

2. A method according to any one of the preceding claims, the pumpable mass comprising at least one particulate component in the form of large pieces, which are characterized by a volume in the range of about 2 ml to about 16 ml, preferably from about 2.5 ml to about 8 ml.

3. A method according to any one of the preceding claims, the pumpable mass having a pH value in the range of 4.5-8, preferably in the range of 5-7.

5.

4. A method according to any one of the preceding claims, with steam being injected at a pressure of 7 to 15 bars during step c).

5. A process according to any one of the preceding claims, step c) resulting in a dilution of the pumpable mass of 4-8% (W / W).

6. A method according to any one of the preceding claims, wherein the flow velocity of the pumpable mass is measured upstream of the DSI (direct steam injection) portion and downstream of the DSI device and / or the system support portion, and velocity data is provided. flow measurements taken before and after the DSI device and / or the holding part are used via a feedback loop to adjust the amount of water that is added in step a).

7. A method according to any one of the preceding claims, the food being a food selected from the group consisting of soups, sauces or stews.

8. Device for preparing a food comprising a continuous liquid phase and one or more particulate constituents according to a process according to any one of the preceding claims, comprising: i) a processing device for transforming consumable ingredients into a pumpable mass comprising a liquid phase and a certain quantity of particulate constituents; ii) a heating device for indirectly heating the pumpable mass obtained in the processing device to a temperature in the range of 75-90°C; iii) a DSI device for treating the hot pumpable mass by direct steam injection, whereby the pumpable mass is diluted to obtain the intended food and whereby the resulting food is further heated to a temperature in the range of 120-150°C;iv) a holding unit to maintain the food temperature for 1-5 minutes between 120-150°C; v) a cooling device for cooling the food to a temperature in the range of 10-45°C; vi) an aseptic storage device suitable for the temporary storage of the cooled food; vii) a filling device for the aseptic filling of a food container with the cooled food.

9. Device according to claim 8, the aseptic storage device being maintained at a pressure in the range of 1.25-15 bar.

10. A device according to claim 9, wherein a bifurcation is disposed between the DSI device and the aseptic storage device, a first branch leading to the aseptic storage device and a second branch leading to a waste line for the disposal of waste streams that are formed during the changeover of the feed to be produced, a back pressure valve being arranged upstream of the bifurcation, which is designed on one hand to be active during the change of feed to be produced, the device being kept under pressure, and on the other hand not to be active when the product is guided to the aseptic storage tank.

11. The method according to claim 1, steps a)-f) being carried out using the device as defined in any one of claims 8-10.