Aseptic filling system, and filling and packaging method

Abstract

The present invention enables the distribution, at ambient temperature, of a processed food that is processed using an extruder, while reducing a thermal history which a material to be processed undergoes. When a processed food processed using an extruder 2 is filled and packaged under an aseptic environment, a heat insulating conduit 3 capable of controlling the temperature to a predetermined sterilization temperature is connected to a discharge port of a barrel part of the extruder 2, and the processed food is sterilized according to a residence time when the processed food discharged from the extruder 2 flows through the heat insulating conduit 3. In addition, when the processed food is filled and packaged using the extruder, the processing conditions are adjusted so that the water activity of the processed food discharged from the extruder becomes less than 0.94, the processed food discharged from the extruder is filled and packaged in a container capable of being hermetically sealed at a temperature of 65-99°C, and the oxygen concentration in the container in which the processed food has been filled and packaged is adjusted to 1% or less.

Description

Aseptic filling system and filling packaging method

[0001] The present invention relates to an aseptic filling system and a filling and packaging method.

[0002] For example, Patent Document 1 discloses a technology for producing a meat-like processed food as a meat substitute by heating and kneading raw materials containing proteins derived from plants such as soybeans and wheat in an extruder.

[0003] Such meat-like processed foods are preferably shipped in a dried state so that they can be distributed at room temperature. One example of such a distribution format is that they are delivered to a food manufacturer as a food ingredient, reconstituted with water, cooked, and then provided to end consumers. In this case, if distribution at room temperature is required, it is conceivable to fill them into a sealed container, sterilize them by pressurizing and heating, and distribute them as retort foods.

[0004] Japanese Patent Application Laid-Open No. 2022-160947

[0005] However, in such a distribution format, the object to be processed may be subjected to a large amount of heat history in addition to the heat history in the extruder, which may cause the flavor to be impaired. Therefore, the inventors of the present invention have conducted extensive research to enable the distribution of processed foods processed using an extruder at room temperature while reducing the heat history of the object to be processed, and as a result have completed the present invention.

[0006] The aseptic filling system of the present invention is configured such that, when processed foods processed using an extruder are filled and packaged in a sterile environment, an insulated conduit capable of being adjusted to a predetermined sterilization temperature is connected to the discharge outlet of the barrel portion of the extruder, and the processed food is sterilized according to the residence time of the processed food discharged from the extruder as it flows through the insulated conduit.

[0007] The filling and packaging method of the present invention is a method for filling and packaging processed food processed using an extruder, adjusting processing conditions so that the water activity of the processed food discharged from the extruder is less than 0.94, filling and packaging the processed food discharged from the extruder into a sealable container at a temperature of 65 to 99°C, and adjusting the oxygen concentration inside the container in which the processed food has been filled and packaged to 1% or less.

[0008] Furthermore, the filling and packaging method of the present invention can be a method in which, when filling and packaging a processed food processed using an extruder, processing conditions are adjusted so that the water activity of the processed food discharged from the extruder is less than 0.94, the processed food discharged from the extruder is filled and packaged in a sealable container made of an oxygen-absorbing packaging material at a temperature of 60 to 99°C, and the oxygen concentration in the container in which the processed food has been filled and packaged is 1% or less.

[0009] According to the aseptic filling system of the present invention, processed foods extruded from an extruder are theoretically confirmed to have been sufficiently sterilized, and then filled and packaged in a sterile environment, thereby reducing the thermal history of the processed objects while enabling processed foods processed using an extruder to be distributed at room temperature.

[0010] The filling and packaging method of the present invention makes it possible to distribute processed foods processed using an extruder at room temperature while reducing the thermal history of the processed object.

[0011] It is an explanatory diagram showing an outline of an example of an aseptic filling system according to an embodiment of the present invention.It is an explanatory diagram showing an example of operation of the aseptic filling system according to an embodiment of the present invention.

[0012] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0013] [Aseptic filling system] First, an aseptic filling system according to this embodiment will be described. Aseptic filling system 1 shown as an example in Figure 1 enables the distribution of processed foods processed using an extruder 2 at room temperature.

[0014] The specific configuration of the extruder 2 is not particularly limited as long as it is configured to process the raw material to be processed by so-called extrusion cooking, in which the raw material to be processed is extruded while being conveyed by compressing, shearing, pulverizing, heating, kneading, etc. The extruder may be either a uniaxial or biaxial type, and in the case of a biaxial type, it may be either a co-rotating or counter-rotating type, or a non-intermeshing type, a partial intermeshing type, or a complete intermeshing type.

[0015] The processed food processed using the extruder 2 is finally guided to the cooling die 4, where it is extruded into any desired shape such as a sheet and cut at predetermined intervals, and then filled and packaged in sealable containers. This series of steps is carried out in a sterile environment. To achieve this, for example, the cooling die 4 may be installed in an aseptic chamber (not shown) in which filling and packaging equipment such as a fill-seal machine or a form-fill-seal machine is installed, so that filling and packaging can be carried out in a sterile environment.

[0016] In the example shown in Figure 1, an aseptic filling system 1 has an insulated conduit 3 between an extruder 2 and a cooling die 4, the conduit 3 being capable of being adjusted to a predetermined sterilization temperature, and the conduit 3 is connected to the outlet of the barrel of the extruder 2 via a three-way valve 5. In this way, by connecting the conduit 3 to the outlet of the barrel of the extruder 2, the processed food discharged from the extruder 2 can be sterilized according to the residence time of the processed food as it flows through the conduit 3.

[0017] The heat-retaining conduit 3 can be temperature-controlled, for example, by having a double-pipe structure in which steam or hot water circulates around the conduit through which the processed food discharged from the extruder 2 flows. Alternatively, the conduit through which the processed food discharged from the extruder 2 flows can be a straight pipe with a constant diameter and a circular cross section, and the sterilization effect on the processed food can be changed by adjusting the piping length. Note that the conduit through which the processed food discharged from the extruder 2 flows is not limited to a circular cross section as long as its cross-sectional area is constant.

[0018] The current Japanese Food Sanitation Act stipulates that, as a manufacturing standard for containerized, pressure-heat-sterilized foods, excluding soft drinks, etc., foods with a pH exceeding 4.6 and a water activity exceeding 0.94 must be pressure-heat-sterilized by heating the center to a temperature of 120°C for 4 minutes or by a method with an equivalent or greater effect. Therefore, in order to distribute foods with a pH exceeding 4.6 and a water activity exceeding 0.94 at room temperature, they must be sterilized by pressure-heating at a temperature equivalent to or greater than the above standard (F ０ It is considered necessary to sterilize the bacteria to a level of 3.1 or higher.

[0019] Here, F ０ The value is an index of the strength of the heat sterilization treatment and is ０ ) is 121.1°C, and the z value (z) is 10°C, and the F value is calculated from the following formula. T: Temperature during heat sterilization treatment (℃) T ０ : Reference temperature (°C) t: Time (min) Z: Temperature difference (°C) required to increase the D value (heating time required to reduce the number of surviving bacteria to 1 / 10) by 10 times

[0020] Also, F ０ The value is the time converted into the number of minutes heated at 121.1°C, and can be calculated using the following formula as the integrated value of the product of the holding time at a certain temperature and the lethality rate at that temperature. L ｉ : Mortality rate at temperature i°C t: Time T(t): Temperature at time t

[0021] For example, the temperature of the heat-retaining conduit 3 is adjusted so that the sterilization temperature is 140°C, and the length of the heat-retaining conduit 3 is adjusted so that the residence time of the processed food discharged from the extruder 2 when flowing in the heat-retaining conduit 3 is 10.00 seconds. ０ The value is 12.94 (10^((140 [℃] - 121.1 [℃]) / 10) x (10.0 [sec] / 60.0 [sec])), which ensures that the sterilization effect on the processed food is sufficient.

[0022] At this time, the throughput of the extruder 2, i.e., the discharge rate of the processed food discharged from the extruder 2, was 0.14 kg / sec, and the specific gravity of the processed food was 1200 kg / m ３In this case, the length of the heat-retaining conduit 3 can be adjusted as follows: In other words, in order to make the residence time of the processed food when it flows through the heat-retaining conduit 3 10.00 seconds, the volume of the conduit should be adjusted to 1.16×10 －３ m ３ ((0.14[kg / sec] / 1200[kg / m ３ Therefore, for example, if the diameter of the conduit through which the processed food extruded from the extruder 2 flows is 30 mm, the length of the conduit should be 1.64 m (1.16 × 10 －３ [m ３ ] / ((30[mm] / 2) ２ ×π)), the above F ０ The value can be secured.

[0023] In this manner, according to the present embodiment, in which the processed food discharged from the extruder 2 is sterilized according to the residence time of the processed food as it flows through the heat-retaining conduit 3, the temperature of which is adjusted to a predetermined sterilization temperature, the sterilization effect on the processed food can be theoretically confirmed. Therefore, by appropriately adjusting the set temperature and piping length of the heat-retaining conduit 3, it is possible to theoretically confirm that the processed food discharged from the extruder 2 has been sterilized to the necessary extent, and then to fill and package the processed food in a sterile environment, thereby enabling distribution of the processed food at room temperature. As a result, for example, it is possible to omit the drying process in the distribution format described above as an example of the background art, and to reduce the thermal history of the processed food.

[0024] Next, the operation of the aseptic filling system according to this embodiment will be described. Note that Fig. 2 is an explanatory diagram showing an example of the operation of the aseptic filling system according to this embodiment.

[0025] [SIP (Instrument Sterilization)] In order to sterilize the path along which the processed food extruded from the extruder 2 flows, in order, through the heat-retaining conduit 3 and the cooling die 4, the three-way valve 5 is switched as shown in the figure to supply steam from the steam inlet pipe 6. During this process, steam or hot water is circulated through the temperature control circuits provided in the heat-retaining conduit 3 and the cooling die 4, respectively, while the outlet temperatures of the heat-retaining conduit 3 and the cooling die 4 are monitored. Then, while confirming that these have reached the set temperatures, steam is continued to be supplied until a predetermined time has elapsed (see FIG. 2(a)).

[0026] [SIP Cooling] After the sterilization process is completed, the supply of steam from the steam inlet pipe 6 is stopped and the three-way valve 5 is switched as shown in the figure. At the same time, the drain valve 8 on the CIP cap 7 side is closed to seal the above-mentioned path. At this time, steam or hot water is left circulating through the temperature control circuit provided in the heat-retaining conduit 3, and cooling water is circulated through the temperature control circuit provided in the cooling die 4 (see FIG. 2(b)).

[0027] [Initial Discharge] After the extruder 2 starts operating, the three-way valve 5 and other valves are switched as shown in the figure until the temperature and pressure reach predetermined values, and the processed food extruded from the extruder 2 is discharged through the back pressure valve 9. At this time, if necessary, steam is supplied from the steam inlet pipe 6 to apply back pressure while discharging. At the same time, sterilized gas or steam such as sterile nitrogen is supplied from the CIP cap 7 side to apply back pressure to the heat retention conduit 3 and cooling die 4 (see FIG. 2(c)).

[0028] [Transition to Production] Once it has been confirmed that the heat-retaining conduit 3 has reached the sterilization temperature, the three-way valve 5 is switched as shown in the figure so that the processed food extruded from the extruder 2 flows first through the heat-retaining conduit 3 and then through the cooling die 4. Next, when the internal pressure of the cooling die 4 begins to rise, the CIP cap 7 is removed from the cooling die 4 and retracted (see Figure 2(d)).

[0029] [Production] After the CIP cap 7 is retracted, the cutter 10 is immediately operated to start production (see FIG. 2(e)).

[0030] [Filling and Packaging Method] Next, a filling and packaging method according to this embodiment will be described. This method is for enabling processed foods processed using an extruder to be distributed at room temperature.

[0031] The specific configuration of the extruder is not particularly limited as long as it is configured to process the raw material to be processed by so-called extrusion cooking, in which the raw material to be processed is extruded while being conveyed by compressing, shearing, pulverizing, heating, kneading, etc. The extruder may be either a uniaxial or biaxial type, and in the case of a biaxial type, it may be either a co-rotating or counter-rotating type, or a non-intermeshing type, a partial intermeshing type, or a complete intermeshing type.

[0032] The processed food processed using the extruder is extruded into any desired shape, such as a sheet, through a die attached to the outlet of the barrel, cut at predetermined intervals, and then filled and packaged in a sealable container. This series of steps is preferably carried out in a sterile environment. To achieve this, for example, the die may be installed in an aseptic chamber equipped with filling and packaging equipment such as a fill-seal machine or a form-fill-seal machine, so that the filling and packaging can be carried out in a sterile environment.

[0033] While the water activity at which many food poisoning bacteria can grow is 0.94 or higher, the lower limit of water activity at which mold can grow is 0.60. From this perspective, in this embodiment, the processing conditions are adjusted so that the water activity of the processed food extruded from the extruder is less than 0.94, preferably 0.90 or less, and more preferably 0.85 or less, thereby creating an environment that inhibits the growth of food poisoning bacteria and suppressing the inclusion of mold, making it possible to distribute processed foods processed using an extruder at room temperature.

[0034] Furthermore, mold is sensitive to heat, and most mold is believed to be killed by heating at 60°C for about 10 minutes. From this perspective, in order to prevent mold contamination, when processed foods processed using an extruder are filled and packaged, the processed food extruded from the extruder is filled and packaged in a sealable container at a temperature of 65 to 99°C. This allows the mold-killing temperature to be maintained for a predetermined time after the processed food is filled and packaged, more reliably killing the mold and preventing mold contamination within the container. Furthermore, by reducing the oxygen concentration within the container to 1% or less, preferably 0.1% or less, mold growth can be suppressed even if mold has been introduced into the container.

[0035] To reduce the oxygen concentration in a container, gas replacement packaging may be used, in which the air in the container is replaced with an inert gas such as nitrogen while the container is filled and packaged. Using a container made of an oxygen-absorbing packaging material (e.g., OXDEC (registered trademark) manufactured by Toyo Seikan Co., Ltd.) or enclosing an oxygen absorber in the container is also effective in reducing the oxygen concentration in the container.

[0036] Furthermore, by using a container made of an oxygen-absorbing packaging material, the oxygen remaining in the container after the processed food is filled and packaged is absorbed, further reducing the oxygen concentration in the container over time. This inhibits mold growth in an environment with a lower oxygen concentration, so mold growth can be suppressed even if the temperature of the processed food when it is discharged from the extruder and packaged in the container is set to 60 to 99°C.

[0037] According to this embodiment, processed foods processed using an extruder can be distributed at room temperature, which makes it possible to omit the drying process in the distribution system described above as an example of the background art, thereby reducing the thermal history of the processed food.

[0038] The filling and packaging method according to the present invention will be described in more detail below with reference to specific examples.

[0039] Example 1 A soybean processed food was processed using a twin-screw extruder while adjusting the processing conditions so that the water activity was 0.85, and the soybean processed food extruded from the extruder was filled into an aluminum-laminated pouch at a product temperature of 65°C. The pouch was then sealed while replacing the gas with nitrogen gas so that the oxygen concentration inside the pouch was 1%, to prepare a sample filled and packaged with the soybean processed food. The sample prepared in this way was stored at room temperature (25°C), and when the filled and packaged soybean processed food was observed after one month, no mold growth was observed.

[0040] [Example 2] A soybean processed food was processed using a twin-screw extruder while adjusting the processing conditions so that the water activity was 0.85, and the soybean processed food extruded from the extruder was filled into an oxygen-absorbing pouch made of an oxygen-absorbing packaging material at a product temperature of 60°C. The pouch was then sealed while replacing the gas with nitrogen gas so that the oxygen concentration inside the pouch was 1%, to prepare a sample filled and packaged with the soybean processed food. The sample prepared in this way was stored at room temperature (25°C), and when the filled and packaged soybean processed food was observed after one month, no mold growth was observed.

[0041] [Example 3] A soybean processed food was processed using a twin-screw extruder while adjusting the processing conditions so that the water activity was 0.85, and the soybean processed food extruded from the extruder was filled into an aluminum-laminated pouch at a product temperature of 65°C in a sterile environment in a clean bench. The pouch was then sealed while gas was replaced with nitrogen gas so that the oxygen concentration in the pouch was 1%, to prepare a sample filled and packaged with the soybean processed food. The sample prepared in this way was stored at room temperature (25°C), and when the filled and packaged soybean processed food was observed after one month, no mold growth was observed.

[0042] Comparative Example 1 A soybean processed food was processed using a twin-screw extruder while adjusting the processing conditions so that the water activity was 0.85, and the soybean processed food discharged from the extruder was filled into an aluminum-laminated pouch at a product temperature of 25°C. The pouch was then sealed without adjusting the oxygen concentration by gas substitution to prepare a sample filled with the soybean processed food. The sample prepared in this way was stored at room temperature (25°C), and when the filled and packaged soybean processed food was observed after one month, mold growth was observed.

[0043] [Comparative Example 2] A soybean processed food was processed using a twin-screw extruder while adjusting the processing conditions so that the water activity was 0.85, and the soybean processed food extruded from the extruder was filled into an aluminum-laminated pouch at a product temperature of 60°C. The pouch was then sealed while gas was replaced with nitrogen gas so that the oxygen concentration inside the pouch was 1%, to prepare a sample filled and packaged with the soybean processed food. The sample prepared in this way was stored at room temperature (25°C), and when the filled and packaged soybean processed food was observed after one month, mold growth was observed.

[0044] The present invention has been described above by showing preferred embodiments, but it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

[0045] The present invention is suitable for, but not limited to, meat-like processed foods made from plant-derived proteins, and can be applied to various processed foods that are processed by extrusion cooking.

[0046] 1. Aseptic filling system 2. Extruder 3. Heat-insulating conduit

Claims

1. An aseptic filling system which, when filling and packaging processed foods processed using an extruder in a sterile environment, comprises connecting an insulating conduit capable of controlling the temperature to a predetermined sterilization temperature to the discharge outlet of the barrel part of the extruder, and sterilizing the processed food according to the residence time of the processed food discharged from the extruder as it flows through the insulating conduit.

2. A method for filling and packaging processed foods processed using an extruder, comprising the steps of: adjusting processing conditions so that the water activity of the processed food discharged from the extruder is less than 0.94; filling and packaging the processed food discharged from the extruder into a sealable container at a temperature of 65 to 99°C; and setting the oxygen concentration in the container in which the processed food is filled and packaged to 1% or less.

3. The method of claim 2, wherein the container is made of an oxygen absorbing packaging material.

4. A method for filling and packaging processed foods processed using an extruder, comprising the steps of: adjusting processing conditions so that the water activity of the processed food discharged from the extruder is less than 0.94; filling and packaging the processed food discharged from the extruder into a sealable container made of an oxygen-absorbing packaging material at a temperature of 60 to 99°C; and adjusting the oxygen concentration in the container in which the processed food is filled and packaged to 1% or less.

5. A filling and packaging method according to any one of claims 2 to 4, in which the processed food extruded from the extruder is filled and packaged in the container in a sterile environment.

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