JP2015194362A - Pinhole inspection method and pinhole inspection apparatus for gas-filled and hermetically sealed packed food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which can perform a quick and safe pinhole inspection of a package body of a gas-filled and hermetically sealed packed food configured by storing a food product in the package body and filling the body with a substitution gas to be hermetically sealed, and which can be easily incorporated in an individual inspection of the product and a food production step by an in-line system.SOLUTION: A pinhole inspection method includes: an air pressure adjustment step S1 of applying a mixed gas obtained by mixing an inert gas with a prescribed ratio of a hydrogen gas, as a substitution gas G for a gas-filled and hermetically sealed packed food configured by removing air from the inside of a package body X1 for encapsulating a food product X2 and filling the package body with the substitution gas G to be hermetically sealed, and setting an inner pressure of the package body X1 to be higher than that of an inspection container 1 in a state where a gas-filled and hermetically sealed packed food X is stored in the inspection container 1 to thereby block inflow and outflow of gases from and to the outside; and a hydrogen gas detection step S2 of detecting the hydrogen gas by collecting the gas in the inspection container 1.

Description

  The present invention relates to a pinhole inspection method and inspection apparatus for food that is hermetically packaged with a filling gas containing an unprecedented tracer gas.

  For the purpose of maintaining quality by preventing the deterioration of food or its components due to oxygen in the air to maintain quality, and for the purpose of long-term storage, etc., inert gas such as nitrogen is used for packaging materials that contain food The method of filling and sealing (referred to as “gas filling packaging” or “gas replacement packaging”) has been used for a long time. In sealed packaged foods filled with gas, if pinholes (small holes) occur in the package and the sealing performance is impaired, it is not suitable for the purpose of quality maintenance and long-term storage, so it must be defective. In the final stage of the food production process, the presence or absence of pinholes is usually inspected. The pinhole is mostly caused by poor heat welding at a seal portion for sealing a package containing food, biting of food into the seal portion, or the like. The occurrence of defective food packaging not only causes the threat of consumer safety due to product deterioration as described above, but also has recently been an important issue that particularly affects the trust and survival of food manufacturers and distributors. You can say that.

  Various pinhole inspection methods and devices have been proposed, but leaking from pinholes in packaging materials in a vacuum environment using a mixture of nitrogen gas and carbon dioxide gas or helium gas as a tracer gas as the filling gas. The technique of detecting the tracer gas from the generated gas is generally used (see Patent Document 1 for carbon dioxide gas and Patent Documents 2 and 3 for helium gas).

Japanese Unexamined Patent Publication No. 7-019986 JP-A-7-120347 JP 2013-014365 A

  By the way, when carbon dioxide gas is used as a tracer gas, first, the inside of a test container (vacuum chamber) for inspecting the presence or absence of pinholes in the sealed packaged food filled with gas is depressurized until it becomes atmospheric pressure or lower, The carbon dioxide concentration in the chamber in that state is used as an index value, and the gas in the chamber is sampled and the carbon dioxide concentration is measured and compared with the index value. If it is detected, it is determined that there is a pinhole. After one pinhole inspection is completed, the gas in the chamber is sufficiently exhausted and replaced, and then the next subject is placed in the chamber. Such a procedure is necessary because carbon dioxide is also present in the atmosphere, so it is necessary to clearly distinguish carbon dioxide in the atmosphere from carbon dioxide used as a tracer gas. Therefore, the conventional pinhole inspection using carbon dioxide as a tracer gas requires a long time for each inspection. In addition, since the specific gravity of carbon dioxide is larger than that of air and carbon dioxide stays at the bottom of the chamber, the accuracy of carbon dioxide gas inspection and the time required for gas replacement in the chamber are also affected. For these reasons, in the food manufacturing field, for example, it is customary to perform batch processing on a case-by-case basis (a state in which a large number of gas-filled hermetically sealed foods are packed in cardboard).

  Such a current situation is particularly remarkable for small and medium-sized food manufacturers due to problems of production / sales volume and cost. Some pinhole inspection devices claim that they can individually inspect gas-filled sealed packaged foods (in-line processing in the food manufacturing process), but for the reasons described above, the inspection time per inspection takes a long time. It is practically difficult to individually test pinholes for filled and sealed packaged foods. The problem with batch processing is that a lot of gas-filled sealed packaged food products are packed in cardboard cases and the like, and pinholes are generated in the gas-filled sealed packaged food located at the bottom of the case. Even if it is, the pinhole is blocked by another gas-filled hermetically sealed package of food, and the filled tracer gas does not leak out, so the pinhole is overlooked and shipped The situation is assumed. Even if pinholes are generated, if carbon dioxide stays at the bottom in the case, there may be a problem that the detection accuracy is lowered. Further, when a pinhole is detected in one inspection, the entire product subjected to the inspection is discarded, so that there is a problem that the yield of the product is lowered and economic loss is not small.

  In the first place, when carbon dioxide gas is applied as a tracer gas, the size of a pinhole that can be detected is generally about 200 μm and at most 100 μm, and pinhole detection smaller than that is practically not performed. . In other words, the current situation is that even smaller pinholes are generated, and even if the food may be exposed to contamination by bacteria or the like, it cannot be detected. In addition, carbon dioxide is easily adsorbed by water due to its nature, and carbon dioxide, which is a tracer gas, dissolves in foods that contain a lot of water, so carbon dioxide gas cannot be used as a tracer gas for pinhole inspection. Therefore, foods to which carbon dioxide gas can be applied are limited, and there is a problem in versatility.

  In addition, helium gas has small atoms, is lighter than air, and hardly exists alone in the atmosphere, so it can be said that the performance as a tracer gas is excellent, but helium gas itself is expensive and easily available Therefore, it is not practical to use helium gas as a tracer gas in gas-filled hermetically sealed foods that are mass-produced. Therefore, due to problems such as running costs, helium gas is used for pinhole inspection of sealed chemicals in relatively expensive and high profitable chemicals.

  In view of the above problems, the present invention has applied the carbon dioxide gas or helium gas as described above as the tracer gas by using a gas that has not been used in the food manufacturing field as the tracer gas. It can solve the problem caused by the problem, and the pinhole inspection of the gas-filled hermetically sealed food can be performed very quickly in response to smaller pinholes. The main object of the present invention is to provide an inspection method and an inspection apparatus that can individually provide a pinhole inspection for a gas-filled hermetically sealed packaged food, which is a product, and further enable in-line continuous inspection.

  That is, the pinhole inspection method for a gas-filled sealed packaged food according to the present invention is a gas having a configuration in which air is removed from the inside of a package that encloses the food that is the content, the replacement gas is filled, and the package is sealed A pinhole inspection method for filled sealed packaged foods, wherein a mixed gas of an inert gas and a predetermined ratio of hydrogen gas is applied as a replacement gas, and one or more gas-filled sealed packaged foods are accommodated in a test container. A pressure adjustment process that shuts off the inflow and outflow of gas to the outside, and makes the pressure inside the package inside the cuvette higher than the pressure inside the cuvette outside the package, and the inside of the cuvette A hydrogen gas detection step of collecting gas and detecting hydrogen gas.

  In the pinhole inspection method of the present invention, it can be said that the greatest feature is the first application of hydrogen gas that has not been used as a tracer gas for pinhole inspection in the food field. The use of hydrogen gas for sealing defects (gas leaks) is already used in the battery and other industrial fields, but due to the customs of the food manufacturing industry, gas other than conventional tracer gas such as carbon dioxide gas is used. The food manufacturing sector has not had the idea of doing it, the danger of excessive hydrogen explosion, and the safety of foods that have been encapsulated with food. Has never used hydrogen gas for pinhole inspection.

  However, as a result of many years of research and verification, the present inventor has found that there is no problem in food safety even when hydrogen gas is mixed with an inert gas and used as a replacement gas, and a constant mixing ratio ( If it is within the volume ratio) there is no risk of hydrogen explosion, hydrogen gas with the property of being lightly insoluble in water can be used as a tracer gas for pinhole inspection of gas-filled hermetically sealed food, The present inventors have found that hydrogen gas can solve the problem that carbon dioxide gas has been conventionally used as a tracer gas, and have reached the present invention.

  Here, in the gas-filled sealed packaged food according to the present invention, the food and the replacement gas, which are the contents, are directly enclosed inside the package, and the individually packaged food is packaged together with the replacement gas ( A plurality of outer bags), an embodiment in which a plurality of foods filled with replacement gas and individually packaged are packed in a package (outer bag), and a food in which replacement gases are filled and individually packaged Is a state in which a plurality of packaging materials (outer bags) are filled with a replacement gas, and a plurality of foods that are individually packed with a replacement gas are sealed together with a replacement gas in the packaging body (outer bag). The food in any product form of the embodiment is included. Moreover, it can be said that the package is preferably made of a material that does not allow hydrogen gas to permeate. However, the package is applied to conventional gas-filled hermetically sealed foods such as synthetic resins, metals such as aluminum, and laminates such as paper, synthetic resin, and aluminum. Any material can be applied to the present invention as long as it is made of a package. The food contained in the package can be widely applied to dried foods, semi-raw foods, raw foods, and beverages in which most of them are occupied by moisture.

  The atmospheric pressure adjustment process may be performed by a method that allows the replacement gas containing hydrogen gas to leak out of the pinhole from the pinhole, for example, by pressing the package body from the outside in the cuvette to increase the atmospheric pressure inside the replacement gas. Various methods such as a method of pushing out from the pinhole and a method of causing the replacement gas to leak from the pinhole by reducing the pressure of the test container to increase the pressure inside the package can be applied. Here, in the present invention, “accommodating the gas-filled sealed packaged food in the inspection container and blocking the inflow and outflow of gas from the outside” means that the internal gas is reduced when the inside of the inspection container is depressurized in the pressure adjustment step. This does not include forcing gas to flow out of the inside of the cuvette, such as exhausting or drawing the gas in the cuvette collected during the hydrogen gas detection process out of the cuvette. The purpose is to block inflow and outflow.

  In addition, since hydrogen alone does not exist in the atmosphere alone, even if the hydrogen gas detection process is performed with the inside of the cuvette in an atmospheric pressure environment, if there is a pinhole in the package, the hydrogen gas in the replacement gas leaked from there Can be detected easily and quickly. Of course, the hydrogen gas detection step can be performed with the inside of the cuvette in a reduced pressure state. In the hydrogen gas detection process, pinholes can be determined only by detecting a very small amount of hydrogen gas, but if a hydrogen gas concentration exceeding a certain threshold is detected, it is determined that pinholes are generated. You may make it do.

  In the present invention as described above, not only batch inspection in which many gas-filled sealed packaged foods are contained in cases, but also gas-filled sealed packaged foods are individually subjected to pinhole inspection, the time required for the food production process Loss does not occur. When performing an individual inspection, the pinhole inspection process may be incorporated into the food manufacturing process, or only the pinhole inspection may be performed alone. This means that the chamber must be ventilated for each pinhole test, and a reference value for the carbon dioxide concentration must be set each time. Carbon dioxide gas, which took a long time for the test, is used as the tracer gas. This is a very significant advantage obtained by the present invention over the prior art. Furthermore, since hydrogen gas is the lightest gas, it does not stay like carbon dioxide, and if there is a pinhole in the package, it can be almost surely leaked and detected. In addition, since hydrogen molecules are extremely small, pinholes on the order of 10 μm that could not be detected or were not guaranteed by the prior art can be detected, improving food safety guarantees and the confidence of food manufacturers. be able to. Also, hydrogen gas is cheaper and easier to obtain than helium gas, so it can be said that it is a technology that is easy to put into practical use as a tracer gas and is easy to introduce into small and medium-sized food manufacturers.

  In particular, the replacement gas applied to the present invention is preferably a mixed gas containing hydrogen gas having a volume ratio of 5% or less and nitrogen gas which is the remaining inert gas. According to the standard of ISO10156: 1996, a mixed gas of nitrogen and hydrogen is considered to be non-combustible if the hydrogen content is 5.7% by volume or less due to atmospheric release. However, hydrogen does not explode unless it is in an environment that coexists with oxygen in the first place, and a small amount of hydrogen leaks from the pinholes. In view of the fact that even if it leaks, it will diffuse into the atmosphere immediately, there is a possibility that it can be used in a mixed gas with nitrogen exceeding 5.7%. However, in reality, it is preferable to use a mixed gas composed of hydrogen gas having a volume ratio of 5% or less and the remaining nitrogen gas, which is easily available and inexpensive, as the replacement gas. Such a mixed gas may be used if a commercially available product is available, or a mixed gas of an appropriate ratio of hydrogen gas and nitrogen gas may be independently prepared.

  Most of the pinholes (nearly 100%) in the package of gas-filled hermetic packaged foods are defects in the seal part sealed at the time of sealing, that is, foods that are defective such as thermocompression bonding or contents in the seal part. It can be said that this is caused by the biting. Therefore, in the present invention, in the hydrogen gas measurement step, collecting the gas in the cuvette in the vicinity of the seal part of the package is effective for quick and reliable hydrogen gas leak detection.

  In this case, in the atmospheric pressure adjustment step, the gas-filled sealed packaged food is stored in the inspection container so that the seal portion is positioned on the upper side, and in the hydrogen gas measurement step, the gas in the inspection container is collected at least at the seal portion. If it is performed in the vicinity immediately above, the extremely light characteristic of hydrogen gas can be fully utilized. In particular, if the food to be sealed in the gas-filled hermetically sealed food is liquid such as water, oil or sol, or gel such as jelly, or contains liquid or gel, Inside the sealed packaged food, the food gathers at the bottom and the replacement gas collects at the top, so that pinholes generated in the seal can be quickly collected and detected, and hydrogen is almost insoluble in water and oil. This characteristic can also be used effectively.

  The pinhole inspection apparatus according to the present invention for realizing the above-described gas filled hermetically sealed packaged food pinhole inspection method removes air from the inside of the package that encloses the food as the contents, and is an inert gas as a replacement gas. In a device that inspects the presence or absence of pinholes that can occur in a gas-filled hermetically sealed packaged food that is filled with a gas mixture of a predetermined proportion of hydrogen gas and hermetically sealed the package, one or more gas-filled hermetically sealed packaged foods are contained In addition, in the inspection container that can block the inflow and outflow of gas from the outside, and the pressure adjustment in the inspection container, the air pressure inside the package is higher than the pressure in the inspection container that is outside the package And a hydrogen gas detection means for collecting the gas in the cuvette and detecting the hydrogen gas in the collected gas.

  As described in the above-described pinhole inspection method, hydrogen gas can be detected even in the atmosphere. Therefore, the inspection container does not need to be completely sealed at the time of inspection. However, for the purpose of improving the detection accuracy of hydrogen gas, it is desirable that the cuvette has a configuration capable of blocking gas inflow and outflow. The hydrogen gas detection means may be provided in the cuvette or may be configured to partially draw the gas collected outside the cuvette. In addition, as described above, as the atmospheric pressure adjusting means, a configuration in which the package body of the gas-filled sealed packaged food is pressed from the outside in the inspection container, or a configuration in which the internal pressure of the package body is relatively increased by reducing the pressure in the inspection container. Etc. can be adopted.

  Such a pinhole inspection apparatus of the present invention can exhibit the merits mentioned in the above-described pinhole inspection method, and can be easily introduced by small and medium-sized food manufacturers.

  In order to perform more rapid hydrogen gas detection and pinhole inspection, the inspection container is configured to be sealed in a state of containing the gas-filled hermetically sealed packaged food, and the atmospheric pressure adjusting means is sealed with the inspection container. It is desirable to comprise from the suction pump which decompresses the inside of a test container.

  When applying such air pressure adjusting means, the package of the gas-filled sealed packaged food is expanded by depressurizing the inside of the cuvette, and if there is a pinhole, the replacement gas is pushed out with the internal pressure of the expanded package Hydrogen gas contained in the leaked replacement gas can be detected efficiently. In this case, if the inner wall of the test container is set at a position where the package that expands when the pressure in the test container is reduced by the suction pump can contact from the inside, the package expands to the extent that the replacement gas leaks from the pinhole ( For example, the package that is expanding at a time prior to expansion to the limit hits the inner wall of the cuvette, and the pressure inside the package can be further increased, so that the replacement gas is pushed out from the pinhole more quickly and actively. Thus, the time required for the pinhole inspection by detecting hydrogen gas can be shortened.

  As described above, since the location where pinholes are generated is almost limited to the seal part of the package, the gas placed in the vicinity of the gas-filled sealed packaged food contained in the test container Consists of a sampling part, a pipe connected to the gas sampling part, a suction pump connected to the pipe, and a hydrogen gas detector connected to the pipe, and the gas sampling part is in the vicinity of the seal part of the package In this way, it is possible to improve the speed and reliability of hydrogen gas detection and pinhole inspection by collecting the gas in the inspection container.

  In the case of adopting such a configuration, if the gas sampling part is disposed in the vicinity immediately above the seal part, the test container is configured to accommodate the gas-filled hermetically sealed food so that the seal part is positioned on the upper side, as described above. As can be seen, the extremely light property of hydrogen gas can be fully utilized. In particular, when the food to be sealed in the gas-filled hermetically sealed food is in the form of liquid or gel or contains it, the food gathers toward the bottom inside the gas-filled hermetically sealed food, and the replacement gas increases. Therefore, the pinhole generated in the seal portion can be quickly collected and detected, and the property that hydrogen is almost insoluble in water and oil can be used effectively.

  Moreover, the pinhole inspection apparatus of the present invention can be applied to the pinhole inspection of gas-filled sealed packaged food regardless of batch processing or individual processing. In particular, when applied to individual processing, as a configuration of the pinhole inspection device, in the inspection container, a drawer-type tray on which the gas-filled sealed packaged food can be placed is provided, and the tray is pushed into the inspection container. It is possible to configure the inside of the cuvette so that gas inflow and outflow from the outside are blocked. In this case, the placement and removal of the gas-filled hermetically sealed food on the tray of the test container and the pulling-out operation of the tray can be performed manually or automatically.

  On the other hand, it is also possible to incorporate the pinhole inspection device into the line of the entire food manufacturing apparatus and to perform the pinhole inspection as an inline process. In this case, the configuration of the pinhole inspection apparatus is such that an entrance door portion and an exit door portion that serve as entrances and exits of the gas-filled sealed packaged food and the gas-filled sealed packaged food are transported from the inlet side to the outlet side into the test container. And the inside of the cuvette is configured to block the inflow and outflow of gas from the outside while the entrance door and the exit door are closed, and the transport mechanism is arranged upstream and downstream of the cuvette. It is beneficial to have a configuration that is continuous with the transport mechanism in the production line of the gas-filled hermetically sealed food disposed on the side. By incorporating the pinhole inspection device of the present invention into an existing food production line, it becomes possible to produce food quickly, reliably and safely while improving the production tact time of the gas-filled sealed packaged food.

  In addition to the above, the cuvette may be composed of a cuvette body disposed on the outermost side and one or more inner containers of different sizes that can be nested within the cuvette body. it can. In this case, the internal space of each inner container is directly or indirectly communicated with the internal space of the cuvette body, and the hydrogen gas detection means is disposed inside the cuvette body and the gas in the cuvette outside all the inner containers. The gas-filled hermetically sealed packaged food can be selectively stored in one of the inspection container main body or the inner container. When such a configuration is adopted, a single pinhole inspection device can cope with gas-filled sealed packaged foods having different sizes as long as the size can be accommodated in the inspection container body. When the gas-filled sealed packaged food is stored in the inner container, it can be stored in the test container body in a state that is larger than the inner container, and the inner space of each inner container communicates with the test container body. Therefore, if a pinhole is generated in the package of the gas-filled sealed packaged food, a gas containing a replacement gas can be collected between the inspection container main body and the outermost inner container. When selecting the inner container, an inner container that is slightly larger than the gas-filled sealed packaged food to be inspected may be employed. At this time, if an inner container is selected so that the package hits the inner wall during the expansion process, the pinhole detection time can be shortened as described above.

  In addition, as the inspection container, it is assumed that the above-described pull-out tray functions as an inner container, or an inner container in which a transport mechanism is penetrated inside an inspection container suitable for the in-line method. In addition, it is possible to employ a cuvette in which the inner container can be manually inserted / removed into / from the cuvette body by opening and closing the sealable door.

  According to the pinhole inspection method and the pinhole inspection apparatus for gas-filled sealed package food according to the present invention, by applying hydrogen gas as the tracer gas, it is faster than the conventional pinhole inspection using carbon dioxide gas as the tracer gas. In addition, pinhole inspection can be performed at a lower cost than pinhole inspection using helium gas as a tracer gas, and pinholes smaller than the conventional inspection limit can be detected. It is possible to provide an advanced inspection method and inspection apparatus that are easy for a business operator to introduce. Moreover, even if hydrogen gas is applied as a tracer gas, there is no fear of an explosion and there is no risk of adversely affecting the preservation of food, which is the content, and it is a safe technology not only for consumers but also for manufacturers and distributors. It can be said. Furthermore, the pinhole inspection method and apparatus of the present invention is suitable not only for batch processing but also for individual inspection of gas-filled hermetically sealed foods. In the case of individual inspection, it should be carried out in a separate process or in-line with the food production line. Therefore, the introduction of the present invention is superior to the conventional one in terms of cost and detection accuracy, but has a great merit that it can be easily introduced.

The schematic process drawing which shows the pinhole inspection method which concerns on one Embodiment of this invention. The schematic perspective view which shows the 1st example (open state of a tray) of the pinhole inspection apparatus which enforces the pinhole inspection method of the embodiment. The schematic perspective view which shows the 1st example (closed state of a tray). The schematic perspective view which shows the 2nd example (open state of an entrance door part and an exit door part) of the pinhole inspection apparatus which implements the pinhole inspection method of the embodiment. The schematic perspective view which shows the 2nd example (closed state of an entrance door part and an exit door part). The schematic perspective view which shows the 3rd example (open state of a cover part) of the pinhole test | inspection apparatus which enforces the pinhole test | inspection method of the embodiment. The schematic perspective view which shows the same 3rd example (closed state of a cover part). The schematic side surface perspective view which shows the same 3rd example (closed state of a cover part). The list which shows a part of test result in the Example of this invention with a comparative example. The list which shows a part of test result in the Example of this invention with a comparative example. The list which shows a part of test result in the Example of this invention with a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The pinhole inspection method according to an embodiment of the present invention is to inspect the presence or absence of pinholes (small holes) that may occur in gas-filled sealed packaged foods, and to detect, identify, and eliminate defective products that have pinholes It is a method performed as In this embodiment, the pinhole inspection method first seals the package in the manufacturing process of the gas-filled sealed packaged food, after the food is stored in the package, and then the replacement gas is filled in the package and replaced with the internal air. It begins to do. As the replacement gas, a mixed gas obtained by mixing nitrogen gas conventionally used as an inert gas and hydrogen gas as a tracer gas is used. In this mixed gas, a volume ratio of 95% nitrogen gas and 5% hydrogen gas is applied. However, hydrogen gas is used in an amount exceeding 0% and within 5% and the balance being nitrogen gas. You can also.

In the pinhole inspection method of the present embodiment, as shown in FIG. 1, the food X2 is accommodated as described above and filled with the replacement gas G (the nitrogen gas N ₂ is indicated by ◯ and the hydrogen gas H ₂ is indicated by ●). The gas-filled hermetically sealed packaged food X in which the seal part X1a of the package X1 is sealed is accommodated in the test container 1, and the atmospheric pressure environment is adjusted so that the atmospheric pressure in the package X1 is higher than the atmospheric pressure in the test container 1. It is composed of two steps: an atmospheric pressure adjustment step S1 and a hydrogen gas detection step S2 in which the gas in the cuvette 1 is collected and the hydrogen gas is detected with the atmospheric pressure adjusted in this way. When the package X1 has a pinhole, the replacement gas leaks from the pinhole by performing the pressure adjustment step S1. Therefore, in the hydrogen gas detection step S2, the gas in the cuvette 1 is collected to detect the hydrogen gas. For example, it can be determined that a pinhole is generated in the package X1 and that the gas-filled sealed packaged food X is a defective product. On the other hand, if hydrogen is not detected from the collected gas, there is no hydrogen alone in the air, so it is determined that no pinholes have occurred and that the gas-filled sealed packaged food X is a good product. Can do. In the present embodiment, the vacuum pump 2 that sucks the gas in the cuvette 1 is applied to adjust the atmospheric pressure, and the hydrogen gas detector 3 that measures and detects the hydrogen gas in the sucked gas is used to detect the hydrogen gas. Is going to apply.

  Hereinafter, three specific examples of the pinhole inspection apparatus to which the pinhole inspection method of the present embodiment is applied will be described. In addition, about the gas filling sealing packaging food X mentioned above and its component, and the vacuum pump 2 and the hydrogen gas detector 3, the same code | symbol is utilized in the following 1st example, 2nd example, and 3rd example. .

<First example of pinhole inspection device>
As shown in FIGS. 2 and 3, the pinhole inspection apparatus A as the first example inspects the presence or absence of pinholes in the package X1 by individually putting in and out the gas-filled sealed packaged food X in the inspection container A1. It is a device to do. This inspection container A1 is a drawer-type tray that opens a part of the front surface of the inspection container main body A11 formed of a substantially rectangular casing that is vacuum-sealed and can be taken in and out of the inspection container main body A11 through the opening. A13 is provided. The tray A13 is configured to open and close the internal space of the cuvette main body A11 by smoothly moving back and forth by a slide mechanism (not shown) provided between the tray A13 and the cuvette main body A11. Note that the tray A13 may be opened and closed (inserted / removed) manually or automatically. In particular, in the closed state of the tray A13 shown in FIG. 3, the internal space of the inspection container A1 is sealed by a hermetic seal structure (packing, O-ring, etc.) provided between the inspection container body A11 and the tray A13. It prevents natural gas from flowing outside.

  Inside the inspection container main body A11, a pipe-shaped gas collection pipe A12 is provided as a gas collection part, and during the pinhole inspection, the gas in the inspection container A1 is collected through the gas collection pipe A12. In order to improve gas collection efficiency, for example, the gas sampling pipe A12 is formed by forming a large number of small holes (not shown) in the longitudinal direction in the body, and one end of the gas sampling pipe A12 is connected to the pipe A12p in the inspection container main body A11. The other end of the pipe A12p is connected to a connector A14 formed on the outer wall of the cuvette body A11. The vacuum pump 2 and the hydrogen gas detector 3 are connected to the connector A14 by a pipe P outside the inspection container main body A11. The connector A14 or the pipe P can be provided with appropriate valves (sampling valve, exhaust valve). A connector 15 provided separately from the connector A14 can be connected to a vacuum pump for preliminary decompression and piping (both not shown) as necessary. When a vacuum pump for preliminary decompression is connected to the connector 15, a vacuum pump having a decompression capability higher than that of the vacuum pump 2 connected to the hydrogen gas detector 3 can be used. It can be performed. However, if the inner volume of the inspection container A1 is sufficiently small, it is not necessary to provide a vacuum pump for preliminary decompression.

  Hereinafter, an operation procedure of the pinhole inspection apparatus A will be described. The gas-filled sealed packaged food in a state where the tray A13 is pulled out from the inspection container main body A11 and opened (see FIG. 2), the package X1 contains the food X2, is filled with the replacement gas G, and the seal portion X1a is sealed. X is placed on the tray X13. Next, the tray A13 is pushed into the inspection container main body A11 to be in a closed state (see FIG. 3), and the inspection container A1 is sealed. When the inside of the inspection container A1 is depressurized by operating the vacuum pump 2 in this state, the pressure inside the inspection container A1 which is outside the pressure inside the packaging body X1 becomes lower, and as a result, the packaging body X1 expands. That is, in this example, the pressure adjusting means is configured by the sealed inspection container A1, the gas sampling pipe A12, the pipe A12p and the connector A14, the vacuum pump 2 and the pipe P. As described above, the atmospheric pressure adjustment step S1 in the pinhole inspection method of the present embodiment is performed.

  And if the pinhole has arisen in the package X1, the internal replacement gas G will leak into the inspection container A1 from the pinhole. Here, if a pinhole occurs, the seal portion X1a is poorly sealed, and the food X2 is sandwiched between the seal portions X1a during sealing, which causes most pinholes. Leakage from the pinhole by positioning the end in the vicinity of the seal portion X1a of the gas-filled hermetically sealed packaged food X in the state of being placed in the tray A13 and accommodated in the inspection container body A11. Thus, the hydrogen gas in the replacement gas G can be efficiently collected.

  If hydrogen gas is detected by the hydrogen gas detector 3 from the gas in the inspection container A1 sucked by the vacuum pump 2, the package X1 of the gas-filled sealed packaged food X contained in the pinhole inspection apparatus A It is determined that a pinhole has occurred. On the other hand, if hydrogen gas is not detected, it is determined that no pinhole is generated in the package X1. That is, in this example, the gas sampling pipe A12, the pipe A12p, the connector A14, the vacuum pump 2, the hydrogen gas detector 3, and the pipe P constitute a hydrogen gas detection means. As described above, the hydrogen gas detection step S2 in the pinhole inspection method of the present embodiment is performed. The gas-filled hermetically sealed packaged food X is withdrawn from the pinhole inspection apparatus A after pulling out the tray A13, and then disposed of when it is determined that there is a pinhole, and packed when it is determined that there is no pinhole. Etc., and the subsequent shipment preparation process. In addition, by opening the tray A13, the gas atmosphere in the cuvette A1 is easily ventilated, and particularly light hydrogen exits the cuvette A1 and dissipates immediately, so that hydrogen remains in the cuvette A1. It does not affect the inspection of the next gas-filled sealed packaged food X. Further, by combining the preliminary decompression, the inside of the cuvette A1 can be more reliably ventilated.

  When hydrogen gas is detected by the hydrogen gas detector 3, the degree of pressure reduction (vacuum degree) by the vacuum pump 2 depends on the content of the detection container A1, the properties of the gas-filled sealed packaged food X and package X1, etc. What is necessary is just to set suitably. Further, if a hydrogen gas concentration exceeding the detection limit of the detector to be used is detected, it may be determined that there is a pinhole, or a predetermined hydrogen gas concentration is set as a threshold value, and the threshold value is exceeded. Only when the hydrogen gas concentration is detected, it may be determined that there is a pinhole. Furthermore, only when it is determined that there is a pinhole, appropriate notifications such as lighting of the lamp and warning sound may be made, and the type of notification may differ depending on the determination of the presence or absence of pinholes. Can also be set.

<Second example of pinhole inspection device>
As shown in FIGS. 4 and 5, the pinhole inspection apparatus B as the second example is used in an in-line method incorporated in the production line of the gas-filled sealed packaged food X. The pinhole inspection apparatus B includes a transport mechanism B15 in the production line disposed upstream and downstream of the inspection container B1, and includes a transport mechanism B15 that is continuous with the upstream transport mechanism 8. The gas-filled hermetically sealed packaged food X that has been sent is temporarily stored and automatically sent to the downstream transport mechanism 9 after the end of the pinhole inspection.

  The cuvette B1 has an entrance door portion B13 and an exit door portion B14 that automatically open and close part of the front side and the back side of the cuvette body B11 formed of a substantially rectangular housing that has been vacuum-sealed. As shown in FIG. 4, the gas-filled sealed packaged food X sent from the upstream transport mechanism 8 is sent to the transport mechanism B15 in the inspection container main body B11 by opening the entrance door B13. By opening the exit door B15, the gas-filled sealed packaged food X is sent out from the transport mechanism B15 in the cuvette body B11 to the transport mechanism 9 on the downstream side. The opening / closing timing of the entrance door portion B13 and the exit door portion B14 is automatically performed in accordance with the execution operation of the pinhole inspection in the inspection container B1. In addition, the opening and closing of the entrance door portion B13 and the exit door portion B14 may be performed at the same time, or the timing may be varied. In the closed state of the entrance door part B13 and the exit door part B14 shown in FIG. 5, the inspection is performed by a hermetic seal structure (packing, O-ring, etc.) provided between the inspection container main body B11 and the door parts B13, B14. The internal space of the container B1 is sealed so that natural gas does not flow between the outside. As the transport mechanism B15, in this example, a belt conveyor type that drives a plurality of rollers B15a and a belt B15b with a motor (not shown) is applied, and the gas-filled sealed packaged food X stored in the inspection container B1 is used. Is conveyed while being placed on the upper surface of the belt.

  Inside the inspection container main body B11, a pipe-shaped gas collection pipe B12 is provided as a gas collection part, and during the pinhole inspection, the gas in the inspection container B1 is collected through the gas collection pipe B12. In order to improve gas collection efficiency, for example, the gas sampling pipe B12 is formed by forming a large number of small holes (not shown) in the longitudinal direction in the body, and one end of the gas sampling pipe B12 is connected to the pipe P in the inspection container main body B11. The other end of the pipe P is drawn out from the cuvette body B11 and connected to the vacuum pump 2, the hydrogen gas detector 3, the sampling valve 4, and the exhaust valve 5. In addition, similarly to the cuvette body A11 of the first example, a connector may be provided on the outer wall of the cuvette body B11, and the pipe P may be connected to the connector.

  Further, the cuvette body B11 is connected to the preliminary decompression exhaust valve 7 and the vacuum pump 6 through the pipe P '. The vacuum pump 6 for preliminary depressurization uses a vacuum pump having a higher depressurization capacity than the vacuum pump 2 connected to the hydrogen gas detector 3 for preliminary depressurization by roughing the gas in the inspection container B1. Therefore, the atmospheric pressure adjustment step S1 can be performed more quickly. However, if the inner volume of the cuvette B1 is sufficiently small, it is not necessary to provide the vacuum pump 6, the exhaust valve 7 and the pipe P 'for preliminary decompression.

  Hereinafter, an operation procedure of the pinhole inspection apparatus B will be described. When the entrance door portion B13 and the exit door portion B14 are opened (see FIG. 4), the gas-filled sealed packaged food X that has been subjected to the pinhole inspection is sent from the opened exit door portion B14 side to the downstream transport mechanism 9. At the same time, the gas-filled sealed packaged food X to be subjected to pinhole inspection is sent from the upstream entrance mechanism B15 from the upstream transport mechanism 8 to the transport mechanism B15 in the inspection container B1, and the gas-filled sealed packaged food X is replaced. Is done. The transport mechanism B15 transports the gas-filled sealed packaged food X to a predetermined inspection position, and closes the inspection container B1 with the entrance door B13 and the exit door B14 closed (see FIG. 5). In this state, by operating the vacuum pump 6 for preliminary decompression, the inside of the cuvette A1 is decompressed to some extent, and then the vacuum pump 6 is stopped. As a result, the package X1 expands as a result of the atmospheric pressure in the cuvette B1 that is outside the pressure inside the package X1 being lower. As described above, the atmospheric pressure adjustment step S1 in the pinhole inspection method of the present embodiment is performed. The exhaust valve 7 may be opened and closed as appropriate according to the operating state of the vacuum pump 6.

  Subsequently, the vacuum pump 2 is operated and detection of hydrogen gas is started. The sampling valve 4 and the exhaust valve 5 may be appropriately opened and closed according to the operating state of the vacuum pump 2. If a pinhole is generated in the package X1, the internal replacement gas G leaks from the pinhole into the inspection container B1. As in the case of the first example, if pinholes occur, the seal portion X1a is poorly sealed, and the food X2 is sandwiched between the seal portions X1a at the time of sealing. The open end of the gas sampling tube B12 is positioned in the vicinity of the seal portion X1a of the gas-filled hermetically sealed packaged food X placed on the belt B15b and accommodated in the inspection container body B11, in particular, in the vicinity of the upper side. The hydrogen gas in the replacement gas G that may leak from the hole can be efficiently collected.

  If hydrogen gas is detected by the hydrogen gas detector 3 from the gas in the inspection container B1 sucked by the vacuum pump 2, the package X1 of the gas-filled sealed packaged food X contained in the pinhole inspection apparatus B It is determined that a pinhole has occurred. On the other hand, if hydrogen gas is not detected, it is determined that no pinhole is generated in the package X1. As described above, the hydrogen gas detection step S2 in the pinhole inspection method of the present embodiment is performed. And if hydrogen gas detection process S2 is completed, the entrance door part B13 and the exit door part B14 will be in an open state as mentioned above, and replacement | exchange of the gas filling sealing packaged food X will be performed automatically. Here, if it is determined that there is a pinhole, it is sent to a transport line for disposal, and if it is determined that there is no pinhole, it is sent to a subsequent shipping preparation line such as boxing. In addition, by opening the entrance door B13 and the exit door B14, the gas atmosphere in the cuvette B1 is easily ventilated, and particularly light hydrogen is quickly emitted from the cuvette B1 and diffused. Hydrogen remains in B1 and does not affect the inspection of the next gas-filled sealed packaged food X. Furthermore, the pre-depressurization by the vacuum pump 6 can more reliably ventilate the cuvette B1.

  That is, in this example, the atmospheric pressure adjusting means is constituted by at least a sealed inspection container B1, a vacuum pump 6, an exhaust valve 7 and a pipe P ′, and a gas sampling pipe B12, a vacuum pump 2, an exhaust valve 5 and a pipe P ′. May play a part of the pressure adjusting means. Further, the hydrogen gas detection means is constituted by the gas sampling pipe B12, the vacuum pump 2, the hydrogen gas detector 3, the sampling valve 4, and the pipe P.

  In this example as well, when hydrogen gas is detected by the hydrogen gas detector 3, the degree of pressure reduction (vacuum degree) by the vacuum pumps 2 and 6 (the degree of vacuum) depends on the internal volume of the detection container B1 and the gas-filled sealed packaging. What is necessary is just to set suitably by the property etc. of the foodstuff X or the package X1. Further, if a hydrogen gas concentration exceeding the detection limit of the detector to be used is detected, it may be determined that there is a pinhole, or a predetermined hydrogen gas concentration is set as a threshold value, and the threshold value is exceeded. Only when the hydrogen gas concentration is detected, it may be determined that there is a pinhole. Furthermore, only when it is determined that there is a pinhole, appropriate notifications such as lighting of the lamp and warning sound may be made, and the type of notification may differ depending on the determination of the presence or absence of pinholes. Can also be set.

<Third example of pinhole inspection device>
As shown in FIGS. 6, 7 and 8, the pinhole inspection apparatus C as the third example is packaged by individually putting in and out the gas-filled sealed packaged food X in and out of the inspection container C1 as in the first example. It is an apparatus for inspecting the presence or absence of pinholes in the body X1. 6 and 7 show only the cuvette C1. This cuvette C1 is configured such that an upper surface C11b having an open central portion of a cuvette main body C11 formed of a substantially rectangular casing subjected to vacuum seal welding is opened and closed by a door C13. Inside the inspection container main body C11, the inner side containers C15 and C16 can be accommodated through the open part by opening the door body C13 (see FIG. 6). Each of the inner containers C15 and C16 is composed of a case C15a and C15b having a bottom without a lid, and flange portions C15b and C16b are formed on the peripheral edges of the upper edges thereof. In this example, the inner container C15 has a size that can be accommodated by being inserted into the inspection container body C11 through the opening of the upper surface C11b, and the flange portion C15b is screwed to the upper surface C11b of the inspection container body C11. It is attached. Further, the inner container C16 has a size that can be accommodated by being inserted into the inner container C15 so that it can be inserted and removed from above, and the flange portion C16b is placed on the flange portion C15b of the inner container C15. As described above, in order to stably install the inner containers C15 and C16 with the inner container C15 and the inner container C16 sequentially inserted in the inspection container main body C11, the bottom surfaces of the inner containers C15 and C16 are provided. Has a plurality of rubber legs C15c and C16c (4 each in this example). Furthermore, punching holes C15ah and C16ah are opened in the peripheral wall 4 surface of each casing C15a and C15b, so that the inner space of each of the inner containers C15 and C16 and the inner space of the cuvette body C11 are made of gas. It communicates so that it can be distributed.

  The lid C13 can open and close the lid main body C13a with respect to the cuvette main body C11 via the hinge C13b. In this example, a lid C13c for manually opening and closing the lid C13 is provided. Provided. In order to ensure the tightness of the cuvette C1 when the lid C13 is in a closed state, a resin that adheres to the flange C11c formed on the upper edge of the cuvette main body C11 on the lower surface of the capping body C13a. A ring-shaped seal member C13d made of, for example, is provided.

  In this example, two types of gas collection units are employed, a gas collection box C12a provided in the lid C13 and a gas collection tube C13b provided upright in the cuvette body C11. The gas sampling box C12a has a configuration in which a central portion of the lower surface of the lid main body C13a is hollowed out in a substantially rectangular shape and is closed with a plate material having a large number of punching holes C12ah from below. The gas collection box C12a has two vent holes C12p communicating with the rear end side of the lid body C13a, and the vent hole C12p is connected to the connector C14a. A pipe P passing through the outside of the lid C13 and the cuvette body C11 is connected to the connector C14a, and this pipe P is connected to the vacuum pump 2 and the hydrogen gas detector 3. On the other hand, the gas sampling tube C12a is fixedly supported after standing along the side wall of the inner container C15 fixed in the inspection container main body C11 in this example. As in the first and second examples described above, the gas sampling tube C12a is formed by forming a large number of small holes (not shown) in the longitudinal direction in the body portion, and the lower end portion of the inspection container main body C11. It is connected to a connector C14b provided at the bottom. The connector C14b is connected to the vacuum pump 2 and the hydrogen gas detector 3 through the pipe P. The pipe P and the pipe P communicating with the gas sampling box C12a are connected to the same vacuum pump 2. Note that a vacuum pump for preliminary decompression and piping (both not shown) can be connected to the cuvette body C11 as necessary.

  Hereinafter, an operation procedure of the pinhole inspection apparatus C will be described. First, as the inner container C16, the gas-filled sealed packaged food X can be accommodated in a posture in which the seal part X1a of the package X1 faces upward, and is slightly larger than the gas-filled sealed packaged food X under atmospheric pressure. Adopt things. With the lid C13 in the open state and the inner containers C15 and C16 accommodated in the inspection container main body C11, the gas-filled sealed packaged food X is accommodated in the inner container C16 (see FIG. 6), and the handle C13c is operated. The lid C13 is closed with respect to the cuvette body C11 (see FIGS. 7 and 8). When the inside of the cuvette C1 is depressurized by operating the vacuum pump 2 in this state, the pressure inside the cuvette C1 that is outside the pressure inside the package X1 becomes lower, and as a result, the package X1 expands. At this time, the packaging body X1 contacts the inner side surface of the housing C16a of the inner container C16 during the expansion process of the packaging body X1. In FIG. 8, the package in this state is indicated by reference numeral X1 'and indicated by a two-dot chain line. Thus, the inspection container in which the inside of the gas-filled sealed packaged food X is depressurized before the package X1 is completely expanded as a result of the package X1 ′ being expanded being pressed against the inner container C16. Since the pressure is higher than the atmospheric pressure in C1, if a pinhole is generated in the seal portion X1a of the package X1, the internal replacement gas G leaks into the inspection container C1 from the pinhole. If the food X2 that is the contents of the gas-filled sealed packaged food X is in the form of a liquid or gel or contains these, the replacement gas G that does not dissolve in the food X2, particularly hydrogen gas, is the upper space in the package X1. Therefore, the replacement gas G leaks quickly from the seal portion X1a positioned on the upper side in the cuvette C1. The gas in the inspection container C1 that may contain the replacement gas G is collected by either or both of the gas collection box C12a and the gas collection pipe C12b.

  If hydrogen gas is detected by the hydrogen gas detector 3 from the gas in the inspection container A1 sucked by the vacuum pump 2, the package X1 of the gas-filled sealed packaged food X contained in the pinhole inspection apparatus C It is determined that a pinhole has occurred. On the other hand, if hydrogen gas is not detected, it is determined that no pinhole is generated in the package X1. And, when the gas-filled sealed packaged food X is taken out from the pinhole inspection device C with the lid C13 opened, it is disposed of when it is judged that there is a pinhole, and when it is judged that there is no pinhole. It will be sent to the subsequent shipping preparation process such as boxing. In addition, by opening the lid C13, the gas atmosphere in the cuvette C1 is easily ventilated, and particularly light hydrogen exits the cuvette C1 and dissipates immediately, so that hydrogen remains in the cuvette C1. This does not affect the inspection of the next gas-filled sealed packaged food X. Furthermore, if the preliminary decompression is combined, the inside of the cuvette C1 can be more reliably ventilated.

  When hydrogen gas is detected by the hydrogen gas detector 3, the degree of pressure reduction (vacuum degree) by the vacuum pump 2 depends on the content of the detection container C1, the properties of the gas-filled sealed packaged food X and package X1, etc. What is necessary is just to set suitably. Further, without using the inner container C16, the gas-filled hermetically sealed packaged food X is accommodated in the inner container C15, an inner container smaller than the inner container C16 is applied, or an inspection container is used without using the inner container. The size of the gas-filled sealed packaged food X can be accommodated by an appropriate configuration, such as using only the main body C11. Further, if a hydrogen gas concentration exceeding the detection limit of the detector to be used is detected, it may be determined that all have pinholes, or a predetermined hydrogen gas concentration is set as a threshold, and the threshold is exceeded. Only when the hydrogen gas concentration is detected, it may be determined that there is a pinhole. Furthermore, only when it is determined that there is a pinhole, appropriate notifications such as lighting of the lamp and warning sound may be made, and the type of notification may differ depending on the determination of the presence or absence of pinholes. Can also be set. In addition, a configuration in which one or more inner containers C15 and C16 are nested in the inspection container main body C11 as described in this example, or a package X1 of the gas-filled sealed packaged food X is expanded during the expansion process. The configuration in which the molester gas G is positively pushed out by hitting the inner wall of the container) can also be applied to the first and second examples.

  As described above, according to the pinhole inspection apparatuses A, B, and C of the first example, the second example, and the third example that implement the pinhole inspection method of the present embodiment, the food X2 is accommodated in the package X1. In the gas-filled sealed packaged food X filled with the replacement gas G and sealed, hydrogen gas, which is hardly present alone in the atmosphere, is applied as the tracer gas, so that pinholes using conventional carbon dioxide gas as the tracer gas are used. As in the detection method and device, the gas in the cuvette is completely replaced over time, and it is no longer necessary to adjust the reference value of carbon dioxide gas one by one. Furthermore, a pinhole smaller than the conventional one (for example, 100 μm or less) Therefore, the presence or absence of a pinhole that may occur in the package X1 can be detected quickly and reliably. In addition, the pinhole inspection can be performed at a lower cost than the conventional pinhole detection method and apparatus using helium gas as a tracer gas. Further, the pinhole inspection apparatuses A and C of the first example and the third example can be individually supplied with the gas-filled sealed packaged food X to perform the pinhole inspection, and the pinhole inspection apparatus B of the second example Is easy to perform individual inspection of gas-filled sealed packaged food X, as it can be incorporated into the production line of gas-filled sealed packaged food X and individually inspected by the in-line method. In addition, it eliminates the waste of conventional pinhole inspection by batch processing, and enables small and medium-sized food manufacturers to handle complete individual inspection of all products. Moreover, in the pinhole inspection apparatuses A and B of each example, the open ends of the gas sampling tubes A12 and B12 are arranged in the vicinity of the upper part of the seal part X1a of the package X1 that is the most occurrence of pinholes. Therefore, when leakage of hydrogen gas that is lighter than air or nitrogen gas occurs, the hydrogen gas can be detected quickly. In particular, in the pinhole inspection apparatus B of the second example, the speed of the pinhole inspection according to the present embodiment makes it possible to perform inline individual pinhole inspection without reducing the tact time of the manufacturing process. It can be said that it brings great benefits to food manufacturers. Further, as in the third example, for a gas-filled hermetically sealed packaged food containing liquid or gel food or food containing liquid or gel that has been difficult with the conventional pinhole inspection method. However, the pinhole inspection can be appropriately performed.

  The configuration of the present invention is not limited to the method and apparatus of the above-described embodiment. In each example described above, the individual inspection of the gas-filled sealed packaged food has been described. However, the present invention can also be applied to batch inspection for each case containing a large number of gas-filled sealed packaged foods. In addition, as the gas-filled sealed packaged food, as described in the above examples, the example in which the replacement gas is filled in a state where the food is directly contained in the package and the seal portion is sealed is described. In addition, foods that are individually packaged in an inner bag or a sheet for individual packaging can be applied. Moreover, the individual package is filled with the replacement gas, and the package that is the exterior can be applied with a configuration not filled with the replacement gas.

  Further, in the above-described embodiment as the atmospheric pressure adjusting means, the sealed inspection container is depressurized so that the pressure of the gas in the inspection container and the package of the gas-filled sealed packaged food housed in the inspection container and sealed are sealed. Although the aspect using the differential pressure with the atmospheric pressure due to the replacement gas has been described, it is also possible to adopt a configuration in which the pressure inside the package is increased by physically pressing the gas-filled sealed packaged food from the outside in the cuvette. . In this case, the hydrogen gas detection means may collect the replacement gas that leaks if a pinhole is generated and detect the hydrogen gas contained therein. Furthermore, in order to improve the detection efficiency of hydrogen gas, it is preferable that the cuvette can be sealed. However, in view of utilizing the property that hydrogen gas alone does not exist in the atmosphere, the cuvette is completely sealed. Even if it is not done, it is possible to detect hydrogen gas in the replacement gas leaking from the pinhole generated in the package of the gas-filled sealed packaged food.

  In the above-described embodiment, a pipe-shaped pipe is used as a gas sampling pipe as an example of the gas sampling section, and a large number of small holes are formed in the body of the gas sampling pipe. The example in which the part is positioned in the vicinity of the seal part in the package of the gas-filled hermetic packaged food has been explained. In view of the properties, a gas sampling tube configured to be able to quickly extract the replacement gas according to the form of the gas-filled sealed packaged food can be appropriately employed. Furthermore, as the gas sampling unit, the gas sampling box and the gas sampling tube as in the third example can be used together, or a gas sampling box of another shape can be adopted.

  Furthermore, the pin of the present invention can be applied not only to food but also to cosmetics and pharmaceuticals as long as the contents are contained in a package similar to the gas-filled sealed package food to which the present invention is applied and the replacement gas is filled and sealed. A hole inspection method and a pinhole inspection apparatus can be applied. In addition, the specific steps of the pinhole inspection method and the specific configuration of the pinhole inspection apparatus can be changed as appropriate as long as the gist of the present invention is followed.

  Since there is no precedent for applying hydrogen gas as a tracer gas to the replacement gas G enclosed in the gas-filled sealed packaged food X, various tests were conducted on food safety when hydrogen gas was used. In each example shown below, the components of the replacement gas G contain 95% by volume of nitrogen gas as an inert gas and 5% of hydrogen gas as a tracer gas. The following tests were all conducted at the request of the Japan Food Analysis Center.

  First, in Examples 1 to 3, hydrogen gas is used for cheese (Example 1), tart (baked Western confectionery) (Example 2), and green tea leaves (Example 3) that are the same as those commercially available. The replacement gas contained was filled, and general bacteria (viable cell count) and coliform bacteria after storage for 22 days were measured. For comparison with each example, general bacteria and coliform bacteria after storing cheese (Comparative Example 1), tart (Comparative Example 2), and green tea leaves (Comparative Example 3) filled with 100% nitrogen gas during the same period. The number of viable bacteria was measured. In addition, the cheese of Example 1 and Comparative Example 1 contains a large number of small-shaped cheeses individually wrapped with a resin film in a package, and the package is made of polyethylene, polypropylene, nylon, vinyl chloride, or the like. A general material is applied. In the tart of Example 2 and Comparative Example 2, the tart is directly contained in a package, and nylon poly (a laminate of nylon and polyethylene films) is applied to the package. The tea leaves of the green tea of Example 3 and Comparative Example 3 are obtained by directly storing tea leaves in an aluminum package.

  The test results are shown in FIG. From the test results, in Comparative Examples 1 to 3 corresponding to Examples 1 to 3 after storage, the number of general bacteria is different depending on the food type, but no significant difference is observed between the Examples and Comparative Examples. It was. Moreover, about the coliform group, the negative result was obtained in each Example and each comparative example. From these results, it was confirmed that even when hydrogen gas was used as the tracer gas and used as the replacement gas G together with the nitrogen gas, the safety level was the same as when the nitrogen gas alone was used as the replacement gas.

  Furthermore, about the tart of Example 2 and Comparative Example 2, the sensory test was done about the thing after a preservation | save. As a result, Example 2 and Comparative Example 2 had almost no difference in appearance, odor, and flavor, and the texture was found that Example 2 was slightly moist than Comparative Example 2. The reason why the texture of Example 2 was slightly better than the texture of Comparative Example 2 is not known at this time.

  Next, Examples 4 to 7 are all baked confectionery equivalent to those commercially available (Example 4, stored for 3 days), cream cheese tart (Example 5, stored for 15 days), steamed soybean (Example) 6 and 7 days storage) and purine (Example 7 and 7 days storage) were filled with a replacement gas containing hydrogen gas, and general bacteria (viable cell count) after storage for each period were measured. For comparison with each example, baked confectionery (Comparative Example 4), cream cheese tart (Comparative Example 5), steamed soybean (Comparative Example 6), and pudding (Comparative Example 7) filled with 100% nitrogen gas were the same. It measured about the general bacteria after period storage. The materials of the packaging material are nylon poly for Example 4 and Comparative Example 4, polyethylene for Example 5 and Comparative Example 5, polyethylene for Example 6 and Comparative Example 6, and Example 7 and Comparative Example 7. Each uses a polypropylene container and a polyethylene lid film.

  The test results are shown in FIG. From the test results, no significant difference was observed in the number of general bacteria in Comparative Examples 4 to 7 corresponding to Examples 4 to 7 after storage. From this result, it was confirmed that even when hydrogen gas was used as the tracer gas and used as the replacement gas G together with the nitrogen gas, the safety level was the same as when the nitrogen gas alone was used as the replacement gas.

  Finally, in Example 8, about 12 items of cut vegetables equivalent to those on the market are filled with a replacement gas containing hydrogen gas, and after 3 days and 7 days from the start of storage in the refrigerator About (viable count), it measured over time. For comparison with Example 8, cut vegetables (Comparative Example 8) containing 12 items without nitrogen gas sealed (still in air) were measured for general bacteria after storage for the same period. Note that the cut vegetables of Example 8 and Comparative Example 8 were stored in a transparent box-shaped container made of polyethylene terephthalate, and then packaged and sealed with a polypropylene package. Such specimens of Example 8 and Comparative Example 8 were prepared separately for individuals to be opened after 3 days and individuals to be opened after 7 days for the measurement of general bacteria.

  The test results are shown in FIG. This test was conducted during the summer, and purchased cut vegetables are usually expected to be eaten on the same day or the next day. A slightly larger number of general bacteria was detected in the test results because the replacement gas G was sealed after the outer packaging and container were once opened. However, the number of general bacteria tended to increase by an order of magnitude over time at the start of storage, after 3 days of storage, and after 7 days of storage. The degree of increase was in Example 8 and Comparative Example 8. And hardly changed. From this result, it was confirmed that even when hydrogen gas was used as the tracer gas and used as the replacement gas G together with the nitrogen gas, the safety level was the same as when the nitrogen gas alone was used as the replacement gas.

  In addition, under the same conditions as in Example 8 and Comparative Example 8, freshness maintenance inspections were performed for the three cut vegetables after 3 days and 7 days after storage by appearance observation, but almost the same in Example 8 and Comparative Example 8. Met.

  From the above results, the pinhole inspection method and inspection apparatus of the present invention can be applied regardless of the material of the package, the nature of the food, and the accommodation form of the food in the package. Even if hydrogen gas was applied as tracer gas, it was confirmed that there was no problem in safety regardless of the kind of food and the water content. Thus, it was confirmed that the pinhole inspection method and inspection apparatus of the present invention are extremely effective as a new pinhole inspection method.

  The present invention can provide a new and simple method in the fields of food production and food safety inspection.

A, B, C: Pinhole inspection device 1, A1, B1, C1 ... Inspection container A11, B11, C11 ... Inspection container body A12, B12, C12b ... Gas sampling part (gas sampling tube)
A13 ... Tray B13 ... Inlet door part B14 ... Outlet door part B15 ... Conveying mechanism C12a ... Gas sampling part (gas sampling box)
C13: Lid C15, C16 ... Inner container G ... Replacement gas 2 ... Suction pump (vacuum pump)
3 ... Hydrogen gas detector X ... Gas-filled sealed packaged food X1 ... Package X1a ... Sealing part X2 ... Food

Claims (12)

A pinhole inspection method for a gas-filled sealed packaged food having a configuration in which air is removed from the inside of a package that encloses the food as a content, and a replacement gas is filled, and the package is sealed,
As the replacement gas, a mixed gas of an inert gas and a predetermined ratio of hydrogen gas is applied,
One or a plurality of gas-filled hermetically sealed packaged foods are accommodated in a cuvette to block the flow of gas to and from the outside, and the air pressure inside the wrapping body in the cuvette is outside the package. An atmospheric pressure adjustment process for making the environment higher than the atmospheric pressure in the cuvette;
A hydrogen gas detection step of collecting the gas in the cuvette and detecting hydrogen gas;
A pinhole inspection method comprising: The pinhole inspection method according to claim 1, wherein the mixed gas contains the hydrogen gas having a volume ratio of 5% or less and the nitrogen gas that is the remaining inert gas. 3. The pinhole inspection method according to claim 1, wherein in the hydrogen gas measurement step, the gas in the inspection container is collected in the vicinity of a seal portion that is sealed when the package is sealed. . In the atmospheric pressure adjustment step, the gas-filled sealed packaged food is stored in the inspection container so that the seal portion is positioned on the upper side,
The pinhole inspection method according to claim 3, wherein in the hydrogen gas measurement step, sampling of the gas in the inspection container is performed at least in the vicinity immediately above the seal portion. A gas-filled hermetically sealed packaged food with a configuration in which air is removed from the inside of the package that encloses the food that is the contents, and a mixed gas of an inert gas and a predetermined ratio of hydrogen gas is filled as a replacement gas, and the package is sealed. In a device for inspecting the presence or absence of pinholes
Including one or a plurality of the gas-filled sealed packaged foods, and equipped with a test container capable of blocking gas inflow and outflow from the outside,
In the inspection container, an atmospheric pressure adjusting means for setting the atmospheric pressure inside the package body to an environment higher than the atmospheric pressure in the inspection container outside the package body,
Collecting gas in the inspection container, hydrogen gas detection means for detecting hydrogen gas in the gas,
A pinhole inspection apparatus comprising: The inspection container is configured to be sealed when containing the gas-filled hermetically sealed food,
6. The pinhole inspection apparatus according to claim 5, wherein the atmospheric pressure adjusting means includes the inspection container and a suction pump that decompresses the inside of the sealed inspection container. The pinhole inspection apparatus according to claim 6, wherein the inner wall of the inspection container is set at a position where the packaging body that expands when the suction pump is decompressed by the suction pump can contact from the inside. The hydrogen gas measuring means includes a gas sampling unit disposed in the vicinity of the gas-filled sealed packaged food stored in the inspection container, a pipe connected to the gas sampling unit, and a suction pump connected to the pipe And a hydrogen gas detector connected to the pipe,
The pinhole according to any one of claims 5 to 7, wherein the gas collection unit is configured to collect the gas in the cuvette in the vicinity of a seal unit sealed at the time of sealing in the package. Inspection device. The inspection container contains the gas-filled hermetically sealed food so that the seal portion is positioned on the upper side,
The pinhole inspection device according to claim 8, wherein the gas sampling unit is disposed in the vicinity immediately above the seal unit. The cuvette includes a drawer-type tray on which the gas-filled hermetically sealed packaged food can be placed, and the gas inside and outside of the cuvette is blocked from flowing into and out of the cuvette while the tray is pushed into the cuvette. The pinhole inspection apparatus according to any one of claims 5 to 9, which is configured as described above. The inspection container includes an entrance door portion and an exit door portion serving as an inlet / outlet of the gas-filled sealed packaged food, and a transport mechanism for transporting the gas-filled sealed packaged food from the inlet side to the outlet side. The inside of the inspection container is configured to be blocked from inflow and outflow of gas with the outside in a state where the section and the outlet door part are closed, and the transport mechanism is disposed on the upstream side and the downstream side of the inspection container. The pinhole inspection device according to any one of claims 5 to 9, wherein the pinhole inspection device is connected to a transport mechanism in the gas-filled sealed packaged food production line. The inspection container is composed of an inspection container main body arranged on the outermost side, and one or more inner containers of different sizes that can be nested inside the inspection container main body,
The internal space of each inner container communicates with the internal space of the inspection container body directly or indirectly,
The hydrogen gas detection means collects the gas outside the inner container in the inspection container body,
The pinhole inspection device according to any one of claims 5 to 11, wherein the gas-filled sealed packaged food is selectively accommodated in one of the inspection container main body and the inner container.

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