JP3783115B2 - Dry food packaging - Google Patents

Description

  The present invention relates to a packaging material for dry food.

  More specifically, the present invention relates to a novel packaging material useful for preventing various foods in a dry state from deterioration of quality due to oxidation over a long period of time.

  Conventionally, various measures for preventing deterioration of quality due to oxidation during storage of food and various packaging materials, packaging methods, and additives to be used for the measures have been proposed, and there are those proposals Things are already in practical use.

  For example, it is a proposal regarding a method for coexisting an article having oxygen absorbing activity in the same packaging system in contact with or adjacent to food and an article having oxygen absorbing activity used therefor.

  In addition, there are many methods for preventing oxidation of food by inserting an article having oxygen-absorbing activity separately from food into a food packaging as a so-called “accessory” or the “accessory” itself. Proposals have been made.

  Furthermore, there is an attempt to use an oxygen-absorbing active article as a food packaging rather than as an independent “attachment”.

  For example, “To prevent spoilage, oxidative degradation, rusting, etc. during storage of various products” “Oxygen absorber composed of iron powder and electrolyte” “After sheet processing of resin composition” “Uniaxial direction The invention concerning “stretched oxygen absorbing sheet” is disclosed (see Patent Document 1). This description does not include means for solving the problems relating to the prevention of oxidation peculiar to dried foods or suggesting the action and function of a deliquescent substance that activates metallic iron powder.

  The idea of using this oxygen-absorbing active article as the packaging material itself occurs when using the “attachment”. B) In addition to the packaging process, there is a new increase in the process for attachment. B) Increase in cost and energy for attachment is inevitable. C) A check process is required to check whether the “attachment” is properly inserted in the package. To a certain extent, there are some problems, such as an increase in new consumption of resources derived from raw materials and packaging materials of “accessories”, and d) accidents caused by misidentifying “accessories” as food. It can be evaluated that it can be avoided or reduced.

However, currently available packaging materials with oxygen-absorbing activity, when used as packaging materials for foods containing a considerable amount of water, can effectively prevent deterioration due to oxidation of the food products, even if they are used to wrap dry food products. When used as a material, there is a problem that it cannot be confirmed to the extent that an effect of preventing deterioration due to oxidation is expected.
Japanese Patent Laid-Open No. 5-116213

  In view of the above problems, an object of the present invention is to obtain a dry food packaging material that is protected from deterioration due to oxidation and can be stored for a long period of time.

  The inventors of the present invention have obtained the following technical knowledge (1) to (6) as a result of intensive studies on the solution of the above problems.

  (1) Currently, a commercially available packaging material having oxygen absorption activity is a structure obtained by processing and molding a sheet material having a plastic layer formed by kneading an oxygen absorbent. The oxygen absorption activity is weak.

  (2) The oxygen absorption activity is actively expressed for the first time when it comes into contact with water vapor or liquid water.

  (3) In order to bring the oxygen absorbent in the sheet material into contact with water vapor or liquid water, the surface of the sheet may be directly sprayed with water vapor or liquid water. The moisture obtained by selectively adsorbing and concentrating water vapor present in the surrounding air or the air contained in the dried food) may be brought into contact with the oxygen absorbent.

  (4) In order to obtain moisture by selectively adsorbing and concentrating water vapor from the surrounding atmosphere, a method of allowing a deliquescent substance to coexist in the vicinity of the oxygen absorbent in the sheet material is practical.

  (5) Conventionally, commercially available packaging materials having oxygen absorption activity can effectively prevent deterioration due to oxidation of foods when used as packaging materials for foods containing a relatively high level of moisture. When used as a packaging material for dried foods, the recognition that effective oxidative degradation prevention effects cannot be confirmed is the elucidation of the relationship between the characteristics of packaging materials with oxygen-absorbing activity and the moisture content of packaged foods Would have been overlooked.

  (6) When using packaging materials having oxygen absorption activity, it is not necessary to use packaging materials composed of oxygen absorption activity materials for all parts of the package. In consideration of the storage period, a packaging material partially made of an oxygen-absorbing material may be used.

The present invention has been completed based on these findings. That is, the first invention according to claim 1 is:
An oxygen absorber / deliverable substance coexisting layer containing a deliquescent substance in which the water activity of the metallic iron powder as an oxygen absorbent and the saturated aqueous solution is equal to or less than the water activity of the dry food to be packaged;
The dry food packaging material is characterized in that an oxygen barrier layer for preventing oxygen from entering from outside is formed on the outside of the packaging material formed for the coexisting content layer.

According to a second aspect of the present invention,
In the first invention, at least one of the dried food side or the outside of the packaging material formed for the oxygen absorbent / deliquescent substance coexisting layer,
A support layer for supporting and protecting the coexisting content layer;
A heat seal layer for forming and bonding sheet materials;
A light shielding layer to protect the package contents from external light and heat;
It is a dry food packaging material characterized in that any one or more layers of a protective layer that relieves an external impact are formed.

  The packaging material for dried foods of the present invention has a sufficient function as a packaging material, and the quality of dried foods deteriorates due to oxidation of the contents over a long period of time, as in the case of foods with relatively high water content. It has the effect that it can be effectively prevented.

  The dry food packaging material of the present invention has an effect that the oxygen absorption activity is activated uniformly and effectively.

In the first invention and the second invention, the sheet material containing the oxygen absorbent and the deliquescent substance to be used is variously formed on the upper layer and / or the lower layer of the plastic layer or the nonwoven fabric layer containing the oxygen absorbent and the deliquescent substance, for example. These are plastic materials having the above functions, film-like materials such as metal foils, nonwoven fabrics, and papers, and composite sheet materials that are laminated so that they do not peel off each other.
Examples of the oxygen absorbent that can be used in the present invention include metal iron powder, aluminum metal powder, sodium bisulfite, vitamin C, vitamin E, and coenzyme Q. Of these, metallic iron powder is the most practical, but it goes without saying that the other oxygen absorbers can be used in place of or in combination with the metallic iron powder.

  In the composite sheet, the oxygen absorbent and the deliquescent material need to be present in close proximity. Preferably, after the deliquescent material is coated on the oxygen absorbent in advance, it is uniformly distributed in the same plastic film. It is good to disperse.

  Alternatively, an oxygen absorbent and a deliquescent material may be simply blended and dispersed in a plastic film.

  The substance that coexists with the oxygen absorbent is a deliquescent substance, that is, a substance that absorbs water vapor from the surrounding atmosphere and nearby articles and dissolves in the absorbed water. At this time, the absorbed water needs to be used for activation of the oxygen absorption function by contacting the oxygen absorbent, and a desiccant that simply absorbs water vapor, such as zeolite (Zeolite), is suitable as a coexisting substance. Not.

  An appropriate weight ratio of the deliquescent substance to the oxygen absorbent coexisting in the composite sheet is 2% or more and 100% or less.

  When a large amount of deliquescent material is present beyond this range, the amount of adsorbed and concentrated water becomes excessive, and contrary to expectations, the oxygen absorption capacity and oxygen absorption rate of the oxygen absorbent are reduced.

  When there is a small amount of deliquescent material that does not reach this range, the amount of water absorbed and concentrated is not sufficient to activate the oxygen absorbent, and the oxygen absorbent's ability to absorb oxygen is fully demonstrated. Not.

  The oxygen absorbent has a function of deoxygenating from the surrounding environment or an adjacent article without needing to be specifically described.

  The oxygen absorbent particles may be fine spheres, fine porous spheres, fine ellipsoids, fine flakes, fine irregular shapes, etc. Various forms can be taken.

  The deliquescent substance has a function of supplying moisture to the oxygen absorbent and activating and promoting the oxygen absorption ability and deoxygenation ability of the oxygen absorbent.

  When the deliquescent substance is calcium chloride, magnesium chloride, lithium chloride or zinc chloride, since these substances are electrolytes, they further have a function of promoting the oxygen absorbing ability and deoxygenating ability of the oxygen absorbent.

  As a deliquescent substance, a substance whose water activity of the saturated aqueous solution is equal to or lower than the moisture of the dry food to be packaged should be selected.

  The water activity is a numerical value adopted as a scale reflecting the amount of free water in foods and other articles, and is defined as follows.

a _w = P / P ₀ = RH / 100
Where _aw is the water activity, P is the water vapor pressure in the container after the food and other articles are left in the closed container to reach the water equilibrium, P ₀ is the water vapor pressure of pure water, and RH is the food and other articles. Is the relative humidity in the container after it has been left in a closed container to reach moisture equilibrium.

  Particularly suitable deliquescent materials include calcium chloride, magnesium chloride, lithium chloride or zinc chloride. However, it is not limited to these deliquescent substances, and depending on the water activity of the dry food to be packaged, for example, sodium chloride (salt) can be used.

  Since it cannot be said that the oxygen absorbent / deliquescent substance coexisting layer film has sufficient functions as a packaging material, films and sheets having various functions above and / or below these layers Overlay the material to complement the properties as a packaging material.

  Table 1 shows each film-like material constituting the sheet material having the oxygen absorbent / deliquescent substance coexistence containing layer film, the necessary functions of the sheet-like material, and the positional relationship between the layers. In Table 1, the upper and lower labels indicate the inner side that comes in contact with the dried food that is the packaged content when a sheet material formed by positioning the oxygen absorbent / deliquescent substance coexisting layer film in the center is formed into a packaging material. The side that becomes the lower layer and the side that becomes the outer side of the molded packaging material are indicated as the upper layer. In the “Position” column of the same table, “upper and lower” means that the layer (film or sheet) exists in either the upper layer or the lower layer, or both the upper and lower layers. means. It is also possible to give a plurality of functions to the same film or sheet.

  The materials of these individual film-like materials and sheet-like materials are suitable ingredients and materials for food packaging, considering that the manufactured composite sheet material is processed and molded as a food packaging material. Selected. Similar considerations apply to the method of integrating layers with oxygen absorber / deliquescent substance coexisting layer film and other film-like and sheet-like materials, and auxiliary materials such as adhesives and plasticizers used at that time. is necessary. As long as the material satisfies the functions described in Table 1 and is within the range of materials that are recognized as being suitable as food packaging materials, a wide variety of materials can be used without particular limitation.

  About the manufacturing method of a film-like thing and a sheet-like thing, it is not limited to the example shown below, The layer structure which is illustrated substantially should just be formed. For example, simultaneous extrusion molding of different resins using a multilayer co-extrusion facility can be used.

  FIG. 1 is a schematic view illustrating a cross-section of an example of the configuration of a sheet material having an oxygen absorbent / deliquescent substance coexisting layer film. In FIG. 1, 1 is an oxygen absorbent / deliquescent substance coexisting layer film, 2 is another film bonded to the lower side of the film (in the case of forming a packaging material, the inside of the packaging), for example, Polyethylene film that imparts heat-sealability to the sheet material, 3 is another film bonded to the upper side of the film (when it is formed into a packaging material, it becomes the outside of the packaging), for example oxygen in the entire sheet material An aluminum foil providing a barrier and paper, polyester film or polypropylene film for protecting the aluminum foil from physical impact are shown.

  In the present invention, a dry food is packaged by using a packaging material including a sheet material having an oxygen absorbent / deliquescent substance coexisting layer film at least in a part of the structure.

  In addition, a packaging material including a sheet material having a film containing a deliquescent substance whose water activity of the saturated aqueous solution is equal to or lower than the water activity of the dry food to be packaged among oxygen absorbers and deliquescent substances at least in a part of the structure Use to package dry food.

  At this time, all the materials constituting the packaging material are deliquescence of the sheet material having the layer film containing the oxygen absorbent and the deliquescent substance or the water activity of the oxygen absorbent and the saturated aqueous solution below the water activity of the dry food to be packaged. There is no need for the sheet material having the active substance coexisting layer film, and for example, only the bottom surface portion or the side surface portion of the packaging material may be composed of these sheet materials.

  Which part of the packaging material is made of these sheet materials is determined in consideration of the moisture content and properties of the dried food to be packaged.

  In addition, the packaging material form and structure suitable for the packaging of the dried food are appropriately selected in consideration of the properties of the dried food to be packaged, the expected storage conditions and the period.

  For example, a “four-sided laminating bag” composed of a sheet material on one side and a transparent film material on the other side, a cup-type container having only the lid portion composed of the sheet material, and the sheet material used for the main body portion. The lid is a cup-type container made of a heat-sealable sheet having a transparent oxygen-blocking ability, a tube-type container using the sheet material for the main body, a plastic bottle or glass bottle cap, and a plastic bottle opening. A paracoat lid that seals the opening of a glass bottle or a glass bottle, a laminated pouch-type container, a non-breathable sheet on the bottom, a standing pouch-type container using the sheet material for the main body, and the sheet for the main body Various container forms such as a tray-type container using a material can be adopted.

  FIG. 2 shows a bottom part (4) made of a sheet material having a layer film containing an oxygen absorbent / deliquescent substance coexisting layer and a lid made of a three-layered plastic material having transparent oxygen barrier properties such as polyester, ethylene vinyl alcohol, and polyethylene. It is a figure which is comprised from the part (5) and illustrates the package body containing the granular dry foodstuff package, for example, a mix nut.

  In the present invention, the food to be packaged is a food in a dry state. The dry state in this case should not be understood in a narrow sense, and covers semi-dried foods in addition to ordinary dry foods. Examples of those dried foods and semi-dried foods are as follows.

(1) Processed seafood: dried scallops, tatami mushrooms, sea bream, processed sea bream, fish fields, fish sprinkles (2) Delicacy foods: beef jerky, mixed nuts, grilled seaweed , Almond, almond flake, cashew nut, galvanso (4) snack foods: potato chips, shoe string, pop corn (5) cereal foods: corn flakes, muesley (6) luxury goods: powder Instant coffee, powdered instant tea, coffee beans, tea (leaves), green tea (leaves), oolong tea (leaves)
(7) Dried noodles / pasta: dried rice cake, dried noodles, macaroni, spaghetti, instant ramen, rice noodles, vermicelli, dry bread, powdered instant potage soup, croutons "Hotcake premix", wheat germ (9) Dried vegetables: dried shiitake mushrooms, dried springspring, freeze dried koji, dried radish, dried seaweed, dried young cloth, dried deer tailed vegetables, perilla powder (10) confectionery: `` Baum Kuchen '', `` Castella '', `` Copper-grilled '', `` Biscuit '', `` Clacker '', `` Cookie '', `` Hanabayashi Sugar '', `` Okoshi '', `` Ochigo '', `` Simple '', `` Yotei '', `` In the middle '', `` Five family treasure '', `` Moroshi ''

(11) Rice confectionery: “Salmon seed”, “Koka decoction”, “Tile decoction”, “Okaki”, “Fried oyster”
(12) Dairy products: Parmesan / cheese powder, skim milk powder, adjusted powdered milk (13) Seasonings: Granule seasoning consisting of fish bun powder and monosodium glutamate, shaved fish bun, grilled, boiled and dried, kelp powder , Powdered pepper, grain pepper

  Hereinafter, the present invention will be described by way of examples. These examples do not limit the idea of the present invention. In the description of Examples, unless otherwise specified, “parts” indicates parts by weight, and “%” indicates weight / weight%.

(Example 1) == Packaging and preservation test of granule seasoning ==
(1-1)-Manufacture of layered film containing metallic iron powder and deliquescent material--
Under dry conditions of a relative humidity of 30% or less, 50 parts of spherical pure soft steel having a particle size of 5 μ and 20 parts of anhydrous calcium chloride powder having a particle size of 20 μ were added to 25 parts of linear low density polyethylene beads. The water activity of the saturated aqueous solution of calcium chloride is 0.3. This resin mixture was premixed with a tumbler mixer and then kneaded at 120 ° C. for 8 minutes with a Banbury kneader to obtain a film mixture.

This film mixture was T-die molded with a 60 mmφ extruder and processed into a 30 μm-thick film at a processing temperature of 260 ° C.
(1-2)-Processing into packaging sheet--
A 15 μm-thick polyethylene film was laminated to the upper and lower surfaces of the metallic iron powder / deliquescent substance coexisting layer film. Further, an aluminum foil having a thickness of 7 μm and a polyester film having a thickness of 12 μm were laminated on the polyethylene film on the upper surface by laminating.

(1-3)-Processing and molding of packaging material--
The bonded packaging sheet obtained in 1-2 was continuously processed and formed into a standing pouch by a bag making machine so that the upper surface of the packaging sheet was outside the container. The empty capacity of the standing pouch was 150 mL.

(1-4)-Filling and packaging of granular seasoning into a standing pouch--
Continuing to the pouch molding process, the water activity of 0.35, the main component of which is fish paste powder, nucleotide sodium salt and glutamic acid sodium salt via an automatic weighing device inside the standing pouch molded in 1-3 The granular seasoning was filled, and the opening was sealed by heat welding. The filling amount per pouch was 100 g / piece.

(1-5)-Prototype of control package--
A packaging sheet was made on the same conditions as in 1-1 and 1-2 except that sodium chloride was used instead of calcium chloride. The water activity of the saturated aqueous solution of sodium chloride is 0.75. Subsequently, the same process as 1-3, 1-4 passed, and the control | contrast package was made as an experiment.

(1-6)-Preservation of test package and control package--
Twenty test packages and control packages manufactured in 1-4 and 1-5 were randomly selected and stored in cardboard boxes, and stored indoors in the dark for 1 year from April. During this period, no particular control or management of temperature or humidity is performed.

(1-7)-Evaluation of test package and control package by storage test--
Two pieces each from the test package and the control package housed in the cardboard box were randomly taken out immediately after packaging, after 1 week, after 3 months, after 6 months and after 12 months. Open the pouch, take 10 g from the contents, put it in a heat-resistant glass pot, dissolve in 1500 mL of hot water kept at 80 ° C., and season the test package and the control package The liquid was obtained.

  These seasonings were allowed to cool to room temperature (20 ° C.) and immediately subjected to a sensory test with 7 panelists. This test compares the seasoning liquid of the test package and the seasoning liquid of the control package without specifying which is the test or control, comparing the two, whether there is a difference between them, and the taste preference. About the taste and the preference of the flavor, it implemented by the test method which asks the scoring evaluation by the 5-point method which makes the highest point 5 points | pieces.

  Table 2 shows the evaluation results of the sensory test after each storage period for the seasoning liquid of the test package and the seasoning liquid of the control package. In Table 2, the numerical value of the result of the sensory test is a numerical value obtained by rounding off the average value of five scores obtained by subtracting the maximum score and the minimum score from each score given by each paneler.

  As shown in Table 2, in the evaluation results of the sensory test, the taste preference of the test package did not change at all even after 12 months of storage, and the taste preference was 12 Only a small change was seen for the first time a month later. The taste preference of the control package changed after 6 months, and a clear deterioration was observed after 12 months. The preference of flavor changed after 3 months of storage, and a clear fish odor was observed after 12 months.

(Example 2) == Packaging and preservation test of “mixed nuts” ==
(2-1)-Preparation of packaging sheet material--
A packaging sheet material was produced from the metallic iron powder / deliquescent substance coexisting layer film produced by the same method as in Examples 1 and 1-1 and other films according to the method 1-2.

(2-2)-Processing and molding of packaging materials--
The packaging sheet material obtained by the method 2-1 was cut into pieces. A film composed of three layers of transparent polyester 12μ, ethylene vinyl alcohol 25μ, and polyethylene 30μ is laminated on three sides around the sheet cut into pieces continuously by keeping a width of 1.5 cm. Laminated. The inner diameter of the processed and molded bag was 18.5 × 32.5 cm.

(2-3)-"Mixed nuts" filling and packaging in bonded bags--
In a humidity control environment, the laminated bags and “mixed nuts” are supplied to each hopper of the continuous automatic weighing and packaging equipment, and the mixed bags are continuously filled with “mixed nuts”, and the openings are opened. Sealed by thermal welding. The filling amount per bonding bag was 300 g / piece.

  The mixing ratio of the “mixed nuts” was 30% butter peanuts, 20% giant corn, 10% almond slices, 20% galvansau and 20% cashew nuts.

(2-4)-Trial manufacture of control package--
Except for using sodium chloride instead of calcium chloride, the same process as in 2-2 and 2-3 was carried out using a packaging sheet produced under the same conditions as in Examples 1-1 and 1-2 in Example 1. Over time, a control package was prototyped.

(2-5)-Preservation of test package and control package--
Ten test packages and control packages manufactured in 2-3 and 2-4 were randomly selected and stored in cardboard boxes, and stored indoors in the dark for one year from April. During this period, no particular control or management of temperature or humidity is performed.

(2-6)-Evaluation of test package and control package by storage test--
One each from the test package and the control package housed in a cardboard box was randomly taken out immediately after packaging, after 1 week, after 3 months, after 6 months and after 12 months. It was opened and subjected to a sensory evaluation test. The evaluation items were 4 items of taste, flavor, texture, and overall evaluation when taking one nut of each “mixed nut” and chewing it in the mouth. The scoring is based on 1-7.

  Table 3 shows the evaluation results (taste and flavor) of the sensory test after the storage period of each test package or control package after the storage period. In Table 3, the numerical value of the result of the sensory test is a numerical value obtained by rounding off the average value of the five scores obtained by subtracting the maximum score and the minimum score from each score given by each paneler.

  As shown in Table 3, in the evaluation results of the sensory test, the taste preference of the test package has hardly changed even after 12 months of storage, and the taste preference is 12 Only a small change was seen for the first time after a month. The taste of the taste of the control package changed as early as one week, and a clear deterioration was observed after 12 months. The flavor preference was also changed after 1 week, and after 6 months and 12 months, the taste and flavor were clearly degraded.

It is a fragmentary sectional view explaining the example of composition in one embodiment of the packaging material for dry foods concerning the present invention. It is explanatory drawing which illustrates one aspect | mode of the granular dry food packaging body packaged with the packaging material for dry food which concerns on this invention.

Explanation of symbols

1 ... Oxygen absorber / deliquescent substance coexisting layer film,
2 ... Other films pasted on the lower side of the film of 1 (the inside of the packaging when molded into packaging)
3... Another film bonded to the upper side of the film of 1 (outside of the packaging when formed into a packaging material),
4 ... Bottom portion of the packaging composed of a packaging sheet including a layer film containing an oxygen absorbent and a hygroscopic deliquescent substance coexisting material,
5. The lid part of the packaging made of a transparent plastic material,
6 ... Granular package,

Claims (2)

An oxygen absorber / deliverable substance coexisting layer containing a deliquescent substance in which the water activity of the metallic iron powder as an oxygen absorbent and the saturated aqueous solution is equal to or less than the water activity of the dry food to be packaged;
A dry food packaging material, characterized in that an oxygen barrier layer is formed on the outer side of the packaging material formed for the coexisting content layer to prevent oxygen from entering from the outside. At least one of the dry food side and the outer side of the packaging material molded for the oxygen absorbent / deliquescent substance coexisting layer,
A support layer for supporting and protecting the coexisting content layer;
A heat seal layer for forming and bonding sheet materials;
A light shielding layer to protect the package contents from external light and heat;
The dry food packaging material according to claim 1, wherein at least one layer of a protective layer that relieves an impact from the outside is formed.

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