JP3898270B2 - Cereal freshness preservation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for maintaining the freshness of packaged cereals using cereals such as rice immediately after milling together with an oxygen scavenger.
[0002]
[Prior art]
Conventionally, a storage bag in which an oxygen scavenger is sealed in a corner of a storage bag for gas-barrier cereals (Japanese Utility Model Publication Nos. 59-143971 and 60-50171), and a storage bag for cereals, etc. Consists of gas barrier outer bag and oxygen permeable inner bag, put oxygen scavenger between outer bag and inner bag, and store stored items such as grains while leaving oxygen scavenger in storage bag A storage bag (Japanese Patent Laid-Open No. 63-67275) that can be taken out from the inside, and a storage bag for cereals, etc., are composed of a gas barrier inner bag and a relatively strong, sun-blocking kraft paper A storage bag containing an oxygen scavenger and an oxygen detector in an inner bag so that the oxygen detector can be visually confirmed from a window provided in the outer bag (Japanese Patent Laid-Open No. 61-203378). )It has been known.
[0003]
In addition, food such as potato chips, rice, and wheat is stored in a sealed bag made of plastic film that is degassed and filled with a chemical that absorbs oxygen and has a function of generating carbon dioxide. It is known that carbon dioxide gas suppresses external deformation of the sealed bag (Japanese Patent Laid-Open No. 4-201878).
[0004]
In addition, a flaky inorganic additive is added to polyethylene, the flaky inorganic additive enters the gaps between the polyethylene molecules, and the grains are put into a bag formed of a material with the gaps narrowed. A packaging method is known in which a vacuum degree is maintained so as not to be deformed after packaging by placing it in a vacuum packaging machine or by putting an oxygen scavenger in the bag and packaging (Japanese Patent Laid-Open No. Hei 3-162268). Issue gazette).
[0005]
Furthermore, a substantially non-breathable packaging material together with an oxygen scavenger formed by sealing cereals in a breathable packaging material having an oxygen scavenger composition with a Gurley air permeability (JISP 8117) of 200-100,000 seconds / 100 ml of air, or A method for controlling pests of cereals is known which is sealed in an airtight container and kept at 5 to 20 ° C. with an oxygen concentration of 0.1% or less to kill the pest eggs attached to cereals and prevent hatching after opening (special No. 64-7739).
[0006]
On the other hand, with recent changes in the rice distribution channel, the rice is in a unit of 5 kg, 10 kg, etc., in a soft package (flexible pack) with a resin material with a large number of small holes drilled in advance to give air permeability However, since these soft-wrapped rice has many small holes, no oxygen scavenger has been used.
[0007]
[Problems to be Solved by the Invention]
Recently, due to the increasing consumer preference to eat really delicious rice, soft wrapping of rice of specific varieties and specific production areas, in some cases right after milling of high quality rice of specific producers in units of 5 kg, 10 kg, etc. There are also an increasing number of sales methods for direct delivery and delivery from consumers to consumers. However, there was a problem that the quality of high-quality rice deteriorated a little before opening the packaged rice and cooked rice, and the flavor and the like were not different from those of ordinary over-the-counter sales, and the merit of direct delivery from the production area was not utilized .
[0008]
The present inventors examined the application of oxygen scavengers from the viewpoint of maintaining the freshness of good quality rice immediately after rice polishing, and the scent of good quality rice during rice polishing after opening and during rice cooking disappeared, Compared to the case where it becomes tasteless compared to the taste of rice grains, or the bad smell from the packaging material is added to the packaged polished rice, for the purpose of antioxidant, insecticidal, sterilization, etc. of grains with ordinary oxygen scavengers, It was found that there are various problems that need to be solved regarding the quality of polished rice. In addition, when storing and transporting pillow-shaped soft packaging bags packed with milled rice, for example, when storing and transporting 10 to 15 tiers of pallets, the stacked rice packaging bags collapse and fall, or the stacked rice It turned out that there was a big problem in practice that the bottom of the packaging bag broke.
[0009]
The object of the present invention is to solve all the above-mentioned problems related to quality such as rice milling and practical problems at the time of storage and transport, and to maintain excellent freshness of grains such as rice immediately after milling in a packaging form using an oxygen scavenger. It is to provide a method.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, we conducted intensive research on the type and performance of soft packaging bag packaging materials, the conditions for using oxygen scavengers, the packaging method of soft packaging bags during filling of milled rice, etc. It has been found that it is possible to maintain excellent freshness of cereals such as rice immediately after milling for the first time when adopting specific combinations such as specific use conditions of oxygen scavenger, specific packaging method of soft packaging bag at filling The present invention has been completed.
[0012]
That is, the present invention, the cereals, together with a deoxygenating agent, with the following oxygen permeability 30cc / m ² / 24hr, the flexible packaging bag comprising a moisture permeability 10g / m ² / 24hr or less than the thickness 40μm of the multilayer barrier film After packaging under reduced pressure, sealing the opening, making a small hole in the flexible packaging bag, setting the atmospheric pressure in the flexible packaging bag to atmospheric pressure, and then closing the small hole again, It is related with the freshness maintenance method of cereals, such as rice immediately after milling, characterized by performing and making it a deoxygenation state for 24 to 96 hours.
[0013]
Also, the present invention, the cereals, together with a deoxygenating agent, with the following oxygen permeability 30cc / m ² / 24hr, the flexible packaging bag comprising a moisture permeability 10g / m ² / 24hr or less than the thickness 40μm of the multilayer barrier film Using a rigid shaping holder, after filling rice in a soft packaging bag, shaping the packaging consisting of a step of sealing out by removing air as much as possible, and deoxidizing in 24 to 96 hours It relates to a method for maintaining the freshness of cereals such as rice immediately after milling.
[0014]
Furthermore, the present invention provides a freshness maintaining method using an iron-based oxygen absorber stored in a breathable packaging material having an air permeability of 3000 to 12000 seconds, and A freshness maintaining method using an oxygen agent containing an adsorbent such as 0.05 to 5% by weight of activated carbon, and the multilayer barrier film has a thickness of 40 to 150 μm and at least a polypropylene film layer and / or an aluminum foil layer It is related with the freshness maintenance method of cereals using what does not have an oxidation smell.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, cereals include rice, barley (including bare barley), wheat, rye, corn, corn, mackerel, horse mackerel, maize, bean mainly composed of soybeans, and buckwheat. It can be illustrated. In the present invention, a solid food material whose quality deteriorates due to oxidation of dried rice cake, tea or the like is also referred to as cereal for convenience.
[0016]
The method for maintaining freshness of the present invention is particularly suitable for rice immediately after milling, more preferably high-quality rice with a grain taste value of 70 or more, and this packaging keeps the freshness of the milled rice as it is after opening and until cooking. It was confirmed that it would sag. The rice grain taste value is an index representing the taste of rice, which is measured by a taste analyzer and the taste value of standard rice is 70.
[0017]
In the present invention, the oxygen scavenger is a composition in which a composition that absorbs oxygen by contact with air is stored in a packaging material such as a breathable sachet or a small container. Examples of such a composition include iron, carbonization, and the like. Reducing properties such as iron powders such as iron, reducing inorganic salts such as sulfites and ferrous salts, polyphenols such as hydroquinone, catechol, pyrogallol and gallic acid, reducing sugars such as glucose, ascorbic acid and erythorbic acid Examples include those containing a reducing agent such as polyhydric alcohol as the main active ingredient, among which iron-based deoxygenated compositions containing iron powder and an electrolyte, such as iron powder and metal halide, are preferred.
[0018]
The oxygen scavenger should be used in a state in which heat generation by the oxygen scavenger is suppressed so that the inside of the soft wrapping bag after shaping and packaging such as cereals will be in the oxygen scavenging state for 24 to 96 hours, preferably 24 to 48 hours. is necessary. When the deoxygenated state is obtained in less than 24 hours, the quality of cereals such as milled rice is degraded by the heat generated by the deoxygenation reaction. Moreover, when using a deoxidation agent on the conditions over 96 hours to be in a deoxygenation state, there exists a possibility that the quality of cereals, such as a rice mill, may deteriorate before it becomes a deoxygenation state.
[0019]
As the oxygen scavenger, in addition to the oxygen scavenging composition, those containing 0.05 to 5% by weight of an adsorbent such as activated carbon and zeolite can be used. If what contains 0.05-5 weight% activated carbon as an oxygen scavenger is used, in addition to the unpleasant odor of cereals, the oxidization odor derived from a multilayer barrier film can also be deodorized.
[0020]
It is preferable to store the deoxygenated composition in a breathable packaging material having an air permeability of 3000 to 12000 seconds. When an oxygen scavenger containing, for example, an iron-based oxygen scavenging composition is applied to a breathable packaging material having an air permeability of 3000 to 12000 seconds to a soft packaging bag that is shaped and packaged after filling 2 to 10 kg of polished rice, Becomes deoxygenated in 24-96 hours.
[0021]
Here, the air permeability means the Gurley-type air permeability of the air-permeable packaging material. Specifically, as the air-permeable packaging material having an air permeability of 3000 to 12000 seconds, a porous material (polyethylene terephthalate / polyethylene) is used. Examples thereof include a resin film made of / water / oil resistant paper / porous polyethylene.
[0022]
In the present invention, the multilayer barrier film is a packaging material of the flexible packaging bag, the oxygen permeability of 30cc / m ² / 24hr or less, preferably below 20cc / m ² / 24hr, moisture permeability 10g / m ² / 24hr or less , preferably 5g / m ² / 24hr or less in thickness 40μm or more, preferably can be used for 40 to 150. When the oxygen permeability is more than 30cc / m2 / 24hr, oxygen penetrates into the flexible packaging bag, it difficult to hold the deoxygenated state, also, those oxygen permeability of less than 20cc / m ² / 24hr is A deoxygenated state can be reliably achieved. Further, when the moisture permeability exceeds 10g / m ² / 24hr, or moisture in the flexible packaging bag causing lowering the freshness of intruding cereals as humidity, moisture milled rice such conversely to escape rice etc. Although dried so that the problems such as stickiness of the cooked rice is eliminated occurs, moisture permeability are the following 10g / m ² / 24hr is almost no such fear. And if the thickness of the multilayer barrier film is less than 40 μm, there is a risk of insufficient strength as a packaging material, and there is a risk that soft packaging bags may be damaged or pinholes may occur in the distribution process. However, it is hard and difficult to handle, and the material cost is high.
[0023]
As the material of the multilayer barrier film in the present invention, biaxially stretched polypropylene (OP), polyvinylidene chloride coated biaxially stretched polypropylene (KOP), aluminum (Al) such as aluminum foil and aluminum vapor deposition, stretched nylon (ON), Polyvinylidene chloride coated stretched nylon (KON), nylon (NY), unstretched polypropylene (CPP), polyethylene terephthalate (PET), polyvinylidene chloride coated polyethylene terephthalate (KPET), polyethylene (PE), polyvinylidene chloride coated polyethylene (KPE) ), Linear low density polyethylene (LLDPE) and the like. Specific examples of the laminated structure include ON / PE, KPET / PE, KON / PE, KOP / PE, KOP / NY / PE / LLDPE, PET / PE / paper / E, ON / PE / paper / PE, KPET / PE / paper / PE, KON / PE / paper / PE, KOP / PE / paper / PE, paper / PE / ON / PE, paper / PE / KPET / PE, Paper / PE / K Coat ON / PE, Paper / PE / KOP / PE, Paper / PE / Vinylidene Chloride / PE, PET / PE / Al / PE, ON / PE / Al / PE, OP / PE / Al / PE And multilayer barrier films such as OP / NY / PE / LLDPE, and multilayer barrier films such as PET / PE / Al / PE, KOP / NY / PE / LLDPE, OP / NY / PE / LLDPE, etc. Film is desirable.
[0024]
In addition to the above, the properties required for the multilayer barrier film in the present invention include good sealing properties and no oxidation odor. When the stored cereals are required to be particularly fresh in flavor, such as good quality rice immediately after milling, it is desirable to use a non-oxidizing odor as the multilayer barrier film, Is also called a lamellar odor or a poly odor, and is caused by thermal deterioration of a plastic melted at the time of laminating in the production process of a multilayer barrier film, and refers to a strange odor caused by an oxide of a film polymer.
[0025]
In the present invention, the soft packaging bag is also called a flexible pack, and means a packaging bag in which grains are stored in a bag formed of a packaging material made of a multilayer barrier film, unlike a container whose shape is fixed in advance.
[0026]
In the present invention, shaped packaging means that air between grains such as the gap between rice grains remains, but excess air in other bags is expelled as much as possible so that the soft packaging bags are almost filled with grains. Packing means a packaging method that does not collapse when, for example, 10 to 15 layers are stacked.
When the oxygen scavenger is applied to this shaped package, oxygen that occupies 20% of the air present in the package bag is absorbed. Therefore, this shaped package is different from the conventional aerated package. In aerated packaging, immediately after packaging, for example, 10 to 15 stacks may become unstable and may collapse or fall, and if stacked, the lower packaging bag may break. Many.
Moreover, it differs from the deaeration pressure reduction packaging which has a deaeration process at the time of packaging. Degassed in advance is significantly deaerated after deoxygenation, and becomes ticked, often causing broken bags and poor seals.
[0027]
As an example of shaped packaging in the present invention, a soft packaging bag is filled and packaged with grains such as milled rice under reduced pressure at a pressure of less than 1 atm. After sealing the opening, one or more small holes are formed in the flexible packaging bag. An example of the packaging method includes a step of making a hole, allowing air to naturally flow from the small hole, and setting the atmospheric pressure in the flexible packaging bag to atmospheric pressure, and then closing the small hole again with a seal or the like.
[0028]
In addition, when not using the vacuum packaging device as described above, the shape of the soft packaging bag after filling is substantially the same as the shape of the flexible packaging bag, for example, a wooden, plastic, metal with a rectangular top opening that has vertical, horizontal, and height dimensions. An example of a packaging method comprising a step of preparing a rigid shaping holder made in advance, filling the flexible packaging bag with rice in this shaping holder, and sealing the unsealed portion by eliminating air as much as possible be able to.
[0029]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples. However, the technical scope of the present invention is not limited to these examples.
Example 1
Akita Komachi (rice grain taste value 80) immediately after milling together with an oxygen scavenger (air capacity 2500 cc compatible product) containing reduced iron powder as a main component in a deoxygenating composition housed in a breathable packaging material with an air permeability of 8000 seconds ) immediately rice to 5kg, OP / NY / PE / LLDPE a composite barrier film (oxygen permeability 25cc / m ² / 24hr, moisture permeability 2g / m ² / 24hr, the soft packaging bag bag making the thickness 100 [mu] m) Filled and degassed and sealed. After sealing, a small hole is made in the flexible packaging bag, the atmospheric pressure in the flexible packaging bag is set to atmospheric pressure (the air capacity in the packaging bag was 2100 cc at this time), and the small hole is sealed again. The plastic packaging was closed by The shaped and packed soft packaging bags were stacked and transported in 15 layers on the pallet, but the stacked soft packaging bags were not collapsed or overturned during that time, and there were no broken bags.
[0030]
The soft wrapping bag filled with the above polished rice was deoxygenated in about 48 hours, opened for 3 months after storage and picked up by hand. The smell of good quality rice from time. When this rice was cooked immediately after opening and 2 days after opening, both had the same aroma and taste of good rice as the rice just after polishing.
[0031]
(Comparative Example 1)
In Example 1, the same procedure as in Example 1 was performed, except that the unsealed portion was sealed under a negative pressure, and then the soft packaging bag was used without being punctured without a small hole. The soft packaging bags were stacked and transported in 15 layers on the pallet, but the stacked soft packaging bags did not collapse or fall during that time, and there were no broken bags, but they were opened after storage for 3 months. When picked up, the rice grains were hardened in a rock shape, and the scent of good quality rice during milling was maintained, but the commercial value was lost in appearance and touch.
[0032]
(Comparative Example 2)
In the same manner as in Example 1, except that oxygen adsorption in the air by the oxygen scavenger was anticipated in advance, and air packaging was performed without shaping packaging. I tried to stack 15 layers of this soft packaging bag on a pallet, but when it was stacked 6 to 7 stages, it became unstable and often collapsed, and it was stacked with holders on both sides to prevent it from collapsing. However, the bottom soft packaging bag broke.
[0033]
(Comparative Example 3)
The same procedure as in Example 1 was performed except that the oxygen-adsorbing agent was adjusted so that the inside of the flexible packaging bag was deoxygenated in 15 hours and 120 hours. When opened for 3 months, both of them lost the scent of good quality rice during milling, and the cooked rice had lost the scent and taste of good quality rice immediately after milling.
[0034]
(Example 2)
For plastic packaging, use a plastic rigid plastic holder with a rectangular top with vertical, horizontal and height dimensions of 8 x 28 x 40 cm, and fill the flexible packaging bag with 5 kg of good quality rice. Then, it carried out like Example 1 except excluding air as much as possible and sealing an opening part.
[0035]
The soft packaging bag filled with the above polished rice was deoxygenated in about 50 hours and opened after being stored for 3 months. As a result, although it was slightly inferior to the case of Example 1, there was a scent of good quality rice during polishing. When this rice was cooked immediately after opening and 2 days after opening, although both were slightly inferior to the case of Example 1, both had the same fragrance and taste of good rice as the rice just after polishing.
[0036]
【The invention's effect】
According to the present invention, in addition to the effects of using conventional oxygen scavengers such as insecticide and antioxidant, there is no addition of off-flavors from the packaging material after opening a soft packaging bag filled with polished rice or during cooking. The polished rice is not dried, and not only the scent of good quality rice at the time of polishing but also the preservation of the taste of the rice grain at the time of polishing can be maintained for about 6 months. In addition, when storing and transporting pillow-shaped soft packaging bags packed with polished rice, etc., for example, when storing and transporting 10 to 15 tiers on a pallet, the stacked rice bags collapse and fall or are stacked The bottom of the bag does not break, and it is possible to maintain the practical freshness of cereals such as rice immediately after milling in a packaging form that is excellent in storage and transport in the form of direct delivery.

Claims (6)

Cereals, together with a deoxygenating agent, with the following oxygen permeability 30cc ^/ m 2 ^/ 24hr, the flexible packaging bag comprising a moisture permeability ^10g / m 2 / 24hr or less double layer over the thickness 40μm of the barrier film, packaged under vacuum Then, after sealing the opening, a small hole is made in the flexible packaging bag, and after the atmospheric pressure in the flexible packaging bag is set to atmospheric pressure, the packaging is performed again by closing the small hole for 24 to 96 hours. A method for maintaining the freshness of cereals, characterized in that it is in a deoxygenated state. Cereals, with oxygen scavenger, oxygen permeability 30cc / m ² / 24 hr or less, water vapor transmission rate 10 g / m ² Shaped packaging consisting of a process of sealing a flexible packaging bag composed of a multilayer barrier film with a thickness of 40 μm or less of 24 hours or less, using a rigid shaping holder, and excluding air as much as possible after sealing. A method for maintaining the freshness of cereals, characterized in that it is deoxygenated in 24 to 96 hours.   The method for maintaining freshness of cereals according to claim 1 or 2, wherein the oxygen scavenger is an iron oxygen scavenger housed in a breathable packaging material having an air permeability of 3000 to 12000 seconds.   The method for maintaining cereal freshness according to any one of claims 1 to 3, wherein the oxygen scavenger contains 0.05 to 5 wt% of an adsorbent.   The method for maintaining freshness of cereals according to any one of claims 1 to 4, wherein the multilayer barrier film has a thickness of 40 to 150 µm, includes at least a polypropylene film layer and / or an aluminum foil layer, and has no oxidation odor.   The method for maintaining freshness according to any one of claims 1 to 5, wherein the cereal is rice immediately after milling.