JPH0998658A - Packing material for edible fungus (flammulina velutipes) and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a packing material for an edible fungus (Flammulina velutipes), excellent in the freshness retention of the mushroom and in appearance after packaging and its production. SOLUTION: In the packing material for an edible fungus (Flammulina velutipes) comprising a pouch made from plastic film, or a deeply drawn plastic vessel and a lid material, the plastic film in case that the material is a pouch, or either of the deeply drawn vessel or its lid are irradiated with a pulse-emitted laser beam to bore one or a plurality of fine holes of 100±20μm so that the oxygen permeability at 23 deg.C is adjusted in the range from 5,000 to 18,000cc/ m<2> .24hrs.atm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging material for keeping the freshness of enokitake mushrooms and a method for producing the same, and more particularly to a freshness-keeping packaging material for harvesting and subdividing the enokitake mushrooms for distribution and sale. And a manufacturing method thereof.

[0002]

2. Description of the Related Art Stretch-wrapped trays are the predominant type of small quantity packaging for distribution and sales of shiitake mushrooms, maitake mushrooms, oyster mushrooms, tsutake mushrooms (mushrooms), and shirotamogi mushrooms (also known as this shimeji mushrooms). Tray material is rigid polyvinyl chloride, expanded polystyrene,
Expanded polystyrene, polystyrene paper, etc. are used, and as the stretch film, soft polyvinyl chloride, polyethylene film, etc. are used. On the other hand, in Enokitake, unstretched polypropylene film,
A bag of linear low density polyethylene (LLDPE) film is used for deaeration and hermetic packaging.

[0003] Mushrooms are generally one of the items that need to be kept fresh at the time of distribution / sale because they have a large respiration rate and a large amount of transpiration. The packaging form of mushrooms as described above has a certain degree of shape retention property at the time of distribution and sale and the following freshness retention effect. That is, it has an appropriate MA (Modified Atmosphere) effect and an appropriate transpiration suppression effect.

Is a technique for keeping the inside of the package at a low oxygen concentration and a high carbon dioxide concentration by utilizing the gas permeability of the film and the breathing action of the contents. This MA effect is also effective in the case of mushrooms, and by reducing the oxygen concentration in the container, there are freshness-retaining effects such as prevention of browning and suppression of aerial mycelia. Mushrooms generally have low oxygen and high carbon dioxide gas. It is an item that is suitable for MA packaging because it is an item that is unlikely to suffer from the above problems.

[0007] In the case of packaging, the reduction of loss due to transpiration is exerted, and when the container has an appropriate water vapor permeability, a high freshness retaining effect is exhibited. It is clear that if the water vapor transmission rate is too high, the product value will decrease due to the loss of dryness of the contents, but if the water vapor transmission rate is too low, the water that has evaporated inside will become a hotbed for mold and rot. Reduce product value.

[0006]

As described above, in order to maintain the freshness of mushrooms, it is essential to have the MA effect and an appropriate water vapor permeability, but in the case of enoki mushrooms,
In order to suppress stem elongation, opening of umbrella and browning after harvesting and subdivided packaging, it is effective to carry out degassing and hermetic packaging with polyethylene or polypropylene film and distribute at low temperature.

However, since enokitake mushrooms are actively breathed even in a low temperature range, alcohol odor is aerobically breathed under hypoxic conditions. At the initial stage of the generation of alcohol odor, the commercial value is not reduced, but as atelectasis progresses, it becomes an intense alcohol odor or an alcohol odor containing a strange odor, and the commercial value is impaired. Also,
Since it is a hermetically sealed package, alcohol odor and off-flavor cannot be confirmed as it is, and it is difficult to judge the commercial value of Enokitake. Further, in the case of the degassing hermetically sealed packaging, the appearance may be deteriorated due to loose degassing, or anxiety about the quality may be caused, which becomes a factor to reduce the consumer's willingness to purchase. That is,
The degassed hermetically sealed packaging of Enokitake promotes a marked decrease in commercial value due to the occurrence of alcohol odor before browning, and further causes looseness of the degassed hermetically sealed packaging due to atelectasis and poor sealing.
There is a problem that the appearance is impaired. Further, even when there is no looseness, there is a problem that the surface becomes uneven due to deaeration, which makes the printing unclear. Therefore, the present invention solves the above problems and is excellent in freshness retention of enokitake mushrooms,
It is an object of the present invention to provide a packaging material for enoki mushrooms that has an excellent appearance after packaging and a method for producing the same.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention opened fine pores with a pulsed laser in a packaging material such as a film for hermetically packaging enoki mushrooms. By adjusting the oxygen permeability, it was found that an enokitake mushroom package having an excellent freshness-retaining effect, an alcohol odor at the time of opening, and an excellent appearance can be prepared, and thus the present invention has been completed. is there.

That is, the invention according to claim 1 is a bag-shaped packaging material obtained by thermally adhering a plastic film provided with fine pores, the oxygen permeability of the plastic film at 23 ° C. The degree is 5000 to 18000 cc /
It is made of enokitake packaging material with fine pores adjusted to m ² · 24hrs · atm. In addition, claim 2
The invention described in (1) is a packaging material comprising a deep-drawing molded container having a flange portion and a lid member of a plastic film that is heat-bonded at the flange portion of the container, wherein one of the lid member and the container, or , Both are provided with fine hole openings,
The oxygen permeability of the packaging material at 23 ° C. is 5,000 to
Consists of packaging material for enoki mushrooms adjusted to 18,000 cc / m ² · 24hrs · atm. Further, in the invention according to claim 3, the fine hole opening portion has a hole diameter of 100 ± 20 μm.
The packaging material for enoki mushroom according to claim 1 or 2, wherein the packaging material for enoki mushroom is a micropore of m. The invention according to claim 4 has an oxygen permeability of 500 at 23 ° C.
A bag for enokitake or a deep-drawing container type packaging material provided with micropore openings for making 0 to 18000 cc / m ² · 24hrs · atm, in a film or container forming the bag or container, A method for producing a packaging material for enoki mushrooms, which comprises providing fine hole openings by irradiating a pulsed laser.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in more detail below. In the packaging material for enokitake of the present invention, when the form is various bags manufactured by thermal bonding, the plastic film used for this uses heat sealing during bag manufacturing and sealing of the openings. Therefore, it is necessary to use a material that has thermal adhesiveness and that absorbs a laser oscillation wavelength because micropores are provided by irradiation with a pulse oscillation type laser. The film having such characteristics is not particularly limited,
For example, heat-sealed stretched polypropylene film,
Besides a non-stretched polypropylene film and a polystyrene film, a laminated film obtained by laminating a stretched polypropylene film with a polyolefin resin such as polypropylene resin or low-density polyethylene resin by extrusion coating can be used. In addition, polyethylene is
Although it is not possible to open holes with a single film because it does not absorb the laser oscillation wavelength, when used by laminating as a sealant on a stretched polypropylene film as described above, the stretched polypropylene film absorbs pulsed laser and melts due to heat generation, This heat can be used to open the polyethylene layer together with the stretched polypropylene film layer.

Further, when the packaging form is a deep-drawing container having a flange portion and a lid member of a plastic film heat-bonded at the flange portion of the container, a deep-drawing container is used. At least at the same time that the flange portion of the molding container and the lid material film can be heat-bonded, at least one of the deep-draw molding container and the lid material film, or both are provided with micropores by irradiation with a pulse oscillation type laser. Either one needs to be a material that absorbs the laser oscillation wavelength. From this point, for example, when a molded container of unstretched polypropylene sheet is used as a deep-drawing molded container, a heat-sealing stretched polypropylene film, a non-stretched polypropylene film, or a stretched polypropylene film with a polypropylene resin or a polyolefin resin is used as the lid material. A laminated film extruded and coated with an easy peeling resin whose main component is, for example, can be used. When the deep drawing container is made of polyethylene, fine holes can be formed in the lid material by using a laminated film of polypropylene and polyethylene as the lid material film.

The bag formed by heat-bonding the film as described above or the deep-draw molding container having the film-made lid material has an oxygen permeability of 5000 at 23 ° C.
It is preferable that the necessary number of fine holes having a diameter of 100 ± 20 μm formed by a pulsed laser are provided and adjusted so as to be ˜18,000 cc / m ² · 24 hrs · atm. In addition, the above oxygen permeability values are determined by experiments to find an appropriate range of oxygen permeability values for individual subdivided packaging so that the values can be adjusted even if the dimensions of the packaging change. It is shown in terms of oxygen permeability per 1 m ² from the surface area of the body.

When the oxygen permeability of the bag or the deep-draw molding container is less than 5000 cc / m ² · 24 hrs · atm, for example, the enokitake mushrooms are removed without forming fine holes in the bag or the deep-draw molding container. In the case of air-tight packaging, as described above, the inside of the package is in a low oxygen state, an offensive odor is likely to be generated due to respiratory disorder, and the commercial value thereof is significantly reduced. On the other hand, oxygen permeability is 18000cc / m ² · 24hrs · at
When it exceeds m 3, the oxygen concentration in the package does not decrease, breathing and transpiration become active, and the freshness such as softening and spoilage due to dew condensation easily occurs, which is not preferable.

In the packaging material for enoki mushroom of the present invention,
The size of the micropores provided for adjusting the oxygen permeability is preferably about 100 ± 20 μm in diameter. In the case of adjusting the oxygen permeability in the above range in a unit of subdivided packaging of Enoki mushroom, it can be usually adjusted by opening one or two fine holes having a diameter of 100 μm. Of course, 100
If even fine holes with a diameter of less than μm, for example, about 50 μm can be opened with a stable size, it is possible to make fine adjustments. However, at present, the diameter is 100 ± 20 μm in consideration of the stability of the opening size and its productivity. It is a thing.

As a method for opening the above-mentioned fine holes, there is a method using a heating needle or the like, but there is a drawback that it is difficult to stabilize the dimensions because the hole diameter is small. In this respect, according to the pulse oscillation type laser, even micropores having a diameter of 100 μm or less can be stably opened with high productivity. A carbon dioxide gas laser, a YAG laser, a semiconductor laser, an argon ion laser, or the like can be used as the type of laser, and is not particularly limited. In order to form the micropores, it is necessary that the packaging material has absorption of the laser oscillation wavelength. From this point, the carbon dioxide laser is particularly preferably used.

A packaging material used for the above-mentioned subdivided packaging, for example, a bag having a length of 17 cm and a width of 10 cm has a diameter of 1
When one micropore of 00 μm is opened, the oxygen permeability is 2
00cc / bag ・ 24hrs ・ atm Increase by about atm. Since the oxygen permeability increases in proportion to the total area of the open holes, it is possible to obtain a packaging material having an oxygen permeability within a substantially desired range by adjusting the number of fine holes to be opened.

The packaging forms made using the above materials can be freely adopted, such as pillow type, three-sided seal type, four-sided seal type, standing pouch, gusset type bags, and deep drawing containers. There is no particular limitation.

[0018]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below. (Example 1) The packaging form is a deep-drawing container type, a non-stretched polypropylene film (hereinafter referred to as CPP film) having a thickness of 40 µm is used as a lid material, and a micropore having a diameter of 100 µm is formed in one packaging unit by a pulsed laser. One hole per hole was opened, and a lid member measuring 17 cm in length and 10 cm in width was prepared. For the deep-drawing container, use a CPP film with a thickness of 80 μm.
7 cm x width 10 cm, flange width 8 mm, depth 30 mm
The rectangular tray shape of was molded by a vacuum / pressure molding method using a mold to prepare a container.

(Example 2) A four-sided seal type bag was used as a packaging form, and a CPP film having a thickness of 30 μm was used, and by using a pulsed laser, two micropores having a diameter of 100 μm were formed in each bag. It has a hole and the outer dimension is 17c
A bag having m × width 10 cm, a seal width of 5 mm and three sides sealed was prepared.

(Comparative Example 1) In the configuration of Example 1, only the fine holes provided in the lid material were omitted, and the other processes were all performed in the same manner as in Example 1 to form a deep-drawing type molding container without fine holes. Was prepared as a container of Comparative Example 1.

(Comparative Example 2) In the structure of Example 1, 4 microholes having a diameter of 100 μm provided in the lid material are provided per packaging unit.
The container was opened as a single piece, and the other parts were processed in the same manner as in Example 1 to prepare a deep-drawing type molded container, which was used as a container of Comparative Example 2.

[Measurement of Oxygen Permeability] Using the deep-drawing type molding containers or bags of Examples 1 and 2 and Comparative Examples 1 and 2 prepared as described above as samples, the oxygen permeability thereof was measured by JI.
It was measured according to SK7126 (method A), and the value is shown in Table 1 in terms of the calculated surface area per m ² .

[0023]

[Table 1]

[Filling, storage test and results of enokitake mushrooms] Each of the 20 containers or bags prepared in Examples 1 and 2 and Comparative Examples 1 and 2 was filled and sealed with 100 g of enokitake mushrooms, and the results were obtained in Examples 1 and 2, respectively. And Comparative Example 1,
It was used as a package of No. 2 enoki mushroom. In addition, only the package of Comparative Example 1 was degassed and hermetically sealed. The above package was stored at 5 ° C. for 2 days, and then stored at 15 ° C. for 4 days, and changes in the gas composition (O ₂ , CO ₂ ) in the package and the quality of Enoki mushroom when stored at 15 ° C. The results are examined and the results are shown in Tables 2 and 3.
Are summarized in.

[0025]

[Table 2] Oxygen and carbon dioxide concentration in the packaging (%) (Note) In the table, ND indicates “not detected”.

[0026]

[Table 3] Quality change of enokitake (odor, appearance)

As is clear from the results shown in Table 3, since the enokitake mushroom packages of Examples 1 and 2 have an appropriately adjusted oxygen permeability due to the opening of fine pores, they are kept at 15 ° C. for 4 days. The eyes (6th day in total) had no discomfort due to a strong alcohol odor, and the appearance was slightly sticky. Also, the appearance of the packaging was good, since it was not degassed packaging and had no wrinkle-like irregularities on the surface. On the other hand, in the package of Comparative Example 1, the alcohol odor was felt from the first day at 15 ° C., and the strong sensation was felt on the fourth day. Further, in the package of Comparative Example 2, although the discomfort due to the alcohol odor at the time of opening was reduced, the dew condensation in the package was remarkable, and
Enokitake softens on the 3rd day and about 50% on the 4th day
Lost the commercial value.

[0028]

As described above in detail, the enokitake mushroom packaging material of the present invention is provided with fine pores and has an oxygen permeability at 23 ° C. of 5000 to 18000 cc / m ² · 24 hrs.
・ Because it is adjusted to atm, deaeration packaging is not required, and even if enoki mushrooms are packaged in an air-containing state, the oxygen concentration in the packaging is maintained at an appropriate level and the generation of offensive odors such as alcohol odor is suppressed. In addition, since the odor is also discharged from the fine holes, it is possible to avoid the unpleasant sensation caused by a strange odor (alcohol odor, etc.) at the time of opening, which makes it possible to extend the freshness-keeping period. Further, since the deaeration operation which has been performed conventionally can be omitted, the packaging work can be speeded up, and the irregularities on the surface of the package due to the deaeration can be eliminated, so that the printing can be clearly seen and the appearance can be improved. Furthermore, the method for producing a packaging material for enokitake mushrooms of the present invention, the bag or the deep-drawing type molding container, fine holes for adjusting the oxygen permeability in a suitable range, by irradiating a pulse oscillation type laser. It is to open a hole. According to this method, even if the number of micropores having a diameter of 100 μm or less, it is possible to continuously provide the required number of micropores with high accuracy and at an arbitrary pitch. Can be manufactured well.

Claims (4)

[Claims] 1. A bag-shaped packaging material obtained by thermally adhering a plastic film provided with fine pores, the oxygen permeability of the plastic film at 23 ° C. being 50.
A packaging material for enoki mushrooms, which has a capacity of from 0 to 18000 cc / m ² · 24 hrs · atm. 2. A packaging material comprising a deep-draw molding container having a flange portion and a lid material of a plastic film which is heat-bonded at the flange portion of the container, wherein either one of the lid material and the container, or Both are provided with fine pore openings, and the oxygen permeability of the packaging material at 23 ° C. is 5000 to 18
A packaging material for enoki mushrooms, which is 000 cc / m ² · 24hrs · atm. 3. The fine hole opening portion has a hole diameter of 100 ± 20 μm.
3. The enokitake mushroom packaging material according to claim 1 or 2, wherein the packaging material is a micropore of m. 4. The oxygen permeability at 23 ° C. is 5,000 to 5,000.
18000 cc / m ² · 24hrs · atm Enoki mushroom bag or deep-drawing container type packaging material provided with micropore openings for pulse oscillation to the film or container forming the bag or container. A method for producing a packaging material for enoki mushrooms, which comprises providing fine pores by irradiating a laser.