JPH07215385A - Mushroom package - Google Patents

Abstract

PURPOSE:To obtain anti-fogging property and vapor permeability in a laminate film for wrapping mushrooms to preserve freshness for a long time by laminating ethylene copolymer resin layers comprising ethylene, polyvinyl acetate ester or the like on both faces of an intermediate layer made of a polyamide resin layer. CONSTITUTION:A laminate film 2 for wrapping mushrooms 1 put in a tray 3 uses laminated layers of ethylene copolymer resin comprising 60 to 95wt.% of ethylene and 40 to 5wt.% of monomer of polyvinyl acetate ester or one selected from aliphatic unsaturated carbonic acid and aliphatic unsaturated monocarbonic acid alkyl ester. The laminate film having vapor permeability of 200 to 600g/m<2>.24hours.atom, oxygen permeability of 400 to 80cc/m<2>.24 hours.atom and carbon dioxide permeability of 2000 to 35000cc/m<2>.24hours.atom is preferably used, thereby obtaining a package for preserving freshness for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for mushrooms such as mushrooms, shiitake mushrooms and shimeji mushrooms, and more particularly to a package capable of maintaining freshness for a long period of time.

[0002]

2. Description of the Related Art Mushrooms, like fruits and vegetables such as bell peppers and cucumbers, have a respiratory action after harvesting, and are known to be active and to deteriorate in quality faster than fruits and vegetables. This breathing action causes consumption of oxygen and generation of carbon dioxide gas. Along with this, heat is generated, and the temperature inside the packaging bag rises. In addition, it also evaporates and releases water.

Therefore, in the package, the oxygen concentration decreases with the passage of time, and the carbon dioxide concentration increases, and the temperature in the package rises accordingly. Due to this temperature rise, the respiratory action and transpiration action of the mushrooms become more active, and the deterioration of the quality of the mushrooms such as rotting due to stuffiness, discoloration to brown or black, mold formation, etc. is accelerated.

At present, mushrooms are mainly packaged by polyvinyl chloride stretch film. However, the polyvinyl chloride film has a large water vapor permeability and has a problem that mushrooms are withered. Furthermore, due to environmental issues, etc., low density polyethylene resin, ethylene-vinyl acetate copolymer resin, etc. Based resins (Japanese Patent Publication No. 2-18953, No. 3-67086, JP-A-3-76647, JP-A 64-14018, etc.)
Is actively being developed.

However, since the film made of the ethylene resin has a large oxygen permeability, the respiratory action of mushrooms becomes active, and the moisture vapor permeability is low, so that the inside of the package becomes damp and the quality of mushrooms deteriorates rapidly.

For the purpose of improving these drawbacks, Japanese Patent Laid-Open No.
Japanese Patent Laid-Open No. 2-235086 discloses a carbon dioxide gas permeability of 40,000 to 180,0 for covering mushrooms in a substantially sealed state.
A diameter of 0.1 mm to 5 per 500 g of mushrooms packaged in a polyvinyl chloride or polyethylene film having a water vapor transmission rate of 800 cc / m ² · 24 hours · atm and a water vapor permeability of 800 cc / m ² · 24 hours · atm. A package of mushrooms having one or more holes having an opening area equivalent to that of a circular hole of 0.0 mm has been proposed. However, since the film is perforated, it has a high carbon dioxide permeability,
As a result, it is not always sufficient to activate the respiratory action and suppress the quality deterioration of mushrooms.

Further, in Japanese Patent Laid-Open No. 4-57763,
Place mushrooms in a container with an open top and use a thin transparent filter.
Water vapor transmission rate of 20-500g when packed in rum
/ M ²・ 24 hr (38 ℃), oxygen gas permeation rate
Is 2,000 to 30,000 ml / m²・ 24 hr ・ a
When using a thin transparent film of tm (23 ° C)
At least the interface where the film contacts the mushroom
In addition, saturated fatty acids having 14 to 22 carbon atoms and polyols
It is characterized by interposing a surfactant mainly composed of tellurium.
A packaging method is proposed.

However, since the above-mentioned film only controls the water vapor and oxygen permeability, and the carbon dioxide gas permeability, which has the most influence on controlling the respiratory action of mushrooms, is not controlled, the freshness retention is not always sufficient.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems in mushroom packaging, and as a result of intensive studies, a resin film for packaging has excellent antifogging property, moderate water vapor permeability, and oxygen content. Not to mention having transparency,
It is an object of the present invention to provide a mushroom package which has appropriate carbon dioxide gas permeability and can retain freshness for a long period of time.

[0010]

MEANS FOR SOLVING THE PROBLEMS The present invention is characterized in that mushrooms are packaged in a laminated film, the laminated film having ethylene and vinyl acetate or an aliphatic unsaturated carboxylic acid on both sides of an intermediate layer comprising a polyamide resin layer, Mushrooms characterized by being laminated with an ethylene copolymer resin layer with a monomer selected from an aliphatic unsaturated monocarboxylic acid alkyl ester, wherein the innermost layer in contact with the mushrooms has antifogging properties A package is provided.

[0011]

The laminated resin film for packaging mushrooms of the present invention is
Its water vapor transmission rate is 80 to 1,000 g / m²・ 24 o'clock
-Atm, oxygen permeability is 300-28,000cc /
m²・ 24 hours ・ atm, carbon dioxide permeability of 1,000
~ 40,000 cc / m ²・ 24 hours ・ atm, preferred
Water vapor permeability of 200 to 600 g / m²・ 24 hours
・ Atm and oxygen permeability of 400 to 11,000 cc / m
²・ 24 hours ・ atm, carbon dioxide permeability is 2,000〜
35,000 cc / m²・ 24 hours ・ Atm, even better
Water vapor permeability is preferably 200-600 g / m²・ 24
Time / atm, oxygen permeability is 400-8,000cc /
m²・ 24 hours ・ atm, carbon dioxide permeability of 2,000
~ 35,000 cc / m²・ 24 hours ・ atm
Since it is a packaging material suitable for breathing and evaporating mushrooms,
The freshness retention time of the package is long.

(Detailed Description of the Invention) As the polyamide resin of the intermediate layer of the laminated film of the intermediate layer packaging material, nylon 6, nylon 11, nylon 12, nylon 6.6, nylon 6/10, nylon 6/12 are used. , Nylon 10/6, Nylon 6/6/6, etc. Highly crystalline polyamide resin and density 1.01 with melting point 145-180 ° C
A copolymer elastomer of ˜1.02 g / cm ² of polyoxyalkylene glycol and ω-laurolactam [eg, E4 of Daiamide-PAE manufactured by Daicel-Hyurus Co., Ltd.]
0, E47, E45, E62 and X4442 are all trade names, or a mixture of two or more thereof is used.

Among them, nylon 6/10 and nylon 1
1, nylon 12, nylon 6/6/6, nylon 6 ・
A mixture of one or two or more of the 6/6 highly crystalline resin and the above-mentioned copolymer elastomer is preferable in terms of balancing the above-mentioned water vapor permeability, oxygen permeability and carbon dioxide gas permeability.

For the purpose of improving the packaging suitability of the film, the intermediate layer has a metal salt (Zn, Na, etc.) of a copolymer composed of an α-olefin such as ethylene or propylene and acrylic acid, methacrylic acid, maleic acid or the like. K, Li, Mg, etc.)
1 to 50% by weight, preferably 10 to 45% by weight may be blended. This polyamide resin layer enhances the permeation of water vapor and lowers the permeation of oxygen and carbon dioxide.

[0015] As the resin for the inner and outer layers are laminated on both sides of the intermediate layer of the inner and outer layer polyamide resins, ethylene from 60 to 95 wt% vinyl acetate esters or aliphatic unsaturated carboxylic acid, fatty unsaturated monocarboxylic acid alkyl ester An ethylene-based copolymer with 5 to 40% by weight of a monomer selected from (the carbon number of the alkyl group is 1 to 4) can be used. Specific examples include an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, an ethylene-methacrylic acid copolymer, an ethylene-ethyl acrylate copolymer, and an ethylene-methacrylic acid methyl ester copolymer.

When the content of the monomer is less than 5% by weight, the appearance of the obtained laminated film is deteriorated or the film is hard and uniform extensibility is difficult to obtain during stretch packaging.
There are problems such as wrinkles on the package and breaks in extremely thin parts. On the other hand, when the content is 25% by weight, the resulting film becomes sticky and wrinkles occur in the package.

Among the above ethylene-based copolymers, the melt flow rate (JIS K-7210; 190 ° C., 2.
An ethylene-vinyl acetate copolymer resin having a load of 16 kg) of 0.1 to 7 g / 10 minutes and a vinyl acetate content of 5 to 25% by weight is preferable from the viewpoint of film appearance and suitability for stretch packaging.

This ethylene-based resin film facilitates inflation molding of the laminated film, and improves the adhesiveness of the laminated film, the heat sealing property when forming a bag, and the fit property to a tray for storing mushrooms.

The ethylene resin in the innermost layer of the laminated film has, for example, 1 to 12 carbon atoms, preferably 1 carbon atom, in order to impart antifogging property, moderate slip property, self-adhesive property and antistatic property. ~ 6 aliphatic alcohol and 10 carbon atoms
22, preferably fatty alcohol fatty acid ester which is a compound with 12 to 18 fatty acids, specifically, monoglycerin oleate, polyglycerin oleate, glycerin triricinoleate, glycerin acetylricinoleate, polyglycerin stearate , Polyglycerin laurate, methyl acetyl ricinoleate, ethyl acetyl ricinoleate, butyl acetyl ricinoleate, propylene glycol oleate, propylene glycol laurate, pentaerythritol oleate, polyethylene glycol oleate, polypropylene glycol oleate, sorbitan oleate, Sorbitan laurate, polyethylene glycol sorbitan oleate,
Polyethylene glycol sorbitan laurate and the like, and polyalkylene ether polyol, specifically, at least one kind of polyethylene glycol, polypropylene glycol and the like are added in an amount of 0.1 to 5% by weight, preferably 1 to 4% by weight.

Further, the above-mentioned additives may be blended in the outer layer and the intermediate layer as well as in the inner layer in an amount of 0.1 to 5 wt%. further,
A freshness-retaining agent such as hinokitiol or zeolite may be added to the inner and outer layers and the intermediate layer for the purpose of sterilization, mildew proofing, and ethylene adsorption.

Laminated Film The laminated film for stretch packaging of the present invention is a well-known laminated film such as a coextrusion method or an extrusion laminating method in which the polyamide resin and the ethylene resin are used in a plurality of extruders to form a multilayer inflation molding or T-die molding. It is laminated and formed by the method. Among them, coextrusion by inflation molding is preferable in order to obtain a laminated film in which mechanical strength such as tear strength in the machine direction and the transverse direction is well balanced, and the blow ratio at that time is 3 to 20 times, preferably 5 to 18 times. Double.

The blow ratio here means the ratio of the circumferential length of the final blown film to the circumferential length of the die slit of the die. Regarding the thickness of each layer of this laminated film, the total thickness is 8 to 30 μm, of which 2 to 10 are the intermediate layers.
It is preferable that the inner layer and the outer layer each have a thickness of 3 to 10 μm.

Mushroom packaging material Mushrooms are packaged in a bag made of this laminated film, or mushrooms 1 are stored in a tray 3 as shown in FIG. 1, and the entire tray 3 is stretched with a laminated film 2. To wrap.

[0024]

【Example】

Example 1 Nylon 6/10 resin [density 1.07 g / c for the intermediate layer]
m ³ , melting point 220 ° C .; BASF Engineering Plastics Co., Ltd., trade name “Ultramid S3”]
Using an extruder with a diameter of 65 mm and L / D25
Kneading at 0 ° C, while ethylene-vinyl acetate copolymer resin [vinyl acetate content 15% by weight, density 0.9
38 g / cm ³ , MFR 2 g / 10 min, melting point 97 ° C .;
Mitsubishi Yuka Co., Ltd., trade name "Mitsubishi Poly-EVA41
H "] 98.0% by weight, diglycerin oleate [manufactured by Riken Vitamin Co., Ltd., trade name" Rikemar O71D "] 1.
A resin composition consisting of 0% by weight and 1.0% by weight of glycerin monooleate (manufactured by Riken Vitamin Co., Ltd., trade name "Rikemar OL100") was used, having a diameter of 50 mm and L / D25.
Kneading at 170 ° C. using an extruder of No. 3 and supplying both to a single annular three-layer die so that inner and outer layers of 5 μm in thickness are laminated on both sides of an intermediate layer of 3 μm in thickness. Inflation molding at a die temperature of 250 ° C. and a blow ratio of 10 times resulted in a total thickness of 13 μm (5 μm /
A laminated film for stretch packaging having a thickness of 3 μm / 5 μm) was produced. Table 1 shows the physical properties of the laminated film and the suitability for saw packaging.

Example 2 Nylon 6/6/6 copolymer resin [density 1.13 g / cm ³ , melting point 196 ° C .; trade name "Ultramid C35" manufactured by BASF Engineering Plastics Co., Ltd.] was used as an intermediate layer. A laminate film for stretch packaging was produced in the same manner as in Example 1 except that it was used. Table 1 shows the physical properties of the laminated film and the suitability for saw packaging.

Example 3 As an intermediate layer, nylon 12 resin [density 1.02 g / c
m ^3, melting point 155 ° C.; Daicel Hiyurusu Ltd., outer with trade name "DAIAMID N1901"] was prepared a laminate film for stretch packaging in the same manner as in Example 1. Table 1 shows the physical properties of this laminated film and its suitability for sawing.
Shown in.

Example 4 Nylon 6/10 resin [Example 1] 7 as an intermediate layer
0% by weight and a metal salt of ethylene-methacrylic acid copolymer [density 0.95 g / cm ³ , melting point 87 ° C .; Mitsui DuPont Polychemical Co., Ltd., product “HIMIRAN 170”
7 "] except that a resin composition consisting of 30% by weight is used,
A laminated film for stretch packaging was manufactured in the same manner as in Example 1. Table 1 shows the physical properties of the laminated film and the suitability for saw packaging.

Example 5 Nylon 6/6 · 6 copolymer resin used in Example 2 was used as the intermediate layer, and ethylene-vinyl acetate copolymer resin 98.0 weight used in Example 1 was used as the inner and outer layers. %, Diglycerin oleate [Example 1] 1.0% by weight and diglycerin monooleate [Riken Vitamin Co., Ltd., trade name "Rikemal DO100"] 1.0% by weight In the same manner as in Example 1, a laminated film for stretch packaging was manufactured. Table 1 shows the physical properties of the laminated film and the suitability for saw packaging.

Comparative Example 1 Table 1 shows the physical properties of the polyvinyl chloride stretch film manufactured by M Company and the suitability for saw packaging.

Comparative Example 2 As an intermediate layer, a cotton-like low density polyethylene resin [density: 0.
920 g / cm ³ , melting point 123 ° C .; manufactured by Mitsubishi Petrochemical Co., Ltd.,
A laminate film for stretch packaging was manufactured in the same manner as in Example 1 except that the product name "Mitsubishi Polyethylene-LL UF240"] was used. Table 1 shows the physical properties of the laminated film and the suitability for saw packaging.

Comparative Example 3 As an intermediate layer, polybutene-1 [density 0.908 g / c
m ³ , melting point 116 ° C .; trade name “M8640” manufactured by Mitsui Petrochemical Co., Ltd.] was used, and a laminate film for stretch packaging was manufactured in the same manner as in Example 1 with a blow ratio of 3 times. Table 1 shows the physical properties of this laminated film and its suitability for sawing.
Shown in.

The physical properties of the film and the suitability for mushroom packaging are as follows. Water vapor permeability JIS Z-0208 Oxygen permeability, carbon dioxide permeability Mitsubishi Yuka Co., Ltd. method

Anti-fogging property After placing fresh mushrooms on a tray made of high-impact polystyrene, stretch-wrapped on the film, the anti-fogging property of the film after 4 days was visually observed. ◯: The product has a good appearance with no fogging or water droplets attached to the inner surface of the film. Δ: Fogging or a small amount of water droplets is present on the inner surface of the film. Poor: The appearance of the product was poor due to noticeable cloudiness or water droplets on the inner surface of the film.

Storability: Mushroom packaging was carried out in the same manner as in the evaluation of antifogging property, and the freshness of the fresh mushrooms was visually observed. X: The freshness was good, but less than 5 days. Δ: The freshness was good for 5 to 7 days. ◯: Freshness was good, but more than 7 days.

Extensibility The raw bamboo shoots are placed on trays made of expanded polystyrene, expanded polystyrene, and impact-resistant polystyrene, respectively, and wrapped by an automatic stretch wrapping machine, A-18X [trade name] manufactured by Fujikikai Co., Ltd., at that time. The stretched state of the film was visually observed. ◯: The film stretches almost uniformly. X: The film stretches unevenly.

Occurrence of tearing The film was wrapped in the same manner as the extensibility evaluation, and the presence or absence of tearing of the film at that time was visually observed. Occurrence of wrinkles Packaging was performed in the same manner as in the extensibility evaluation, and the presence or absence of wrinkles in the film at that time was visually observed.

[0037]

[Table 1]

[0038]

EFFECTS OF THE INVENTION A mushroom package having excellent anti-fogging properties, proper water vapor permeability, oxygen permeability and carbon dioxide gas permeability and capable of maintaining freshness for a long period of time was obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a mushroom package of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location B65D 65/40 A 77/20 R (72) Inventor Mie Toyota 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Yuka Co., Ltd. Inside the Yokkaichi Research Institute

Claims (2)

[Claims] 1. Mushrooms are packaged in a laminated film, and the laminated film has 60 to 95% by weight of ethylene and vinyl acetate or an aliphatic unsaturated carboxylic acid or an aliphatic unsaturated resin on both sides of an intermediate layer composed of a polyamide resin layer. It is characterized in that it is formed by laminating an ethylene copolymer resin layer with 40 to 5% by weight of a monomer selected from saturated monocarboxylic acid alkyl ester, and the innermost layer in contact with mushrooms has antifogging property. Mushroom packaging. 2. The laminated film has a water vapor permeability of 200.
~ 600g / m ² · 24 hours · atm, oxygen permeability 4
0 to 8,000 cc / m ² · 24 hours · atm and carbon dioxide permeability of 2,000 to 35,000 cc /
The mushroom package according to claim 1 having a m ² · 24 hours · atm.