JPH0258902B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for preserving live mushrooms in packaging, and its purpose is to simultaneously adjust the moisture and gas atmosphere inside the package to enable long-term preservation of live mushrooms. Even after harvest, live mushrooms continue to undergo respiration and transpiration just like fruits and vegetables, so not only do their quality change rapidly, but their respiration rate is greater than that of fruits and vegetables, so there are few ways to suppress quality changes. The current situation is that there is no such thing. In particular, moisture loss due to respiration and transpiration, discoloration, and elongation are significant, often leading to a decrease in commercial value. Furthermore, even when preserved at low temperatures, the effects of respiration and transpiration are relatively large, and quality deterioration progresses in the same way as at room temperature, making preservation of living mushrooms extremely difficult from the perspective of maintaining quality. has been done. Conventionally, refrigeration has been considered the most effective method for preserving mushrooms, especially for preserving freshness. In addition, attempts have been made to store gas in polyethylene packaging, that is, so-called gas-controlled storage by polyethylene packaging and refrigeration, but even with this method, long-term storage is extremely difficult. In addition, some attempts have been made to distribute the gas at room temperature in order to utilize the gas storage effect of polyethylene packaging, but the extension of storage was limited to about 1 to 2 days at most. In view of the above-mentioned circumstances, the present invention has made it possible to effectively preserve live mushrooms even at room temperature.Moreover, by using simple packaging, the shelf life can be extended even at room temperature. It has been confirmed. Next, to explain the present invention, the present invention is a method that enables long-term preservation of mushrooms by simultaneously adjusting the moisture content and the gas atmosphere inside the package. This is done using a sheet, and the gas atmosphere inside the package is adjusted using a chemical that has the ability to absorb carbon dioxide gas well.
Together, these features allow live mushrooms to be stored safely for long periods of time even at room temperature in simple packaging. That is, the present invention stores live mushrooms in a semi-closed package such as a corrugated paper packaging box so that the periphery thereof is surrounded by a water-absorbing resin holding sheet, and in the same package, mainly absorbs carbon dioxide gas. The gist of this paper is a method for packaging and preserving live mushrooms, in which a drug is inserted so as to be placed side by side. The present invention is a method for packaging and preserving mushrooms that change rapidly, such as fresh shiitake mushrooms, matsutake mushrooms, shimeji mushrooms, and pine mushrooms.
Remarkable effects were observed in reducing weight loss, preventing discoloration, and maintaining freshness. The method of the present invention will be explained in more detail below. The water-absorbing resin holding sheet used in the method of the present invention is a sheet obtained by applying a water-absorbing resin together with a binder to a porous base material such as paper, non-woven fabric, or knitted fabric, impregnating it and drying it, or a sheet made by using a similar porous base material as layers on both the front and back sides. , a sheet in which a water-absorbing resin is bonded in a sandwich pattern as an intermediate layer between the two, one layer is a water-impermeable plastic film such as polyolefin film, and the other layer is a porous base material such as paper, nonwoven fabric, knitted fabric, etc. Although various configurations can be used, such as sheets with a water-absorbing resin bonded to the intermediate layer in the form of a sandwich, it has been recognized that a sheet made of one-sided water-impermeable plastic film is suitable for practical use. Ta. The water-absorbing resin used in the water-absorbing resin storage sheet used in the present invention is suitably one that has a water-supply performance capable of absorbing approximately 1000 g of water per 1 m ³ , retains water for a long period of time, and retains water in the form of steam. It is something that can continue dissipating. In addition, the water-absorbent resin in the water-absorbent resin holding sheet used in the present invention absorbs water well, increases volume, maintains a gel-like or solid shape, and
All of them do not release water even under some pressure, and under normal conditions there is little volatilization in the form of water vapor, and they are made of water-absorbing resin alone or a mixture of this with porous inorganic powder. Good. For example, water-soluble resins are partially cross-linked to make them water-insoluble, such as starch-sodium acrylate graft polymers, starch-acrylonitrile graft polymer hydrolysates, and partially cross-linked starch-polymethyl methacrylate hydrolysates. products, and starch-graft polymerization products such as salts of the above substances,
Alternatively, crosslinked synthetic resins such as methacrylic acid-vinyl acetate copolymer hydrolysates are suitable. These water-absorbing resins are capable of absorbing and retaining water and aqueous solutions tens to thousands of times their own weight, and in the method of the present invention, they are used in the form of a fine powder together with a non-aqueous resin binder as a non-aqueous coating liquid. use The porous inorganic powder to be mixed with the water-absorbing resin is an inorganic powder having a special shape such as pores or petals, such as zeolite, perlite, calcium silicate, etc. The water-absorbing resin and porous inorganic powder as described above have a powder diameter of 35 mesh or less, preferably 100 μm or less, and 5 μm or more, and a shape close to a sphere is suitable. These powders are used as a coating solution together with a resin binder consisting of alcohols, acetic esters, Kents, hydrocarbon solvent resins, or melted plastic resins, thereby forming a water-absorbing resin coating impregnated layer. let This binder has low solubility in the water to be absorbed or in liquids that are compatible with water, including water, and has low solubility in the water to be absorbed,
It is desirable to use a flexible resin that exhibits effective adhesion even when the volume increases during swelling and impregnation; for example, ethylene-
Examples include, but are not limited to, vinyl acetate copolymers, chlorinated polypropylene, urethane resins, and linear thermoplastic polyester resins. The absorbent resin layer is formed by applying a coating liquid containing at least 20 parts by weight, preferably 50 parts by weight or more, of a water-absorbing resin or a mixture thereof with porous inorganic powder to 100 parts by weight of the binder. Alternatively, it may be formed by coating the vapor gas permeable layer by a gravure method, roll coating method, or silk screen method and drying. Further, the water-absorbing resin layer preferably has a partial pattern shape from the viewpoints of adhesion between the vapor barrier layer and the vapor gas permeable layer, improvement of adhesion strength in lamination, absorption, and liquid retention efficiency. In the method of the present invention, in order to maintain the strength when the base material of the water-absorbing resin holding sheet absorbs water, it is necessary to use paper that has been subjected to non-sizing processing to reduce the sizing degree of the paper. desirable. Next, a description will be given of the gas atmosphere regulating agent, which is mainly composed of a chemical that absorbs carbon dioxide gas and is used in the method of the present invention. Alkaline hydroxide aqueous solutions such as sodium hydroxide, potassium hydroxide aqueous solutions, calcium hydroxide water additives, barium hydroxide water additives, or mixtures thereof have been known as carbon dioxide absorption agents. In the present invention, a carbon dioxide absorbent alone does not have sufficient effect, so in the present invention, a mixture of ferrous sulfate heptahydrate, calcium hydroxide, and other additives is used as an air-permeable and vapor-permeable packaging material. It is suitable to use a sealed sachet as a gas regulator. In this case, examples of the other additives include a mixture of activated carbon and bentonite, which can absorb and remove ethylene, aldehyde, and other off-flavor gases generated from fruits and vegetables. The following examples are suitable for the components and blending ratio of the gas regulator, which mainly consists of a drug that absorbs carbon dioxide gas. Ferrous sulfate heptahydrate 100 parts by weight Calcium hydroxide 300-400 parts by weight Activated carbon 250-400 parts by weight Bentonite 250-400 parts by weight The semi-closed package in the method of the present invention functions as a transportation container. Corrugated paper packaging boxes with Then, the absorbent resin holding sheet is provided on the inner surface of this corrugated paper packaging box, or
Alternatively, a package may be obtained by pasting a water-absorbing resin holding sheet on the inner surface of corrugated paperboard and forming a box. Examples are described below. Example 1 As shown in FIG. 1, fresh shiitake mushrooms 1 are inserted into a corrugated paper packaging box 2, and a water-absorbent resin holding sheet 3 is installed on the inner surface of the packaging box 2 to cover the surroundings of the fresh shiitake mushrooms 1. and then wrap the packaging box 2.
An appropriate number of gas regulating chemicals 4 containing a medicine that mainly absorbs carbon dioxide gas well is placed in a pouch so as to come into contact with the fresh shiitake mushrooms 1. The water absorbent resin holding sheet 3, gas regulating agent 4, and corrugated paper packaging box 2 in this case are as follows. (b) Water-absorbing resin holding sheet One layer is a stretched polypropylene film (20 μ), and the other layer is unsized processed cardboard (60 g/m ² ), with cross-linked starch-polymethyl methacrylate hydrated. Decomposition products (5.1
g/m ² ) A water-absorbing resin holding sheet in which a water-absorbing resin layer that can absorb approximately 1000 g of water per 1 m ³ is adhered to a grid of urethane adhesive (2.5 g/m ² ). (b) Gas regulating agent After thoroughly mixing 1.5 g of ferrous sulfate heptahydrate, 4.5 g of calcium hydroxide, 4.0 g of activated carbon, and 4.0 g of bentonite, mix fine paper (52.3 g/m ² )/polyethylene crack. Three-sided sealed bag (60 x 120 mm) composed of cloth (20 g/m ² )/open-hole polyethylene (40 μ)
Filled and sealed. (c) Corrugated paper packaging box K (kraft) liner (220g/m ² )/center
SCP (semi-chemical pulp) (125g/m ² )/K
A packaging box made of corrugated paper with (kraft) liner (620g/m ² ). (d) Packaging method and storage conditions (A) Corrugated paper packaging box of (c) above 400 x 400 x 100
600 x 600 mm absorbent resin holding sheet from (a) above is placed on the bottom and inner circumferential surface of the mm size with the paper side facing inside, 500 g of Mana Shiitake mushrooms are inserted, and a small bag containing 14 g of the gas regulating agent from (b) above is placed. After putting the 5 pieces in, the top was covered with a 400 x 400 mm water-absorbing resin holding sheet from (A) above with the paper side facing inside, and the lid was covered with the corrugated paper from (C), followed by semi-sealing with tape. . This was stored in a room at 20-25℃ and 50% RH for one month, and the weight change over time, degree of color change, and freshness were compared using the methods (B), (C), and (D) described below.
Table 1 shows the results of the comparison. Methods (B), (C), and (D) for comparison are as follows. (B) A method in which fresh shiitake mushrooms are simply stored in the corrugated paper packaging box described in (c) above. (C) A method in which a polyethylene film (40μ) is used as the interior of the corrugated paper packaging box in (c) above and the mushrooms are wrapped in a handkerchief. . (D) A method in which five gas regulating agents of (B) above are placed in the same package (C) as described above, as in the present invention (A). The test results were as shown in Table 1 below.

[Table] Evaluation of the degree of discoloration in Table 1: Evaluation where the initial whiteness of the back side of the fresh shiitake mushroom cap is ○, × is browning, and the middle is △. Similarly, evaluation of freshness: ○ indicates that the appearance is fresh at the beginning, △ indicates slight wilting, and × indicates dryness or abnormal odor. Example 2 When the same test as in Example 1 was conducted on matsutake, it was found that, similarly to Example 1, it was possible to preserve it for about 3 weeks by the method of the present invention. As mentioned above, when the method of the present invention is used, it is possible to preserve the freshness of live mushrooms, which are subject to rapid changes, and to package and preserve them, which has a significant effect in contributing to the improvement of the distribution and preservation of live mushrooms as products. It is recognized that

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of the method of the present invention. 1... Fresh shiitake mushrooms, 2... Cardboard paper packaging box,
3...Water absorbent resin holding sheet, 4...Gas adjustment drug bag.

Claims (1)

[Scope of Claims] 1. Live mushrooms are stored in a semi-closed package so as to be surrounded by a water-absorbing resin holding sheet having a water absorption capacity of about 1000 g per 1 m ³ , and A method for packaging and preserving live mushrooms, which is characterized by inserting a drug that absorbs carbon dioxide gas well in parallel with the drug. 2. The semi-closed package is a packaging box made of corrugated paper, and a water-absorbing resin storage sheet is installed on the inner surface of the packaging box made of corrugated paper, and the mushrooms are surrounded by this water-absorbing resin storage sheet. A method for packaging and preserving live mushrooms according to claim 1. 3. A mixture of ferrous sulfate heptahydrate, calcium hydroxide, and other additives is used as a vapor-permeable packaging material for placing living things in a semi-closed package as a drug that mainly absorbs carbon dioxide gas. 2. A method for packaging and preserving live mushrooms according to claim 1, which uses the method of packaging and preserving live mushrooms.