JPH02299514A - Freshness-preservative container for agricultural product - Google Patents

Abstract

PURPOSE:To provide the title container afforded with an inorganic material layer on the inner surface thereof to improve its dew condensation-proofness and hygroscopicity, make the odor generated from foods stored adsorbable and also make the freshness of agricultural products preservable for a long time. CONSTITUTION:The inner surface of a container 1 consisting of a synthetic resin foam, corrugated cardboard box or wood box is provided with a layer 3 made of an inorganic material (e.g. a mixture comprising baked powder of diatomaceous earth, gypsum, sand and a curing agent). The objective container thus obtained will be improved in dew condensation-proofness and hygroscopicity leading to the absorption of the moisture vaporized from foods stored therein without causing dew condensation, and the odor generated from such foods can be adsorbed, thus the freshness of agricultural products can be preserved for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to containers for preserving the freshness of agricultural products. More specifically, it has excellent dew-proofing and moisture-absorbing properties, and it absorbs evaporated water from the items stored in the container without condensation, and also absorbs odors generated from the items stored in the container, preserving the freshness of agricultural products for a long time. Containers for preserving the freshness of agricultural products.

[Conventional technology] In recent years, the decline in freshness of fresh produce harvested by farmers and other producers during the distribution process until it is sent to the market has been reconsidered. Since the freshness of fresh agricultural products deteriorates significantly when they are transported, research is being conducted to maintain such freshness.

The basic way to maintain the freshness of fresh produce is by immediately pre-cooling the fresh produce harvested at the production area, storing it in a refrigerated truck or refrigerated container, and transporting it at a low temperature. A method of retaining the information is required. Examples of such methods include (a) wrapping fresh produce in newspapers moistened with water to replenish moisture and prevent water from evaporating; Agricultural products are placed in a plastic bag, and an ethylene adsorbent made of inorganic lumber such as Oya stone, Cristobal stone, or zeolite is placed inside the bag to adsorb and remove ethylene, which is generated from fresh produce and is the cause of deterioration of freshness. Methods of packaging fresh agricultural products with anti-fog film, etc. have been adopted.

However, with method (a), rot may occur at the contact area between wet newspaper and fresh produce, and newspaper dries in a relatively short time, so it is not an effective method, and fresh produce may The disadvantage is that it is time-consuming because each item must be wrapped in newspaper. Also,
In the method (b) above, the ethylene adsorbent is expensive;
Moreover, they are not recyclable, their safety has not been established, and they have drawbacks such as the cumbersome process of putting fresh produce into plastic bags one by one. In addition, in the method (1) above, the water condensed on the inner surface of the anti-fogging film comes into contact with the agricultural products, and the water is absorbed by the pumping phenomenon, causing the produce to shrivel or begin to rot from the contact surface. There is.

[Problems to be Solved by the Invention] In view of the above-mentioned prior art, the present inventors have conducted intensive research to develop means for safely holding fresh agricultural products for long periods of time, and have found that, for example, cardboard boxes, wooden Surprisingly, when a transport container such as a box or a foamed resin container is provided with a layer of inorganic material, the freshness of fresh produce is maintained for a long time, and it does not cause any negative effects on the fresh produce. The inventors discovered for the first time the completely new fact that there is no need for the troublesome work of wrapping fresh agricultural products in newspapers, plastic bags, etc., and completed the present invention.

[Means for Solving the Problems] That is, the present invention provides: (1) a container for preserving the freshness of agricultural products, characterized in that an inorganic material layer is provided on the inner surface of the container, and (2) a base material provided with an inorganic material layer inside the container. (2) A freshness-keeping container for agricultural products, characterized in that the container is provided with a breathable bag containing an inorganic material.

[Operations and Examples] The freshness preserving container of the present invention is provided with an inorganic material inside the container, and since the inorganic material is a porous body mainly composed of diatomaceous earth, it can be used with various materials. It has excellent adhesion to the container, and exhibits a breath-wicking effect similar to earthen walls, adsorbs water vapor evaporated from fresh produce, prevents condensation from forming inside the container, and maintains an appropriate level of humidity inside the container. Because it adsorbs gases released from fresh produce, such as ethylene, that inhibit freshness, fresh produce can be kept fresh for a long time.

Containers used in the present invention include containers used for transporting fresh agricultural products, such as wooden boxes, cardboard boxes, plastic containers, and containers made of synthetic resin foam. It is not limited by the type of container. Among these containers, containers made of synthetic resin foam are particularly preferred because they are lightweight, have strong heat insulation properties, and have excellent cushioning properties. Examples of the flexible synthetic resin foam include foams made of foamed polystyrene, foamed polypropylene, foamed polyethylene, foamed polyurethane, foamed polyvinyl chloride, and the like.

The size and shape of the container are not particularly limited, and are preferably adjusted as appropriate depending on the shape and amount of fresh produce usually placed in the container.

The inorganic material mainly contains calcined powder of diatomaceous earth, but may also contain other ingredients such as gypsum, sand,
Contains a hardening agent and the like.

As the calcined powder of diatomaceous earth, approximately 8% of diatomaceous earth is used.
After firing and drying in an air atmosphere at 00°C,
Powdered particles with a particle size of about 0 mesh are used.

The purity and porosity of the diatomaceous earth are not particularly limited in the present invention, but the purity and porosity of the diatomaceous earth are as high as possible,
Moreover, it is preferable that the porosity is large. The content of calcined diatomaceous earth powder in the inorganic material is 5 to 95% (wt%).
, hereinafter the same), preferably 10 to 70%, particularly preferably 15 to 30%. If the content of the calcined diatomaceous earth powder is less than 5%, the dew proofing and heat insulating properties will be low, and if it exceeds 95%, the dew proofing and heat insulating properties will be poor, but the mechanical Strength tends to decrease.

The above-mentioned gypsum has the function of solidifying diatomaceous earth and improving its mechanical strength, and such gypsum includes:
Powdered calcined gypsum, dead calcined gypsum, etc. to a particle size of about 150 mesh is used. The content of gypsum in the inorganic material is 90% or less, preferably 15-30%, particularly preferably 20-25%. The content of the gypsum is 90
%, dew resistance tends to decrease.

The sand has the function of improving the heat insulating effect and mechanical strength, and as such sand, silica sand or the like adjusted to a particle size of about No. 5 is used. The content of sand in the inorganic material is 80% or less, preferably 20% or less.
~70%, particularly preferably 45-65%. If the content of the sand exceeds 80%, the dew resistance tends to decrease.

The curing agent has the function of imparting mechanical strength, and examples include Fujibeton (trade name, manufactured by Fujimasu Research Institute), Toughlock (manufactured by Jushimasu Cement),
Examples include products such as (trade name) used as soil stabilizers to increase the bearing capacity of soft soils such as loamy soils and clayey soils, and cements. The content of the curing agent in the inorganic material is 50% or less, particularly preferably 1 to 5%. If the content of the curing agent exceeds 50%, dew resistance tends to decrease and cracks tend to occur more easily.

As a compound containing the constituent components of the inorganic material, for example, SR Coat (trade name, manufactured by Ishiura Co., Ltd.) is easily available, and this material can be used very suitably as the inorganic material in the present invention. be.

In addition, in order to prevent cracks from occurring in the inorganic material even when the freshness preserving container of the present invention is used repeatedly, and to improve the adhesive strength between the inorganic material and the container, the components of the inorganic material are Furthermore, it is preferable to add, for example, polyvinyl acetate, ethylene-vinyl acetate copolymer, acrylic resin, polyester, polyurethane, polymethyl methacrylate, silicone resin, butyl rubber, modified epoxy resin, etc. in the form of an emulsion. Among these, ethylene-vinyl acetate copolymer acts as a particularly excellent binder for inorganic materials, and when this ethylene-vinyl acetate copolymer is added, crack resistance is dramatically improved. This is preferable because it has the effect of improving. The content of the resin in the material forming the inorganic material is 5 to 30%
, preferably 10 to 25%. If the content is less than 5%, the effect of improving crack resistance is small, and if it exceeds 30%, the porosity of diatomaceous earth tends to decrease, and therefore the dew resistance tends to decrease.

The inorganic material usually exhibits a white to brass color, but if necessary, pigments, dyes, etc. may be added to the inorganic material to obtain a desired color.

The amount (area) of inorganic material provided in the container depends on the type and content of the container, the type and amount of fresh produce to be filled in the container, the surrounding environment in which the container is placed, and the amount of fresh produce in the container. This varies depending on the period of time for which it is retained, etc., and cannot be determined in general, so it is desirable to adjust it appropriately according to these conditions.

As a method for forming the inorganic material as an inorganic material layer on the inner surface of a container, for example, after preparing and mixing each of the above-mentioned components, water is added to obtain a viscosity suitable for forming the inorganic material layer. Kneading, such as brushing, troweling,
Examples include methods of forming by means such as spraying and impregnation.

In the present invention, the inorganic material layer specifically includes an inorganic material layer directly formed on the inner surface of the container by the above-described means, such as a metal plate, woven fabric, nonwoven fabric, wood board, paperboard, etc.
Examples include inorganic material layers formed on the surface of plate-shaped base materials such as plastic plates, for example, inorganic material layers provided on packaging paper used for fruits such as apples and pears, partitions, and fillings. However, in the present invention, it is sufficient that there is a portion containing an inorganic material in the container, and the container is not limited by the form of the inorganic material layer. In addition, when the inorganic material layer is provided directly on the inner surface of the container, it is provided on at least one of the ceiling surface, bottom surface, and wall surface within the container.

The thickness of the inorganic material layer cannot be determined unconditionally because it varies depending on the form of the part on which the inorganic material layer is provided, but it is usually 0.1 to 10 mm.

It is approximately <0.2 to 5 mm.

By subjecting the thus formed inorganic material layer to natural drying or hot air drying, a usable portion having an inorganic material layer is formed.

As described above, the inorganic material provided in the freshness preserving container of the present invention has excellent adhesion to various materials, and is lightweight because it is itself porous. Because it is a component, it exhibits a breathing wicking effect similar to that of earthen walls, preventing the formation of condensation inside containers, and adsorbing gases that reduce the freshness of fresh produce, such as ethylene. This effectively prevents spoilage caused by condensation and loss of freshness caused by gases such as ethylene. In addition, inorganic materials do not contain harmful ingredients that adversely affect fresh agricultural products, so there is no problem in terms of safety and health.
Unlike concrete or cement layers, it has excellent flexibility, so it does not cause cracks or cracks due to external pressure or impact, so it can be used on the inner surface of containers that are easily bent, such as synthetic resin foam or cardboard. It has the advantage that it can be formed directly on the surface, and that it can be easily subjected to post-processing or cutting with a knife or the like, if necessary, within a range that does not cause cracks.

In addition, in the present invention, a freshness preservation container in which a powder or particulate inorganic material is placed inside a breathable bag can maintain freshness by simply replacing the used bag. This is one particularly preferred embodiment because the container can be used as is.

-12 Next, an example of the freshness preserving container of the present invention will be explained based on the drawings.

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the freshness-keeping container for agricultural products of the present invention. In Figure 1, the container body (1
) is provided with a container lid (2), and an inorganic material layer (3) is provided over the entire surface of the inner surfaces of the container body (1) and container lid (2).

FIG. 2 is a longitudinal sectional view showing another embodiment of the container for preserving the freshness of agricultural products of the present invention. In Figure 2, the container body (
An inorganic material layer (3) is fitted between the container lid (2) and the container lid (2). The inorganic material layer (3) is made of, for example, paper,
It is formed by applying or impregnating an inorganic material on a base material such as a film, foam board, or cloth, and as shown in Figure 2, the container body (1) and the container lid (2) are separated. It may be fitted between the container body (1) and the container lid (2), or it may be fixed to the inner surfaces of the container body (1) and the container lid (2) partially or entirely by pasting or coating. Even if it is simply installed on the bottom of the inside. ,stomach.

FIG. 3 is a longitudinal cross-sectional view showing another embodiment of the freshness-keeping container for agricultural products of the present invention. In FIG. 3, a container lid (2) is provided on the top of the container body (1). When the container body (1) is filled with stored items (5) such as fruits such as apples as shown in FIG.
A partition (4) is provided between each of the stacked fruits in order to prevent the stored items (5) from being damaged due to impact during transportation, for example. The freshness preserving container shown in FIG. 3 has an inorganic material layer provided in the partition (4). The material for the partition (4) is as follows:
For example, various films, foamed films, paper, cardboard,
Nonwoven fabrics, woven fabrics, foam boards, etc. may be used, but the present invention is not limited by the material of the partition (4). Note that the inorganic material layer provided on the partition (4) is formed, for example, by means such as coating or impregnation, but it goes without saying that the present invention is not limited to such means.

FIG. 4 is a longitudinal sectional view showing another embodiment of the container for preserving the freshness of agricultural products of the present invention. In FIG. 4, a container lid (2) is provided on the top of the container body (1). When the container body (1) is filled with stored items (5) such as fruits such as melons, wood wool or cut paper is usually placed between each stored item (5) to prevent them from colliding with each other. , foamed beads, cut films, foamed extrusion chips, etc. (6) are filled. The present invention provides such a filling (6
) is provided with an inorganic material layer. The inorganic material layer is formed, for example, by applying or impregnating the filler (6) with an inorganic material.

FIG. 5 is a longitudinal sectional view showing another embodiment of the container for preserving the freshness of agricultural products of the present invention. In FIG. 5, a container lid (2) is provided on the top of the container body (1), and when stored items (5) such as fruits such as mandarin oranges are stacked inside the container body (1), If the sizes of the stored items (5) are particularly irregular, a filling material (7) is inserted to prevent glands from forming at the top, corners, walls, etc. of the container body (1). Examples of the filler (7) include various flexible foams such as sponge, wood wool, and the like. The freshness preserving container shown in FIG. 5 has an inorganic material layer provided on the filler (7), and the inorganic material layer is formed by coating or impregnating the filler (7) with an inorganic material. formed by.

FIG. 6 is a longitudinal cross-sectional view showing one embodiment of the container for preserving the freshness of agricultural products of the present invention. In Figure 6, the container body (1
) A container lid (2) is provided on the top of the container body (
1) A breathable bag (8) containing a base material provided with an inorganic material layer is provided inside. The bag (8) is not particularly limited as long as it has air permeability, and examples thereof include nonwoven fabric, woven fabric, and a film with holes. The usage amount of the base material provided with the inorganic material layer to be placed in the bag (8) and the number of bags (8) to be placed in the container body (1) are determined by the amount of storage to be placed in the container body (1). Since it varies depending on the amount of items, etc., it cannot be determined unconditionally, and it is preferable to adjust it appropriately depending on the items normally stored. Further, the size and shape of the inorganic material placed in the bag (8) are arbitrary, and may be in powder form (
Furthermore, the inorganic material may have a cube-like shape or a spherical shape, and the present invention is not limited by the size and shape of the inorganic material.

Next, the freshness preserving container of the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.

Example 1 Container body made of synthetic resin foam Container body made of foamed polystyrene resin (manufactured by Kanebuchi Chemical Co., Ltd., trade name Nika Nepal, grade: SGB, foaming ratio: 50 times) (inner dimensions: vertical 28 cm x Width 39cm x depth 18
cm) and a container lid were used.

The materials forming the inorganic material layer are: 22.5% calcined powder of diatomaceous earth (particle size: 150 mesh), 22.5% gypsum (particle size: 150 mesh), 50% silica sand (particle size: No. 5), and 5% cement. Using a mixture of An inorganic material layer with a thickness of 0.5+ nm was formed on the entire side surface and the inner surface of the lid of the container by spraying.

Next, the physical properties of the obtained freshness-preserving container were evaluated for adhesion, dew-proofing property, and ability to maintain the freshness of fresh agricultural products based on the following methods. The results are shown in Table 2.

(Adhesion) Cut the interface between the container and the inorganic material layer of the obtained freshness-preserving container with a knife to a position 3 cm from the end of the inorganic material layer, and attach a jig to the container and the inorganic material layer respectively. The state of peeling was visually observed and evaluated based on the following criteria.

(Judgment Criteria) ○: The container and the inorganic material layer could not be uniformly peeled off.

×: The container and the inorganic material layer could be easily separated.

(Dew-proofing property) An inorganic material layer was provided on the obtained freshness-preserving container, and a sample was prepared by cutting the inorganic material layer into a square shape with a side length of 10c+n. : Approximately 80° C., relative humidity: 98%) The surface of the sample was affixed to the ceiling after 1 hour had elapsed and evaluated based on the following criteria.

(Judgment criteria) ○: No dew condensation was observed on the surface of the sample.

×: Condensation was observed on the surface of the sample.

(Freshness retention of fresh produce) 12 pieces of freshly harvested broccoli were packed in the obtained freshness preservation container as shown in Figure 7, a lid was placed on the container, and the container was placed in a constant temperature and humidity chamber (room temperature: 35°C). , relative humidity = 50%), removed after 72 hours, compared the broccoli (9) with the target sample, visually inspected for differences, and olfactorily inspected for abnormal odors. The presence or absence of condensation was also examined. The judgment criteria are shown below.

(Judgment criteria) (b) Visual test ○: No difference from the target sample was observed.

Δ: Slightly less fresh than the target sample.

×: The freshness is clearly lower than that of the target sample, and the yellowing is noticeable.

(b) Smell test ○: Almost the same as harvested broccoli.

△: Slightly unpleasant odor is produced.

×: It emits a rotten odor and is not in a state that can be eaten.

(l ~ Presence of dew condensation ○: No condensation ×: Condensation
, relative humidity = 85%) for 72 hours.

= 20 - Comparative Example 1 The container made of expanded polystyrene used in Example 1 was used as a freshness preservation container without providing an inorganic material layer, and the freshness preservation of fresh agricultural products was measured in the same manner as in Example 1. . The results are shown in Table 2.

Example 2 In Example 1, as the materials forming the inorganic material layer, the content of calcined diatomaceous earth powder was 27%, the content of gypsum was 18%, the content of silica sand was 50%, and the content of cement was 5%, add vinyl acetate resin emulsion (resin solid content 20%) to this at 20% based on the total amount of the material forming the inorganic material layer, and then add water and stir thoroughly. In the same manner as in Example 1, an inorganic material layer was provided on the bottom surface of the container and the inner surface of the lid by spray coating on the same container made of polystyrene used in Example 1 to obtain a freshness-preserving container. The physical properties of the obtained freshness-keeping container were examined in the same manner as in Example 1. The results are shown in Table 2.

Examples 3 and 4 A first layer was placed on the bottom and lid of a container having the same shape as that used in Example 1 and made of the synthetic resin foam shown in Table 1.
A freshness preserving container was made in the same manner as in Example 1, except that an inorganic material layer having the composition shown in the table was formed by brush coating. The physical properties of the obtained freshness-keeping container were examined in the same manner as in Example 1. The results are shown in Table 2.

Example 5 In Example 1, instead of directly forming an inorganic material layer on the inner surface of the container body and the inner surface of the container lid, a cardboard (B liner, basis weight 125 g/■2, height 28 cm, width 39
Prepare two plates with the same inorganic material layer (thickness 1 m+n) as used in Example 1 on one side of the container (c+n), and adhere the plates to the bottom of the container body and the inner surface of the container lid, respectively. A freshness-preserving container was created by attaching it to the medicine. The physical properties of the obtained freshness-keeping container were examined in the same manner as in Example 1. The results are shown in Table 2.

Examples 6 to 8 Example 1 except that the container body shown in Table 2 (however, the content is the same as the container used in Example 1) and the container lid were used instead of the container used in Example 1. In the same manner as above, a freshness preserving container was prepared in which an inorganic material layer was provided on the bottom surface of the container and the inner surface of the lid. The physical properties of the obtained freshness-keeping container were examined in the same manner as in Example 1. The results are shown in Table 2.

[Margin below] Table 2 Example 9 A container made of the same synthetic resin foam as used in Example 1 was used.

Using the same material forming the inorganic material layer as used in Example 1, fruit wrapping paper (length: 25 cm, width: 25 cm) was made into a shape to accommodate broccoli.
The inorganic material layer was applied to the inner surfaces of 12 sheets by spray coating to a thickness of about 1 mm.

Next, each of the 12 broccoli pieces was wrapped in the fruit wrapping paper, and then packed in the container made of the synthetic resin foam, and the physical properties of the container were examined in the same manner as in Example 1. It had excellent quality and freshness retention properties for fresh produce, and no abnormalities were observed.

Example 10 A container made of the same synthetic resin foam as used in Example 1 was used.

The same inorganic material used in Example 1 was used with a particle size of 3 to 5 mI.
30g of the granules were placed in a bag made of spunbond nonwoven fabric (vertical: 80InII, width: 60m).
m), and the opening was sealed.

After putting the resulting bag into the container, broccoli was added, and the physical properties of the container were examined in the same manner as in Example 1.
No abnormality was observed.

From the above results, it can be seen that the freshness-keeping container for agricultural products of the present invention has excellent dew-proofing properties and can maintain the freshness of fresh agricultural products for a long time even at high temperatures.

[Effects of the Invention] The part having the inorganic material layer provided in the freshness-keeping container for agricultural products of the present invention is inexpensive, lightweight, has excellent dew resistance, and is free from ethylene and other substances generated from agricultural products. Since it adsorbs gases that promote spoilage, it is said to be able to suppress spoilage and maintain the freshness of agricultural products, even when they are transported by truck from harvest areas to consumption areas during high-temperature seasons such as summer. be effective.

In addition, the container for preserving the freshness of agricultural products of the present invention adsorbs odors and gases that do not contribute to deterioration of freshness, so that the product image will not be spoiled due to odors emitted from agricultural products, seafood, general foods, etc. when the container is opened. It's something that doesn't exist.

4 Brief Description of the Drawings Figures 1 to 6 are longitudinal cross-sectional views showing one embodiment of the container for keeping fresh produce of the present invention, and Figure 7 is an explanatory diagram regarding a method for examining the freshness retention of fresh produce.

(Main symbols on drawings) (1): Container body (2): Container lid (3): Inorganic material layer Figure 1 Third part 7th part container body container lid Inorganic material layer

Claims (1)

[Claims] 1. A container for preserving the freshness of agricultural products, characterized in that an inorganic material layer is provided on the inner surface of the container. 2. The freshness preserving container according to claim 1, wherein an inorganic material layer is provided on at least one of the ceiling surface, bottom surface and wall surface within the container. 3. Claim 1, wherein an inorganic material layer is provided on the entire inner surface of the container.
Freshness preservation container as described. 4. A container for preserving the freshness of agricultural products, characterized in that the container is provided with a base material provided with an inorganic material layer. 5. A container for preserving the freshness of agricultural products, characterized in that the container is provided with a breathable bag containing an inorganic material. 6. Claim 1, wherein the container is made of synthetic resin foam.
, 2, 3, 4 or 5. 7. The freshness preserving container according to claim 1, 4 or 5, wherein the container is a cardboard box or a wooden box. 8 The inorganic material is 5 to 95% by weight of calcined diatomaceous earth powder.
6. The freshness-preserving container according to claim 1, 4 or 5, wherein the container contains: