JPH0233596B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a package that can preserve fresh vegetable products in a fresh state for a long period of time, and more specifically, the present invention relates to a package for storing vegetables, etc. in a case such as a cardboard case for transportation and storage. The present invention relates to a packaging body that can maintain the freshness of vegetables, etc., and prevent a decrease in the strength of the case due to moisture and the accompanying loading. The term "fresh plant products" as used in the present invention has a broad concept that includes vegetables, fruits, fresh flowers, mushrooms, etc., and it is necessary to deliver them from producers to end consumers in a fresh state. The term "vegetables" will be used to represent these types of vegetables. With the development of distribution systems, remote production areas and consumption areas have become directly or indirectly connected, and it has become common for vegetables to be transported from production areas to consumption areas far away. . Under these circumstances, it takes a considerable amount of time from the time the product leaves the producer's hands to the time it reaches the consumer, and during that time, the product may wilt, yellow, or
This may lead to deterioration of freshness due to rot, odor, frostbite, etc. As a result, the fresh flavor and appearance are lost, and while consumers have become accustomed to this, there is also a movement to seek a new distribution system that directly connects producers and consumers, and it has become a social problem. The present invention was made in consideration of these circumstances, and aims to provide a package that can maintain freshness as much as possible even when stored for a certain period of time. This is the purpose. The packaging body of the present invention that has achieved the above object has gas barrier properties and water vapor permeability that have an oxygen permeability of 0.1 to ^{5000c.c./m2.24hr.atm} . Degree is 0.1~100g/ ^m2・24hr・
A film or sheet with a thickness of 4 to 200 μm that has moisture resistance of 90% RH and anti-fogging properties is placed inside, and vegetables are stored on top of the film or sheet.Then, the periphery of the film or sheet is folded and the vegetables are placed inside. The main purpose of this method is to wrap the food in the container before tightening the lid, and it was discovered that the cause of the above-mentioned deterioration in freshness was due to water exposure and the gas composition inside the case, and these inconvenient conditions could be corrected. The configuration of the present invention was arrived at as a result of examining conditions that could prevent this occurrence within the case as much as possible. In other words, the above-mentioned vegetables are stored and packaged directly or in small portions in cardboard cases, etc., but dark breathing occurs under the influence of the air existing in the space inside the case and the outside temperature, and O ₂ is released. CO ₂ and H ₂ O are generated along with the uptake. In response to a decrease in O ₂ and an increase in CO ₂ , ventilation inside and outside the case promotes equilibrium with the atmosphere, so the O ₂ and CO ₂ concentrations inside the case are maintained at values close to those in the atmosphere, and continue to increase. dark breathing is promoted. In other words, the dark respiration of vegetables proceeds without being hindered at all, so the temperature inside the case rises, which helps rottenness, and the production and transpiration of moisture inside the case further progresses and accumulates, resulting in the inside of the case Condensation occurs, which grows into water beads (water droplets) and gradually merges to form a puddle. When this moisture comes into contact with vegetables, they begin to wilt or discolor from the wet areas. Also, water adhering to the walls of cardboard cases, etc.
It penetrates into the paper that makes up the case and causes it to lose its rigidity, so when cardboard cases are stacked in multiple tiers, the lower tiers become deformed due to the stacking load, leading to stacking and collapse of the cargo. That was also the case. In contrast, in the present invention, as mentioned above, a film or sheet (hereinafter simply referred to as the film of the present invention) having a gas barrier property, moisture proof property, and fog proof property and having a certain thickness is attached to the body of a case such as a cardboard case. ) is lined inside the case and the vegetables are wrapped inside it, so even if dark breathing of the vegetables progresses, gas passage inside and outside the case is inhibited and the gas concentration inside the case is low.
O ₂ / high CO ₂ ] state, and dark respiration of vegetables becomes difficult to proceed. That is, temperature rise due to respiration is stopped and oxidative deterioration of the vegetables themselves is suppressed. In addition, while the generation and transpiration of new water is suppressed, the water that has already evaporated becomes a thin film on the surface of the film of the present invention, so there is no risk of it growing into water droplets, and the above-mentioned rot due to water wetting is also avoided. Prevented. In addition, the case itself is less likely to suffer from a decrease in rigidity due to moisture absorption, and the resulting damage to the load or collapse of the load. 1 to 4 are sectional views showing the outline of the packaging procedure according to the present invention. First, in FIG. 1, a bag-shaped or wrapping-shaped film 2 of the present invention is lined inside a case body 1. Then, store vegetables 3 as shown in Figure 2,
Further, as shown in FIG. 3, the peripheral edge 2a of the film is folded to enclose the vegetables 3, and then the flap 1a is folded and the lid is tightened as shown in FIG. Although the figure shows an example of storing the product in a cardboard case, the present invention can be carried out using the same procedure in a general paper case with a lid and a body, or in a case other than paper. . The film 2 must have a thickness of about 4 to 200 μm, preferably about 9 to 60 μm. If the thickness is less than 4 μm, the strength and stiffness of the film will be insufficient, leading to problems in processability and workability when laminating it to the inner surface of cases such as cardboard cases. On the other hand, even if the upper limit exceeds 200 μm, the film cost will only increase, and the effect commensurate with the increase in thickness will not be obtained. Next, regarding anti-fog properties, it is preferable that the material be treated so that evaporated water does not condense and condense when the outside air changes from about -20°C to +40°C. If the anti-fogging property maintenance function under these conditions is insufficient, the anti-fogging agent on the film surface will be washed away by water droplets during the distribution process of the package, and the aforementioned rotting and discoloration due to water exposure will easily progress. Although there is a fear that the condensed water will freeze if the temperature is as low as -20°C, we have confirmed that there are no practical problems as the heat generated by the vegetables' breathing has the effect of suppressing freezing. Next, regarding gas barrier properties, oxygen permeability is 0.1
It must be ~5000c.c./ ^m2・24hr・ATM, but within this condition range, 1~4000c.c./ ^m2・24hr・
ATM, more preferably 10~3000c.c./ ^m2・24hr・
Those on the order of atm are particularly meaningful in the present invention. In other words, if the oxygen permeability is less than 0.1cc/ ^m2・24hr・atm, the O ₂ concentration inside the case will be too low and CO ₂
If there is too much, vegetables will begin to breathe anaerobically, causing gas problems and reducing their freshness. on the other hand
If it exceeds ^{5000c.c./m2/24hr/atm} , the inside of the case will
The O ₂ and CO ₂ concentrations will approach those of the atmosphere, and the respiratory suppression effect will no longer be exerted. Furthermore, in addition to the above conditions, the present invention also stipulates water vapor permeability as an essential requirement, and the condition range is set as 0.1 to 100 g/m ² / 24 hr / 90% RH, but within this range Especially 1~60g/ ^m2・
24hr/90%RH is suitable. If it has such a moisture-proof property, it can also substantially prevent water from entering from the outside, so the effect of preserving the quality of vegetables is extremely significant. All films having such properties can be used in the present invention, but particularly suitable ones include polyester, polyamide, polypropylene, polybutadiene, polystyrene, vinyl chloride, vinylidene chloride, ethylene vinyl acetate, polyvinyl alcohol, and ethylene-vinyl alcohol. A film having antifogging properties such as a copolymer or a foam made from the resin is used. Of course, copolymers and mixtures of the above resins are also included, and among these, films of polypropylene, polybutadiene, polystyrene, etc. are most preferred. Depending on the water evaporation rate, respiration rate, or seasonal factors of the vegetables to be stored, it is also possible to provide ventilation holes in the film 2 or to relax the sealing properties at the folded portions of the film. In other words, when the dark respiration of vegetables is active and the amount of water transpiration is extremely large, the water evaporates out of the case, and conversely, when the respiration is calm and the amount of water transpiration is small, the cardboard case is not moistened by the evaporated water. The above-mentioned partial bonding and vent hole formation have positive or negative significance. In the present invention, vegetables may be stored in a naked state, but if necessary, they may be divided into smaller pieces and then stored in cardboard cases. In this case, even in subdivided packaging, there is a similar problem of wilting of vegetables due to droplets of generated transpiration water, so
It is recommended to use a film similar to that described above. In addition, when such subdivision is performed, some ventilation holes are formed in the subdivision film so that some of the water generated and evaporated from the vegetables becomes a thin film on the inner surface of the subdivision film, and the remainder is transferred to the inner surface of the cardboard case or Since the outer surface of the subdivided film can be made thinner and the gas barrier properties are also improved, the freshness preservation effect becomes even more remarkable. Since the vegetable package of the present invention has the above-described structure, the following effects can be obtained. (1) The transpiration water produced by dark breathing of vegetables does not condense on the film surface and forms a thin film over the entire surface, so it does not form water droplets and cause wilting, partial corrosion, discoloration, etc. due to contact with the water droplets as in the past. The occurrence of strange odors has become less common. (2) Since moisture absorption and deterioration of cardboard cases and the like due to the above-mentioned evaporated water no longer occurs, damage to the cargo and collapse of the cargo can now be prevented. (3) Since there is less gas conversion inside and outside the cardboard case, the low oxygen and high carbon dioxide atmosphere formed by the respiration of vegetables is maintained as much as possible.
Oxidative deterioration of vegetables is significantly suppressed. In some cases, it has become possible to omit storing ice at the same time. (4) Corrugated cardboard cases often have hand-drilled holes, but this results in a loss of gas barrier properties at the top of the case, and there is a possibility that the progress of wilting can be seen from close to the area. However, in the case of subdivided packaging, even if there are such holes, gas replacement within the subdivided packaging does not proceed, so the effect of maintaining freshness is exhibited. Next, embodiments of the present invention will be described. Example 1 20 μm thick Pylene Film F (trademark, manufactured by Toyobo Co., Ltd., biaxially stretched polypropylene film with anti-fog properties on one side, oxygen permeability: 2500 c.c./m ² 24 hr ATM, water vapor) in a cardboard case. Transparency:
7g/ ^m2・24hr・90%RH) with the anti-fog side facing inside (Example 1), without film lining (Comparative Example 1), polypropylene film without anti-fog properties (Comparative Example 2), polystyrene film coated with antifogging agent (thickness: 15μm, oxygen permeability: 8600c.c./m ²・24hr・
ATM, water vapor permeability: 150g/ ^m2・24hr・90%
RH) (Comparative Example 3), a film made by laminating aluminum foil (thickness: 9 μm) and polyethylene film (thickness: 30 μm) (oxygen permeability: 0 c.c./m ² , 24 hr, atm) , water vapor permeability:
0g/m ² /24hr・90%RH) (Comparative Example 4) were prepared, and 20 bundles (4 rows x 5 rows) of spinach from Ichinomiya (variety: Pope) were placed in them, and heated at 30℃ 80
The samples were left in an environment of %RH for about 3 days, and changes in quality were examined. The freshness retention characteristics were evaluated based on the following criteria. 5 points Leaves remain green and maintain their freshness at the time of cultivation without wilting. 4 points: Some wilting was observed on the leaves, the green color had faded, and the weight had decreased by approximately 0.5 to 1.5%. 3 points: Withering of leaves is clearly observed with the naked eye,
In addition, there are small yellow-green areas in some areas, which can be said to be at the limit of practical use. 2 points: The leaves are clearly wilting, the yellowing is spreading, and a foul odor is emitted, and there is clear rot in some areas. 1 point: Significant wilting and yellowing, slimy,
Something with a strong odor. The evaluation criteria are as described above, but in order to be able to sell at the desired price, an average score of 3.5 or higher is required, and a score of 3 requires a significant discount. Table 1 is a list of the results, showing the temperature change inside the case and the average evaluation score of the 20 bundles.

[Table] Leaf wilting in Example 1 was 10% higher than in Comparative Example.
The process progresses with a delay of ~20 hours or more, and the freshness of items other than the top shelf in the case is particularly good, and the decrease in freshness occurs after a full day delay. In Comparative Example 1, since there was no air-blocking property, the freshness deteriorated quickly, and yellowing was observed early in all five stages. The polypropylene film of Comparative Example 2 exhibited good atmospheric barrier properties, so the results after 10 to 20 hours were good.
Due to the lack of antifogging properties, water droplets formed on the film surface within 20 to 30 hours, causing a rapid decline in freshness. In Comparative Example 3, the effect of suppressing breathing inside the case was low due to low gas barrier properties and moisture proof properties, and therefore the temperature rose within a relatively short period of time, resulting in poor freshness keeping effect. In Comparative Example 4, the case was completely airtight, so there was too much CO ₂ inside the case, and the freshness decreased due to gas disturbance. Example 2 200g/bundle of spinach [Total 40 bundles (5 horizontal rows x
4 rows)] was wrapped in an anti-fogging film (FG20 μm manufactured by Toyobo Co., Ltd.) and tested for freshness retention using the cardboard box of Example 1.
The test temperature was 10°C. After 4 days of use of the present invention, the body temperature was 18.8°C, the freshness was 4.5, and the weight loss rate was 0.2%, which was extremely good. The product of Comparative Example 1 had a body temperature of 19.9℃, a freshness of 2.3, a weight loss rate of 6.4%, and yellowed.
The product value significantly decreased due to marked wilting.

[Brief explanation of drawings]

1 to 4 are cross-sectional explanatory views showing the procedure for storing vegetables in the present invention.

Claims (1)

[Claims] 1. Oxygen permeability: 0.1 to 5000c.c./m ^2.24hr.atm
Gas barrier property shown by and water vapor permeability: 0.1 to 100g/ ^m2・24hr・90%RH
A film or sheet with a thickness of 4 to 200 μm, which has a moisture-proof property shown by A packaging body for fresh vegetable products, characterized in that the fresh vegetable products are wrapped in a package and then the lid is tightened. 2. A package for fresh vegetable products as set forth in claim 1, in which the fresh vegetable products are packaged in portions using an anti-fog film or sheet and then stored and packaged in a case.