JPH0453445A - Packaging bag for retaining freshness of vegetables and fruits - Google Patents

Abstract

PURPOSE:To obtain the subject packaging bag, composed of a film provided with openings having a specific whole opening area ratio, suitable for packaging vegetables and fruits performing vigorous physiological action even after harvesting thereof and useful for vegetables, root vegetables, fruits, cut flowers, mushrooms, etc. CONSTITUTION:The objective packaging bag is composed of a film provided with one or more openings (preferably having a size of 0.2-1.0mm diameter) with 0.0002-0.010%, preferably 0.0002-0.008% total opening area ratio based on the whole opening surface area of the film.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a packaging bag for preserving the freshness of vegetables, root vegetables, fruits, cut flowers, mushrooms, etc. (hereinafter referred to as fruits and vegetables in this specification). It is.

[Conventional technology] In recent years, the production of fruits and vegetables has often shifted from open field cultivation to planned multiplex and diversified cultivation using horticultural facilities. Often has to be packaged.

In addition, even for fruits and vegetables that are mainly grown in open fields, there is a fixed harvest time, so a large amount of the harvest must be packaged and shipped within a short period of time, and these packaged fruits and vegetables are not available to general consumers. The most important issue in the distribution process is how to maintain freshness at the time of harvest.

The most effective way to maintain the freshness of fruits and vegetables is to control the residue in the storage atmosphere (mainly oxygen, nitrogen, and carbon dioxide) to a certain composition, namely CA (=C
(controlled atomosphere) condition. This method has been studied by many people for a very long time, and optimal CA conditions have been determined for each type of fruit or vegetable. Large-scale storage equipment for storing under CA conditions is actually sold, but it is not widely used by general farmers because of the high cost. Therefore, research is being actively conducted to improve containers and packaging bags that can be stored more easily under CA conditions. For example, JP-A-62-2
35088 and JP-A-1-309621 disclose a container in which the inflow and outflow of oxygen and carbon dioxide is controlled by having a microporous gas permeable panel in a part of the substantially gas impermeable container. has been done. Also, JP-A-56-
JP-A No. 13361, JP-A-61-216640, and JP-A-63-102634 disclose packaging bags in which a film with a high gas permeability is used to bring the gas composition within the bag closer to the CA condition.

[Problems to be solved by the invention] However, although there is no problem with conventional materials when used under low temperature conditions, when the respiration rate of fruits and vegetables increases as the temperature rises, scum permeation occurs. Even polybutadiene, which is commonly used as a highly durable plastic material, has insufficient scum permeability, resulting in suffocation due to the oxygen concentration inside the bag becoming too low, and abnormal physiological activities due to the carbon dioxide concentration becoming too high. The problem of not coming here is gone. On the other hand, for example, JP-A-54-40793 and JP-A-63-
1'19647, a bag with holes partially provided has been devised, but the opening area is too large (that is, the permeability of the scum is too large), making it impossible to adjust the gas composition. This is not satisfactory.

An object of the present invention is to provide a packaging bag for preserving the freshness of fruits and vegetables that exhibits oxygen and carbon dioxide permeability that can lead to CA conditions suitable for the physiological effects of fruits and vegetables.

[Means for Solving the Problems] The present inventors have been conducting research on packaging bags for preserving the freshness of fruits and vegetables. As a result, we found that by providing appropriate openings in part or the entire surface of the freshness-preserving packaging bag, it was possible to bring the inside of the bag containing fruits and vegetables to CA conditions.
The present invention has now been completed.

That is, in the present invention, the total surface area of the film is 0°000
The present invention relates to a packaging bag for preserving the freshness of fruits and vegetables, characterized in that it is made of a film provided with one or more holes having a total opening area ratio of 2 to 0.010%.

The following is a detailed description of the invention.

According to the present invention, in order to obtain oxygen and carbon dioxide permeability that can lead to CA conditions, a total pore area ratio of 0.0002 to 0.010% relative to the total surface area of the film of the packaging bag, preferably o, oo.

It is necessary that at least one aperture having a total aperture area ratio of 2 to 0,000% is provided. If the total open pore area ratio is less than 0.0002%, the amount of oxygen in the bag will be insufficient as the fruit and vegetables will be consumed by respiration, and the minimum required respiration for maintaining vitality will be inhibited, leading to a decrease in freshness. Additionally, excess carbon dioxide may cause physiological disorders. On the other hand, if the total pore area ratio exceeds 0.010%, the amount of oxygen within the bag cannot be reduced enough to suppress respiration, and aging progresses. Moreover, the amount of carbon dioxide becomes too low, and the anti-corrosion effect and the respiratory suppressing effect are no longer effectively exhibited.

The size of the opening is preferably 0.2 mm or more and 1.0 mm or less in diameter so that the hole is not noticeable in appearance and maintains strength. Pores can be formed by, for example, heating a very thin needle such as a microsyringe to pierce the film and melting the hole, or using a carbon dioxide laser.

The material of the film is preferably polyolefin resin.
In particular, low-density polyethylene is preferred because it is inexpensive and has excellent transparency. Furthermore, the film constituting the bag may contain lubricants, anti-blocking agents, antioxidants, ultraviolet absorbers, colorants, antistatic agents, and the like, if necessary.

The thickness of the film is determined by adding relatively heavy fruits and vegetables,
Usually 20~
100 μm is used.

The method of processing the film into bags is not particularly limited, but
For example, a bag obtained by heat-sealing and cutting a film formed into a cylinder by ordinary inflation molding is used.

In addition, the size of the bag is adjusted to the shape of the fruits and vegetables so that the bag does not become too large for the fruits and vegetables, and the bag has a head space ratio (ratio of the air volume in the bag to the volume of the fruit or vegetables) of 3 or less.

It is of course preferable to store the bag at a low temperature, but the bag of the present invention is generally used in a temperature range of 5°C to 20°C because it can follow changes in the respiration rate of fruits and vegetables due to temperature changes.

[Effects of the Invention] By packaging fruits and vegetables with the packaging bag of the present invention and guiding the waste composition within the bag to conditions effective for maintaining freshness, the gas composition is adjusted and freshness is maintained over a long period of time.

In addition, it is particularly suitable for packaging fruits and vegetables that undergo intense physiological effects even after harvesting, and can increase the commercial value of packaged products by effectively exerting a freshness-preserving effect.

Normally, maintaining the freshness of fruits and vegetables by adjusting waste has often required the use of large storage rooms, but the present invention is characterized by being simple and economical, as it is only necessary to package the fruits and vegetables in perforated bags. Another advantage is that if the products are packaged individually at the place of production, they can be sold as is without having to be repackaged later, making them convenient to handle.

[Example] Examples of the present invention will be shown below, but the present invention is not limited thereto.

The gas composition inside the bag can be determined by sampling the gas inside the bag by inserting a syringe needle into a 1cm area of the rubber seal attached to a part of the bag (IOCC), an oxygen concentration meter, and a carbon dioxide concentration meter. Measurements were made using a meter (manufactured by Toshi Engineering Co., Ltd.). In addition, freshness was evaluated by visually observing changes in appearance and color, and odor was sensory-evaluated based on the following criteria for abnormal odors coming from inside the bag.

Color ○: No discoloration at all △: Slight discoloration ×: Completely discolored odor ○: No odor at all △: Slightly odor X: Rotten with a severe odor O : Not rotten at all △ : Slightly rotten parts X : Totally softened with many rotten parts Note that the CA conditions for various fruits and vegetables are summarized in Table 1.

Table 1 Optimal CA conditions for various fruits and vegetables Yokendo "Distribution, storage and processing of garden foods" p. 152, Takayuki Taruya and Hirotoshi Kitayo, 1986 Daisei 1 Low-density polyethylene bag with a total surface area of 0.1 m2 ( size 2
5x20cm, thickness 60μm, oxygen permeability 4190cc
/m2-day, carbon dioxide permeability 188600c/
m2・da, heat a microsyringe needle and pierce it into a packaging bag with two holes of 0.5 mm in diameter (total hole area ratio 0.0004%).
0g) and heat sealed at 20℃, 65%
It was placed in the RH storage room.

Table 2 shows the results of measuring the waste composition in the bag and observing the freshness of the broccoli for 10 days.

From the results in Table 2, it can be seen that in Example 1, 2
After ~3 days, the gas composition within the bag reached equilibrium approaching the optimal CA conditions for broccoli (2% oxygen, 10% carbon dioxide) and did not change until 10 days later. It also maintained its freshness well, remaining green with no rotting or odor.

Comparison 5. Example 1 is the same as Example 1 except that the total open pore area ratio is 0%. The results are shown in Table 2.

Comparison Side 2 In Example 1, the test was conducted under the same conditions as in Example 1, except that broccoli was not packaged in a bag and the lid was closed.

The evaluation results are shown in Table 2.

As mentioned above, in Comparative Example 1, in which no holes were provided, there was a lack of oxygen in the bag and an excess of carbon dioxide, and although the green color was maintained, there was a strange odor and the product value was lost. Furthermore, in Comparative Example 2, due to the high oxygen concentration, respiration could not be suppressed, resulting in yellowing, and there was significant wilting due to water evaporation.

Example: About 190 g of strawberries were placed in a low-density polyethylene bag (size 25 x 20 cm, diameter 60 μm) with a total surface area of 0.1rn2.
, oxygen permeability: 4190 cc/m2・day, carbon dioxide permeability: 18,860 cc/m2・da Next, as in Example 1, heat the microsyringe needle and pierce it to make a diameter of 0.
Packaging bag with three 5mm holes (total hole area ratio 0.
0006%) and heat sealed at 20℃.
It was placed in a storage room at 65% RH. Table 3 shows the results of measuring the gas composition in the bag and observing the freshness.

From the results shown in Table 3, in Example 2, the oxygen concentration in the bag reached approximately 10% in one day, reaching equilibrium under the optimum CA conditions. Also,
Freshness was also maintained well.

Comparative Width 3 Example 2 is the same as Example 2 except that the total open pore area ratio is 0%. The results are shown in Table 3.

Comparative Story 4 Tests were conducted under the same conditions as in Example 2, except that broccoli was not packaged in a bag.

The evaluation results are shown in Table 3.

As shown in Table 3, the results deviated from the CA conditions and could not maintain freshness.

About 165g of fresh shiitake mushrooms are powdered in a low-density polyethylene bag with an area of 0.1m2 (size 25x20cm, thickness 60μm,
Oxygen permeability: 4190 cc/m2・day, carbon dioxide permeability: 18860 cc/m2・da Next, as in Example 1, heat the microsyringe needle and pierce it to make a needle with a diameter of 0.5.
Packaging bag with 12 mm-sized holes (total hole area ratio 0.
0024%) and heat sealed at 20°C.
It was placed in a storage room at 65% RH. Table 4 shows the results of measuring the gas composition in the bag and observing the freshness.

From the results in Table 4, in Example 3, after one day, the gas composition in the bag was 9% oxygen and 11% carbon dioxide, almost the optimal CA conditions, and spoilage was suppressed.

Comparative Example 5 Example 3 is the same as Example 3 except that the total open pore area ratio is 0%. The results are shown in Table 4.

Comparison 5: Testing was conducted under the same conditions as in Example 3, except that broccoli was not packaged in a bag.

The evaluation results are shown in Table 4.

As shown in Table 4, the results did not meet the CA conditions and freshness could not be promoted.

Claims (2)

[Claims] (1) 0.0002 to 0.01 relative to the total surface area of the film
A packaging bag for preserving the freshness of fruits and vegetables, characterized in that it is made of a film provided with one or more apertures having a total aperture area ratio of 0%. (2) The size of the opening is 0.2 mm or more and 1.0 mm in diameter.
The freshness-keeping packaging bag according to claim 1, which is as follows.