JP3268025B2 - Broccoli freshness preserving method and package thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for maintaining freshness of broccoli and a package thereof for suppressing a decrease in freshness. More particularly, the present invention relates to a method for preserving freshness for hermetically packaging broccoli and maintaining an appropriate gas composition in the packaging bag, and a package thereof.

[0002]

2. Description of the Related Art Broccoli rapidly decreases in freshness after harvesting, and at room temperature, yellowing rapidly progresses within a few days after harvesting, and its commercial value is reduced. For this reason, especially in the case of transporting to a remote place, a device for suppressing yellowing is required in order to maintain commercial value, and various methods for maintaining freshness have been conventionally attempted.

[0003] As a conventional technique relating to the technique of maintaining freshness of broccoli, use of a low temperature is known, which suppresses yellowing. In addition, the so-called MA (Modified Atmosphere), which keeps the inside of the package with low oxygen and high carbon dioxide using the film sealed packaging and the respiration of fruits and vegetables
Storage is known to be effective. At present, broccoli is usually packaged in the form of only a cardboard box at the time of normal temperature distribution, but in some localities, simple MA packaging by film folding is also performed.
In this case, as the film to be used, polyethylene, an inorganic material kneaded film, a biaxially stretched polypropylene film subjected to antifogging processing, or the like is used.

[0004]

In the case of broccoli flowing at room temperature, the respiratory action is very vigorous, so that in the form of a cardboard box alone, it completely yellows in a few days.
In addition, when performing MA packaging of broccoli at room temperature, a high oxygen permeability is required as a film to be used, and if the oxygen permeability of the film is insufficient, the oxygen concentration in the packaging bag decreases rapidly, and the An obstacle occurs, causing an unpleasant odor / obstacle and losing its merchantability.

According to the experiments by the present inventors, the oxygen permeability at 23 ° C. of the film for MA packaging when broccoli flows directly at room temperature is required to be 10,000 to 100,000 cc / m ² · 24 hrs · atm. It is very difficult to obtain this value with a general-purpose polymer film, and when MA packaging is performed in a sealed state, there is a risk of respiratory failure due to lack of oxygen in the packaging bag, and it is suitable for broccoli for MA packaging. There was no film.

For this reason, an appropriate MA effect has to be obtained in the wrapping package. However, in this case, the oxygen and carbon dioxide gas concentrations vary greatly depending on the degree of fold, and a constant freshness maintaining effect cannot be obtained. Therefore, it has a serious drawback that the freshness is reduced. Broccoli also generates a large amount of water vapor, which causes dew condensation inside the package. If the water drops drop on the broccoli by their own weight, they cause mold and rot, resulting in a remarkable deterioration in quality. This amount of condensation is incomparable with other agricultural products, and cannot be prevented by a film which has been subjected to ordinary anti-fog processing.

[0007] Further, since the above-mentioned packaging form is a form used as an inner bag of cardboard, freshness is maintained only from harvest to distribution, and freshness is not maintained at all after sales at stores. That is the current situation. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method optimal for maintaining freshness of broccoli and a package thereof.

[0008]

Means for Solving the Problems To achieve the above object, the present inventors have conducted intensive studies and found that the oxygen and carbon dioxide gas concentrations in the broccoli package are closely related to the maintenance of freshness of the broccoli. Having found this, the present invention has been completed. That is, according to the present invention, the broccoli is sealed and packaged with a film having micropores and an appropriate water vapor permeability, and the oxygen concentration in the pouch is maintained at 3 to 15% and the carbon dioxide gas concentration is maintained at 6 to 18%. A broccoli freshness maintaining method characterized by the gist, and a broccoli package having the above gas conditions is also a gist.

[0009] In order to achieve the above conditions, the film used for packaging has an oxygen and carbon dioxide gas permeability of 1%.
As a ^{0000~100000cc / m 2 · 24hrs · atm} , fine pores of average diameter 100~300μ the film to form a 10 to 500 pieces / m ^2, fine below 50 per pouch as package What has formed the hole is used. Furthermore, in addition to the above conditions, this film has a water vapor permeability of 40 ° C. and 90%
Those having an RH of 100 to 300 g / m ² · 24 hrs are used.

Hereinafter, the present invention will be described in detail. According to the method of the present invention, broccoli is hermetically packaged with a film having pores, the oxygen concentration in the pouch is 3 to 15%, and the carbon dioxide concentration is 6 to
We will keep it at 18%. According to experiments by the present inventors, when the oxygen concentration is 3% or less or the carbon dioxide gas concentration is 18% or more, broccoli is not metabolized normally and generates an organic gas which causes an odor. On the other hand, the oxygen concentration is 15%
As described above, when the carbon dioxide concentration is 6% or less, the respiratory action is active, and the yellowing progresses remarkably. For this reason, it is necessary to maintain the oxygen concentration in the pouch at 3 to 15% and the carbon dioxide gas concentration at 6 to 18%.

The permeability of oxygen and carbon dioxide gas at 23 ° C. of the entire film having pores used in the present invention is 10,000.
~100000cc / m is ² · 24hrs · atm, more preferably 2
It is a ^{0000~60000cc / m 2 · 24hrs · atm} . In other words, the range of the gas permeability is such that the oxygen concentration in the pouch is 3 to
It is a range that can be maintained at 15% and a carbon dioxide concentration of 6 to 18%.

When the film of the present invention is used, since the oxygen and carbon dioxide gas permeability are almost the same, the gas concentration in the pouch necessarily reaches a state of low oxygen and high carbon dioxide. For this reason, a double freshness effect of low oxygen and high carbon dioxide gas can be simultaneously obtained. Therefore, even when the oxygen concentration is 15%, a gas composition having a carbon dioxide concentration of about 6% can be obtained.
The range of the gas composition that can obtain the freshness maintaining effect is very wide, and the risk of generation of off-flavor due to excessively low oxygen can be reduced.

[0013] The broccoli packaging film of the present invention comprises:
The film has micropores with an average diameter of 100-300μ. The oxygen and carbon dioxide permeability of the film depends on the pore diameter and the number thereof, that is, the pore area. According to the experiments of the present inventors, the oxygen and carbon dioxide permeability of each pore is 100 to 900 c.
c / 24hrs · atm. This means that the permeation amounts of oxygen and carbon dioxide gas from the micropores are the same, and the permeation amount is proportional to the pore area. For example, when the pore diameter is 100μ, the oxygen and carbon dioxide gas permeability per pore is 100cc / 24hrs
-It has been clarified by experiments of the present inventors that it is about atm. Therefore, it becomes possible to control the oxygen permeability of the film by changing the number of holes per square meter, in the case of broccoli, for example, a microporous diameter 100 microns, when the microporous number is 10 to 500 pieces / m ² , Oxygen and carbon dioxide permeability at 23 ° C 10,000
You will get a ^{100000cc / m 2 · 24hrs · atm} .

As the method for forming the micropores, any of a physical means such as a heating needle and an optical means such as a laser can be used. If the pore diameter is 100 to 300 μm, it is within a range in which the pores can be sufficiently opened even by using physical means, which is advantageous in terms of cost. Needless to say, the hole can be opened even by a laser or the like. In this case, the hole diameter can be controlled more precisely. In the present invention, when a laser is used for pore opening, it is necessary that the target film efficiently absorbs laser light.For example, when processing is performed with a CO ₂ laser, the absorptance at an oscillation wavelength of 10.6 μm is required. A polystyrene film having a high particle size is more suitable for micropores, and can efficiently perform micropores with a lower output laser.

The film used in the present invention is 40
It is desirable that the water vapor permeability at 90 ° C. and 90% RH is 100 to 300 g / m ² · 24 hrs. Since the evaporation of water vapor depends on the water vapor permeability of the base film, not the micropores in the present invention, it is necessary to use a film having a water vapor permeability in the above numerical range in order to prevent dew condensation due to the evaporation of broccoli. If the water vapor permeability is 100 g / m ² · 24 hrs or less, a large amount of dew is formed in the packaging bag, causing the broccoli, which is the content, to rot or generate mold, which may lead to a deterioration in quality. Conversely, if it is 300 g / m ² · 24 hrs or more, it may cause wilting and weight loss due to evaporation, resulting in quality deterioration.
Films satisfying the water vapor permeability include polystyrene film, cellophane, nylon, vinylon, polybutadiene, etc., but are not particularly limited thereto.

The film used in the present invention may be a single layer or a multilayer. Examples of the multilayer include polyamide / unstretched polystyrene, polyamide / polybutadiene, biaxially oriented polystyrene, and polypinyl alcohol / Examples include stretched polystyrene and polypinyl alcohol / polybutadiene. The anti-fogging process itself does not suppress the rot and mold of broccoli, but it is preferable to apply the process in order to enhance the marketability of broccoli.

In the present invention, it is essential to carry out hermetic packaging in order to maintain the gas composition in an appropriate range.
Although the sealing method is not particularly limited, it is obvious that if the innermost layer of the film of the present invention can be heat-sealed at a low temperature, the sealing can be easily obtained by heat-sealing, and it is more preferable. However, a back seal that is stopped using a tape that is currently in the mainstream can have a sufficient hermeticity, and thus the sealing method is not particularly limited.

In the present invention, the effect of maintaining freshness can be maintained for a longer time by using a single package. Usually, the unit of purchase of broccoli by a consumer is one unit, so if a single package is sold, freshness can be maintained even after the sale until immediately before opening. If this packaging work is performed in the production area, freshness can be maintained from the time of harvesting, and it is more desirable. However, when packed in the backyard of a supermarket or other retail store, the shelf life after the store can be extended. .

The broccoli packaging film of the present invention enables MA storage in which broccoli is stored in a low oxygen and high carbon dioxide gas state.

[0020]

Next, the present invention will be described more specifically with reference to examples of the present invention and comparative examples, but the present invention is not limited thereto. (Example 1) A packaging film used in the present invention shown in Fig. 1-2 was prepared under the following conditions. That is, on a 30-axis biaxially stretched polypropylene film (manufactured by Tokyo Cellophane Paper Co., Ltd.) that can be heat-sealed on one side and has an anti-fog treatment, micropores with an average diameter of 140 μm are formed.
/ m ² was continuously opened using a heating needle.

COMPARATIVE EXAMPLE 1 Micropores having an average diameter of 140 μm were continuously formed in the same film as in the example using a heating needle so that the number of holes was adjusted to 30 holes / m ² by adjusting the hole interval and the number of holes. Drilled. Comparative Example 2 Micropores having an average diameter of 140 μm were continuously formed in the same film as in the example using a heating needle so that the number of holes was adjusted to 750 / m ² by adjusting the hole interval and the number of holes.

Comparative Example 3 The same film as in the example was used without opening. Test Example 1 For the films of Example 1 and Comparative Examples 1 to 3, 23 ° C.
Table 1 shows the results of measuring the oxygen permeation rate per square meter in Table 1.

As is clear from Table 1, the film of this example has an appropriate oxygen and carbon dioxide gas permeability for packaging broccoli at room temperature.

[0024]

[Table 1]

Test Example 2 The film of the above-mentioned Example and Comparative Examples 1 to 3 had an outer size of 210 ×
Create a 300mm pouch (inner pouch surface area 0.1m ² )
And one strain of broccoli were hermetically packaged and stored at 25 ° C. for 3 days to examine changes in internal gas composition, changes in broccoli quality and changes in vitamin C content. The results are shown in Tables 2 and 3.

[0026]

[Table 2]

[0027]

[Table 3]

As is apparent from Table 2, in the present embodiment, the inside of the pouch can be maintained at a moderately low oxygen concentration and a high carbon dioxide gas concentration, which is effective for preventing broccoli from yellowing, and is effective for preventing broccoli from yellowing. Did not generate an off-flavor due to low oxygen. On the other hand, in Comparative Example 2, yellowing advanced due to the high oxygen concentration. Further, in Comparative Examples 1 and 3, an unpleasant odor was generated due to an excessively low oxygen and high carbon dioxide gas state, and the commercial properties were lost. Further, as is clear from Table 3, the reduction rate of vitamin C was smaller in the examples of the present invention than in the non-packaged and comparative examples.

Example 2 Fine pores having an average diameter of 140 μm were formed in non-stretched polystyrene 30 μm (manufactured by Toko Material Co., Ltd.) so that the number of pores and the number of pores were adjusted to 80 / m ^2. The holes were continuously opened using a heating needle. Comparative Example 4 Micropores having an average diameter of 140 μm were formed in the same film as in Example 2,
The holes were continuously opened using a heating needle so that the number of holes was adjusted to 30 / m ² by adjusting the hole interval and the number of holes.

Comparative Example 5 Micropores having an average diameter of 140 μm were formed in the same film as in Example 2.
The holes were continuously opened using a heating needle so that the number of holes was adjusted to 750 / m ² by adjusting the hole interval and the number of holes. Comparative Example 6 The same film as in Example 2 was used without opening.

Comparative Example 7 LLDPE 40 μm incorporating an inorganic substance. As is clear from Table 4,
The film of this example has oxygen and carbon dioxide permeability suitable for packaging broccoli at room temperature.

[0032]

[Table 4]

Test Example 3 The film of Example 2 and Comparative Examples 4 to 6 was used to obtain an outer dimension of 210.
Create a pouch of × 30mm (inner size pouch surface area 0.1m ² )
, One broccoli strain in a sealed package and packed in a cardboard box (12
It was folded and packed as a co / pouch and packed in a cardboard box. This was stored at 25 ° C. for 3 days, and the internal gas composition, change in appearance of broccoli, and the results of the sensory test were examined. Table 5 shows the results.

[0034]

[Table 5]

As is clear from Table 5, in this embodiment, the inside of the pouch can be maintained at a moderately low oxygen concentration and a high carbon dioxide gas concentration, which is effective for preventing broccoli from yellowing, and furthermore, in packaging. Since the body has a high water vapor permeability, it was possible to maintain high quality without causing rot and mold, and conversely without causing wilting. On the other hand, in Comparative Examples 4 and 6, the oxygen concentration was extremely low and the carbon dioxide gas concentration was too high. In Comparative Examples 6 and 7, mold generation and decay of the cut end were observed, and off-flavors were generated and the product was lost. Was. In Comparative Example 5 and the unpacked test plot, yellowing advanced due to the high oxygen concentration.

[0036]

As described above, the present invention is constructed as described above, so that it is possible to maintain freshness of broccoli by MA packaging during normal temperature distribution of broccoli, and to reduce the freshness of broccoli from the distribution stage to the sales and consumption stages. It can be suppressed to the maximum, which is extremely useful industrially.

[Brief description of the drawings]

FIG. 1 is a perspective view of a broccoli freshness preserving package in an individual package form, which is an example of the present invention.

[Explanation of symbols]

 1 ... broccoli 2 ... pouch with micropores 3 ... micropores

──────────────────────────────────────────────────続 き Continuation of the front page (72) Noriko Sugawara 1-1-1 Ichigaya Kagacho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. (56) References JP-A-63-44837 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) A23B ⁷ /00-7/148 B65D 85/50

Claims (6)

(57) [Claims] 1. Broccoli is hermetically packaged with a film having micropores having an average diameter of 100 to 300 μm, the oxygen concentration in the pouch is maintained at 3 to 15%, and the carbon dioxide concentration is maintained at 6 to 18%. It is composed of a single layer or multiple layers, and the film material itself has a water vapor permeability of 100 to 300 g / m ² at 40 ° C. and 90% RH.
-A method of maintaining freshness of broccoli, which is characterized by being 24 hrs. 2. Broccoli is hermetically packaged with a film having micropores having an average diameter of 100 to 300 μm, maintaining the oxygen concentration in the pouch at 3 to 15% and the carbon dioxide gas concentration at 6 to 18% at 23 ° C. Oxygen and carbon dioxide permeability of 10,000 to 100,000 cc / m ²
・ 24hrs ・ atm, the film is composed of a single layer or multiple layers, and the water vapor permeability of the film material itself is
A method for preserving freshness of broccoli, characterized by 100 to 300 g / m ² · 24 hrs at 40 ° C. and 90% RH. 3. The method for preserving freshness of broccoli according to claim 1, wherein the packaging form is a single package, and the number of micropores per pouch is 50 or less. 4. Sealing and packaging with a film having micropores having an average diameter of 100 to 300μ, the oxygen concentration in the pouch is maintained at 3 to 15% and the carbon dioxide gas concentration is 6 to 18%, and the film is formed of a single layer or A broccoli package composed of multiple layers and having a water vapor permeability of the film material itself of 100 to 300 g / m ² · 24 hrs at 40 ° C. and 90% RH. 5. Sealing and packaging with a film having micropores with an average diameter of 100 to 300 μm, the oxygen concentration in the pouch is maintained at 3 to 15%, the carbon dioxide gas concentration is 6 to 18%, and oxygen and carbon dioxide at 23 ° C. The gas permeability is 10,000 to 100,000 cc / m ² · 24 hrs · atm, the film is composed of a single layer or a multilayer, and the water vapor permeability of the film material itself is 40 ° C., 90% RH.
Package of broccoli is a 100~300g / m ² · 24hrs. 6. The broccoli package according to claim 4, wherein the packaging form is a single package, and the number of micropores per pouch is 1 to 50.