JPH061263U - Bamboo shoot freshness preservation package - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] Among the properties related to keeping freshness of bamboo shoots, based on the relationship with oxygen concentration (under nitrogen balance), problems such as bag breakage in the distribution process Develop an excellent freshness-maintaining package that can be eliminated. [Structure] Maximum tensile strength within 50% elongation is 0.5 kgf /
Oxygen permeability of 5000 mm or more and 15 mm or more
ml / m ² · 24 hr · 1 atm. multi-layer packaging material (eg paper,
A multilayer material composed of one or more kinds of non-woven fabric 1, cloth and plastic net 3 and plastic film 2) is used as a freshness-keeping package for bamboo shoots.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a high-strength freshness-retaining package having a function of retaining the freshness of bamboo shoots.

[0002]

[Prior art]

 Bamboo shoots such as Moso Chiku are harvested from early spring and are widely enjoyed as seasonal vegetables. Bamboo shoots have a short harvesting period and their freshness decreases rapidly after harvesting, so their use as fruits and vegetables is limited. For this reason, various freshness preservation techniques have been used for a long time, but they still do not meet the requirements. One of these is to try to keep bamboo shoots in an environment of low oxygen and high carbon dioxide concentration, but there is no definitive study on the concentration range, and the uncertainty of the handler is unclear. It was usually a good experience. As a means of constructing this environment, packaging using plastic film is used, but bamboo shoots have a sharp shape, so they break during distribution and this environment is rarely destroyed. Not lost.

[0003]

[Problems to be solved by the device]

 The problem to be solved by the present invention is to solve the above-mentioned difficulties in the conventional freshness keeping technique of Bamboo shoots and to develop a freshness keeping package according to actual distribution circumstances.

More specifically, among the properties related to keeping freshness of bamboo shoots, based on the relationship with the oxygen concentration (under nitrogen balance), excellent freshness that can solve problems such as bag breakage in the distribution process. It is intended to develop a holding package.

[0005]

[Means for Solving the Problems]

In order to solve the above problems, the present invention is a multi-layer packaging material having an elongation of 50% or less, a maximum tensile strength of 0.5 kgf / 15 mm or more, and an oxygen permeability of 5000 to 70000 ml / m ² , 24 hr, 1 atm. A freshness-keeping package of bamboo shoots is used.

In order to overcome the above-mentioned problems and to find a better freshness-retaining package, the present inventor actually takes bamboo shoots at 20 to 25 ° C. in consideration of the maximum temperature at the time of shipping and varies the nitrogen balance. It was stored under the environment of the oxygen concentration and the carbon dioxide concentration, and the examination was repeated.

As a result, under an oxygen concentration of about 20%, which is almost the same as that of the atmosphere, even if the carbon dioxide concentration is increased to 10% or even 20%, the respiration rate of bamboo shoots is almost the same as the respiration rate in the atmosphere. No decrease was observed. Moreover, the generation of ethylene was not suppressed.

On the other hand, when the oxygen concentration is lowered, the respiratory volume of bamboo shoots sharply decreases, at 5% oxygen concentration it decreases to 40% of that in the atmosphere, and at 2% oxygen concentration it decreases to nearly 30%. There was found.

However, when the oxygen concentration was further reduced to 1%, anaerobic respiration occurred, and acetoaldehyde and ethyl alcohol were generated. When the bamboo shoots were boiled and the taste was examined, an unpleasant taste was felt.

Further, when the respiration rate was examined in the presence of a high concentration of carbon dioxide at a low oxygen concentration of up to 2%, no further remarkable respiratory depression effect of carbon dioxide was observed.

However, when the carbon dioxide concentration was increased at a low oxygen concentration of 1% or less, anaerobic respiration became more severe, and alteration of bamboo shoots progressed.

From the results of these examinations, it was found that bamboo shoots were relatively insensitive to the carbon dioxide concentration and were strongly affected by the oxygen concentration. As a result of further research, the bamboo concentration was 2 to 15%. A low oxygen concentration has been found to be suitable.

When the environment for maintaining the freshness of bamboo shoots is determined in this way, then the materials that can form this environment are studied, and then among the materials that can form and maintain this environment, the freshness of special items called bamboo shoots (of course , Including keeping freshness during transportation) must be developed.

In such a state, the present inventor further researches, and first, as a packaging material capable of forming and maintaining the above environment, oxygen gas permeability is 5,000 to 70,000 ml / m ² · 24Hr. A film of 1 atm. Was found to be suitable. This oxygen gas permeability is a considerably high value for a film, and in order to have such oxygen gas permeability, the film thickness should be reduced, or butadiene rubber resin, polyorganosiloxane resin, etc. It is necessary to use a resin film having high oxygen gas permeability.

However, these thin films and films of these resins such as butadiene rubber have relatively low strength, and if the oxygen gas permeability exceeds a predetermined range, the strength as a packaging material is anyway. Was found to be low.

On the other hand, bamboo shoots are often distributed in packaging units of 2 kg, 4 kg, and 10 kg, and since bamboo shoots have a sharp shape, the packaging body requires a packaging material having high strength.

As a result of various studies on the packaging body satisfying these contradictory requirements, the present inventor has found that the maximum tensile strength within an elongation rate of 50% is 0.5 kgf / 15 mm or more and the oxygen permeability is 5,000 to 70,000 ml / m ^2. -By using a multi-layer packaging material of 24 hr-1 atm., It was found that a bamboo shoot package with a high freshness-retaining effect that overcomes these difficulties can be made, and the present invention was completed.

[0018]

[Function of the device]

In the present invention, a bamboo shoot is packaged using a packaging material having an elongation of 50% or less and a maximum tensile strength of 0.5 kgf / 15 mm or more and an oxygen permeability of 5000 to 70000 ml / m ² · 24 hr / 1 atm. It is the body. As a constitution of this packaging material, in principle, any material satisfying the above requirements may be used, and for example, at least one kind of paper, non-woven fabric, cloth, plastic net, and the like, and a multi-layer material made of a plastic film may be used. Preferred examples include a multilayer material in which the basis weight of the paper, non-woven fabric and cloth layers is 10 to 180 g / m ² or less and the thickness of the plastic film layer is 7 to 100 μm.

Even if the basis weight of the paper or non-woven fabric layer exceeds 180 g / m ² , there is no problem in terms of strength and gas permeability, but when the basis weight becomes high, the thickness and rigidity increase, which causes difficulty in handling. It

As the strength of the multi-layer material, it is preferable that the maximum tensile strength within an elongation of 50% is 0.5 kgf / 15 mm or more. This strength is strength as a multi-layer material, and each single layer itself constituting the multi-layer material does not necessarily have the above-mentioned strength. If it is less than this strength, it often breaks during transportation, outside air flows into the package from the broken part, and it becomes impossible to maintain a suitable oxygen concentration. When the plastic net is compounded, the strength is not less than the above-mentioned predetermined value, and the thickness of the plastic net is not particularly limited.

As the plastic film layer, for example, low density polyethylene (LD PE) resin, high density polyethylene (HDPE) resin, butadiene rubber (BR) resin, ethylene vinyl acetate copolymer (EVAc) resin, polyorganosiloxane ( SI) resin, polypropylene resin (PP), polystyrene resin (PS) and the like can be exemplified as typical examples, and the resin film layer may be a single layer or a multi-layer film. Here, the low density polyethylene (LDPE) resin usually means a resin having a density of less than 0.93 g / ml, and the bulk density polyethylene (HDPE) resin means a resin having a density of 0.93 g / ml or more.

The tensile strength of the packaging material is a value measured according to JIS “Testing method for tensile strength of paper and paperboard” P8113. However, the gripping interval of the sample was 50 mm.

The means for forming the composite material itself is not particularly limited, and is not particularly limited as long as it is a means capable of forming a predetermined material in a predetermined thickness. A typical example is a method of coating a non-woven cloth with a plastic film. More specifically, for example, a polypropylene spunbonded non-woven fabric having a basis weight of about 18 g / m ² is coated with LDPE film as an extruder. The method of coating to a predetermined thickness can be exemplified.

A typical example of the composite structure of the composite material is as shown in FIGS. 1 and 2, for example. FIG. 1 shows an example in which a non-woven fabric 1 and a plastic film 2 are combined, and FIG. 2 shows an example in which a plastic net 3 is interposed between the non-woven fabric 1 and the plastic film 2. In these examples, the non-woven fabric 1 may be paper or cloth instead of this, and the plastics shown in FIGS. 1 and 2 are preferably LDPE, EVAc, BR and the like.

When the package of the present invention is used, it is usually used as a flat bag or a gusset type bag and may be used in combination with an outer corrugated cardboard case. Furthermore, it is particularly preferable to use a water absorbing sheet or the like in the present package.

Further, since bamboo shoots generate ethylene gas during storage and transportation, it goes without saying that if a freshness-keeping agent such as an ethylene remover is used in combination with the freshness-keeping package of the bamboo shoots, the freshness can be better maintained.

[0027]

【Example】

 In order to make the features of the present invention clearer, examples will be described below. The products were shipped from Kyoto to Tokyo in early April, and the oxygen concentration in the packaging and the freshness preservation status of bamboo shoots at the time of arrival (3 days during this period) were investigated. The results are shown in Tables 1 and 2. However, Table 1 shows the case where a nonwoven fabric is used as the first layer, and Table 2 shows the case where paper, net or cloth is used as the first layer.

Here, the PET / PE composite fiber is a fiber in which a low-density polyethylene resin is coated on the outside of a polyethylene terephthalate resin. The abbreviations used for the non-woven fabric and the plastic film are as follows.

PP: Polypropylene resin. LDPE: Low density polyethylene resin. HDPE: High density polyethylene resin. EVAc: represents an ethylene vinyl acetate copolymer resin, and the content of vinyl acetate is 17% (W / W). BR: Butadiene rubber. PDMSI: Polydimethylsiloxane resin (a kind of polyorganosiloxane resin)

[0030]

[Table 1]

[Table 2]

[Brief description of drawings]

[0031]

[Figure 1]

FIG. 3 is a cross-sectional view showing an example of the bamboo shoot freshness retaining package of the present invention.

[0033]

[Fig. 2]

FIG. 3 is a cross-sectional view showing an example of the bamboo shoot freshness retaining package of the present invention.

[0035]

[Explanation of symbols]

 1-Nonwoven fabric 2-Plastic film 3-Plastic net

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Claims (3)

[Scope of utility model registration request] 1. The maximum tensile strength within an elongation of 50% is 0.5 k.
gf / 15mm or more and oxygen permeability of 5000-700
Freshness-keeping package of bamboo shoots made of a multi-layer packaging material having a volume of 00 ml / m ² , 24 hr, 1 atm. 2. The multi-layer packaging material is a multi-layer material composed of at least one of paper, non-woven fabric, cloth and plastic net and a plastic film, and the basis weight of at least one of the paper, non-woven fabric and cloth layer is: The bamboo shoot freshness-keeping package according to claim 1, wherein the plastic film layer has a thickness of 10 to 180 g / m ² and a thickness of the plastic film layer of 7 to 100 μm. 3. The plastic film layer is a single layer or a multi-layer film made of polyethylene resin, polypropylene resin, polystyrene resin, butadiene rubber resin, ethylene-vinyl acetate copolymer resin, and polyorganosiloxane resin. 1. A freshness-keeping package for bamboo shoots according to 1.