Method for retaining freshness of cut cabbage, and vegetable package

Abstract

A method for retaining the freshness of cut cabbage according to the present invention includes: a step (I) for storing cut cabbage (A) and an atmosphere adjusting agent package (B), which has oxygen absorbing capacity, in a packaging material (C) to obtain a vegetable package (X); and a step (II) for holding the vegetable package (X). In step (I), the vegetable package (X) satisfies the following requirements (i) and (ii). Requirement (i) is that the ratio of the oxygen reduction rate to the oxygen exchange rate is 0.4 to 2.0. Requirement (ii) is that the ratio of the rate of carbon dioxide increase to the rate of carbon dioxide exchange is 0.2 to 2.0.

Description

Method for maintaining the freshness of cut cabbage, and vegetable packaging

[0001] This invention relates to a method for preserving the freshness of cut cabbage and to a vegetable packaging material.

[0002] Fresh produce such as vegetables and fruits are distributed while continuing their life activities even after harvesting, and both quality and freshness are required. Freshness can be divided into appearance (discoloration, wilting, loss of volume), mass reduction, changes in components, and disease. The factors that maintain the freshness of vegetables have been clarified by research conducted by the USDA in the United States, and in Japan by the National Agriculture and Food Research Organization (NARO) and universities. For example, methods that reduce biological activity to the extent that life activities can be maintained have been widely used to maintain the freshness of vegetables. Specifically, such methods of reducing biological activity include refrigeration of vegetables, adjustment of the gas atmosphere such as oxygen and carbon dioxide, and removal of ethylene gas, which is a hormonal substance. These methods make it possible to maintain relatively high levels of sugars and acids stored in vegetables. In recent years, refrigerated distribution (cold chain) has become widespread, and freshness management by adjusting the gas atmosphere has also been carried out. In particular, gas atmosphere adjustment can be expected to have a high freshness preservation effect if the gas atmosphere is properly managed. Methods for preserving vegetables by adjusting the gas atmosphere include CA (Controlled Atmosphere) preservation, which involves installing gas adjustment equipment in warehouses or containers, and MA (Modified Atmosphere) packaging, which utilizes gas exchange through vegetable respiration. What is important here is the adjustment and management of the gas atmosphere according to the vegetable. Since the growth state and respiration rate of vegetables differ depending on the variety, origin, harvest time, and cultivation method, optimization of the gas atmosphere is required according to the vegetable. CA preservation has the problem that it is difficult to diversify the gas atmosphere to be optimized because the equipment is large, and it cannot respond to breaks in the cold chain. On the other hand, MA packaging can be implemented on a smaller scale than CA preservation and has the advantage of making it easier to optimize the gas atmosphere for each vegetable. For example, Patent Document 1 proposes a technology in which perforated polymer film and non-perforated polymer film are used in a package containing fruits and vegetables that is sealed with polymer film, and the ratio of the open area of ​​the perforated polymer film is set to a predetermined range.

[0003] Japanese Patent Application Publication No. 5-168400

[0004] However, in the case of fruit and vegetable packaging like that described in Patent Document 1, the gas atmosphere adjustment only becomes functional when the respiration rate of the vegetables and the air permeability of the isolation membrane reach equilibrium. Therefore, compared to using a dedicated gas atmosphere adjustment device like those used for CA preservation, it takes longer to reach equilibrium, and there is a problem that sugars and water are lost from the vegetables due to respiration and transpiration during that time. Furthermore, uniform isolation membrane control is difficult because the respiration rate differs for each vegetable, making gas atmosphere adjustment difficult and requiring optimized responses for each vegetable. As a result, it becomes necessary to prepare isolation membranes of various materials according to the type of vegetable. For this reason, although MA packaging can be expected to have a freshness-preserving effect, its actual use is currently limited to vegetables for which mass production benefits can be expected. This makes it difficult for farmers cultivating multiple varieties or for the small-lot, multi-variety distribution that has been growing in recent years through internet sales to cope with this, and thus its widespread adoption is hindered. In addition, to simplify vegetable preparation and enable the sale of vegetables in small quantities, cut raw vegetables are packaged and sold as cut vegetables. These cut vegetables have many cut surfaces, so they deteriorate quickly and are difficult to store for long periods. Cut cabbage, in particular, is in high demand as an ingredient in salads and other dishes, and there has been a need for a method to preserve cut cabbage for a long period of time while maintaining its freshness. Therefore, the present invention aims to provide a method for preserving the freshness of cut cabbage that can create a suitable storage atmosphere (optimal oxygen concentration and optimal carbon dioxide concentration) for cut cabbage, thereby maintaining its freshness for a long period of time, and a vegetable package that can easily and quickly adjust the inside of the package to a suitable storage atmosphere for cut cabbage, thereby maintaining the freshness of cut cabbage for a long period of time.

[0005] In other words, the gist of the present invention is as follows:

[0006] [1] A method for preserving the freshness of cut cabbage, comprising the steps of (I) of placing cut cabbage (A) and an atmosphere adjusting agent packaging body (B) having oxygen absorption capacity inside a packaging material (C) to obtain a vegetable package (X), and (II) of holding the vegetable package (X), wherein in step (I), the vegetable package (X) satisfies the following requirements (i) and (ii). Requirement (i): The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.0. Requirement (ii): The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.0. However, in requirement (i), "oxygen exchange rate" is the sum of the oxygen permeation rate of the packaging material (C) and the ventilation rate of the vegetable package (X). Also, in requirement (ii), "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable package (X). [2] The method for preserving the freshness of cut cabbage according to [1], wherein the atmosphere adjusting agent packaging (B) further has the ability to generate carbon dioxide. [3] The method for preserving the freshness of cut cabbage according to [1] or [2], wherein the atmosphere adjusting agent packaging (B) contains at least one selected from the group consisting of ascorbic acid-based atmosphere adjusting agents and polyhydric phenol-based atmosphere adjusting agents. [4] The method for preserving the freshness of cut cabbage according to any one of [1] to [3], wherein the packaging material (C) contains at least one selected from the group consisting of polypropylene and polyethylene. [5] The method for preserving the freshness of cut cabbage according to any one of [1] to [4], wherein the packaging material (C) has one or more through holes. [6] A method for preserving the freshness of cut cabbage according to any one of [1] to [5] above, wherein step (I) includes inserting cut cabbage (A) and an atmosphere adjusting agent package (B) into the packaging material (C) through an opening in the packaging material (C), then sealing the opening, and perforating the packaging material (C), the order of the two steps is not important. [7] A method for preserving the freshness of cut cabbage according to any one of [1] to [6] above, wherein the holding temperature of the vegetable package (X) in step (II) is 0°C or higher and 40°C or lower.[8] A vegetable package comprising cut cabbage (A), an atmosphere adjusting agent package (B) having oxygen absorption capacity, and a packaging material (C) containing these, wherein the vegetable package satisfies the following requirements (i) and (ii). Requirement (i): The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.0. Requirement (ii): The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.0. However, in requirement (i), "oxygen exchange rate" is the sum of the oxygen permeation rate of the packaging material (C) and the ventilation rate of the vegetable package. Also, in requirement (ii), "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable package. [9] The vegetable package according to [8] above, wherein the atmosphere adjusting agent package (B) further has carbon dioxide generation capacity.

[10] The vegetable packaging according to [8] or [9] above, wherein the atmosphere adjusting agent packaging (B) contains at least one selected from the group consisting of ascorbic acid-based atmosphere adjusting agents and polyhydric phenol-based atmosphere adjusting agents.

[11] The vegetable packaging according to any one of [8] to

[10] above, wherein the packaging material (C) contains at least one selected from the group consisting of polypropylene and polyethylene.

[12] The vegetable packaging according to any one of [8] to

[11] above, wherein the packaging material (C) has one or more through holes.

[0007] According to the present invention, it is possible to create a suitable storage atmosphere for cut cabbage (optimal oxygen concentration and optimal carbon dioxide concentration), thereby maintaining the freshness of the cut cabbage for a long period of time. Furthermore, it is possible to provide a vegetable package that can easily and quickly adjust the inside of the package to a suitable storage atmosphere for cut cabbage, thereby maintaining the freshness of the cut cabbage for a long period of time.

[0008] Embodiments of vegetable packaging and a method for preserving the freshness of cut cabbage according to the present invention will be described in detail below. In this specification, the terms "A to B" in relation to numerical values ​​mean "A or more and B or less" (when A < B) or "A or less and B or more" (when A > B). In addition, in the present invention, a preferred combination of embodiments is a more preferred embodiment.

[0009] [Method for maintaining the freshness of cut cabbage, and vegetable packaging] The present invention provides a method for maintaining the freshness of cut cabbage, comprising the steps of (I) of placing cut cabbage (A) and an atmosphere adjusting agent packaging body (B) having oxygen absorption capacity inside a packaging material (C) to obtain a vegetable packaging body (X), and (II) of holding the vegetable packaging body (X), wherein in step (I), the vegetable packaging body (X) satisfies the following requirements (i) and (ii). Requirement (i): The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.0. Requirement (ii): The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.0. However, in requirement (i), "oxygen exchange rate" is the sum of the oxygen permeation rate of the packaging material (C) and the ventilation rate of the vegetable packaging body (X). Furthermore, in requirement (ii), the "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable packaging (X).

[0010] The present invention also includes the following vegetable packaging. Specifically, the vegetable packaging of the present invention comprises cut cabbage (A), an atmosphere adjusting agent packaging (B) having oxygen absorption capacity, and a packaging material (C) that contains these, wherein the vegetable packaging satisfies the following requirements (i) and (ii). Requirement (i): The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.0. Requirement (ii): The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.0. However, in requirement (i), "oxygen exchange rate" is the sum of the oxygen permeation rate of the packaging material (C) and the ventilation rate of the vegetable packaging. Also, in requirement (ii), "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable packaging.

[0011] The present invention's method for preserving the freshness of cut cabbage and its vegetable packaging, having the above-described configuration, can create a suitable storage atmosphere for cut cabbage (optimal oxygen concentration and optimal carbon dioxide concentration), thereby preserving the freshness of the cut cabbage for a long period. The reason why the present invention's method for preserving the freshness of cut cabbage and its vegetable packaging achieve the above effects is thought to be as follows. Even after harvesting, vegetables continue their life activities, obtaining energy for life maintenance by breaking down respiratory substrates such as sugars and organic acids. A typical respiratory substrate is glucose, which is broken down into carbon dioxide and water using oxygen obtained through respiration, as shown in the following chemical formula (I). ６ H １２ O ６ +6O ２ → 6CO ２ +6H ２ O + 636 kcal ... (I) The energy generated is stored as an energy source for biochemical reactions and is also released as heat. When vegetables have a moderate amount of heat and oxygen, their respiration becomes vigorous, leading to increased consumption of respiratory substrates and a decrease in freshness. Increased respiration also leads to increased transpiration of water from the vegetables, causing wilting and other problems. Therefore, it is preferable to store vegetables in a low-oxygen environment. By creating a low-oxygen environment, respiration is suppressed, the consumption of respiratory substrates is reduced, and respiratory heat is also suppressed. In addition, carbon dioxide has the effect of suppressing or promoting the production of ethylene, one of the growth hormones of vegetables, depending on its concentration, the type of vegetable, and the growth stage at harvest. Therefore, for vegetables in which ethylene gas production is suppressed at higher carbon dioxide concentrations, it is preferable to store them in a high-carbon dioxide environment. Furthermore, higher carbon dioxide concentrations can also suppress vegetable respiration. The optimal values ​​for carbon dioxide concentration in the storage environment for each type of vegetable are publicly available information from organizations such as the USDA and the National Agriculture and Food Research Organization. According to preferred embodiments of the freshness preservation method and vegetable packaging of the present invention, it is possible to create a suitable storage atmosphere for cut cabbage in a particularly short time, thereby preserving the freshness of cut cabbage for a longer period of time.

[0012] The following describes the components and requirements of the method for maintaining the freshness of cut cabbage according to the present invention. The "vegetable packaging of the present invention" has the same components and requirements as the "vegetable packaging (X)" used in the method for maintaining the freshness of cut cabbage, and the following description of the "vegetable packaging (X)" will serve as the description of the components and requirements of the "vegetable packaging of the present invention."

[0013] <Step (I)> Step (I) of the present invention for preserving the freshness of cut cabbage is a step of obtaining a vegetable package (X) by placing cut cabbage (A) and an atmosphere adjusting agent package (B) having oxygen absorption capacity inside a packaging material (C), wherein the vegetable package (X) satisfies the following requirements (i) and (ii). Requirement (i): The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.0. Requirement (ii): The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.0. However, in requirement (i), "oxygen exchange rate" is the sum of the oxygen permeation rate of the packaging material (C) and the ventilation rate of the vegetable package (X). Also, in requirement (ii), "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable package (X).

[0014] <Cut Cabbage (A)> Cut cabbage (A) in the present invention is suitable because its freshness can be maintained by storing it at a low oxygen concentration and a high carbon dioxide concentration. In particular, it is more suitable for cut cabbage to be stored at an oxygen concentration of 3 to 5 volume% and a carbon dioxide concentration of 10 to 15 volume%. Cut cabbage (A) in the present invention is mainly an aggregate of cabbage leaves that have been cut into flakes or strips. Processing methods include julienne, thinly sliced, diced, roughly chopped, and irregularly chopped. There are no restrictions on the shape of a piece of cut cabbage (A), but examples include square, triangular, polygonal, strip-shaped, and thread-shaped. There are no restrictions on the size of a piece of cut cabbage (A), but in the case of square, triangular, polygonal, etc., the longest diameter is preferably 1 to 10 cm, more preferably 2 to 5 cm, and even more preferably 3 to 4 cm. In the case of strips, threads, etc., the longer side is preferably 1 to 10 cm, more preferably 3 to 7 cm, and even more preferably 4 to 6 cm, and the shorter side is preferably 1 to 10 mm, more preferably 2 to 5 mm, and even more preferably 2 to 3 mm. The cut cabbage (A) used in the freshness preservation method of the present invention is preferably washed with water or the like after the cutting process and before being subjected to this step.

[0015] <Atmosphere Adjusting Agent Packaging (B)> The atmosphere adjusting agent packaging (B) obtained in step (I) of the method for maintaining the freshness of cut cabbage according to the present invention has oxygen absorption capacity. Furthermore, the atmosphere adjusting agent packaging (B) provided in the vegetable packaging (X) has oxygen absorption capacity. Preferably, the atmosphere adjusting agent packaging (B) also has carbon dioxide generation capacity. By using an atmosphere adjusting agent packaging (B) that has carbon dioxide generation capacity, the respiration of the cut cabbage can be suppressed, and thus the freshness of the cut cabbage can be maintained.

[0016] The atmosphere conditioning agent package (B) preferably contains an atmosphere conditioning agent (b1) having oxygen absorption capacity, and the atmosphere conditioning agent (b1) is packaged by a packaging material (b2). One or more atmosphere conditioning agent packages (B) are included in the vegetable package (X) obtained in step (I). When multiple atmosphere conditioning agent packages (B) are used, it is sufficient that the multiple packages as a whole exhibit oxygen absorption capacity and preferably carbon dioxide generation capacity, and the functions of each atmosphere conditioning agent package (B) may be the same or different.

[0017] (Atmosphere adjusting agent (b1)) The atmosphere adjusting agent package (B) preferably comprises an atmosphere adjusting agent (b1) and a packaging material (b2) that contains it. The atmosphere adjusting agent (b1) is not particularly limited and may be selected according to the application. For example, the atmosphere adjusting agent (b1) is preferably an iron-based oxygen absorbing substance such as iron powder or iron compounds as the main agent for the oxygen absorption reaction; a non-ferrous oxygen absorbing substance such as a reducing organic substance or metal complex, or a polymer compound having a carbon-carbon double bond; and more preferably a non-ferrous oxygen absorbing substance.

[0018] The atmosphere adjusting agent (b1) may contain other components as needed. Examples of other components include alkaline substances, catalysts, carriers, water, swelling agents, heat suppressants, and odor adsorbents. In particular, the atmosphere adjusting agent (b1) preferably contains a non-ferrous oxygen-absorbing substance and one or more substances selected from the group consisting of alkaline substances, catalysts, carriers, swelling agents, and water, and more preferably contains a non-ferrous oxygen-absorbing substance and at least an alkaline substance, a catalyst, and a carrier.

[0019] <Non-ferrous oxygen-absorbing substances> Examples of non-ferrous oxygen-absorbing substances include ascorbic acid, ascorbate, erythorbic acid (isoascorbic acid), erythorbate, and other ascorbic acid derivatives; and polyhydric phenols such as gallic acid and catechol. These may be used individually or in combination of two or more.

[0020] When the atmosphere adjusting agent (b1) contains a non-ferrous oxygen-absorbing substance as its main component, the content of the non-ferrous oxygen-absorbing substance in the atmosphere adjusting agent (b1) is preferably 15% by mass or more and 70% by mass or less, more preferably 45% by mass or more and 65% by mass or less, and even more preferably 45% by mass or more and 60% by mass or less.

[0021] <Alkaline Substances> Alkaline substances are used to rapidly advance the oxidation reaction of non-ferrous oxygen-absorbing substances and to control the reaction field to an alkaline region. Examples include carbonates, hydroxides, and salts composed of a weak acid and a strong base. In particular, the alkaline substance is preferably one or more selected from the group consisting of alkali metal carbonates, alkali metal hydroxides, and alkaline earth metal hydroxides. Furthermore, from the viewpoint of solubility in water when it is formed as a salt with a non-ferrous oxygen-absorbing substance such as ascorbic acid, it is more preferable that the alkaline substance is one or more selected from alkali metal carbonates and alkali metal hydroxides.

[0022] Suitable alkali metal carbonates include water-soluble alkali metal carbonates such as sodium carbonate, sodium bicarbonate, and sodium carbonate hydrate, with sodium carbonate being particularly preferred. Suitable alkali metal hydroxides include potassium hydroxide and sodium hydroxide, with sodium hydroxide being preferred. Suitable alkaline earth metal hydroxides include calcium hydroxide and magnesium hydroxide.

[0023] If the atmosphere adjusting agent (b1) contains an alkaline substance, the content of the alkaline substance in the atmosphere adjusting agent (b1) is preferably 5% by mass or more and 20% by mass or less, and more preferably 8% by mass or more and 15% by mass or less.

[0024] <Catalyst> Catalysts play a role in improving the amount and rate of oxygen absorption, and examples include transition metal catalysts. By including a catalyst in the composition, an atmosphere modifier (b1) with high oxygen absorption capacity can be obtained. The transition metal catalyst is preferably a transition metal salt. The transition metal salt is preferably one or more transition metal salts selected from the group consisting of Cu, Fe, Co, Ni, Cr, and Mn, and more preferably one or more transition metal salts selected from the group consisting of Mn and Fe, considering oxygen absorption performance and safety, and even more preferably a salt of Fe. In addition, as the transition metal salt, inorganic salts such as hydrochloride salts, sulfates, chloride salts, nitrates or double salts, or hydrates thereof, or organic salts such as fatty acid salts and acetylacetone metal salts can be suitably used, and sulfates are more preferred among them.

[0025] If the atmosphere adjusting agent (b1) contains a catalyst, the catalyst content in the atmosphere adjusting agent (b1) is preferably 2% by mass or more and 10% by mass or less, more preferably 5% by mass or more and 10% by mass or less.

[0026] <Carrier> The carrier supports a non-ferrous oxygen-absorbing substance and a catalyst, and plays a role in improving the amount and rate of oxygen absorption. By including a carrier in the composition, the components of the atmosphere adjusting agent (b1) can be granulated and handled as a powder. Examples of carriers include activated carbon; calcium hydroxide; silicates such as calcium silicate, silica, diatomaceous earth, zeolite, and vermiculite. These may be used individually or in mixtures of two or more. Among these, activated carbon is preferred. Activated carbon not only serves as a carrier but also has the function of suppressing odor generation, and the raw material may be wood, coconut shell, coal, etc.

[0027] If the atmosphere adjusting agent (b1) contains a carrier, the carrier content is preferably 5 to 25 parts by mass, more preferably 10 to 20 parts by mass, per 100 parts by mass of the main component, a non-ferrous oxygen-absorbing substance. By setting it within this range, oxygen absorption capacity is obtained and granulation becomes easier. Furthermore, the carrier content in the atmosphere adjusting agent (b1) is preferably 1% to 20% by mass, more preferably 5% to 10% by mass.

[0028] <Swelling Agent> A swelling agent is a substance that swells with moisture and has a binding function to maintain the shape of the granules, and plays a role in improving the amount and rate of oxygen absorption. The swelling agent may be used in a substantially dry state, or in a semi-swollen or swollen state after absorbing water.

[0029] As a swelling agent, there are no particular restrictions as long as it is a generally known swelling agent; known swelling agents, binders, adhesives, and binders used in food products can be used. Examples of inorganic swelling agents include clay minerals such as sodium bentonite, calcium bentonite, and sodium montmorillonite. Examples of organic swelling agents include organic bentonite; natural products such as defatted frozen tofu, agar, starch, dextrin, gum arabic, gelatin, and casein; semi-synthetic products such as crystalline cellulose, carboxymethylcellulose, sodium carboxymethylcellulose, calcium carboxymethylcellulose, hydroxyethylcellulose, ligninsulfonic acid, and hydroxyethylated starch; and synthetic products such as water-insoluble polyvinyl alcohol and polyvinyl methyl ether. The above-mentioned swelling agents can be used individually, or two or more can be used in combination as needed. Commercially available swelling agents may also be used.

[0030] Among the aforementioned swelling agents, it is preferable that at least one is selected from the group consisting of clay minerals and cellulose-based semi-synthetic products. Clay minerals are preferred because they are inexpensive and have excellent performance. Clay minerals are also known as inorganic soaps and have the function of a lubricant. Furthermore, clay minerals swollen with water are known to exhibit high thixotropy and also exhibit adhesive properties, making them preferred. Cellulose-based semi-synthetic products are also preferred because they exhibit excellent swelling properties. Among these, carboxymethylcellulose, sodium carboxymethylcellulose, calcium carboxymethylcellulose, and bentonites such as calcium bentonite and sodium bentonite are preferred because they are inexpensive and have strong adhesive properties. In particular, it is more preferable that the swelling agent contains one or more selected from the group consisting of calcium carboxymethylcellulose, sodium carboxymethylcellulose, calcium bentonite, and sodium bentonite.

[0031] If the atmosphere adjusting agent (b1) contains a swelling agent, the amount of swelling agent in the atmosphere adjusting agent (b1) is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 20% by mass or less, even more preferably 0.5% by mass or more and 15% by mass or less, and even more preferably 0.5% by mass or more and 10% by mass or less.

[0032] <Heat Suppressant> The heat suppressant plays a role in suppressing excessive heat generation associated with the oxygen absorption reaction of non-ferrous oxygen-absorbing substances (e.g., oxidation reaction of ascorbic acid compounds), and a thermoplastic resin can be used, for example. There are no particular restrictions on the type of thermoplastic resin, but for example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, elastomer, or mixtures thereof can be used. Low molecular weight polyethylene, polypropylene, or mixtures thereof with a molecular weight of 10,000 or less are particularly preferred because the softening point can be easily adjusted and the odor has little effect.

[0033] From the perspective of miscibility with other components, the thermoplastic resin preferably has a particle size of 1 μm or more and 500 μm or less, more preferably 10 μm or more and 300 μm or less. Also, from the perspective of more effectively suppressing heat generation, the softening point of the thermoplastic resin is preferably 90°C or more and 125°C or less.

[0034] When the atmosphere conditioner (b1) contains a heat generation inhibitor, the content of the heat generation inhibitor in the atmosphere conditioner (b1) is preferably 35 parts by mass or more and 300 parts by mass or less, more preferably 60 parts by mass or more and 200 parts by mass or less, based on 100 parts by mass of the non-ferrous oxygen absorbent.

[0035] When the main component of the atmosphere conditioner (b1) is ascorbic acids, from the perspective of promoting the oxidation reaction of ascorbic acids, the content of the thermoplastic resin in the atmosphere conditioner (b1) is preferably 35 parts by mass or more and 300 parts by mass or less, more preferably 60 parts by mass or more and 200 parts by mass or less, based on 100 parts by mass of ascorbic acids.

[0036] The atmosphere conditioner (b1) is preferably a non-ferrous atmosphere conditioner, more preferably at least one selected from the group consisting of ascorbic acid-based atmosphere conditioners and polyphenol-based atmosphere conditioners, and even more preferably an ascorbic acid-based atmosphere conditioner from the perspective of oxygen absorption ability and carbon dioxide generation ability. That is, the atmosphere conditioner package (B) preferably contains a non-ferrous atmosphere conditioner, more preferably at least one selected from the group consisting of ascorbic acid-based atmosphere conditioners and polyphenol-based atmosphere conditioners, and even more preferably contains an ascorbic acid-based atmosphere conditioner from the perspective of oxygen absorption ability and carbon dioxide generation ability.

[0037] (Ascorbic acid-based atmosphere regulator) The ascorbic acid-based atmosphere regulator contains, as the main ingredient (non-ferrous oxygen-absorbing substance), preferably one or more selected from the group consisting of ascorbic acid, ascorbate, ascorbic acid ester, erythorbic acid, erythorbate and erythorbic acid ester, and more preferably further contains an alkaline substance, a catalyst and water. For example, those containing one or more selected from the group consisting of ascorbic acid, ascorbate, ascorbic acid ester, erythorbic acid, erythorbate and erythorbic acid ester, an alkaline substance, a catalyst, water, a carrier and a swelling agent can be preferably used. According to such an ascorbic acid-based atmosphere regulator, by utilizing the oxidation reaction of ascorbic acids and the generation of carbon dioxide which is a decomposition product during the reaction, the inside of the vegetable package can be quickly brought into a low-oxygen, high-carbon dioxide state.

[0038] Examples of the ascorbate include sodium ascorbate. Examples of the ascorbic acid ester include stearic acid ascorbic acid ester, palmitic acid ascorbic acid ester, ascorbic acid 2-glucoside and the like. Examples of the erythorbate include sodium erythorbate. For the other components, it is as described above.

[0039] (Polyphenols-based atmosphere regulator) The polyphenols-based atmosphere regulator contains, as the main ingredient (non-ferrous oxygen-absorbing substance), preferably one or more selected from gallic acid and catechol, and more preferably further contains an alkaline substance. According to such a polyphenols-based atmosphere regulator, by utilizing the oxidation reaction of polyphenols and the generation of carbon dioxide which is a decomposition product during the reaction, the inside of the vegetable package can be quickly brought into a low-oxygen, high-carbon dioxide state. For the other components, it is as described above.

[0040] The amount of atmosphere adjusting agent (b1) in the vegetable packaging (X) can be selected and determined by comprehensively considering the respiration rate of the cut cabbage, the gas permeation rate of the vegetable packaging (X), the performance of the atmosphere adjusting agent (e.g., oxygen absorption rate), and the desired storage period. However, from the viewpoint of maintaining the freshness of the cut cabbage for a long period, the amount is preferably 0.1 to 50 parts by mass, more preferably 0.2 to 30 parts by mass, even more preferably 0.3 to 10 parts by mass, even more preferably 0.5 to 5.0 parts by mass, and even more preferably 0.5 to 3.0 parts by mass per 100 parts by mass of cut cabbage (A).

[0041] (Packaging material (b2)) The atmosphere conditioning agent packaging (B) preferably includes a packaging material (b2) for containing the atmosphere conditioning agent (b1) described above. The packaging material (b2) is not particularly limited as long as it is made of packaging material used for atmosphere conditioning agent applications, but from the viewpoint of obtaining sufficient oxygen absorption performance, it is preferably made of a highly breathable packaging material. Examples include a bag made by bonding two breathable packaging materials together, a bag made by bonding one breathable packaging material and one non-breathable packaging material together, or a bag made by folding one breathable packaging material and sealing the edges together except for the folded part.

[0042] Here, if the breathable packaging material and the non-breathable packaging material are rectangular in shape, the packaging material (b2) may be made by overlapping two breathable packaging materials and heat-sealing all four sides to form a bag, or by overlapping one breathable packaging material and one non-breathable packaging material and heat-sealing all four sides to form a bag, or by folding one breathable packaging material and heat-sealing the three sides excluding the folded part to form a bag. Alternatively, the packaging material (b2) may be made by forming the breathable packaging material into a tube and heat-sealing both ends and the body of the tube to form a bag.

[0043] The shape of the packaging material (b2) is preferably one selected from the group consisting of bag-shaped, three-sided sealed, four-sided sealed, stick-shaped, cylindrical, and box-shaped, and more preferably one selected from the group consisting of bag-shaped, stick-shaped, cylindrical, and box-shaped. Furthermore, if the packaging material (b2) is bag-shaped or three-sided sealed, its size is, for example, 10 mm to 120 mm in length and 10 mm to 120 mm in width.

[0044] <Permeable Packaging Materials> As permeable packaging materials, packaging materials that allow oxygen and carbon dioxide to pass through are particularly selected. Examples include nonwoven fabrics made from various fibers such as Japanese paper, Western paper, and rayon paper, pulp, cellulose, and synthetic resin fibers, plastic films or perforated versions thereof, or microporous films stretched after the addition of calcium carbonate, and further laminates made by laminating two or more of these. As for the plastic films mentioned above, for example, laminated films can be used, which are made by laminating and bonding films such as polyethylene terephthalate, polyamide, polypropylene, and polycarbonate with films such as polyethylene, ionomer, polybutadiene, ethylene acrylic acid copolymer, ethylene methacrylic acid copolymer, or ethylene vinyl acetate copolymer as a sealing layer. Preferred permeable packaging materials include laminates of perforated polyethylene film and paper, nonwoven fabrics made of polyethylene, or laminates of nonwoven fabric and microporous film.

[0045] In particular, as a breathable packaging material, one with an air permeability resistance of 600 seconds or less, more preferably 90 seconds or less, as measured by the Gahl-type testing machine, is preferably used. Here, air permeability resistance refers to the value measured by the method of JIS P8117:1998. More specifically, it refers to the time required for 100 mL of air to pass through the breathable packaging material using a Gahl-type densometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.).

[0046] Various methods can be used to impart breathability, including perforation with cold or hot needles. When imparting breathability through perforation, the degree of breathability can be freely adjusted by the diameter, number, and material of the holes to be perforated.

[0047] Furthermore, the thickness of the laminated film is preferably 50 μm to 300 μm, and particularly preferably 60 μm to 250 μm. In this case, compared to cases where the thickness falls outside the above range, a packaging material can be made that maintains strength and has excellent heat sealability and packaging suitability.

[0048] <Non-permeable packaging materials> Examples of non-permeable packaging materials include packaging materials containing aluminum foil, etc. For example, if a permeable packaging material is used on one side of an atmosphere-adjusting agent packaging body (B) and a non-permeable packaging material is used on the other side, oxygen can be absorbed from only one side.

[0049] The packaging material (b2) contains the above-mentioned atmosphere adjusting agent and other components added as needed, but the amounts of these contents are not particularly limited and can be adjusted as appropriate depending on the method of use of the atmosphere adjusting agent packaging. For example, from the viewpoint of versatility, oxygen absorption performance, carbon dioxide generation capacity, moisture generation capacity and productivity of the atmosphere adjusting agent packaging, the amount of contents per atmosphere adjusting agent packaging (B) is preferably 0.1 g to 100 g, more preferably 0.5 g to 50 g, even more preferably 1 g to 20 g, and even more preferably 3 g to 20 g.

[0050] <Packaging Material (C)> Step (I) is a step of obtaining a vegetable package (X) by placing the cut cabbage (A) and the atmosphere adjusting agent package (B) inside the packaging material (C). The packaging material (C) contains the cut cabbage (A) and the atmosphere adjusting agent package (B) and acts as a separator between the inside and outside of the vegetable package (X). The packaging material (C) is not particularly limited as long as it can contain the cut cabbage (A) and the atmosphere adjusting agent package (B) and separate the inside and outside of the vegetable package (X). However, in order to satisfy requirements (i) and (ii) of the present invention for the freshness preservation method and vegetable package, a packaging material made of a breathable packaging material is preferred. The breathable packaging material can be appropriately selected from known breathable packaging materials according to the desired gas permeability (air permeability). It may be a non-porous film or a perforated film as long as it has adequate breathability, but a perforated film is preferred from the viewpoint of making it easier to control the gas permeability.

[0051] Examples of non-porous films with breathability include nonwoven fabrics made from paper or various fibers, microporous films, and laminates made by laminating two or more of these selected from among, all of which have the desired breathability.

[0052] Examples of perforated films include perforated materials obtained by applying a perforation treatment to the above-mentioned non-perforated film having breathability, or to the non-perforated packaging material described later, and laminates thereof. The packaging material (C) preferably has one or more through holes. A through hole is a hole obtained by applying a perforation treatment to the breathable packaging material or the non-perforated packaging material as described above, and is a hole of a size that allows for easy gas exchange between the inside and outside of the package without creating a pressure difference. Among these, perforated materials obtained by applying a perforation treatment to the non-perforated packaging material described later are preferred from the viewpoint of making it easier to control the amount of gas permeation, and perforated materials obtained by applying a perforation treatment to the resin film described later are more preferred.

[0053] When the packaging material (C) is a packaging material made of a perforated film, examples of the through-holes include perforations formed using a needle, fine holes formed using a laser, holes formed using punching, and the like. The number of through-holes is preferably 1 to 10, more preferably 1 to 5, still more preferably 2 to 4, even more preferably 2 to 3, and even more preferably 2. The total area of the openings of the through-holes is preferably 1 to 20 mm 2 and more preferably 3 to 15 mm 2 and still more preferably 4 to 15 mm 2 and even more preferably 5 to 10 mm 2 and even more preferably 5 to 7 mm 2 and is.

[0054] Step (I) of the method for maintaining the freshness of cut cabbage according to the present invention preferably includes a step of perforating the packaging material (C). In this specification, even when the packaging material (C) is a packaging material made of a perforated film, for convenience, the packaging material before perforation may also be referred to as "packaging material (C)". Therefore, in the method for maintaining the freshness of cut cabbage according to the present invention, step (I) preferably includes a step of inserting cut cabbage (A) and an atmosphere regulator package (B) into the packaging material (C) from the opening of the packaging material (C), and then sealing the opening, and a step of perforating the packaging material (C). Also, the order of the above two steps is not limited. When the step of inserting cut cabbage (A) and an atmosphere regulator package (B) into the packaging material (C) from the opening of the packaging material (C) and then sealing the opening is defined as step (I-1), and the step of perforating the packaging material (C) is defined as step (I-2), the order of step (I-1) and step (I-2) is not limited, and step (I-1) may be performed first and then step (I-2), or step (I-2) may be performed first and then step (I-1).

[0055] In addition to perforation, another method for creating through-holes is to seal a portion of the packaging material (C) in a breathable state. By sealing a portion of the packaging material (C) in this breathable state, the vegetable package (X) will be such that a portion of the packaging material (C) is sealed in a breathable state. Furthermore, the vegetable package (X) obtained by the method for preserving the freshness of cut cabbage according to the present invention will be such that a portion of the packaging material (C) is sealed in a breathable state. The method for sealing a portion of the packaging material (C) in a breathable state is not particularly limited, but examples include loosely bundling the opening of the bag-shaped packaging material (C) and securing it with a binding member such as a clip, rubber band, binding tape, or string, or securing the opening with a partial seal method that leaves a gap when heat sealing.

[0056] The non-permeable packaging material used in the perforated film can be appropriately selected from known non-permeable packaging materials, and specifically, a non-permeable film can be suitably used.

[0057] Examples of films that do not have air permeability include, regardless of whether they have gas barrier properties, resin films that have not undergone perforation treatment, and laminates of such resin films and air permeable films. Examples of the above resin films include single-layer films of polyethylene terephthalate, polyamide, polypropylene, polycarbonate, polyethylene, ionomer, polybutadiene, ethylene acrylic acid copolymer, ethylene methacrylic acid copolymer, or ethylene vinyl acetate copolymer, and laminated films obtained by laminating and bonding two or more selected from the group consisting of these. In particular, the packaging material (C) preferably comprises at least one selected from the group consisting of polypropylene and polyethylene, and more preferably comprises at least one selected from the group consisting of polypropylene and polyethylene. Furthermore, the packaging material (C) is more preferably comprises at least one selected from the group consisting of perforated polypropylene and perforated polyethylene, and even more preferably comprises at least one selected from the group consisting of perforated polypropylene and perforated polyethylene. These are preferred because they can be obtained at low cost and the amount of ventilation can be easily adjusted by perforation processing or partial sealing.

[0058] The thickness, shape, size, etc., of the packaging material (C) are not particularly limited and should be selected appropriately according to the size, number, and weight of the cut cabbage (A) to be contained, the size of the distribution container that will contain the vegetable package (X), etc.

[0059] The thickness of the packaging material (C), that is, the thickness of the packaging material constituting the packaging material (C), is, from the viewpoint of strength and availability, for example, 10 μm or more and 500 μm or less, preferably 20 μm or more and 400 μm or less, more preferably 20 μm or more and 100 μm or less, and even more preferably 20 μm or more and 50 μm or less.

[0060] Examples of packaging material (C) shapes include bags, cylinders, sheets, and boxes. If the packaging material (C) is bag-shaped or cylinder-shaped, the cut cabbage (A) and the atmosphere-adjusting agent package (B) can be placed inside, and the opening (both ends in the case of a cylinder) can be tied or sealed. If the packaging material (C) is sheet-shaped, the cut cabbage (A) and the atmosphere-adjusting agent package (B) can be placed inside, and the ends can be tied or sealed. Among these, a bag shape is preferred from the viewpoint of ease of placing the cut cabbage (A), etc.

[0061] The size of the packaging material (C) is, for example, if the packaging material (C) is a rectangular or square bag, the width is preferably 150 mm to 550 mm, more preferably 150 mm to 450 mm, even more preferably 200 mm to 400 mm, and even more preferably 250 mm to 300 mm. The length is preferably 150 mm to 550 mm, more preferably 150 mm to 450 mm, even more preferably 200 mm to 400 mm, and even more preferably 300 mm to 400 mm. The width is defined as the side with the opening of the bag, and the length is defined as the side without the opening.

[0062] <Characteristics of the Vegetable Packaging> The vegetable packaging (X) obtained in step (I) of the method for preserving the freshness of cut cabbage according to the present invention satisfies the following requirements (i) and (ii). The vegetable packaging of the present invention also satisfies the following requirements (i) and (ii). Requirement (i): The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.0. Requirement (ii): The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.0. However, in requirement (i), "oxygen exchange rate" is the sum of the oxygen permeation rate of the packaging material (C) and the ventilation rate of the vegetable packaging (X). Also, in requirement (ii), "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable packaging (X). Furthermore, as described above, the vegetable packaging (X) used in the freshness preservation method of the present invention satisfies requirements (i) and (ii), and preferably satisfies requirements (i) and (ii) during process (II), but at least satisfies requirements (i) and (ii) at the start of process (II) (end of process (I)). More specifically, requirements (i) and (ii) are satisfied when both the process of inserting the cut cabbage (A) and atmosphere adjusting agent packaging (B) into the packaging material (C) and sealing it, and the process of perforating the packaging material (C) are completed, and at least the vegetable packaging (X) is completed. Also, as described above, the vegetable packaging of the present invention satisfies requirements (i) and (ii), and preferably satisfies requirements (i) and (ii) while holding the vegetable packaging (while preserving the cut cabbage), but at least satisfies requirements (i) and (ii) when holding the vegetable packaging (X) begins. More specifically, requirements (i) and (ii) are met when both the process of inserting the cut cabbage (A) and the atmosphere adjusting agent packaging (B) into the packaging material (C) and sealing it, and the process of perforating the packaging material (C) are completed, and at least the vegetable packaging is finished.

[0063] (Requirement (i)) Requirement (i) is that the ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is between 0.4 and 2.0. The "oxygen exchange rate" is the sum of the oxygen permeability rate of the packaging material (C) and the ventilation rate of the vegetable packaging (X). The "oxygen permeability rate of the packaging material (C)" is the oxygen permeability of the packaging material constituting the packaging material (C) [mL / (day·m) ２ The effective area of ​​the packaging material corresponding to the vegetable packaging (X) [m²] is [atm]. ２ The value obtained by multiplying by ] and dividing by 24 [h (hours)] is the oxygen permeation rate [mL / h] of the packaging material (C) per hour under standard atmospheric pressure. Therefore, the oxygen permeation rate of the packaging material (C) in requirement (i) refers to the oxygen permeation rate of the packaging material (C) before perforation processing, if the packaging material (C) is a perforated film. The "ventilation rate of the vegetable packaging (X)" is the ventilation rate per hour through the through holes (ventilation rate of the through holes) [mL / h] when the packaging material (C) constituting the vegetable packaging (X) has through holes. The "oxygen reduction rate" is obtained as the sum of the oxygen consumption per hour (oxygen consumption rate) [mL / h] due to the respiration of the cut cabbage (A) and the oxygen absorption per hour (oxygen absorption rate) [mL / h] of the atmosphere adjusting agent packaging (B). The above oxygen permeability, ventilation rate, oxygen consumption, and oxygen absorption can be obtained by the method described in the examples.

[0064] The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.0, preferably 0.5 to 2.0, more preferably 0.8 to 2.0, even more preferably 1.0 to 2.0, even more preferably 1.4 to 2.0, and even more preferably 1.5 to 1.9, from the viewpoint of maintaining the freshness of cut cabbage for a long period of time.

[0065] (Requirement (ii)) Requirement (ii) is that the ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is between 0.2 and 2.0. The "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable packaging (X). The "carbon dioxide permeation rate of the packaging material (C)" is the carbon dioxide permeability of the packaging material constituting the packaging material (C) [mL / (day·m) ２ The effective area of ​​the packaging material corresponding to the vegetable packaging (X) [m²] is [atm]. ２ The carbon dioxide permeation rate [mL / h] of the packaging material (C) under standard atmospheric pressure is obtained by multiplying by ] and dividing by 24 [h]. Therefore, the carbon dioxide permeation rate of the packaging material (C) in requirement (ii) refers to the carbon dioxide permeation rate of the packaging material (C) before perforation processing, if the packaging material (C) is a perforated film. The "ventilation rate of the vegetable packaging (X)" is the ventilation rate (ventilation rate of the through holes) [mL / h] per hour through the through holes when the packaging material (C) constituting the vegetable packaging (X) has through holes. The "carbon dioxide increase rate" is obtained as the sum of the amount of carbon dioxide generated per hour (carbon dioxide generation rate) [mL / h] by the respiration of the cut cabbage (A) and the amount of carbon dioxide generated per hour (carbon dioxide generation rate) [mL / h] of the atmosphere adjusting agent packaging (B). The carbon dioxide permeation rate, ventilation rate and carbon dioxide generation rate can be obtained by the method described in the examples.

[0066] The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.0, preferably 0.3 to 1.8, more preferably 0.4 to 1.7, even more preferably 0.5 to 1.6, even more preferably 0.7 to 1.5, and even more preferably 1.0 to 1.4, from the viewpoint of maintaining the freshness of cut cabbage over a long period of time.

[0067] The vegetable packaging (X) allows for adequate ventilation both inside and outside, which helps suppress the deterioration of freshness of cut cabbage due to anaerobic respiration and enables it to be used with vacuum pre-cooling, which is a major method in the cold chain widely used in vegetable distribution.

[0068] Since the MA state is expressed within the packaging material (C) of the vegetable packaging (X), it is possible to store it individually or in combination in packing materials (within distribution containers) such as cardboard boxes or plastic containers.

[0069] The vegetable packaging (X) allows for gas atmosphere control similar to CA storage, but on a size comparable to a standard cardboard box used for distribution (for example, a box with a total length, width, and depth of approximately 600 mm to 1600 mm). Compared to container-based gas adjustments like those used in CA storage, this allows for a greater variety of optimized gas atmospheres. In particular, because the gas balance is adjusted using an atmosphere adjusting agent (B), it can flexibly respond to variations in the optimal storage environment depending on the vegetable type, origin, harvest time, etc.

[0070] <Step (II)> Furthermore, the method for preserving the freshness of cut cabbage according to the present invention includes step (II) of holding the vegetable package (X) obtained in step (I). This step allows the inside of the vegetable package (X) to be adjusted to a storage atmosphere suitable for cut cabbage, and the freshness of the cut cabbage can be maintained for a longer period of time.

[0071] According to the present invention's method for preserving the freshness of cut cabbage, a suitable storage atmosphere for cut cabbage can be achieved in a shorter time compared to conventional MA storage. Specifically, the vegetable packaging (X) containing the cut cabbage can achieve an optimal storage atmosphere for the cut cabbage by satisfying requirements (i) and (ii).

[0072] Furthermore, maintaining a humidity of 80% RH or higher inside the vegetable packaging (X) helps to suppress the drying of the cut cabbage. From this perspective, the humidity is more preferably 85% RH or higher. The upper limit of the humidity is not particularly limited and may be 100% RH.

[0073] Furthermore, the holding temperature of the vegetable package (X) in step (II) is preferably 0°C to 40°C, more preferably 0°C to 20°C, and even more preferably 3°C to 10°C. By setting the holding temperature within the above range, the freshness of the cut cabbage can be maintained for a longer period of time.

[0074] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and includes all aspects included in the concept and claims of the present invention, and can be modified in various ways within the scope of the present invention.

[0075] The present invention will now be described in more detail with reference to examples, but the present invention is not limited thereto. Furthermore, various measurements and evaluations in each manufacturing example, example, and reference example were carried out as follows.

[0076] <Oxygen Absorption Rate> The oxygen absorption rate of the atmosphere conditioning agent packaging used in the examples and comparative examples was calculated by placing the atmosphere conditioning agent packaging in a bag (capacity 20 L) made of gas barrier packaging material, sealing in 15,000 mL of air, and then calculating the oxygen absorption rate from the difference in oxygen concentration at the initial stage and after 48 hours.

[0077] <Oxygen Consumption Rate> The oxygen consumption rate of the cut cabbage used in the examples and comparative examples was calculated by placing the cut cabbage in a bag (capacity 10L) made of gas barrier packaging material, sealing in 3000 mL of air, and then measuring the difference in oxygen concentration between the initial state and after 48 hours of storage.

[0078] <Carbon Dioxide Generation Rate> The carbon dioxide generation rate of the atmosphere conditioning agent packaging used in the examples and comparative examples was calculated by placing the atmosphere conditioning agent packaging in a bag (capacity 20L) made of gas barrier packaging material, sealing in 15,000 mL of air, and then calculating the carbon dioxide generation rate from the difference in carbon dioxide concentration at the initial stage and after 48 hours. The carbon dioxide generation rate of the cut cabbage used in the examples and comparative examples was calculated by placing the cut cabbage in a bag (capacity 10L) made of gas barrier packaging material, sealing in 3,000 mL of air, and then calculating the carbon dioxide generation rate from the difference in carbon dioxide concentration at the initial stage and after 48 hours of storage.

[0079] <Oxygen Permeation Rate of Packaging Materials> The oxygen permeation rates of the packaging materials used in the examples and comparative examples were calculated as follows: According to JIS K7126-2:2006 (isobaric method), the oxygen permeability [mL / (day·m)] was calculated. ２ The oxygen permeability [mL / (day·m)] is measured, and the oxygen permeability [mL / (day·m)] is measured. ２ • Effective area of ​​packaging material [m²] (atm) ２ The oxygen permeation rate was determined by multiplying by ] and dividing by 24 [h (hours)] (oxygen permeation rate per hour [mL / h] under standard atmospheric pressure).

[0080] <Carbon Dioxide Permeation Rate of Packaging Materials> The carbon dioxide permeation rate of the packaging materials used in the examples and comparative examples was calculated as follows: Carbon dioxide permeability [mL / (day·m)] according to JIS K7126-1:2006 (differential pressure method) ２ The carbon dioxide transmission rate [mL / (day·m)] is measured, and the carbon dioxide transmission rate [mL / (day·m)] is measured. ２ The effective area [m²] of the packaging material used in the examples and comparative examples is shown in [atm]. ２ The value obtained by multiplying by ] and dividing by 24 [h (hours)] (carbon dioxide permeation rate per hour [mL / h] under standard atmospheric pressure) was defined as the carbon dioxide permeation rate.

[0081] <Ventilation rate of through-holes in packaging material> The ventilation rate of through-holes in packaging material was calculated by filling a gas barrier packaging material (capacity 5L) with 4000mL of a mixed gas adjusted to 1% oxygen and 99% nitrogen, inserting a metal needle with an inner diameter of 1.94mm and a length of 15mm to create a ventilation opening, and measuring the difference in oxygen concentration between the initial state and after 48 hours.

[0082] [Manufacturing of Atmosphere Adjusting Agent Packaging] Manufacturing Example 1 (Atmosphere Adjusting Agent Packaging 1) 100 g of sodium erythorbate (Fuso Pharmaceutical Industries, Ltd. "Sodium Erythorbate"), 13.3 g of ferrous sulfate, 20 g of sodium carbonate, 15.0 g of activated carbon (Futamura Chemical Co., Ltd. "Taiko S"), 1.7 g of sodium bentonite (Kunimine Industries Co., Ltd. "Neo Kunibond"), and 20.0 g of water were mixed to obtain a mixture. The obtained mixture was pressure-molded using a compression molding machine (Kurimoto Iron Works Co., Ltd. "Compactor MRCP-80") to obtain a plate-shaped molded body with a thickness of 0.8 mm. Subsequently, the molded body was passed through a granulator to obtain granular ascorbic acid-based atmosphere adjusting agent with a particle size of approximately 1.5 mmφ. Next, a breathable three-layer packaging paper, made by laminating perforated polyethylene film, water- and oil-resistant paper, and perforated low-density polyethylene, was prepared by stacking two sheets with the low-density polyethylene on the inside and melt-sealing three sides to create a bag (60 mm wide, 65 mm long). 13 g of the ascorbic acid-based atmosphere adjusting agent was sealed into the bag, and the opening was melt-sealed to obtain an atmosphere adjusting agent package 1. The oxygen absorption rate of the obtained atmosphere adjusting agent package 1 was 62.8 mL / h. The carbon dioxide generation rate of the obtained atmosphere adjusting agent package 1 was 62.8 mL / h.

[0083] Manufacturing Example 2 (Atmosphere Adjusting Agent Packaging 2) 100 g of sodium erythorbate (Fuso Pharmaceutical Industries, Ltd. "Sodium Erythorbate"), 13.3 g of ferrous sulfate, 20 g of sodium carbonate, 15.0 g of activated carbon (Futamura Chemical Co., Ltd. "Taiko S"), 1.7 g of sodium bentonite (Kunimine Industries Co., Ltd. "Neo Kunibond"), and 20.0 g of water were mixed to obtain a mixture. The obtained mixture was pressure-molded using a compression molding machine (Kurimoto Iron Works Co., Ltd. "Compactor MRCP-80") to obtain a plate-shaped molded body with a thickness of 0.8 mm. Subsequently, the molded body was passed through a granulator to obtain granular ascorbic acid-based atmosphere adjusting agent with a particle size of approximately 1.5 mmφ. Next, a breathable three-layer packaging paper, laminated with perforated polyethylene film, water- and oil-resistant paper, and perforated low-density polyethylene, was prepared by stacking two sheets with the perforated low-density polyethylene on the inside and melt-sealing three sides to create a bag (60 mm wide, 55 mm long). 9 g of the ascorbic acid-based atmosphere adjusting agent was sealed into the bag, and the opening was melt-sealed using the ultrasonic sealing machine to create the atmosphere adjusting agent package 2. The oxygen absorption rate of the obtained atmosphere adjusting agent package 2 was 35.0 mL / h. The carbon dioxide generation rate of the obtained atmosphere adjusting agent package 2 was 35.0 mL / h.

[0084] [Preservation of Cut Cabbage] Example 1 <Step 1> 300 g of 1 mm shredded cabbage was prepared as cut cabbage (oxygen consumption rate: 6.9 mL / h, carbon dioxide generation rate: 6.9 mL / h). As packaging material, an anti-fog OPP bag 1 (biaxially oriented polypropylene, manufactured by Shimojima Co., Ltd., thickness 0.02 mm, width 260 mm, length 380 mm, oxygen permeation rate: 10.7 mL / h, carbon dioxide permeation rate: 32.1 mL / h) was prepared by inserting two metal needles with an inner diameter of 1.94 mm and a length of 15 mm into the bag to create two through-holes (ventilation rate of the through-holes: 26 mL / h). 300 g of the above cut cabbage and one atmosphere adjusting agent package 1 made in Production Example 1 were placed in the above packaging material, and the opening of the packaging material was melt-sealed to obtain a vegetable package 1.

[0085] <Step 2> Vegetable package 1 was placed in a cardboard box (depth 220 mm, length 310 mm, width 230 mm) which was used as packing material, and the lid was closed. Vegetable package 1 inside the packing material was stored under conditions of 5±2℃ and humidity 50-65% RH. On the 5th day, it was opened and the storage condition of the cut cabbage was evaluated. The evaluation results are shown in Table 1. The storage condition of the cut cabbage was evaluated by visual observation of the smell inside the vegetable package after storage and the appearance of the cut cabbage. Regarding the smell inside the vegetable package after storage, packages with little or no off-odor were considered to be in good storage condition, and packages with no off-odor were considered to be in even better condition. Regarding the appearance of the cut cabbage, packages with little or no discoloration were considered to be in good storage condition.

[0086] Example 2 In Example 1, the only differences were that in step 1, the amount of cut cabbage was changed from 300g to 1000g, the atmosphere adjusting agent packaging 1 was changed to the atmosphere adjusting agent packaging 2, the packaging material was changed from anti-fog OPP bag 1 (width 260mm, length 380mm) to anti-fog OPP bag 2 (biaxially oriented polypropylene, manufactured by Shimojima Co., Ltd., thickness 0.02mm, width 300mm, length 450mm, oxygen permeation rate: 14.6 mL / h, carbon dioxide permeation rate: 43.8 mL / h), and the number of metal needles inserted into the packaging material was changed from two to three, creating three through-holes (ventilation rate of through-holes: 39 mL / h). Otherwise, vegetable packaging 2 was obtained in the same manner as in Example 1, and then step 2 was performed to evaluate the storage condition of the cut cabbage. The evaluation results are shown in Table 1.

[0087] Comparative Example 1 In the same procedure as in Example 1, except that the atmosphere adjusting agent packaging 1 was not used in step 1 of Example 1, the packaging material was changed from an anti-fog OPP bag 1 to a PE bag (polyethylene, width 150 mm, length 180 mm, oxygen permeation rate of the PE bag: 2.9 mL / h, carbon dioxide permeation rate of the PE bag: 8.7 mL / h), and through holes were not provided, a vegetable packaging 3 was obtained, and then step 2 was performed to evaluate the storage condition of the cut cabbage. The evaluation results are shown in Table 1.

[0088] Comparative Example 2 In the same procedure as in Example 1, except that the atmosphere adjusting agent packaging 1 was not used in step 1 of Example 1, and the number of metal needles inserted into the packaging material was changed from two to three, creating three through-holes (ventilation rate of the through-holes: 39.0 mL / h), a vegetable packaging 4 was obtained, and then step 2 was performed to evaluate the storage condition of the cut cabbage. The evaluation results are shown in Table 1.

[0089]

[0090] As shown in Table 1, it can be seen that the freshness of the cut cabbage preserved according to the freshness preservation method of the example can be maintained for a long period of time. Furthermore, it can be seen that the freshness of the cut cabbage preserved in the package can be maintained for a long period of time by using the vegetable packaging of the example. From this, it can be seen that the freshness preservation method of the present invention makes it possible to create a storage atmosphere suitable for cut cabbage (optimal oxygen concentration and optimal carbon dioxide concentration), and in particular it can be made suitable for cut cabbage in a short time, and the freshness of the cut cabbage can be maintained for a long period of time. Furthermore, the vegetable packaging of the present invention makes it possible to adjust the inside of the package to a storage atmosphere suitable for cut cabbage, and the freshness of the cut cabbage can be maintained for a long period of time.

Claims

1. A method for preserving the freshness of cut cabbage, comprising the steps of (I) of placing cut cabbage (A) and an atmosphere adjusting agent packaging body (B) having oxygen absorption capacity inside a packaging material (C) to obtain a vegetable package (X), and (II) of holding the vegetable package (X), wherein in step (I), the vegetable package (X) satisfies the following requirements (i) and (ii). Requirement (i): The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.

0. Requirement (ii): The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.

0. However, in requirement (i), "oxygen exchange rate" is the sum of the oxygen permeation rate of the packaging material (C) and the ventilation rate of the vegetable package (X). Furthermore, in requirement (ii), the "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable packaging (X).

2. The method for preserving the freshness of cut cabbage according to claim 1, wherein the atmosphere adjusting agent packaging (B) further has the ability to generate carbon dioxide.

3. The method for preserving the freshness of cut cabbage according to claim 1 or 2, wherein the atmosphere conditioning agent packaging (B) contains at least one selected from the group consisting of ascorbic acid-based atmosphere conditioning agents and polyhydric phenol-based atmosphere conditioning agents.

4. The method for preserving the freshness of cut cabbage according to claim 1 or 2, wherein the packaging material (C) includes at least one selected from the group consisting of polypropylene and polyethylene.

5. The method for preserving the freshness of cut cabbage according to claim 1 or 2, wherein the packaging material (C) has one or more through holes.

6. A method for preserving the freshness of cut cabbage according to claim 1 or 2, wherein step (I) includes inserting cut cabbage (A) and an atmosphere adjusting agent package (B) into the packaging material (C) through an opening in the packaging material (C), then sealing the opening, and perforating the packaging material (C), the order of the two steps is not important.

7. The method for preserving the freshness of cut cabbage according to claim 1 or 2, wherein the temperature at which the vegetable packaging (X) is held in step (II) is 0°C or higher and 40°C or lower.

8. A vegetable package comprising cut cabbage (A), an atmosphere adjusting agent package having oxygen absorption capacity (B), and a packaging material (C) containing these, wherein the vegetable package satisfies the following requirements (i) and (ii): Requirement (i): The ratio of the oxygen reduction rate to the oxygen exchange rate [oxygen reduction rate / oxygen exchange rate] is 0.4 to 2.

0. Requirement (ii): The ratio of the carbon dioxide increase rate to the carbon dioxide exchange rate [carbon dioxide increase rate / carbon dioxide exchange rate] is 0.2 to 2.

0. However, in requirement (i), "oxygen exchange rate" is the sum of the oxygen permeation rate of the packaging material (C) and the ventilation rate of the vegetable package. Also, in requirement (ii), "carbon dioxide exchange rate" is the sum of the carbon dioxide permeation rate of the packaging material (C) and the ventilation rate of the vegetable package.

9. The vegetable packaging according to claim 8, wherein the atmosphere adjusting agent packaging (B) has the ability to generate carbon dioxide.

10. The vegetable packaging according to claim 8 or 9, wherein the atmosphere adjusting agent packaging (B) contains at least one selected from the group consisting of ascorbic acid-based atmosphere adjusting agents and polyhydric phenol-based atmosphere adjusting agents.

11. The vegetable packaging according to claim 8 or 9, wherein the packaging material (C) comprises at least one selected from the group consisting of polypropylene and polyethylene.

12. The vegetable packaging according to claim 8 or 9, wherein the packaging material (C) has one or more through holes.

Images