JPH08294360A - Preservation of vegetable and fruit - Google Patents

Abstract

PURPOSE: To provide a method for preserving vegetables or fruits, capable of maintaining their freshness and distributing the vegetables or fruits without causing a trouble, by hermetically sealing the vegetables or fruits in a packing bag having an oxygen-permeating amount calculated on various factors such as the respiration amount of the vegetables or fruits, a time exposed to a high temperature. CONSTITUTION: A method for preserving vegetables or fruits comprises hermetically sealing the vegetables or fruits in a container having a needed oxygen- permeating volume calculated by an equation: P=(0.8 to 1.2)× H×RTmax ×W +(CO2 min-Ceq)÷100×Vo}/s/d [P is the needed oxygen-permeating amount (O2 cc/m<2> .hr.atm); H is a time (hr) exposed to a high temperature; Vo is the effective volume (cc) of the container; RTmax is the absorption volume (CO2 cc/kg.hr) of the vegetables or fruits at the maximum temperature; W is the amount (kg) of the content; Co2 min is the minimum oxygen concentration (%) in the container; S is the effective packing area (m<2> ) of the used container; Ceq is a desired oxygen concentration (%) in an equilibrium state; d is a day (24hr)].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to MA (Modified Atomospher) when distributing fruits and vegetables from a production area to a store in a consumption area.
e) In order to maintain the freshness of the packaging, adjust the oxygen permeation amount of the bag used to maintain the freshness of the fruits and vegetables in response to a sudden temperature change that may occur in the distribution and store the fruits and vegetables. It is about the method.

[0002]

2. Description of the Related Art Conventionally, it has been difficult to maintain the freshness of fruits and vegetables, and they have been produced and supplied in the suburbs of the regions where they are consumed. But,
In recent years, soaring land has reduced the profitability of small-scale production, and due to lack of labor, production areas are moving away from consumption areas, and this phenomenon is still being promoted. Therefore, keeping the freshness of fruits and vegetables has become more important, and various methods have been devised. For example, in addition to truck transportation and freight car transportation, recently, air transportation has been used as a means of distribution. In addition, temperature control is effective for maintaining freshness,
The development of containers with a refrigerated transportation system is in progress. As for packaging materials, the development of styrofoam boxes, cardboard boxes, cold storage materials, etc., which have a high heat-retaining effect, is progressing. Ideally, fruits and vegetables are ideally transported from the production site to the store at a low temperature in a short time, except for some that cause low temperature damage. However, domestic transportation of fruits and vegetables is collected from the production area to the central market and further delivered to each store. Also, in some cases, what is collected in the center,
It is not uncommon to be transferred to local fruit and vegetable markets, and transportation time is becoming longer. In the transportation from the production area to the store, temperature change occurs at each relay point each time the means changes, which results in stress on fruits and vegetables, further promoting the deterioration of freshness. Recently CA (Controlled Ato)
The use of MA packaging, which is based on the conditions of mosphere), has started to be used in some areas, but there are many methods of using it at a constant temperature, and there is no one suitable for actual distribution.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to measure parameters such as the respiration rate of fruits and vegetables and the time of exposure to high temperatures when using MA packaging in an actual distribution system of fruits and vegetables. By sealing fruits and vegetables in a packaging bag having an oxygen permeation amount calculated based on it, the freshness is maintained more than ever and a means for distribution without accident is provided.

[0004]

DISCLOSURE OF THE INVENTION According to the present invention, in a package comprising a container or a bag in which fruits and vegetables are hermetically sealed, freshness is maintained by MA packaging in a distribution state in which a rapid temperature change is caused in distribution from a production area to a store. Then, the general formula P = (0.8 to 1.2) × {H × _RT max × W + (Co ₂ min−Ce
q) ÷ 100 × V ₀ } / S / d P: Required oxygen permeation amount [O ₂ cc / m ² · hr · atm] H: Exposure time to high temperature [hr] V ₀ : Effective container Volume [cc] R _T max: Respiration rate of fruits and vegetables at maximum temperature [CO ₂ cc / kg ・
hr] W: Contents [kg] Co ₂ min: Minimum required oxygen concentration in container [%] S: Effective packaging area of container used [m ² ] Ceq: Desired oxygen concentration in equilibrium [%] d : Calculate the oxygen transmission rate required for one day [24hr], set the oxygen transmission rate of the container to be used to the calculated oxygen transmission rate, fill the container with fruits and vegetables, and seal it. This is a characteristic preservation method for fruits and vegetables.

MA (Modified Atomosphere) packaging will now be described. Vegetables and fruits live and breathe even after harvest, which is a major difference from meat and fish.
Freezing kills the cells and impairs their freshness. Therefore, supplying a certain amount of oxygen to fruits and vegetables to keep them breathing leads to maintaining freshness. Respiratory action is a physiological action for living organisms, and after harvest, fruits and vegetables breathe while consuming the nutrients in the body. In order to maintain the freshness of fruits and vegetables, it is necessary not to stop breathing by freezing, but to control at a low temperature. Due to the nature of fruits and vegetables, respiration is suppressed in the presence of certain carbon dioxide in the environment in which they live. Also, respiration tends to be suppressed at lower temperatures. The conditions under which the temperature and gas concentration are ideally adjusted to control the respiration of fruits and vegetables to the minimum state are called CA (Contoroled Atomosphere) conditions. It is impossible to keep the CA condition as it is under an environment accompanied by a temperature change such as a distribution state, and it is necessary to create an environment according to the temperature. The condition at this time is M
Say A. In MA, it is difficult to make adjustments depending on the distribution conditions, and until now, adjustments have been made mostly based on intuition, and accidents during transportation have frequently occurred.

When the temperature changes like during distribution, MA
What is necessary to maintain freshness in packaging is that oxygen in the container is insufficient when exposed to high temperatures, the concentration becomes 2% or less, and carbon dioxide further increases, exceeding 20%,
That is to become anaerobic. When it becomes anaerobic, it starts anaerobic breathing. Anaerobic respiration consumes more nutrients than normal respiration, and the fruits and vegetables are damaged more quickly. In order to avoid such a state, it is possible to solve it by supplying oxygen required from the outside at the temperature at which breathing becomes the most intense. The amount of oxygen required is the amount of oxygen contained at the time of packaging and the total amount of breathing during the time of exposure to the maximum temperature. In order to determine the total respiration, the respiration rate R _T max of fruits and vegetables at the maximum temperature in the circulating temperature zone is determined by a basic test, and the retention time at the maximum temperature is multiplied. The method of calculating the respiration rate is to flow a constant flow of air into a container containing fruits and vegetables and measure the amount of carbon dioxide increased by breathing, and simply seal the fruits and vegetables in a gas impermeable container and then in the container. There is also a method of obtaining the increase in carbon dioxide concentration from the initial gradient. In the present invention, the latter method was used to determine the respiratory volume at each temperature.

Without oxygen permeation, the oxygen content in the container is 0%
Therefore, in order to prevent anaerobic breathing, secure the minimum required oxygen Co ₂ min in the container. The minimum oxygen requirement varies depending on fruits and vegetables, but it is generally about 2 to 5%, and exceptionally, fruits and vegetables that cause carbon dioxide injury require an oxygen concentration of 15% or more, and fruits and vegetables that do not cause carbon dioxide injury. Needs to set the oxygen concentration to 1 to 3%. Air is present in the voids of fruits and vegetables in the container, of which 21% is oxygen. The actual amount of oxygen is the amount excluding the initial amount of oxygen. This oxygen can be ignored when the fruits and vegetables are densely packed in the container, but it must be taken into consideration when there are many voids. The effective volume V ₀ of the container is the volume obtained by removing the volume of fruits and vegetables from the internal volume of the container when the shape is fixed. On the other hand, in the case of a bag, when it is stored at the maximum temperature, the volume of the fruits and vegetables is subtracted from the volume of the bag in a swelled state due to the water vapor pressure inside.

[0008] The distribution temperature changes in the same way if it follows the same route, but it is not constant because it actually depends on the daily climate. If the difference between the maximum temperatures measured is within ± 15 ° C, the required oxygen transmission amount falls within 0.8 to 1.2 times the obtained value. The concentration of carbon dioxide affects the respiratory depression of fruits and vegetables. The concentration of carbon dioxide becomes maximum when kept at the maximum temperature, but it should not exceed 20% as much as possible. It is also necessary to confirm the concentration at a stable temperature during distribution. The stable concentration can be analogized by measuring the respiratory volume at each temperature. If carbon dioxide exceeds 20% when measured at a stable temperature, it is necessary to check if there was an error in the measurement of respiratory volume at the maximum temperature or because carbon dioxide injury had occurred. is there.

Since the gas concentration in the container is adjusted in MA packaging, the container may have any shape, but it is required that the container is made of a material that can be sealed and adjusted to the calculated permeation amount. . The container used may be an aluminum container, a plastic container, a cardboard box whose inner surface is sealed, a cardboard box with a plastic bag, a plastic bag, or the like in various packaging forms. Particularly preferred is a plastic bag or a cardboard box containing a plastic bag.
In order to provide the necessary oxygen and carbon dioxide gas permeation amounts in the sealed container, adjust the thickness of the material if it has air permeability, and if the air permeability is insufficient, adjust appropriate holes. . The diameter (r) of the hole may be arbitrarily determined, but the gas permeation amount (F) from the hole is calculated by the general formula (D is the diffusion coefficient, C ₂ -C ₁ is the concentration gradient between the bag and the outside air, and x is the thickness of the film), and the size of the hole is the average diameter 1
0 to 150 μm is desirable.

[0010]

【Example】

Example 1 Inner size of 650 mm × 800 mm, thickness 50 μ
A packaging bag made of laminated polyethylene and polyethylene of m was attached to the inner surface of a cardboard box having an inner size of 370 mm × 320 mm × 160 mm, 3 kg of broccoli was packaged, and the bag was tightly sealed with a wire. Such a container can be stored in a cold container at 10 ℃ from the place of production for 20 hours, or about 3 in the market.
It was left at 0 ° C for 12 hours and then transported to the store at 30 ° C for 3 hours. After that, it was displayed and sold at 15 ° C. The oxygen permeation amount was obtained by substituting each numerical value into the above equation, assuming that it was held at 30 ° C. for 15 hours, which is the holding time in the market and the transportation time to the store. The broccoli respiration rate R _T max at 30 ° C. was 1600 CO ₂ cc / kg · hr. Also, since broccoli emits a strong offensive odor in an anaerobic state, Co ₂ min was set to 3%. As a result of the calculation, the required oxygen permeation amount P was 5500 cc / m ² · hr · atm. 7 to supply the necessary oxygen to the bag with this container
330 holes of 0 μm were opened and an actual test was conducted, and the results are shown in Table 1. The volume of the bag was the volume of a cardboard box, and Ceq was set to 10% as the oxygen concentration at 15 ° C.

<Example 2> 8 of the bag used in Example 1
A bag of 4480 cc / m ² · hr · atm having an oxygen transmission rate of 1.5% was prepared, and the same test was performed. The results are shown in Table 1. Example 3 A bag of 6490 cc / m ² · hr · atm having an oxygen permeation rate of 118.5% of the bag used in Example 1 was prepared, and the same test was performed. The results are shown in Table 1. . << Comparative Example 1 >> A bag having an oxygen permeation rate of 70% of the bag used in Example 1 of 3850 cc / m ² · hr · atm was prepared, and the same test was conducted. The results are shown in Table 1. << Comparative Example 2 >> A bag of 7150 cc / m ² · hr · atm having an oxygen permeation rate of 130% of the bag used in Example 1 was prepared, and the same test was conducted. The results are shown in Table 1.

Example 4 A packing bag made of stretched polypropylene having an inner size of 90 mm × 700 mm and a thickness of 25 μm was used in 10
0 g of leek was packaged and sealed. 220mm x 7
30 bundles were packed in a cardboard box of 20 mm × 180 mm. This is left in a cold container at 15 ℃ for 20 hours from the production site, and at the market at about 30 ℃ for 12 hours.
Transported at 3 ° C for 3 hours. After that, it was displayed and sold at 12 ° C. The cardboard box has a volume of 28512 cc. The bag in which the small green onions are packed expands only to the volume of the box even if air is taken into the box, so the volume of the cardboard box per bag is divided by 30 bundles of 30 to obtain a volume of 950 cc. Ceq is the oxygen concentration at 12 ° C, but was set to 10%. 15 hours of holding time in the market and transportation time to the store
Each value was substituted into the above equation on the assumption that the temperature was kept at 30 ° C., and the required oxygen permeation amount was obtained. 3 small onions
Respiration rate R _T max at 0 ° C is 585 CO ₂ cc / kg · h
r and Co ₂ min were set to 3%. As a result of the calculation, the oxygen permeation amount P was 231 cc / m ² · hr · atm. In this container, 13 holes of 50 μm were formed to supply necessary oxygen to the bag, and an actual test was conducted. The results are shown in Table 2.

<Example 5> 11 of the bag used in Example 4
A bag of 272 cc / m ² · hr · atm having a gas permeation rate of 8% was prepared and the same test was performed. The results are shown in Table 2. Example 6 A bag of 190 cc / m ² · hr · atm having a gas permeation amount of 82% of the bag used in Example 4 was prepared, and the same test was performed. The results are shown in Table 2. Comparative Example 3 A bag of 305 cc / m ² · hr · atm having a gas permeation rate of 132% of the bag used in Example 4 was prepared, and the same test was performed. << Comparative Example 4 >> A bag having a gas permeation rate of 70% of the bag used in Example 4 of 162 cc / m ² · hr · atm was prepared, and the same test was conducted. The results are shown in Table 2.

[0014] The storage temperature after transportation was 15 ° C, and the container was opened and stored.

[0015] The storage temperature after transportation was 12 ° C, and the container was opened and stored.

[0016]

By calculating with the theoretical formula of the present invention,
The bag used for distribution of MA packaging can be easily determined, and can be put into practical use promptly.

Claims (1)

[Claims] 1. When freshness is maintained in MA (Modified Atomosphere) packaging in a distribution state in which a rapid temperature change is caused in distribution from a production area to a store, a general formula P = (0.8 to 1.2) × {H × _RT max x W + (Co ₂ min-Ce
q) ÷ 100 × V ₀ } / S / d P: Required oxygen permeation amount [O ₂ cc / m ² · hr · atm] H: Exposure time to high temperature [hr] V ₀ : Effective container Volume [cc] R _T max: Respiration rate of fruits and vegetables at maximum temperature [CO ₂ cc / kg ・
hr] W: Contents [kg] Co ₂ min: Minimum required oxygen concentration in container [%] S: Effective packaging area of container used [m ² ] Ceq: Desired oxygen concentration in equilibrium [%] d : Calculate the oxygen transmission rate required for one day [24hr], set the oxygen transmission rate of the container to be used to the calculated oxygen transmission rate, fill the container with fruits and vegetables, and seal it. A characteristic method of storing fruits and vegetables.