JP3416296B2 - Environmentally controlled storage of fruits and vegetables - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an environmentally controlled storage method (CA storage method) for controlling the atmosphere in a storage where fruits and vegetables are stored. [0002] In order to maintain a stable shipment of fruits and vegetables such as tangerines, kabosu and apples throughout the year, a method of storing these fruits and vegetables for a long period of time without reducing their freshness has been proposed. Various studies are underway. Basically, the fruits and vegetables are stored by controlling or removing the following environmental factors of the atmospheric gas. (1) The concentration of oxygen gas according to the type of each fruit and vegetable. (2) The concentration of carbon dioxide gas according to the type of each vegetable. (3) Temperature according to the type of each vegetable. (4) Humidity according to the type of each fruit and vegetable. (5) Volatile organic substances such as ethylene, acetaldehyde, terpene and the like, which are factors that give rise to fruit aging, plague, and off-flavors that occur as the fruit and vegetable matures. [0003] Among these environmental factors, the low-temperature storage method for controlling the environmental factor (3) is widely used. Further, regarding the method for removing the environmental factor of the above (5),
The degree to which the fruits and vegetables are wrapped in a wrapping paper having a surface coated with an organic substance decomposer, or a plastic bag enclosing the organic substance decomposer, and the volatile organic substance is adsorbed and decomposed by the organic substance decomposer. It is. However, the above-mentioned storage method of wrapping fruits and vegetables in a wrapping paper, a bag, or the like, causes a decrease in the effectiveness of the organic substance decomposing agent when the humidity of the atmospheric gas is increased, thereby hindering the storage. It has been confirmed by tests that freshness of fruits and vegetables packed in an environment where atmospheric gas is stagnant is reduced earlier than those with good circulation of atmospheric gas. Further, it has been confirmed that the above-mentioned packaging method requires a lot of labor, is difficult to store under uniform and appropriate conditions, and has unevenness in freshness. SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems, and it is an object of the present invention to store fruit and vegetables in a labor-saving and proper manner over a long period of time while maintaining high freshness. It is an object of the present invention to provide an environmentally controlled storage method which can be performed. [0006] SUMMARY OF THE INVENTION The present invention is, relative humidity by introducing atmospheric gas in the reservoir containing the volatile organic substances and moisture generated from the fruit vegetables in adsorption tower desiccant filled But
A step of dehumidifying to 10% or less, and containing hypobromite or active bromine as an organic substance decomposing agent using the atmospheric gas.
A step of decomposing and removing the volatile organic substance by introducing into a decomposition tower filled with activated carbon; and a step of applying the atmospheric gas to another adsorption tower filled with a dehumidifier in a moisture-adsorbed state by the following formula (1).
The environment for fruit and vegetables characterized by comprising a step of introducing under a fixed regeneration pressure condition, removing moisture from the dehumidifier and increasing the humidity, and a step of refluxing the atmospheric gas to the storage. It is a controlled storage method. _{G 1 = 1.2 × G 0 ×} P d / P a (1) where, P _a is the adsorption pressure (atm), P _d is the regeneration pressure (at
m), G ₁ is the amount of gas regeneration step, G ₀ is the amount of gas adsorption process
Is shown. As the dehumidifying agent, for example, zeolite 3
A-type zeolites such as A can be mentioned. Since such a zeolite has a window diameter of 0.3 nm, it selectively adsorbs water molecules (0.28 nm), which are the smallest molecules in the atmosphere gas, by a molecular sieving effect. Examples of the organic substance decomposing agent include activated carbon containing hypobromite or active bromine. The activated carbon has a relative humidity of atmospheric gas of 10
%, The volatile organic substance is decomposed, but deactivated when the relative humidity exceeds 10%. According to the present invention, an atmosphere gas in a storage containing volatile organic substances and moisture generated from fruits and vegetables is introduced into an adsorption tower in which a dehumidifier is introduced, and dehumidified. When the gas is introduced into the decomposition tower filled with the organic substance decomposer, the organic substance decomposer can decompose and remove the volatile organic substance without being deactivated. When the atmosphere gas is introduced into another adsorption tower filled with a moisture-absorbing dehumidifier, the atmosphere gas releases moisture from the dehumidifier to a humidity required to maintain the freshness of fruits and vegetables. Humidified,
Refluxed into the storage. Since the dehumidifier is dried and regenerated by the increase in the humidity of the atmospheric gas, when the atmospheric gas in the storage is subsequently introduced into the other adsorption tower, the atmospheric gas is dehumidified. Thereafter, as described above, the volatile organic substance in the atmospheric gas is decomposed and removed by the decomposition tower, and the atmospheric gas is introduced into the adsorption tower used at the time of the first dehumidification. Since moisture is adsorbed by the wetting agent, the atmospheric gas is humidified by this moisture and is returned to the storage. Since such a process is repeatedly performed,
From the discharge of the atmospheric gas containing the volatile organic substance from inside the storage, dehumidification of the discharged atmospheric gas, decomposition and removal of the volatile organic substance in the atmospheric gas, humidity increase of the atmospheric gas, the volatility The process up to the reflux of the atmosphere gas from which the organic substance has been removed into the storage can be repeatedly and continuously performed. As a result, the concentration of the volatile organic substance in the storage can be maintained at an extremely low value, and the fruits and vegetables can be stored for a long period of time while maintaining high freshness. An embodiment of the present invention will be described below in detail with reference to FIG. Embodiment 1 FIG. 1 is a schematic diagram showing an environment control device used in an embodiment of the present invention. In FIG. 1, 1 is a storage, 2a and 2b are first and second adsorption towers each packed with 5 kg of a dehumidifier (for example, zeolite 3A), and 3 is an organic substance decomposer (for example, contains hypobromite). (Activated carbon). The storage 1 is connected to the inlet-side pipes 6a, 6b of the adsorption towers 2a, 2b through a first outward path 4, first branch outward paths 5a, 5b. Valves 7a, 7b
Are interposed in the branch outgoing paths 5a and 5b, respectively. Outlet pipes 8a, 8b of the adsorption towers 2a, 2b are connected to the decomposition tower 3 through second branch outgoing paths 9a, 9b and a second outgoing path 10. Valves 11a, 11b
Are interposed in the branch outgoing paths 9a and 9b, respectively. The decomposition tower 3 includes a first return line 12, a first branch return line 13
a and 13b are connected to outlet pipes 8a and 8b of the adsorption towers 2a and 2b. Valves 14a, 14b
Are installed on the branch return paths 13a and 13b, respectively. Inlet pipes 6a, 6b of the adsorption towers 2a, 2b
Are connected to the storage 1 through second branch return paths 15a and 15b and a second return path 16. Valve 17a,
17b is interposed in the branch return paths 15a and 15b, respectively. The heat exchanger 18 is connected to the first outward path 4 and the second return path 16 and exchanges heat with the atmospheric gas flowing through these flow paths. The vacuum pump 19 is interposed in the second return path 16 located between the connection part of the heat exchanger 18 and the branch parts of the branch return paths 15a and 15b. Next, a method of controlling and storing Cabos using the above-described environment control device will be described in detail. The storage 1
Stores 1 ton of kabos. The composition of the atmosphere gas in the storage 1 was adjusted to 5 vol% of oxygen, 5 vol% of carbon dioxide, and 90 vol% of nitrogen, and the temperature of the atmosphere gas was adjusted to 5 ° C. and the relative humidity was adjusted to 80%.
Volatile organic substances such as ethylene, acetaldehyde, and terpene are generated from the cabos in the storage 1. In the first step, the valves 7a, 11a, 1
4b and 17b and open the valves 7b, 11b and 1
This is performed in a state where 4a and 17a are closed. In this case, the atmospheric gas is circulated in the apparatus through the following channels. In the outward path, the atmospheric gas in the storage 1 is introduced into the adsorption tower 2a through the outward path 4 (the heat exchanger 18), the branch outward path 5a, and the pipe 6a, and the pipe 8a, the branch, and the branch from the adsorption tower 2a. A process of introducing the decomposition tower 3 through the outward route 9a and the outward route 10 is taken. The return path passes the atmospheric gas in the decomposition tower 3 to the return path 12 and the branch return path 13.
b, introduced into the adsorption tower 2b through the pipe 8b, from the adsorption tower 2b to the pipe 6b, the branch return path 15b,
A return path to the storage 1 through the return path 16 (the heat exchanger 18) is taken. The flow rate of the atmospheric gas flowing in the apparatus by the operation of the vacuum pump described later is 2
Nm ³ / h is maintained. The vacuum pump 19 is driven to discharge the atmospheric gas containing the volatile organic substance and water from the storage 1 and the temperature is raised to room temperature by the heat exchanger 18. When the atmospheric gas is introduced into the adsorption tower 2a, the atmospheric gas is caused to flow in the adsorption tower 2a in a cocurrent at a pressure of 1.05 atm, and the zeolite 3A has a dew point of -20 ° C.
Is dehumidified up to the amount of water vapor. Along with this, the water adsorption zone of the zeolite 3A is moved near the outlet of the adsorption tower 2a. The time required for the dehumidifying step is 2.5 minutes. The dehumidified atmospheric gas is introduced into the decomposition tower 3. At this time, since the relative humidity of the atmosphere gas has been reduced to 10% or less, the activated carbon (organic substance decomposer) containing hypobromite in the decomposition tower 3 is not deactivated, and It acts on volatile organic substances to decompose and remove them. Next, the atmospheric gas from which the volatile organic substances have been removed is introduced into the adsorption tower 2b filled with zeolite 3A on which water molecules have been adsorbed. The zeolite 3A
Is performed by setting the pressure of the atmospheric gas to a regeneration pressure value calculated from the following equation proposed by Skarstrom. [0017] _{G 1 = 1.2 × G 0 ×} P d / P a (1) (1) P a in formula adsorption pressure, P _d is the regeneration pressure, G
₀ amount of gas adsorption process, G ₁ represents the amount of gas regeneration step. Here equal gas quantity G ₁ of the regeneration step and the gas amount G ₀ of the adsorption step, the adsorption pressure P _a is 1.05Atm, regeneration pressure P _d of said zeolite 3A is 0.8atm
become. Therefore, the atmospheric gas is supplied to the vacuum pump 19.
Then, the pressure is reduced to 0.8 atm, and the water is caused to flow countercurrently in the adsorption tower 2b, thereby removing moisture from the zeolite 3A and increasing the humidity. Along with this, the moisture adsorption zone of zeolite 3A near the outlet of the adsorption tower 2b is moved near the entrance of the adsorption tower 2b, and the zeolite 3A is regenerated. The time required for the humidification step is 2.5 minutes. The humidified atmosphere gas is introduced into the heat exchanger 18, cooled to 5 ° C., and then returned to the storage 1. In the second step, the eight valves are switched to open the valves 7b, 11b, 14a, 17a,
The operation is performed with the valves 7a, 11a, 14b, 17b closed. In this case, the atmospheric gas is circulated in the apparatus through the following channels. In the outward path, the atmospheric gas in the storage 1 is introduced into the adsorption tower 2b through the outward path 4 (the heat exchanger 18), the branch outward path 5b, and the pipe 6b, and the pipe 8b, the branch, It takes a course of introduction to the decomposition tower 3 through the outward path 9b and the outward path 10. The return path introduces the atmospheric gas in the decomposition tower 3 into the adsorption tower 2a through the return path 12, the branch return path 13a, and the pipe 8a, and from the adsorption tower 2a to the pipe 6a, the branch return path 15a. , And return to the storage 1 through the return path 16 (the heat exchanger 18). Table 1 below summarizes the moisture adsorption and regeneration of the adsorption towers 2a and 2b in the first step and the second step. Table 1 First step Second step Adsorption tower 2a Cocurrent adsorption Countercurrent regeneration Adsorption tower 2b Countercurrent regeneration Cocurrent adsorption Atmospheric gas containing the volatile organic substance by repeating the first step and the second step. Is discharged from the storage 1, and the discharged atmospheric gas is dehumidified, the volatile organic material in the atmospheric gas is decomposed, the atmospheric gas is humidified, and the volatile organic material is removed. Can be continuously performed, and the concentration of the volatile organic substance in the storage 1 can be maintained at an extremely low value. actually,
The concentration of the volatile organic substance contained in the atmospheric gas discharged from the storage 1 was 10 ppm for ethylene, 5 ppm for acetaldehyde, and 2 ppm for terpene before the environmental control. The concentration of any substance in the recirculated atmosphere gas is reduced to 0.01 ppm or less. Kabos was stored in the storage 1 for a long period of 5 months while maintaining high freshness. Example 2 One ton of Matsutake mushrooms was stored in the storage 1, and the composition of the atmosphere gas in the storage 1 was adjusted to 2 vol% of oxygen and 5 to 10 vol% of carbon dioxide. Storage was carried out in the same manner as in Example 1 except that the temperature was adjusted to ° C. As a result, the Matsutake mushrooms stored by the method of Example 2 maintained high freshness without a decrease in hardness, generation of nets, generation of off-flavors, etc. over a period of 2 to 3 weeks. On the other hand, when 1 ton of Matsutake was stored in an air atmosphere at 2 ° C., one week later, the hardness decreased due to condensation on the surface, nets were generated due to propagation of various bacteria, and off-flavors were generated, and the commercial value was lost. Was. In addition, it was confirmed that when ozone was sterilized in the initial stage of storage in the method of Example 2, the generation of mold, net and the like was suppressed for a long period of time, and high freshness was maintained. Example 3 One ton of Ome was stored in the storage 1, and the composition of the atmosphere gas in the storage 1 was adjusted to 2 vol% of oxygen and 5 to 10 vol% of carbon dioxide, and the temperature of the atmosphere gas was adjusted to 2 vol%. Storage was carried out in the same manner as in Example 1 except that the temperature was adjusted to ° C. As a result, the ume stored by the method of Example 3 maintained high freshness for 23 days. On the other hand, when 1 ton of Ome was stored in an air atmosphere at 2 ° C., a physiological disorder occurred about 3 days later, and freshness was reduced. As described above in detail, according to the environmentally controlled storage method of the present invention, fruits and vegetables can be stored labor-saving and properly over a long period of time while maintaining high freshness. There is a remarkable effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an environment control device according to an embodiment of the present invention. [Description of Signs] 1 storage, 2a, 2b adsorption tower, 3 decomposition tower, 18
Heat exchanger, 19 ... vacuum pump.

Continued on the front page (72) Inventor Osamu Matsuzaki 2-1-47 Shiobara, Minami-ku, Fukuoka City, Fukuoka Prefecture Within the Research Institute of Kyushu Electric Power Co., Inc. (72) Inventor Jun Ichimi 5-7-17-1 Fukahoricho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industry Co., Ltd. Nagasaki Research Institute (72) Inventor Takashi Morimoto 5-717-1 Fukahoricho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries Co., Ltd. Nagasaki Research Center (72) Inventor Tsubakizaki Sen City 5-717 Fukahoricho, Nagasaki City, Nagasaki Prefecture 1 Mitsubishi Heavy Industries, Ltd. Nagasaki Research Institute (72) Inventor Hiroyuki Tsutaya 5-717-1 Fukahori-cho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Research Center (72) Inventor Koichi Araki 1, Atsunouracho, Nagasaki City, Nagasaki Prefecture No. 1 Inside Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (56) References JP-A-63-229118 (JP, A) JP-A-53-52646 (JP, A) JP-A-64-43148 (JP, A) JP-A-62-122553 (JP, A) JP-A-7-313052 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A23B7 / 00-9/34

Claims (1)

(57) [Claim 1] Atmospheric gas in a storage containing volatile organic substances and moisture generated from fruits and vegetables is introduced into an adsorption tower filled with a dehumidifying agent, and a relative humidity of 10 is obtained. % Or less, and the atmosphere gas is hypobromite as an organic substance decomposing agent.
Or a step of decomposing and removing the volatile organic substance by introducing into a decomposition tower filled with activated carbon containing active bromine, and transferring the atmospheric gas to another adsorption tower filled with a dehumidifier in a moisture adsorption state. A step of introducing under a regeneration pressure condition defined by the following formula (1) to remove moisture from the dehumidifier to increase the humidity, and a step of refluxing the atmospheric gas to the storage. An environmentally controlled storage method for fruits and vegetables, comprising: _{G 1 = 1.2 × G 0 ×} P d / P a (1) where, P _a is the adsorption pressure (atm), P _d is the regeneration pressure (at
m), G ₁ is the amount of gas regeneration step, G ₀ is the amount of gas adsorption process
Is shown.