JPH01247032A - Method for retaining freshness of vegetables, fruits and flowering plants - Google Patents

Abstract

PURPOSE:To prevent the ability to remove ethylene from deteriorating under high-temperature conditions and facilitate regeneration, by removing ethylene generated from vegetables, fruits and flowering plants with an ethylene removing agent prepared by carrying and immobilizing silver on a porous carrier. CONSTITUTION:A silver compound, such as silver nitrate, is dissolved or suspended in a solvent, such as water, and a porous carrier, such as active carbon, activated alumina or zeolite, is dipped in the resultant solution and dried to prepare an ethylene removing agent. If the above-mentioned ethylene removing agent is utilized, a gas in a storehouse 1 is introduced through a blower 2 into a scrubber 3 filled with the ethylene removing agent 4 to remove ethylene. The gas emerging from the scrubber 3 is then returned into the storehouse 1 to prevent the ethylene from accumulating in the storehouse. The afore- mentioned ethylene removing agent has better ability to remove the ethylene generated from vegetables, fruits and flowering plants than that of a conventional agent.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for preserving the freshness of fruits, vegetables, and flowers, and more specifically, the present invention relates to a method for preserving the freshness of fruits, vegetables, and flowers, and more specifically, to preserve the freshness of fruits, vegetables, and flowers by removing ethylene generated from the fruits, vegetables, and flowers during storage, and preserving the freshness of fruits, vegetables, and flowers. Relates to methods for preserving the freshness of flowers and plants.

[Conventional technology and its problems] To maintain the freshness of harvested fruits, vegetables, and flowers, low-temperature storage and carbon
Al113'Kura (Controlled Atmosp
hereStorage) or sealed packaging using polyethylene bags, etc. are generally employed.

Even after they are harvested, fruits, vegetables, and flowers take in oxygen and continue to sustain life using organic matter stored in their bodies (starch, sugars, proteins, amino acids, etc.) as energy sources, and release carbon dioxide, water, ethylene, etc. as metabolites. are doing. Of these, ethylene is a plant hormone that promotes the overripeness and aging of fruits and vegetables, as well as the flowering and growth of flowers. Therefore, in order to maintain the freshness of fruits, vegetables, and flowers after harvesting, even during storage or during the reverse flow process, it is desirable to remove the ethylene generated from them.

As methods for preserving the freshness of fruits, vegetables, and flowers during storage or distribution, there are known methods for removing ethylene generated from them using an adsorbent and using an oxidizing agent. In this case, as an adsorbent, a porous adsorbent such as activated carbon or zeolite 1 is used, and as an oxidizing agent, potassium permanganate or chlorine dioxide is used as a zeolite 1.
-, etc., or bromine compounds supported on activated carbon are used.

However, the atmosphere in which fruits, vegetables, or flowers are stored or packaged for transportation generally has high humidity and a high carbon dioxide concentration.

For this reason, the method of using an adsorbent has the disadvantage that the adsorbent cannot have a high ethylene adsorption capacity due to the influence of coexisting moisture and carbon dioxide gas, and there is also a risk that the adsorbed ethylene may be desorbed. A sufficient ethylene removal effect cannot be expected. On the other hand, regarding the method of using an oxidizing agent, although potassium permanganate has excellent ethylene removal performance, it is a poisonous substance and can become a source of environmental pollution depending on how it is handled, leading to problems in its disposal. Furthermore, methods using chlorine dioxide are not recommended because the chlorine gas comes into direct contact with fruits and vegetables. Furthermore, methods using bromine compounds such as bromate salts also have problems in terms of treatment of generated hydrogen bromide.

[Means for Solving the Problems] The present invention uses an ethylene removal agent comprising silver immobilized on a suitable porous carrier to remove ethylene generated from fruits, vegetables, and flowers.

The ethylene removing agent of the present invention can be prepared by dissolving or suspending silver nitrate or other silver compounds in a suitable solvent such as water, immersing a carrier in this solution, or spraying the solution onto the carrier, and then drying. It can be prepared.

Supports on which silver is immobilized include carbonaceous porous materials such as activated carbon or those oxidized with air, activated aluminum, alumina-based supports such as alumina sol, zeolite, diatomaceous materials, white clay (acidic clay, activated clay), etc. ), bentonite, kaolin, vermiculite, and various other naturally occurring minerals (aluminosilicate) can be used, and the shape can be arbitrarily selected from powder, granule, fiber, honeycomb, etc. Furthermore, a plastic packaging film for keeping freshness can be obtained by mixing the ethylene removing agent of the present invention with a gas-permeable film raw material resin such as polyethylene or polypropylene and forming the mixture into a film.

The carrier is preferably porous and has a large specific surface area, but is not particularly limited, and in practice it is suitable to select one that is non-toxic, inexpensive, and easy to handle. The amount of silver immobilized on the carrier is suitably about 0.1 to 50% by weight. If the amount is too small, sufficient effect will not be obtained, and if it is too large, the ethylene removal effect will not be improved.

Furthermore, although the temperature at which the ethylene removing agent of the present invention is used is preferably low, it exhibits sufficient effects at temperatures ranging from 1°C to room temperature, which is the general storage temperature.

The ethylene removing agent of the present invention can be filled into a suitable container made of, for example, a bag made of breathable nonwoven fabric, paper, cloth, polyethylene, etc., or wire mesh, and placed in a packaging box or packaging for fruits, vegetables, or flowers. Accordingly, the freshness of fruits, vegetables, or flowers can be maintained. It is also possible to maintain the freshness of fruits and vegetables by storing them in a plastic packaging film made by mixing the present ethylene removing agent.

Furthermore, when maintaining the freshness of fruits and vegetables accumulated in a storage, ethylene in the storage can be removed even if a breathable container filled with the ethylene removing agent of the present invention is placed inside the storage. However, alternatively, one or more scrubbers filled with the ethylene removal agent of the present invention may be utilized to remove ethylene within the warehouse. FIG. 1 is a flow diagram of such an embodiment, in which the gas in the storage 1 is passed through the blower 2 to the ethylene removing agent 4 of the present invention.
The ethylene is removed by introducing the gas into a scrubber 3 filled with gas and returning the gas exiting the scrubber to the storage 1.

Prevents ethylene from accumulating inside the refrigerator. In this case, the ethylene removal ability of the scrubber decreases over time by passing the gas inside the refrigerator, but this decrease in ability can be prevented by heating the ethylene removal agent of the present invention to about 100° C. in the chamber 21i1 or It can be recovered by circulating air as shown in the figure.

The ethylene removing agent of the present invention can be used in combination with conventionally known oxygen scavengers, carbon dioxide regulators, etc., if necessary, thereby further improving the freshness retention effect.

[Function] The ethylene removing agent of the present invention, in which silver is immobilized on a porous carrier, is generated from fruits, vegetables, and flowers.

The ability to remove ethylene, which causes aging of these materials, is significantly superior to that of a carrier alone. In addition, since this remover utilizes weak complex formation between a silver compound and ethylene, it can be easily regenerated by raising the temperature slightly or exposing it to air, so it has the characteristic of being able to be used repeatedly. have.

[Examples] Activated carbon, activated alumina, bentonite, and acid clay as carriers were each immersed in a 5% silver nitrate aqueous solution, filtered, and dried at 50 to 120°C.

0.5 g of the ethylene removing agent of the present invention thus obtained was
00- in a glass container, and add ethylene 50 to this container.
Air containing 0 ppm was injected and maintained at room temperature, and changes in ethylene concentration over time were analyzed using gas chromatography. Table 1 shows the ethylene concentration after 1 hour when the ethylene concentration became almost stable. Further, after the test was completed, the ethylene removing agent was regenerated by heating to 80° C., and then the test was conducted in the same manner. The results of repeating this procedure five times are shown in Table 1. For comparison, Table 1 also shows the results for the carrier without silver nitrate and for the carrier only.

Table 1 [Effects of the Invention] Ethylene removing agents containing potassium permanganate, which have been conventionally used to maintain the freshness of fruits and vegetables, require a carrier to carry a large amount of harmful potassium permanganate;
Potassium permanganate is consumed by reaction with ethylene and cannot be reused; however, the ethylene removing agent of the present invention is not consumed by contact with ethylene. The ethylene removing agent of the present invention gradually loses its ethylene removing ability when it comes into contact with ethylene, but it easily recovers its ethylene removing ability by slight heating. Furthermore, it easily recovers its ethylene removal ability even if it is left in the air or placed under gas flow. Therefore, the ethylene removing agent of the present invention can be used repeatedly. Furthermore, since the ethylene removal agent of the present invention does not utilize the ethylene adsorption ability of the porous material used in the carrier, the ethylene removal effect will not decrease even when used in high humidity conditions. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram when the method of the present invention is applied to a fruit and vegetable storage. 1...Storage 2,5...Blower 3...Scrubber 4...Ethylene removal side floor Patent applicant Sumitomo Heavy Industries, Ltd. Procedural amendment --- July 8, 1963 2, Invention Name of Freshness Preservation Method for Fruits, Vegetables, and Flowers 3, Person Who Makes Corrections

Claims (1)

[Scope of Claims] 1. A method for preserving the freshness of fruits, vegetables, and flowers, which comprises removing ethylene generated from the fruits, vegetables, and flowers using an ethylene removing agent in which silver is immobilized on a porous carrier. 2. The method according to claim 1, characterized in that the ethylene removing agent is contained in a breathable container, and the fruit, vegetables, or flowers are hermetically packaged together with the container. 3. The method according to claim 1, characterized in that the method is packaged with a plastic film mixed with the ethylene removing agent. 4. The method according to claim 1, characterized in that the gas in the refrigerator for storing fruits, vegetables, or flowers is passed through the bed filled with the ethylene removing agent.