JPH04126035A - Preservation of freshness and freshness preserving composition used therefor - Google Patents

Abstract

PURPOSE:To suppress respiration action of fruits, vegetables or flowering plants and to prevent molds from occurring by dissolving a hinokitiol in a carbon dioxide gas used for controlled atmosphere preservation method which is a preservation method of freshness of fruits, vegetables or flowering plants and using. CONSTITUTION:In preserving fruits, vegetables or flowering plants in an atmosphere containing a carbon dioxide gas, preservation is carried out in an atmosphere containing 50-500mg/m<3> of a hinokitiol. The same effects can be obtained by preserving in an atmosphere containing 2.5-25g/m<3> purified oil of plant prepared from a plant of the family Cupressaceae of needle-leaf tree. A hinokitiol or the purified oil of plant obtained from a plant of the family Cupressaceae of needle-leaf tree is dissolved in a liquefied carbon dioxide gas and used for controlled atmosphere preservation. The concentrations of the hinokitiol and the purified oil of plant obtained from a plant of the family Cupressaceae of needle-leaf tree in a liquefied carbon dioxide gas are 0.01-0.25% and 0.5-7%, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for preserving the freshness of fruits, vegetables, flowers, etc., and a composition for preserving freshness used therein.

More specifically, fruits, vegetables, flowers, etc. are stored in a carbon dioxide atmosphere containing hinokitiols and/or plant essential oils obtained from coniferous plants of the Cupressaceae family. The present invention relates to a method for preserving the freshness of fruits, vegetables, flowers, etc., which also prevents the growth of microorganisms such as bacteria (hereinafter simply referred to as mold), and a freshness-keeping composition used therein.

[Prior art/problems to be solved by the invention] Conventionally, as a method for preserving the freshness of harvested fruits, vegetables, and flowers, CA (Control
LED Atmosphere) storage methods are known. This method maintains the inside of the storage room at a low temperature, high humidity, high carbon dioxide concentration, and low oxygen concentration when storing fruits, vegetables, flowers, etc., suppresses the respiration of the fruits, vegetables, and flowers, and prolongs their freshness. It is something that holds over time. The present inventors have proposed a freshness-keeping container suitable for transporting vegetables, fruits, flowers, and other products using this method, and have filed a patent application (Japanese Patent Application No. 2-163530).

C as a method for preserving the freshness of fruits, vegetables, flowers, etc.
Although storage method A is an excellent method, it is not sufficient to prevent mold from forming if storage is for a long period of time.

Therefore, the best way to maintain freshness is to take sufficient measures to prevent the growth of mold.

Although the conditions for mold growth vary depending on the type of mold, there are generally four factors: (1) temperature, (2) humidity (moisture), (2) nutrient sources, and (2) oxygen. Of these, with regard to oxygen, mold can be sufficiently grown even in a very small amount. As for the nutrient source, the stored food itself can be the nutrient source. Regarding moisture, it is not preferable to eliminate it due to the nature of the stored material. It is also important to keep the temperature low.
Perhaps it is a characteristic of the storage method, but lowering the temperature more than necessary is not preferable because it may have a negative effect on some stored items.

For example, in the case of tropical fruits,
Storage is usually carried out at 8 to 15°C, since temperatures below 8°C cause low temperature damage.

It is difficult to prevent the growth of mold at this low temperature. In this way, it is extremely difficult to suppress the growth of mold based solely on environmental conditions.

Therefore, in the CA storage method, in order to prevent the growth of mold, a method using a fungicide is generally practiced.

However, in the case of stored products or foods, it is naturally required that the fungicide used be safe.

BACKGROUND ART Plant essential oils obtained from needle-leaved, cross-grained plants of the Cupressaceae family and hinokitiols contained in the plant essential oils are known as one of the fungicides that are safe for use in foods. In other words, the so-called "hiba oil" obtained by steam distilling the wood of plants belonging to the cypress family, for example, hinokitiol and β-drapurin (both of which are referred to as hinokitiols), is contained in approximately These ingredients have antimicrobial effects, and various patents and applications have been filed focusing on their effectiveness (Japanese Patent Application Laid-Open No. 2-10861).
No. 0, Japanese Patent Application Publication No. 2-62809).

In other words, hinokitiols contained in plant essential oils obtained from plants of the cypress family are: (1) natural products and safe;

■ It has strong antibacterial and antifungal effects.

■ It has the effect of inhibiting the growth of hyphae on mushrooms.

■ It has a repellent effect against earth.

It not only has excellent properties as a fungicidal, antibacterial, and insect repellent agent, but also has an anti-ethylene production effect on fruits and vegetables, making it the best antifungal agent for preserving the freshness of food.

Examples of the use of hinokitiol to prevent mold, bacteria, and insects on vegetables, fruits, etc. include JP-A-60-108359 and an improved version of JP-A-1-153601. In the methods described in these documents, a tape or sheet containing hinokitiol is attached to the inner bottom surface, inner surface, etc. of a packaging container to obtain antifungal, antibacterial, and insecticidal effects. However, even if we try to apply this method to the CA storage method, the reality is that the environmental temperature in the CA storage method is often relatively low, and the volatilization of hinokitiol, an active ingredient, is small and sufficient effects cannot be obtained. It is.

[Means to solve the problem]

As a result of further intensive studies on freshness preservation methods using hinokitiol, the present inventors found that if hinokitiol is dissolved in carbon dioxide gas used in the CA storage method,
There is no concern about contamination caused by solvents, which is a problem when used dissolved in an organic solvent, and a gas environment containing hinokitiol at a relatively high concentration can be created even at low temperatures. The present invention was achieved by discovering that it is possible to have fungicidal, antibacterial, and insecticidal effects as well as suppression, and to maintain freshness in a more perfect state.

That is, the gist of the present invention is as follows: (1) A method for storing fruits, vegetables, flowers, etc. in an atmosphere containing carbon dioxide gas, in which hinokitiol is
~500■/rr1', or 2.5% of plant essential oil containing hinokitiol obtained from needle-leafed cypressaceae plants.
The present invention relates to a method for preserving the freshness of fruits, vegetables, flowers, etc., characterized in that the method is carried out in an atmosphere containing ~25 g/rn'', and (2) a composition for preserving freshness used in the method (1) above.

The hinokitiol in the present invention can be prepared by a conventional method from a plant essential oil obtained by steam distillation from a needle-leaved, cross-grained plant of the Cupressaceae family.

For example, hinokitiols can be obtained by treating an acidic oil obtained by treating a plant essential oil with Na0t (and H2SO4), followed by extraction and purification with n-hexane/chloroform or the like.

The vegetable oil obtained from the needle-leaved cross-grained Cupressaceae plant used in the present invention contains a tropolone-based compound such as hinokitiol or β-drapurin as an active ingredient. β-Drapurine is easily converted to hinokitiol by hydrogenation, and its antibacterial properties are known to be equivalent to hinokitiol, and it is usually used without being separated.

Here, the needle-leafed plants of the Cypress family are not particularly limited; examples include Asunaro of the genus Asunaro, Cypress asunaro (Aomori hiba), Ibuki and Hibari of the genus Musashi, and Arborvitae of the genus Arborvitae (Aomori Hiba). Western red sheave, Japanese cypress of the genus Jescens cedar, and Formosan cypress of the genus Cypress. Among them, Aomori Hiba (Hinoki Asunaro), also known as Aomori Hiba, is preferably used because it has a high content of hinokitiol.

Plant essential oils can also be obtained by extraction from these wood chips and from wood sawdust by steam distillation or by using fluids in a subcritical or supercritical state.

In the present invention, hinokitiols or plant essential oils obtained from needle-leafed plants of the Cupressaceae family are dissolved in carbon dioxide gas.
A: Used for storage.

The method for dissolving hinokitiols or plant essential oils in carbon dioxide gas is not particularly limited, and usually involves placing a predetermined amount of hinokitiols or plant essential oils in a cylinder.
It can be easily prepared by filling liquefied carbonic acid and shaking thoroughly to homogenize the inside.

Hinokitiol and β-dorapurine are normally found in the environment (
If present in an amount of 50 to 500 mg/m3 (as gas or mist), preferably 100 to 200 ml/rr1', its antifungal, antibacterial, and insecticidal effects will be exhibited. Furthermore, when using plant essential oils, the content of hinokitiol and β-drapurin in the plant essential oil is usually about 1% each, so the content of the plant essential oil in the environment is usually 2.5 to 25 g/r.
n', preferably 5 to Iog/m1'.

If the amount is less than 2.5 g/rn', the antifungal, antibacterial, and insect repellent effects will not be sufficient, and if the amount is more than 25 g/rn', there will be no commensurate effect, so it is not a good idea.

The content of hinokitiol or plant essential oil in the liquefied carbon dioxide gas can be adjusted to any desired concentration as long as it is below its solubility. Usually, the content of hinokitiols in liquefied carbon dioxide gas is preferably 0.01 to 0.25%, and in the case of vegetable essential oils, the concentration is preferably 0.5 to 7%.

Furthermore, in the present invention, hinokitiols and plant essential oils may be used in combination. In this case, the total amount of hinokitiol contained in the plant essential oil and hinokitiol as a purified product may be adjusted as appropriate so that the content of hinokitiol is substantially the same as described above.

The thus obtained liquefied carbon dioxide containing hinokitiol and/or plant essential oil is used in the same manner as normally used for CA storage.

〔Example〕

The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A plant essential oil obtained by steam distilling the wood of Cypress japonica was treated with NaOH and H2SO in a conventional manner to obtain an acidic oil (containing about 20% hinokitiol + β-drapurin), and then treated with phosphoric acid. The crude crystals of hinokitiol were obtained by treatment with n-hexane/chloroform.

2.5 g of the obtained crude crystals of hinokitiol were placed in a small cylinder, filled with 2.5 kg of liquefied carbonic acid, and thoroughly shaken to make the inside a homogeneous liquid, thereby preparing liquefied carbon dioxide gas containing hinokitiol.

Example 2 A plant containing plant essential oil was prepared in the same manner as in Example 1, except that 125 g of plant essential oil obtained by steam distilling the wood of the Japanese hinokitiol was used instead of the crude crystals of hinokitiol in Example 1. Liquefied carbon dioxide gas was prepared.

Example 3 Five Okinawa mangoes of generally uniform size and ripeness were placed in three glass desiccators.

The gas environment inside the glass desiccator was adjusted as follows.

NαI: The lid of the desiccator was removed and the air was made to be the same as the outside air.

Nα2: A standard gas consisting of 025% and 95% N2 and carbon dioxide gas were introduced into the desiccator at a flow rate ratio of 95:5 until the gas environment inside the desiccator became constant, and the desiccator was sealed.

k3: In the Nα2 desiccator, the gas environment was adjusted in the same manner as in 2 except that the liquefied carbon dioxide gas containing hinokitiol prepared in Example 1 was used instead of carbon dioxide gas,
Sealed.

(The concentration of hinokitiol in the desiccator is 98■/m?
) The above three desiccators were placed in a storage at a temperature of 15° C., and changes over time on the surface of the mangoes in the desiccators were observed. The results are shown in Table-1.

Table 1 Example 4 In Example 3, instead of the liquefied carbon dioxide gas containing hinokitiol, the liquefied carbon dioxide gas containing plant essential oil obtained in Example 2 was used, and the NcL3 desiccator white concentration was 4.9 g/rn'
The gas environment inside the desiccator was adjusted in the same manner as in Example 3, except that the change in the surface of the mango over time was observed. The results were similar to Example 3.

Example 5 The liquefied carbon dioxide containing hinokitiol prepared in Example 1 was poured into a 300 g strawberry (onnaho) pack so that the carbon dioxide concentration was 10%.The concentration of hinokitiol was 196/rrl'. ) and left in a storage at 20°C.

After this treatment, the appearance did not change even after 3 days from when it was collected.

〔Effect of the invention〕

By carrying out the present invention, in addition to the respiratory inhibitory effect and anti-ethylene production effect caused by the carbon dioxide environment in conventional CA storage methods, the antifungal effect of hinokitiols and/or plant essential oils obtained from coniferous plants of the Cupressaceae family can be achieved. It is also possible to have both. Therefore, the freshness of fruits, vegetables, flowers, etc. can be maintained in a more perfect state.

Claims (7)

[Claims] (1) In a method for storing fruits, vegetables, flowers, etc. in an atmosphere containing carbon dioxide gas, hinokitiol is added at 50 to 50%
A method for maintaining the freshness of fruits, vegetables, flowers, etc., characterized in that the method is carried out in an atmosphere containing 00 mg/m^3. (2) In a method of storing fruits, vegetables, flowers, etc. in an atmosphere containing carbon dioxide gas, a plant essential oil containing hinokitiol obtained from a coniferous plant of the Cupressaceae family is added at a concentration of 2.5 to 25%.
A method for preserving the freshness of fruits, vegetables, flowers, etc., characterized in that the method is carried out in an atmosphere containing g/m^3. (3) The method according to claim (2), wherein the plant of the order Coniferaceae belongs to the genus Asunaro of the family Cupressaceae. (4) hinokitiol and/or a plant essential oil containing hinokitiol obtained from a coniferous plant of the Cupressaceae family;
and a freshness-preserving composition containing liquefied carbon dioxide. (5) The freshness-preserving composition according to claim 4, wherein the plant of the order Coniferaceae belongs to the genus Asunaro of the family Cupressaceae. (6) The freshness-keeping composition according to claim (4), wherein the concentration of hinokitiol in the liquefied carbon dioxide gas is 0.01 to 0.25%. (7) The freshness-preserving composition according to claim (4), wherein the concentration of the plant essential oil obtained from the coniferous Cupressaceae plant in the liquefied carbon dioxide gas is 0.5 to 7%.