JP2804999B2 - How to remove astringent persimmon from ethyl alcohol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing astringent persimmons with ethyl alcohol.

[0002]

BACKGROUND OF THE INVENTION It is said that the astringency of persimmons is based on sibuol in tannin cells present in tissues, and if this is soluble in water in the fruit, a person feels astringency with his tongue. Therefore, a method of artificially promoting the production of acetaldehyde and the like, reacting with a soluble astringent substance to make it insoluble, and removing the astringency of astringent persimmon (removing astringency) has been performed. One of the main methods of this astringent removal method is an astringent removal method using ethyl alcohol. In the deaeration method using ethyl alcohol, persimmons are placed in a simple airtight container such as a keg or a low-density polyethylene bag with a thickness of 50 μm, and a 40% aqueous solution of ethyl alcohol is sprayed inside, or ethyl alcohol is absorbed into absorbent cotton or the like. This is performed by enclosing the absorbed material. Persimmons that have been astringently removed by ethyl alcohol are shipped to the market as "Kokesa persimmons" and have a unique flavor, which is favored by many people.

In order to remove the astringency of astringent persimmon with ethyl alcohol, commercially available bags of low-density polyethylene film having a thickness of about 50 μm, or composite cardboard cases obtained by laminating a low-density polyethylene film having a thickness of about 15 μm on a cardboard case are commercially available. It is used as a container. Conventionally, low-density polyethylene has been used because it is easily available, and it can be expected to retain alcohol vapor. However, in the conventional method of removing astringent using a low-density polyethylene film, "contaminated fruit" in which a part of the persimmon fruit surface turns black has occurred, which has been a great barrier to commercial astringent removal. Therefore, in order to suppress the occurrence of contamination, a water-absorbing sheet, a water-absorbing mat, and the like have been used in combination, but in reality, they have not exerted a sufficient effect.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned difficulties in the conventional method for removing astringent persimmon with ethyl alcohol. In other words, it is intended to prevent the occurrence of "contaminated fruit" which is observed in the conventional method of removing astringent persimmon with ethyl alcohol, and to prevent the deterioration of persimmon quality after removing the astringent.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide a container having an appropriate moisture permeability and an appropriate property of blocking ethyl alcohol gas, that is, a moisture permeability of 35 g / m ² · 24 h or more and 500 g / m ² · 24 h or less. The problem is solved by using a plastic container having an ethyl alcohol permeability of 500 ml / m ² · 24 h or less for the deaeration treatment.

[0006]

The present invention relates to a method for removing astringent persimmons with ethyl alcohol by changing the environmental conditions such as the temperature and humidity in the container or the container materials during the removal of astringent persimmons. As a result of intensive examination of the relationship with the occurrence of, the blackening of the pericarp during deaeration is likely to occur due to excessive humidity or condensation in the container, and excessive humidity in the container or condensation in the container, It has been found that this can be prevented by using a packaging container having high moisture permeability.

That is, excessive humidity and dew condensation in the container are suppressed by appropriate permeation of water vapor, and the occurrence of "contaminated fruit" is suppressed, thereby satisfactorily removing the astringency.

Further studies have revealed that even in these containers having high moisture permeability, if the permeability of ethyl alcohol gas is high, the removal of astringent persimmon does not proceed well.

Therefore, as a result of further study on various containers, it was found that the moisture permeability was 35 g / m ² · 24 h or more and 500 g / m ² ·
By using a plastic container having an ethyl alcohol gas permeability of not more than 24 hours and an ethyl alcohol gas permeability of not more than 1,500 ml / m ² · 24 hours, it is possible to prevent the occurrence of “contaminated fruits” and to be able to remove the astringent persimmon satisfactorily. I found it. Further, when the same plastic is combined with a highly rigid cardboard case, it was found that the plastic can be applied in the form of a thin film, and the use thereof is further facilitated, and the present invention has been completed.

[0010] The container used in the present invention is required to have a moisture permeability and an ethyl alcohol permeability each within the above specific ranges. At this time, the moisture permeability is 35 g / m ² · 24 h
If the temperature does not reach, the dew condensation is liable to occur, and the humidity becomes too high, and contaminated fruits are generated. Conversely, 500g / m ² · 24
When it is larger than h, no dew condensation occurs, but the fruit is withered and the quality is deteriorated, which is not preferable as a degassing container. In particular, a preferable range of the moisture permeability is more than 250 g / m ² · 24 h and 500 g / m ² · 24 h or less.

In addition, the permeability of ethyl alcohol is 1500 ml.
/ M is more than ² · 24h and tend to de-astringency is incomplete, particularly preferred range is 10 ml / m ² · 24h or more 15
00 ml / m ² · 24 h or less.

In the present invention, the above-mentioned moisture permeability and ethyl alcohol permeability are determined in principle by the type of plastic and its thickness, and the thickness is adjusted so long as the plastic has the above range of permeability. , Various plastics can be used. In the case of compounding with a corrugated cardboard case, the thickness of plastic that can be used as a packaging container can be expanded to a thinner range, and handling can be simplified.

Among the types of plastics, plastics having at least one hydrophilic group such as an alcoholic hydroxyl group, a carboxyl group, an amino group, or an amide group in the molecular structure, or plastics having an ether or ester bond in the trunk polymer are preferable. For example, polyvinyl alcohol, acetalized polyvinyl alcohol, ethylene-vinyl alcohol copolymer resin, modified polyacrylic acid resin, polyamide resin, cellulose derivative resin, polyacrylamide resin,
Examples include a polyethylene glycol resin, a polyacetal resin, an aliphatic polyester resin, and a polyvinylpyridine resin. Particularly, those having an alcoholic hydroxyl group are excellent in moisture permeability and ethyl alcohol gas barrier properties. More preferably, polyvinyl alcohol has a degree of saponification of usually about 90 to 100%, and acetalized polyvinyl alcohol has a degree of acetalization of 30%.
The ethylene-vinyl alcohol copolymer resin has an ethylene content of about 30 to 50%. As the cellulose derivative resin, acetylated cellulose, cellulose nitrate, acetalized cellulose and the like are preferable.

As a container for removing astringent persimmons, basically, any of these moisture-permeable plastic containers can be used. For example, a bag, a molded container, a film bag, or a wrap of a film or sheet is used. Packaging and the like. At this time, the thickness of the container wall and the thickness of the film are not particularly limited as long as the above two specific physical properties are satisfied.

However, when these plastics are formed into a film and laminated on a cardboard case having high rigidity, the plastics can be used without giving much consideration to the strength of the plastics. Within this range, the film can be used in the thinnest film thickness, and the strength required as a transport container can be replaced with a cheap cardboard case, so that the cost as a container can be reduced.

By combining the cardboard case with the cardboard case itself rather than using the cardboard case and the plastic film bag together, operations such as box packing are further simplified, and handling during distribution becomes easier. In addition, the advantage of being able to remove the astringent during transportation is maximized.

Although there is no particular limitation on the method of laminating the film on the cardboard case, it is economical to perform lamination at the stage of the base paper before processing into the cardboard sheet. The lamination can be performed by directly coating the resin film by melting the resin film. When an adhesive is used, the so-called wet laminating or non-wetting using an aqueous emulsion resin adhesive can be performed from the viewpoint of taking advantage of the properties of the container. A so-called dry lamination using a water-based resin solution adhesive is preferred. When a molten resin is used as an adhesive, existing techniques such as minimizing the amount of use and performing partial bonding can be applied in order to secure the characteristics of the container.

The form of the composite cardboard case is JIS
The most common 0201 specified in -Z-1507
Basically, it can be appropriately selected from basically any form such as a mold, a mold easily sealed such as a 0206 type, a 0212 type, a 0303 type, a 0309 type, or a box assembled from a single uncorrugated cardboard sheet. . This embodiment has excellent advantages as a mass transport container.

In the present invention, the operation procedure for removing the astringent by using the container of the present invention is not different from the conventional procedure at all, and after spraying with ethyl alcohol and sealing, it is sealed at room temperature (about 20 ° C.).
It is good to leave it for about a day.

[0020]

[Experimental Examples] The present invention will be described below with reference to experimental examples.

[0021]

EXPERIMENTAL EXAMPLE 1 14 μm thick polyvinyl alcohol (PV
A, saponification degree: 98.5%) film, 12 μm thick biaxially stretched PVA (BOPVA) film, 20 μm thick acetalized PVA (APVA) film (acetalization degree: 40%), 15 μm thick ethylene-vinyl alcohol Copolymer (EVOH) film (ethylene: 32%),
20 μm thick EVOH film (ethylene: 44%),
15 μm thick biaxially stretched EVOH (BOEVOH) film, 15 μm thick low density (density: 0.915) polyethylene (LDPE), 30 μm thick LDPE film,
Table 1 shows the moisture permeability and gas permeability of 10 types of a 5 μm-thick ethylene-vinyl acetate copolymer (EVAc) film (ethylene: 83%) and a 30 μm-thick butadiene rubber (BR) film. However, the moisture permeability in Table 1 is JI
The value is based on S-Z0208 (40 ° C., 90% RH).

Table 2 shows the persimmon fruits and the like and the ethyl alcohol gas permeability of the films when the astringent persimmons were astringently removed (at 20 ° C. for 7 days) using these film bags.

The ethyl alcohol gas permeability is determined by measuring the concentration of ethyl alcohol in the bag after 24 hours at 20 ° C. by filling a bag with a fixed amount of ethyl alcohol and air into the bag with the above film. Was measured by gas chromatography, and the ethyl alcohol gas permeability was calculated.

[0024]

[Table 1]

[0025]

[Table 2]

The evaluation of the occurrence of contaminated fruits and the removal of astringency in Table 2 were based on the following criteria.

<Evaluation Criteria for Occurrence of Stained Fruit> 0: No occurrence 1: Occurrence is observed, but there is merchantability 2: Occurrence is conspicuous and the grade is deteriorated 3: Occurrence is remarkable and there is no merchantability

<Evaluation Criteria for Removal of Astringency> 1: No removal of astringency 2: Evidence of a little removal of astringency 3: Slightly removal of astringency but not endurable for edible 4: Almost removal of astringency but removal of astringency The taste remains 5: Complete astringency

[0029]

Experimental Example 2 Biaxially stretched PVA (BOPV) having a thickness of 12 μm
A) 0201 type film laminated corrugated cardboard case with film wet-laminated on the back liner surface, 1
Using a 0201-type film-laminated corrugated cardboard case and a 0201-type normal corrugated cardboard case in which an LDPE film with a thickness of 5 μm is laminated between the back liner layers, the state of persimmon fruit, etc., when the persimmon persimmon is removed (at 20 ° C. for 7 days) Are shown in Table 3.

Further, the period during which the ethyl alcohol concentration was maintained in the case was measured. A water-absorbing paper impregnated with a fixed amount of ethyl alcohol was fixed to the ground inside the case, and a tape H shape was attached and sealed. Table 4 shows the ethyl alcohol concentration in the case when this was allowed to stand. Here, the inner size of the cardboard case was 385 × 308 × 187 mm.

[0031]

[Table 3]

The evaluation in Table 3 was based on the same criteria as in Table 2.

[0033]

[Table 4]

[0034]

According to the method of the present invention, astringent persimmon can be astringently removed with ethyl alcohol, and is very useful in the distribution process.

Claims (3)

(57) [Claims] 1. A plastic container having a moisture permeability of 35 g / m ² · 24 h or more and 500 g / m ² · 24 h or less and an ethyl alcohol gas permeability of 1,500 ml / m ² · 24 h or less is charged with ethyl alcohol. A method for removing astringent persimmons, which is put together with it and subjected to astringent removal processing. 2. The method for removing astringent persimmons according to claim 1, wherein the container is a composite cardboard case obtained by laminating the plastic film. 3. The method for removing astringent persimmons according to claim 1, wherein the plastic has a hydrophilic group in its molecular structure.