JPS60248130A - Method for removing astringency from astringent persimmon - Google Patents

Abstract

PURPOSE:To remove the astringency with an alcohol in an amount about half that in the conventional method, by placing a specific laminated material impregnated with an alcohol on the topmost layer of astringent persimmons piled in a corrugated box in layers. CONSTITUTION:A laminated material for impregnating an alcohol is constituted of a porous base material layer/modified polyvinyl alcohol layer/liquid-impermeable layer, e.g. a laminated material of a nonwoven fabric or pulp and kraft paper as the porous base material, saponified monomethyl maleate-vinyl acetate copolymer as the modified polyvinyl alcohol layer and polyethylene film as the liquid-impermeable layer. The laminated material is placed to face the liquid-impermeable layer to the side of the astringent persimmons without fail. Preferably, the corrugated box for putting persimmons therein is constituted of kraft paper/polyethylene film/corrugated board from the inside.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for removing astringency from astringent persimmons, and its purpose is to remove astringency from astringent persimmons more efficiently and easily using less alcohol. It also prevents persimmons from softening, rotting and developing black spots.

(Prior Art) Various proposals have been made to remove astringency from astringent persimmons, but generally a method of treating astringent persimmons with a lower alcohol such as ethanol has been adopted.

In Hyogo, astringent persimmons are stacked in several tiers in a container such as a tiered pole, and ethanol or ethanol aqueous solution is sprayed on top.
Once the container is sealed, the astringency will progress during transportation, and the astringency will have been removed by the time the product reaches the point of consumption. However, with this method, problems such as the appearance of brown or black spots on the surface of persimmons, which are not clearly known, and which significantly reduce the commercial value of persimmons, or the persimmons becoming too soft, occur, and it is difficult to adjust the alcohol treatment conditions. The problem is that it is extremely difficult. As a countermeasure against this problem, there has been a proposal (Japanese Patent Application Laid-Open No. 55-50850) of placing a breathable cushioning material on top of a soft porous material impregnated with alcohol and having ventilation holes, and arranging persimmons on top of the material and storing the persimmons in a container. , a proposal to store a water-absorbing and water-retaining sheet that absorbs and retains alcoholic water in a storage container together with astringent persimmons (Japanese Patent Laid-Open No. 58-15
B559'I has been made.

(Problem to be solved by the invention) However, according to the inventor's follow-up test, JP-A No. 1185
5-50850 can prevent persimmons from softening, but
The occurrence of black spots is unavoidable, JP 58-13853
Even in JP-A-55-50850, the problem has been revised much more in JP-A-55-50850, but the occurrence of black spots is still observed, and a complete solution has not been reached. In response to the occurrence of such black spots, the applicant proposed placing a porous material impregnated with coal. However, further experiments conducted by the present inventors revealed that even with this method, it was not possible to remove astringency unless the amount of alcohol used was relatively large, and furthermore, depending on the conditions, black spots could be removed even with this method. It turns out that this can occur.

The amount of alcohol used is closely related not only to the problem of black spots, but also to the effect of removing astringency and the time required for complete removal of astringency, and although various companies have reported this in the past, In practical terms, K requires 10 days to 2 weeks to completely remove astringency. In addition, when such a large amount of alcohol is used, there is a difficulty in controlling the period for removing astringency, that is, when the astringency is removed during transport from the place of production to the destination. This is a problem that must be resolved as soon as possible. (Means for solving the problem) However, the present inventor has developed a method that can sufficiently remove astringency in a shorter period of time even with a smaller amount of alcohol, and eliminates the problems of softening and black spots. As a result of intensive research on possible solutions, we focused on the structure of the container, which had not been considered in the past, and devised the structure and the sheet impregnated with alcohol.Thus, we solved the above problem. This discovery led to the completion of the present invention. That is, the present invention provides a method for removing astringency from astringent persimmons by placing an alcohol-impregnated sheet on the top layer of astringent persimmons stacked in a corrugated pole box. The structure of the alcohol-impregnated sheet is kraft paper/water-resistant film/corrugated cardboard, and the structure is porous base material layer/carboxyl group-modified polyvinyl alcohol thread resin (hereinafter simply abbreviated as modified PVA). layer/liquid impermeable layer or porous substrate layer/modified PVA layer/porous substrate layer/liquid impermeable layer, and a sheet having such a configuration is placed on the surface of the liquid impermeable layer. Of course, in the present invention, the configuration of the base material of the corrugated pole and the configuration of the sheet are basically as described above. It is within the scope of the present invention to optionally add one or more other layers to this.

The corrugated pole box and alcohol-impregnated sheet will be explained below.

The basic structure of the base material of a corrugated pole box is kraft paper/water-resistant film from the inside of the box.
Examples thereof include polyethylene film, polypropylene film, polyethylene terrestrial film, polyvinyl chloride film, polystyrene film, nylon film, etc., and polyethylene film is particularly preferably used. The water-resistant film prevents the alcohol gas for removing astringency from evaporating out of the container and promotes its absorption into the astringent persimmons, and it is essential that the film generated by the persimmons' breathing be inside the cardboard. On the other hand, the purpose of the kraft paper is to appropriately absorb the moisture caused by the persimmon's breathing and prevent water droplets from forming on the water-resistant film. Required.

The basic composition of the sheet impregnated with alcohol is either porous base material layer/modified PVA layer/liquid impermeable layer, or porous base material layer/modified PVA layer/porous base material layer/liquid impermeable layer. Must be a transparent layer.

Both the porous substrate layer and the modified PVA layer must be made of a material that can temporarily impregnate a lower alcohol and allow the lower alcohol to evaporate under normal temperature and pressure conditions. The reason why this modified PVA is used separately from other general porous substrates is that when this modified PVA is used, the diffusion (evaporation) rate of alcohol within the box is most appropriate. Such modification P
It is about VA level, and its manufacturing method is typically L1 using unsaturated monomers containing carboxyl groups, such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, monoalkyl maleate, and fumaric acid. , a method of copolymerizing monoalkyl fumarate, icconic acid, monoalkyl itaconate with vinyl acetate and saponification, or a method of post-reacting or grafting a carboxyl group to general polyvinyl alcohol using an appropriate method. Among these, monoalkyl maleate2.
A copolymer of 0 to 10.0 mol % and 98.0 to 90.0 mol % of vinyl acetate, which is oxidized to about 92.0 to 99.9 mol %, exhibits the most preferable performance.

Usually, it is more efficient to use the modified PVA after heat treatment (approximately 130 to 150° C. for 60 to 180 minutes) or post-treatment such as radiation or electron beam irradiation.

Porous base material layers include natural fibers, synthetic fibers, pulp and nonwoven fabrics made from these, crepe paper, plastic foams such as polyethylene, polystyrene, and polycrethane, starch, cellulose, polyacrylic acid, and polyacrylic. Any conventionally known super absorbent resins such as crosslinked acid salts, acrylic acid graft copolymer sites, etc. can be arbitrarily combined.
The liquid-impermeable layer in the present invention, which can be used in combination of two or more layers, is intended to prevent the alcohol impregnated into a porous substance from coming into direct contact with the surface of the persimmon, so the general Vc/ fi thickness 20~200
μ polyethylene, polypropylene, polyvinyl chloride,
Plastic films such as polyester and polyvinyl alcohol are used, but paper, woven fabric, non-woven fabric, etc. that have been further treated with resin or oil can also be used.

Therefore, it is desirable that the sheets composed of the porous base material layer, the modified PVA layer, and the liquid impermeable layer are laminated so that the cross-sectional area is slightly smaller than that of the cardboard box. The shape of the porous base material layer and modified PVA layer may be in the form of particles, lumps, strings, etc. other than sheet-like, and may be dispersed on the flexible base material layer or on the liquid-impermeable layer, or dispersed and swollen in water or alcoholic water. The layer may be formed by coating the powder after the resin is mixed or dispersed in a resin binder in order to fix the powder on the layer. Known binders such as FipvA1 polyamide resin and phrethane resin can be used.The thus laminated sheet can be made easier to handle if the outer envelope is fixed by heat sealing or the like, if necessary. The most practical representative example of such a sheet structure is a laminate of a nonwoven fabric made of pulp and kraft paper as a porous base layer, and a layer of monomethyl inoate-vinyl acetate copolymer as a modified PVA layer. The most preferred example is a sheet made of polyethylene film as the compound/the same porous substrate layer/liquid impermeable layer. Note that a skin contact agent may be used between each layer, if necessary.

In the present invention, the purpose can be achieved with a much smaller amount of alcohol than in the past, so there is no particular need for porous inorganic fine powder, which is normally used to increase the absorption of liquid, but if necessary, it may be used in each layer. Subacid lucicum, silicate lucicum, etc. may be added to the hydroxide.

The sheet obtained in this way) 11. The sheet must be placed so that the side of the liquid-impermeable layer is the side of the stacked astringent persimmons. Even if you place the sheet on the astringent persimmon side or place a sheet on the middle or lower part, it is not possible to prevent the occurrence of black spots.
Furthermore, similar results are obtained when a liquid-impermeable layer is not used in the sheet structure. Incidentally, a cushioning material such as a fruit net is appropriately used between the sheet and the astringent persimmon or between the persimmons.

As the alcohol with which the sheet is impregnated, lower alcohols, particularly ethyl alcohol, are preferably used, and these are used as aqueous solutions with a volume concentration of 18 to 45%.

The amount of the aqueous solution used is (vertical 60-1 horizontal 67118
．． A sufficient effect can be obtained by stacking persimmons in 4 rows and 5 rows (50 to 100+r+t' (58 volumes of ethanol aqueous solution) in 4 stages with a height of 251 cm). Of course, it is also possible to use such mass-market alcohol. The sheet may be impregnated with the alcohol in advance and placed on the astringent persimmon, or the sheet may be placed on the Vi astringent persimmon and alcohol is sprayed onto it. Also good.

After the astringent persimmons and sheets are stored in the cardboard box, it is only necessary to seal the box to the extent that alcohol vapor does not easily escape to the outside, and it is not necessary to completely seal the box.

(Effects of the invention) By using the method described above, not only can astringency be completely removed in a short period of time using about half the amount of alcohol used in the conventional method, but also prevention of softening and
The prevention of the occurrence of black spots can be very completely achieved, and the method of the present invention will be explained in more detail with reference to Examples below.

The following items are prepared as corrugated pole boxes and sheets, however, (
Actual) means a structure having the structure of the present invention, and (ratio) means a structure having a structure other than the present invention.

Cardboard box (actual): From the inside of the box, the base material is kraft paper (basis weight 50 y/rr?) / polyethylene film (thickness 15μ) / double-sided corrugated paper (basis weight 7602 layers)
Good luck, the size of the box is Length x Width x Height = 50m x 37c
s x 25 m Corrugated pole box (ratio): The size is the above corrugated pole box (!if the same sheet (protrusion) - 1 = porous base material layer 1 sheet of pulp material nonwoven fabric (60 ?Ar? per tsubo 1) and 7 sheets of crepe paper (basis weight 269/rl) are stacked as /modified PVA layer with carboxyl group-containing Jl 2.4 mol% male 40 f?/rr? (Resin solid content conversion) / Nonwoven fabric as porous base layer / Polyethylene film (thickness 100μ) as liquid impermeable layer
The outermost nonwoven fabric and polyethylene film are heat-sealed (height 26-width 34-inch).
．． -s, average thickness of about 0.5 side) Sheet (Real) -2: Sheet (Contains) -1 without using the nonwoven fabric between the modified PVA layer and the polyethylene film (Length 26em x
Width 34cm+.

(Average thickness: approx. 0.4 cm) Sheet (actual) - 6 = Sheet (actual) - 1 Modified PV
As layer A, a sheet (thickness 100μ) of a 98.5 mol% cyanide of monomethyl maleate-vinyl acetate copolymer with a carboxyl group content of 4 mol% was heat-treated at 30°C for 120 minutes and swelled in water. Same as the same sheet except that it was laminated in the same position.

Sheet (real) -4: 94 of slag in sheet (kyo) -1
．． Except that 1 mol% saponified material was humidified to a water content of 25.6% by weight and irradiated with an electron beam at 7.5 Mrads, and then fixed using a PVA binder so that the coating amount was 54 f/rII. Same on the same sheet.

Sheet (ratio)-1: Sheet (ratio)-1 without the polyethylene film layer Sheet (ratio)-2
: In sheet (container)-1, starch-acrylic acid graft copolymerization was used without using modified PVA.Examples 1 to 4: Pre-starting cardboard box (Astringent persimmons were placed in the cardboard box from the top of the cardboard box)
~ For the 6th layer, stack 6 layers with 4 rows vertically and 5 rows horizontally as one layer, and fill the bottom of the box, that is, the 4th layer from the top, with 5 rows vertically and 6 rows horizontally, 90 pieces in total, and put the astringent persimmons in the top layer. Place a sheet (1) on top so that the liquid-impermeable layer side is on the astringent persimmon side.
4 was placed on the P sheet, and the concentration of ethyl alcohol water 1 to 4 was 3814% by volume.

The results are shown in Table 1. Comparative Examples 1 to 4 A corrugated pole box was used as the container, but sheet (ratio) -1 was used as the sheet (comparative example 1), sheet (ratio) -1 was used as the sheet, )-2 (comparative example 2), sheet (actual)
-1 placed with the porous base layer side facing the astringent persimmon (Comparative Example 5), sheet (center) -1 placed with the liquid impermeable layer side down and the second tier. An experiment similar to that in the example was conducted on the persimmons placed between the persimmons in the 6th row and the persimmons in the 6th row (Comparative Example 4), and the degree of astringency removal and the occurrence of black spots were investigated.

The results are shown in Table 2.

Comparative Example 5.6 A similar investigation was conducted using a cardboard box (ratio) as the corrugated pole box and sheets (actual) -1 and 2 (liquid impermeable paper was placed next to the persimmons). Ta.

Table 1! ! J2 Table ★ Same procedural amendment as in Table 1 April 9, 1932 () Manabu Shiga, Director General of the Patent Office 1, Indication of the case 1982 Patent Application No. 104982 2, Relationship with the title of the invention case Patent Applicant 4 amends "20" in column 5 of the detailed description of the invention in the specification to be amended, page 9, line 8 of the specification of contents of the amendment, to read "2.OJ."

that's all

Claims (1)

[Claims] In a method for removing astringency from astringent persimmons by placing an alcohol-impregnated sheet on the top layer of astringent persimmons stacked in a cardboard box, the structure of the base material of the cardboard box is different from that of the box. From the inside, the sheets are composed of kraft paper/water-resistant film/cardboard, and (2) the structure of the alcohol-impregnated sheet is a porous base material layer/carboxyl group-modified polyvinyl alcohol resin layer/liquid-stopping non-persistent layer. or porous substrate layer/
Carboxyl group-modified polyvinyl alcohol resin & Jl
A method for removing astringency from astringent persimmons, which comprises: /porous base material layer/liquid impermeable layer, and a sheet having such a structure is placed so that the surface of the soapstock impermeable layer faces the astringent persimmons. .