JP5056249B2 - Citrus-containing package and citrus preservation method - Google Patents

Description

  The present invention relates to a citrus-containing package.

  Citrus may be stored for a long period of more than one month for the purpose of shipping adjustment after harvesting or reducing acid contained in citrus. During this time, rot, wilting, mold, and other phenomena occur, and the citrus fruits are being deteriorated during storage. Many of them are used for processed products such as juice and are discarded, and improvement in yield is required. In addition, although there are citrus fruits that are required to be extended for four months or more, there is no such effective means.

  Regarding the preservation of freshness of citrus fruits, there is JP-A-2004-208558, and in the claims of the publication, citrus fruits coexist with a natural allyl isothiocyanate-containing preparation, and the allyl isothiocyanate space concentration is 1 to 50 mg / L. A method for maintaining the freshness of fruits and vegetables, characterized by being stored under the following conditions, is described. Thus, the antifungal effect is exhibited, and the defective rate of citrus fruits can be reduced. However, this method has problems such as the use of chemicals, the fact that the chemicals are volatile and difficult to handle, the conditions of use are difficult, and the smell of chemicals may penetrate into the fruit.

In Japanese Patent Application Laid-Open No. 10-243767, the oxygen permeation per 1 gr of Sudachi is 3.6 to 35 cc / 24 h · atm and the carbon dioxide permeation is 3.6 to 39.4 cc / 24 h · atm under the temperature condition of 10 to 35 ° C. And a freshness-preserving package of Sudachi that is hermetically sealed with a plastic film having a water vapor transmission rate of 40 gr / 24 h · m ² (JIS Z0208, 40 ° C., 90% RH, 0.1 mm) or less. ing. As a method for preventing spoilage occurring during storage, it is described that the package body has an appropriate gas composition, and in the examples of the publication, the results of storage for 14 days are described, but more citrus fruits are stored for a long time. There is no mention of what to do.
JP 2004-208558 A JP-A-10-243767

  It is an object of the present invention to provide a package capable of storing citrus fruits for a long period of time without using chemicals, thereby reducing obstacles such as citrus rot and improving yield or extending the shipping period.

A package in which citrus fruits are packaged with a synthetic resin film, and the oxygen transmission rate per 100 g of citrus fruits in the package is 130 to 7000 cc / 100 g · day · atm, and the citrus fruits have a mass at the time of harvest of the citrus fruits. On the other hand, it is a citrus-containing package packaged in the package body after reducing the mass by 2 to 13%.
As a more preferable form, the synthetic resin film has a citrus-containing package having a water vapor permeability of ² to 30 g / m ² · day (40 ° C., 90 RH), the synthetic resin film has micropores, and per 100 g of citrus fruits. The opening area of the package is 3.1 × 10 ^{−3 to} 8.5 × 10 ⁻² mm ² , and the package contains citrus fruits.
Moreover, it is the preservation | save method of the citrus preserve | saved using the package containing a citrus fruit as described above.

  According to the method of the present invention, it is possible to reduce the decay of citrus fruits during storage, improve the yield of citrus fruits, and therefore, it is possible to store citrus fruits for a longer period of time than before. It becomes possible to adjust the shipment, and it is possible to supply citrus fruits at a time when it was not normally distributed. Moreover, since the detention period in distribution / market can be lengthened, citrus decay in distribution / market can be reduced.

The present invention relates to a citrus package. The type of citrus fruit is not particularly limited, and the present invention can be applied. For example, Shiranui, Ponkan, Kiyomi Kan, lemon, lime, Kawachi Bankan, Kanatsu, Yawata, Buntan, New Summer Orange, Harumi , Seto, Navel, Color Mandarin, Iyokan, Satsuma mandarin, etc. Among these, the present invention can be preferably used for late-night citrus fruits such as Shiranui, color mandarin and sweet summer, and perfumed citrus fruits such as lemon and lime.
The present invention is particularly effective when storing these citrus fruits over a long period of one month or longer. Among these, middle and late citrus citrus fruits and perfumed citrus fruits are desired to be stored for a long period of time for acid reduction and shipping adjustment, and improvement in yield during storage is required.

  These citrus fruits are preferably packaged after harvesting after reducing the mass by 2 to 13% with respect to the mass of the citrus fruits at the time of harvest. Decreasing the mass of citrus fruits by 2 to 13% of the citrus fruits at the time of harvesting, and then packaging the citrus fruits, resulting in rot, burns (symptoms of the skin becoming brown and sinking), and mold generation It becomes easier to suppress. If the mass reduction is less than 2%, the effect of suppressing the occurrence of spoilage and mold is reduced, and if it exceeds 13%, the wilting of the fruit may be noticeable and the merchantability may be lost. Preferably, the mass is reduced by 3 to 10% with respect to the mass of the citrus fruits at the time of harvest, and more preferably 5 to 9%.

Citrus fruits are usually stored once in a farmer's barn, warehouse, shipping area, etc. within the day after harvesting, and then often transported to a working place for packaging and packing according to the shipping schedule. The reduction in mass in the present invention is by measuring the mass from when it is stored once in a barn, warehouse, collection place, etc. after harvesting the citrus fruits, and packaging the citrus fruits when it reaches a predetermined mass reduction. It is found that it is suitable for long-term preservation of citrus fruits.

The method for reducing the mass by 2 to 13% with respect to the mass of the citrus fruits at the time of harvesting is not particularly limited. For example, about 10 to 20 kg of citrus fruits without packaging is placed in a container at room temperature in a well-ventilated warehouse. There is a method of storage, and there is a method of storage in a warehouse that can be adjusted to a constant temperature or a constant temperature and humidity. As a general rule, the storage period is about 5 to 40 days, but there are differences depending on the year, place of production, harvest time, variety, storage conditions, etc., so we measure the mass change of some fruits by sampling. It is preferable to confirm this. The storage may be in the refrigerator, but it takes time if the humidity is too high. In this case, it is preferable to store without excessive humidity.

When these citrus fruits reach a predetermined mass reduction, they are packaged in a packaging bag made of a synthetic resin film to form a citrus package. After putting citrus fruits in the packaging bag, the opening of the packaging bag is closed. As a method of closing the opening of the packaging bag, for example, heat sealing, caulking, back sealing, rubber band, binding band, gluing, tape stopper, bundling the opening and bundling the bundling opening or bundling the bundling opening, Furthermore, the method of pressing down an opening part by making it contact with the fruit's own weight or an adjacent fruit, etc. are used, However It is not this limitation.

These citrus packaging bodies are preferably packaged in a packaging bag with a small number of citrus fruits of about 1 to 3, more preferably only one.
It is inevitable that citrus fruits will rot and mold to some extent due to wounds during harvesting and cultivation, adhesion of pathogenic bacteria, and the like. For example, when a large amount of citrus fruit is put in a large bag, if such a symptom occurs in one, it may be transmitted to surrounding individuals. In addition, fruit that has begun to produce produces ethylene, which is a kind of plant hormone, which induces other fruits to wither and fall off. In order to prevent these, it is preferable to package one by one.

Although it does not specifically limit as a material of the synthetic resin film of the packaging bag used for a package, For example, synthetic resin films, such as a polypropylene, a polyethylene terephthalate, polyethylene, nylon, a polystyrene, polylactic acid, are used. Any one of these materials may be used alone or in a plurality of layers. These may be stretched or may be subjected to antifogging or printing. Among these, expanded polypropylene (OPP), unstretched polypropylene (CPP), high density polyethylene (HDPE), low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) are low in price and have moderate moisture retention. It is more preferable from having.

The thickness of these synthetic resin films is economically preferably 60 μm or less, and is preferably 10 μm or more in terms of strength. More preferably, they are 20 micrometers or more and 45 micrometers or less. More preferably, it is 25-40 micrometers.

The water vapor permeability of the synthetic resin film used in the package of the present invention is preferably ^{2 to} 30 g / m ² · day (40 ° C., 90 RH). If the water vapor transmission rate is less than ² g / m ² · day (40 ° C, 90RH), condensation in the package will increase, and deterioration such as burns will easily occur, resulting in 30 g / m ² · day (40 ° C, 90RH). If it exceeds, citrus fruits may wilted during storage. More preferably, it is 2-20 g / m < ² > * day (40 degreeC, 90RH).

In the package of the present invention, the oxygen transmission rate of the package per 100 g of citrus fruits at 23 ° C. is 130 cc / 100 g · day · atm or more and 7000 cc / 100 g · day · atm or less. If the oxygen permeation rate is less than 130 cc / 100 g · day · atm, the skin will rot or have a bad odor due to lack of oxygen or carbon dioxide gas, and if it exceeds 7000 cc / 100 g · day · atm, the rot will die and spoilage will increase. More preferably, the oxygen transmission rate of the package per 100 g of citrus fruits is 160 cc / 100 g · day · atm or more and 4200 cc / 100 g · day · atm or less.

Although the synthetic resin film itself used in the present invention permeates oxygen, in order to adjust the oxygen transmission rate of the package, the synthetic resin film has scratches, cracks, fine pores with an average pore diameter of 10 to 100 μm, It is preferable to perform a process such as cutting with a length of 1 mm or more and 8 mm or less. If the micropores are too small, a large number of holes are required. If the micropores are too large, the oxygen permeation rate per hole is too large, and it may be difficult to adjust the oxygen permeation rate of the package. Micropores having a pore diameter of 10 to 100 μm are preferred.
In consideration of the appearance of the package, the size of the scratches and cracks is preferably 100 μm or less. If the length per cut exceeds 8 mm, the number of cuts per bag decreases, and the accuracy of adjusting the oxygen permeation rate and carbon dioxide permeation rate of the package may deteriorate. preferable. More preferably, the cut is a cut of 1 mm or more and 5 mm or less. Micropores are preferred from the viewpoint of easy control of the oxygen transmission rate.

The method for measuring the oxygen transmission rate of the synthetic resin film is as follows.
(1) Preparation of a bag A bag is made with a film for measuring the oxygen transmission rate. At this time, a bag is created and sealed by heat sealing so that oxygen does not leak from other than the film. The size of the bag to be measured is such that the inner surface area of the bag is 0.06 m ² or more. All the following operations are performed in the atmosphere.
(2) After sealing the bag with a nitrogen gas sealed heat seal or the like, the bag is deaerated using an aspirator or the like. Deaerate until both sides of the bag stick. Next, this bag is filled with nitrogen gas (purity 99.9% or more) using a white hard syringe. The amount of gas to be injected depends on the bag size, but it is measured using the scale of the syringe barrel as much as possible within the range where the film is not tensioned. The gas is deaerated and injected by inserting a needle into the bag. When piercing the needle, a double-sided tape is applied to the film, and an adhesive tape made of polypropylene film (hereinafter referred to as “PP tape”) is applied thereon. Moreover, after removing the needle, the needle hole is immediately closed with PP tape. The tape to be attached to the bag should be within an area of 4.5 cm ² or less. In the case of a microporous film, care is taken not to block the micropores.

(3) Initial oxygen concentration measurement The initial oxygen concentration (C ₀ ) in the bag immediately after nitrogen gas filling (t = ₀ ) is measured. The gas in the bag is sampled, and the initial oxygen concentration (C ₀ ) in the bag is determined by gas chromatography (TCD). C ₀ is 0.2% or less, and when it exceeds this value, the operation is repeated.
The sampling gas for measuring the oxygen concentration is 10 cc or less. When injecting into gas chromatography, inject about 1 cc.
(4) Bag storage The bag whose initial oxygen concentration was measured is stored at 23 ° C. and 60% RH (a constant temperature and humidity chamber). At this time, it is left still so that an object may not be put on a bag, or the wind of the fan of a constant temperature and humidity chamber may hit directly.

(5) Measurement of oxygen concentration in the bag and calculation of oxygen permeation during storage Measurement of the oxygen concentration in the bag is performed within the range of oxygen concentration of 1% to 7% immediately after filling with nitrogen gas and after 3 hours or more. It is necessary to measure a total of three or more points, and to establish a proportional relationship (correlation coefficient of 0.98 or more) between the elapsed time t (hr) and the oxygen concentration in the bag. If the correlation coefficient does not hold, retest.
If the oxygen permeation amount of the film is too large and the oxygen concentration in the bag increases too quickly, and this condition cannot be cleared, a part of the film is smaller than the film whose oxygen permeation amount is measured, and is a known film of the same material The bag can be made in the same way. At this time, the portion of the bag having a surface area bonded to another known film is excluded, and the oxygen permeation amount of the measurement film is obtained by subtracting the oxygen permeation amount of the known film portion from the obtained oxygen permeation amount.
For the oxygen permeation amount, Equation 1 is calculated using the value with the longer elapsed time.

F = 1.143 × (C _t −C ₀ ) × V / t / s (Formula 1)
F: Oxygen permeation amount (cc / m ² · day · atm)
C _t : oxygen concentration in bag (%) at time t after nitrogen gas filling
C ₀ : oxygen concentration in bag immediately after filling with nitrogen gas (%)
V: Amount of nitrogen gas charged (cc)
t: Elapsed time from gas filling (hr)
s: bag surface area (m ² )

The water vapor permeability of the synthetic resin film was measured by a moisture permeable cup method (JIS Z0208).

The opening area of the micropores is preferably 3.1 × 10 ^{−3 to} 8.5 × 10 ⁻² mm ² per 100 g of citrus fruits. If the opening area is less than 3.1 × 10 ⁻³ mm ² , the citrus fruits are likely to be spoiled, off-flavored and off-flavor, and if it is greater than 8.5 × 10 ⁻² mm ² , the freshness maintaining effect may be weakened. More preferably, the opening area is 4.3 × 10 ^{−3 to} 8.5 × 10 ⁻² mm ² per 100 g of citrus fruits. It is preferable to provide two or more fine holes per package.

When storing citrus fruits for a long time, the storage temperature is preferably 5 ° C. or higher and 15 ° C. or lower. If the temperature is lower than 5 ° C, the skin may be pitted due to low-temperature damage (the skin is browned and dented). If the temperature exceeds 15 ° C, the material may wither, decay, mold, etc. is there. More preferably, it is 5 degreeC or more and 12 degrees C or less.

By using the present invention, citrus fruits can be stored for a long period of 1 month or longer, and in combination with temperature control at a low temperature, a long-term storage of 6 months or longer is also possible. As such citrus fruits, For example, there is a lemon. As a matter of course, citrus fruits are stored for a long period of time for the purpose of shipping adjustment and the like. In this case, a plurality of individual citrus packages are packaged in, for example, a suitable cardboard box and shipped to the market.

The following examples illustrate the invention. In addition, this invention is not limited to this Example.
Example 1
A 30-μm thick anti-fogging biaxially stretched polypropylene (OPP) film (water vapor permeability 5 g / m ² · day (40 ° C., 90% RH)) was used to produce a bag having an inner size of 130 × 170 mm. Three holes with an opening area of 3.4 × 10 ⁻³ mm ² were made in the bag. One domestic lemon (weight when packaging, average 135 g) whose mass was reduced by 9% by storing at room temperature without packaging after harvesting was put into this bag, and the opening was sealed with a heat seal. The number of samples is 50 bags.
At this time, the oxygen transmission rate per lemon 100g at 23 ° C. of the package is 337cc / 100g · day · atm, the opening area per lemon 100g is ^{7.6 × 10 -3 mm 2 / 100g} .
When this lemon package was stored at 8 ° C for 187 days (starting in late October) and the quality of the lemon was evaluated, wilting, rot, etc. were reduced, and the defective rate (rate of unsellable fruit) was 7%. Sufficiently maintained a practical level on a commercial basis.
Example 2
A 30-μm thick anti-fogging biaxially stretched polypropylene (OPP) film (water vapor permeability 5 g / m ² · day (40 ° C., 90% RH)) was used to produce a bag having an inner size of 130 × 170 mm. Five holes with an opening area of 4.3 × 10 ⁻³ mm ² were made in the bag. Into this bag, one domestic lemon (weight at packaging, 136 g on average) that was stored at room temperature without packaging after harvesting and reduced in mass by 4% was put, and the opening was sealed with a heat seal. The number of samples is 50 bags.
At this time, the oxygen transmission rate per lemon 100g at 23 ° C. of the package is 657cc / 100g · day · atm, the opening area per lemon 100g is ^{1.6 × 10 -2 mm 2 / 100g} .
This lemon package was stored at 8 ° C for 187 days (starting from the end of October) and the quality of the lemon was evaluated. As a result, wilting, rot, etc. were reduced, and the defective rate (rate of unsellable fruits) was 8%. Sufficiently maintained a practical level on a commercial basis.
Example 3
A 30-μm thick anti-fogging biaxially stretched polypropylene (OPP) film (water vapor permeability 5 g / m ² · day (40 ° C., 90% RH)) was used to produce a bag having an inner size of 130 × 170 mm. Three holes with an opening area of 3.4 × 10 ⁻³ mm ² were made in the bag. In this bag, 1 domestic lemon (weight when packaged, average 137 g) which was stored at room temperature without harvesting and reduced in mass by 9% after harvesting was put, and the opening was sealed with a heat seal. The number of samples is 50 bags.
At this time, the oxygen transmission rate per lemon 100g at 23 ° C. of the package is 332cc / 100g · day · atm, the opening area per lemon 100g is ^{7.5 × 10 -3 mm 2 / 100g} .
When this lemon package was stored at room temperature for 153 days (starting in late October) and the quality of the lemon was evaluated, wilting, rot, etc. were reduced, and the defective rate (rate of unsellable fruits) was 4%. Sufficiently commercial and practical level was maintained.

Example 4
A bag having an inner size of 150 × 200 mm was prepared using a linear low density polyethylene (LLDPE) film (water vapor permeability of 16 g / m ² · day (40 ° C., 90% RH)) having a thickness of 25 μm. Twenty-six holes having an opening area of 5.1 × 10 ⁻³ mm ² were made in the bag. One domestic color mandarin (weight at packaging, average 166 g) whose mass was reduced by 4% by storing at room temperature without packaging after harvesting was collected in this bag, and the opening was sealed with a heat seal. The number of samples is 44 bags.
At this time, the oxygen transmission rate per color mandarin 100g at 23 ° C. of the package is 3979cc / 100g · day · atm, the opening area per color mandarin 100g is a 8.1 × 10 ^-2 mm ² / 100g is there.
This color mandarin package was stored at room temperature for 30 days (starting in mid-April) and evaluated for quality of color mandarin. As a result, wilting, rot, etc. were reduced, and the defective rate (rate of unsellable fruits) was 4%. And kept a practical level on a commercial basis.
Example 5
A bag having an inner size of 200 × 200 mm was prepared using a linear low density polyethylene (LLDPE) film (water vapor permeability: 16 g / m ² · day (40 ° C., 90% RH)) having a thickness of 25 μm. Seven holes with an opening area of 4.5 × 10 ⁻³ mm ² were made in the bag. Into this bag, 1 domestically produced Shiranui (weight when packaging, average 273 g) which was stored at room temperature without packaging after harvest and reduced in mass by 5% was sealed, and the opening was sealed with a heat seal. The number of samples is 49 bags.
At this time, the oxygen transmission rate per Shiranuhi 100g at 23 ° C. of the package is 711cc / 100g · day · atm, the opening area per Shiranuhi 100g is ^{1.2 × 10 -2 mm 2 / 100g} .
When this Shiranui package was stored at 8 ° C for 80 days (starting from the middle of March) and the quality of Shiranui was evaluated, rot, mold, etc. were reduced, and the defective rate (rate of unsellable fruit) was 9%. Sufficiently commercial and practical level was maintained.

<< Comparative Example 1 >>
The opening was sealed with a heat seal in the same manner as in Example 1 except that one domestic lemon immediately after harvesting was added (weight at packaging, average 137 g). At this time, the oxygen transmission rate per lemon 100g at 23 ° C. is 332cc / 100g · day · atm, the opening area per lemon 100g is ^{7.5 × 10 -3 mm 2 / 100g} .
When this lemon package was stored at 8 ° C for 187 days (starting from the end of October) and the quality of the lemon was evaluated, wilting was not seen, but a lot of rot, mold, etc. occurred, and the defect rate ( The rate of fruit that cannot be sold) was 25%, which was difficult to put into practical use.
<< Comparative Example 2 >>
Except that the mass loss of lemon was 1%, one domestic lemon (weight when packaging, average 139 g) was put in the same manner as in Example 1, and the opening was sealed with a heat seal.
At this time, the oxygen transmission rate per lemon 100g at 23 ° C. of the package is 327cc / 100g · day · atm, the opening area per lemon 100g is ^{7.4 × 10 -3 mm 2 / 100g} .
When this lemon package was stored at 8 ° C for 187 days (starting from the end of October) and the quality of the lemon was evaluated, wilting was not seen, but a lot of rot, mold, etc. occurred, and the defect rate ( The rate of fruit that cannot be sold was 24%, which was difficult to put into practical use.
<< Comparative Example 3 >>
When the mass of the lemon after harvesting was reduced by 14% by storing it at room temperature in an unwrapped state, it was wilted and the skin was not glossy and looked bad, softened, and 94% of the fruit was not commercial. It is had. (Save starts from the end of October)

<< Comparative Example 4 >>
A 30-μm thick anti-fogging biaxially stretched polypropylene (OPP) film (water vapor permeability 5 g / m ² · day (40 ° C., 90% RH)) was used to produce a bag having an inner size of 130 × 170 mm. Eight holes with a diameter of 5 mm were made in the bag. Into this bag, 1 domestic lemon (weight at packaging, average 133 g) which was stored at room temperature without packaging after harvesting and reduced in mass by 9% was put, and the opening was heat sealed. The number of samples is 50 bags.
At this time, the oxygen transmission rate per lemon 100g at 23 ° C. of the package is unmeasurable too large, the opening area per lemon 100g is ^{1.2 × 10 2 mm 2 / 100g} .
The lemon package was stored at room temperature for 187 days (starting from the end of October) and the quality of the lemon was evaluated. As a result, wilting, mold, etc. occurred, and the defect rate (rate of unsellable fruits) was 100%.
<< Comparative Example 5 >>
A bag having an inner size of 150 × 200 mm was prepared using a linear low density polyethylene (LLDPE) film (water vapor permeability of 16 g / m ² · day (40 ° C., 90% RH)) having a thickness of 25 μm. In the bag, 50 holes with an opening area of 5.3 × 10 ⁻³ mm ² were made. One domestic color mandarin (weight when packaged, average 170 g) was put in this bag without reducing the mass after harvesting, and the opening was sealed with a heat seal. The number of samples is 44 bags.
At this time, the oxygen transmission rate per color mandarin 100g at 23 ° C. of the package is 7463cc / 100g · day · atm, the opening area per color mandarin 100g is a 1.6 × 10 ^-1 mm ² / 100g is there.
When this color mandarin package was stored at room temperature for 30 days (starting in mid-April) and the quality of color mandarin was evaluated, there was a lot of spoilage and mold, and the defective rate (rate of unsellable fruit) was 64%. It was an impractical level on a commercial basis.
<< Comparative Example 6 >>
A bag having an inner size of 200 × 200 mm was prepared using a linear low density polyethylene (LLDPE) film (water vapor permeability: 16 g / m ² · day (40 ° C., 90% RH)) having a thickness of 25 μm. One hole with an opening area of 9.1 × 10 ⁻⁴ mm ² was made in the bag. In this bag, one domestically produced Shiranui (weight during packaging, average 276 g) was put without mass reduction after harvesting, and the opening was sealed with a heat seal. The number of samples is 49 bags.
At this time, the oxygen transmission rate per Shiranuhi 100g at 23 ° C. of the package is 116cc / 100g · day · atm, the opening area per Shiranuhi 100g is ^{3.3 × 10 -4 mm 2 / 100g} .
When this Shiranui package was stored at 8 ° C for 80 days (starting from the end of March) and the quality of Shiranui was evaluated, it showed rotting, mold, off-flavor, and off-flavor. ) 100%.

  INDUSTRIAL APPLICABILITY The present invention can be used for packaging of citrus fruits, and according to the present invention, it is possible to reduce the decay of citrus fruits during storage and improve the yield of citrus fruits. Citrus can be stored.

Claims (2)

A package obtained by packaging the lemon in polypropylene or polyethylene resin film, the water vapor permeability of polypropylene or polyethylene resin film 2 to 20 g / ^{m 2} · day (40 ° C., 90 RH) is, the lemon packaging bag 1 package, the synthetic resin film has micropores, and the opening area of the package per 100 g of lemon is 3.1 × 10 ^{−3 to} 8.5 × 10 ⁻² mm ^2. The oxygen permeation rate per 100 g of lemon in the body is 160 to 4200 cc / 100 g · day · atm, and the lemon is reduced in mass by 4 to 10 % with respect to the mass at the time of harvesting the lemon , and then the package body Package with lemon , characterized by being packaged in A method for storing lemons , wherein the lemon- containing package according to claim 1 is stored.