JP2008054668A - Package for preserving freshness of citrus fruit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package capable of preserving the freshness of citrus fruits. <P>SOLUTION: The package for preserving the freshness of citrus fruits is such that the citrus fruits cut off at their stems are packaged with a synthetic resin film, wherein the moisture permeability of the package per 100 g of the citrus fruits is 0.7 g/day or less; besides, the rate of oxygen permeation of the package per 100 g of the citrus fruits is 200 cc/(100 g day atm) or greater, the citrus fruits in question are medium and late ripening citrus and/or vinegary ones, and the cutoff part width of the stem of each of the citrus fruits is 5 mm or less. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a citrus freshness-maintaining package.

When citrus fruits are stored and stored in a naked state after harvesting, wilting is remarkably generated and it is difficult to maintain commercial properties. However, deterioration still occurs during storage due to phenomena such as withering of seeds (seed withering), falling down (referring to dripping, removing from the fruit), decay, mold, wilting, and off-flavoring. Ordinarily, 5-10% of fruits are discarded, and 50% or more are discarded when bad. Even during distribution and sales, blue lemon (lemon harvested in green), lime, sudachi, kabosu, etc. are prone to yellowing of the skin and withering of lacquer, and improvement in yield is desired.

Regarding preservation of freshness of citrus fruits, there is JP-A No. 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, which is characterized by being stored under the above conditions, is described, whereby the occurrence of phytotoxicity can be prevented, an antifungal effect can be exhibited, and the defect rate 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, and the smell of chemicals may penetrate into the fruit.

  Japanese Patent Application Laid-Open No. 2002-97106 discloses a method for inhibiting biosynthesis of ethylene that promotes plant senescence, fruit ripening and the like by using a compound having a specific structure. However, with increasing interest in safety and security, consumer resistance to using compounds is not limited.

Therefore, although there is a need for a means of preserving citrus fruits that does not depend on these methods, it is possible to prevent the citrus fruits from withering, yellowing, browning, wilting, falling off, mold generation, yellowing of the skin, etc. No means has been found. In particular, the presence or absence of good or bad fragility is a factor that determines whether it can be sold as fruit, sold for processing, or disposed of, and has a significant impact on the commercial value of citrus fruits. Therefore, improvement measures are required.
JP 2004-208558 A JP 2002-97106 A

  An object of the present invention is to provide a package that can maintain the freshness of citrus fruits, and in particular, can reduce the loss of citrus fruits derived from citrus fruits withering, falling off, mold generation, etc.

It is a packaged body in which citrus fruits cut at the culm are wrapped with a synthetic resin film, and the citrus freshness-maintained packaged body has a moisture permeability of 0.7 g / day or less per 100 g of the citrus fruits.
In a more preferred embodiment, the oxygen permeation rate per 100 g of citrus fruits is 200 cc / 100 g · day · atm or more, the citrus fruits are citrus fruits and / or vinegar citrus fruits, and the width of the cut portion of the citrus fruit is 5 mm. It is the freshness maintenance package of the citrus fruit which is the following.
Moreover, it is the citrus freshness maintenance method using the citrus freshness maintenance package as described above.

According to the method of the present invention, it is possible to prevent the citrus fruits from withering, yellowing of the citrus fruits, browning, wiping, wiping, mold generation, and yellowing of the peel, and to provide a package effective for maintaining the freshness of the citrus fruits. Can do. Furthermore, the citrus fruits using this package have a longer storage period than before, making it easier to adjust the shipment of citrus fruits.

The present invention relates to a citrus package. Examples of the types of citrus fruits used in the present invention include, for example, Wenzhou mandarin orange, grapefruit, Valencia orange, navel orange, Angkor, Seminole, kumquat, color mandarin, Kawachi bankan, sweet summer, Iyokan, Hinata summer, Hassaku, Buntan, Se And Sudachi, kabosu, lemon and lime. In particular, color mandarin, Kawachi bankan, sweet summer, Iyokan, Hinata summer, hassaku, buntan, setoka, and other citrus fruits, sudachi, kabosu, lemon and lime are often problematic. It is preferable to use it for vinegared citrus fruits.

The material of the packaging bag used for the package is not particularly limited. For example, a film made of a synthetic resin such as polypropylene, polyethylene terephthalate, polyethylene, nylon, polystyrene, or polylactic acid is used. Any one of these films may be used alone or laminated. These may be stretched or may be subjected to antifogging or printing. Among these, biaxially oriented polypropylene (OPP), low density polyethylene (LDPE), and linear low density polyethylene (LLDPE) are more preferable because they are low in price and have moderate moisture retention.
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, they are 25 micrometers or more and 45 micrometers or less.

  In the package of the present invention, the moisture permeability of the package per 100 g of citrus fruits is preferably 0.7 g / day or less (40 ° C., 90% RH). If the moisture permeability is 0.7 g / day (40 ° C., 90% RH) or less, the effect is greater for preventing citrus wetting during storage.

In the package of the present invention, the oxygen transmission rate of the package per 100 g of citrus fruit is preferably 200 cc / 100 g · day · atm or more. This is for maintaining the respiration of the packaged citrus normally, and in particular, in the preservation of citrus, it is more preferably 200 cc / day · atm or more in terms of preventing the generation of off-flavors and rot.

The oxygen transmission rate of the package per 100 g of citrus fruits is more preferably 200 to 11700 cc / 100 g · day · atm. If the oxygen transmission rate is within this range, it is more effective for maintaining the freshness of citrus fruits. More preferably, it is 200-5000cc / 100g * day * atm.

The packaging bag used in the present invention preferably has a flaw, a crack (fissure), a fine hole, a notch with a length of 1 mm or more and 12 mm or less. More preferably, the cut is a cut of 5 mm or more and 10 mm or less. In consideration of the appearance of the package, the size of the scratches and cracks is preferably 100 μm or less.
When the length of the cut per piece exceeds 12 mm, the number of cuts per bag is reduced, and the accuracy of adjusting the oxygen transmission rate and the carbon dioxide transmission rate of the package may be deteriorated. .

The opening area of the micropores is preferably 1.9 × 10 ^{−9 to} 1.6 × 10 ⁻⁶ m ² per 100 g of citrus fruits. When the opening area of the micropores is within this range, it is more preferable in terms of preventing the generation of odors and deterioration of citrus fruits. More preferably, the opening area is 3.8 × 10 ^{−9 to} 1.6 × 10 ⁻⁶ m ² per 100 g of citrus fruits.
It is more preferable that the opening area per hole of the micropores is 3.1 × 10 ⁻¹⁰ or more and 7.9 × 10 ⁻⁹ m ² or less in terms of the freshness maintaining effect of citrus fruits.

Usually, citrus fruits are damaged when harvested with a hard butter curd, so cut off the portion at the base as shown in Fig. 2 and harvest it in this state. It is often packed with.

In this invention, it is preferable to cut | disconnect citrus fruits with a curd and package with the packaging bag of this invention. As shown in FIG. 1, the curd is a portion that connects a citrus tree and a branch, and indicates a hard part that connects a fruit tree to a branch. Cutting with an infarction may cause it to wither or fall off, and it is difficult for deterioration to occur, including mold generation and growth, and it may be difficult for the mold generated at the cut end to come into contact with the pericarp and spread to the entire fruit. , Found to be preferable.

It is preferable that the width of the cut portion of the fruit must be 5 mm or less. The width of the cut part is preferably as small as possible, but if it is 5 mm or less, it is more effective for preventing mold. More preferably, it is the range of 1-4 mm. In addition, the width | variety of the cut part of an inflection is the thickness (diameter) of the inflection of the cut part.

In the package of the present invention, it is necessary to close the opening of the bag. In general, heat seal, caulking, back seal, rubber band, banding band, gluing, tape fixing, etc. are used, but not limited thereto. In the case of citrus fruits, a method of bundling and folding the opening of a package containing citrus fruits and pressing the portion with the weight of the fruit itself is also used.

Withering citrus fruits, peeling off, discoloration, decay, mold generation, etc., proceed more easily as the temperature rises, and progress particularly fast at 20 ° C or higher. Therefore, when storing, it is preferably less than 20 ° C. More preferably, it is stored at a temperature of 15 ° C. or lower. Moreover, in order to prevent generation | occurrence | production of the citrus pericarp damage etc., the preservation | save at 6 degreeC or more is preferable.

  The citrus fruits in the present invention are preferably packaged at 200 g / bag or less or 1 bag / bag. Citrus fruits are easily rotted if the skin is damaged or sick, and can spread to surrounding individuals if symptoms occur. In order to prevent this, it is preferable to store in such a unit, but of course, collective packaging using large bags may be used. However, for example, citrus fruits with small fruits such as sudachi may be packaged in plural / bag.

  The following examples illustrate the invention. In addition, this invention is not limited to this Example.

<Measurement of oxygen permeability of bag>
(1) Preparation of bag The bag described in the Example and the comparative example was created. 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 the film is not tensioned by the injected gas and is put in as much as possible within a slightly loose range, and is measured using the scale of the syringe barrel. The gas is deaerated and injected by, for example, inserting an injection 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. When the object is a microporous film, the micropores are not blocked with tape.

(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, a fixed amount of about 1 cc is injected. The standard gas (at least two points including about 1% oxygen and about 10%) is also measured by injecting the same amount of gas to create a calibration curve.
(4) Bag storage The bag whose initial oxygen concentration was measured is stored at 23 ° C. and 60% RH (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 during storage and calculation of oxygen transmission rate The oxygen concentration in the bag is measured 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 3 to 5 points in total, 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 transmission rate of the film is too high and the oxygen concentration in the bag is too high to clear this condition, a part of the film is known to be smaller than the film whose oxygen transmission rate is being measured and is of the same material The bag can be made in the same way. In this case, the oxygen transmission rate of the measurement film is obtained by subtracting the oxygen transmission rate of the known film portion from the obtained oxygen transmission rate, except for the portion of the bag that is bonded to another film having a known surface area.
For the oxygen transmission rate, Equation 1 is calculated using the value with the longer elapsed time.

F = 1.143 × (C _t −C ₀ ) × V / t (Formula 1)
F: Oxygen permeation rate (cc / bag / 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)

<Moisture permeability>
The moisture permeability was measured by a moisture permeability test method (cup method) for moisture-proof packaging materials (JIS Z0208).

<Humidity in the bag>
The humidity in the bag was measured with a thermohygrometer (Vaisara Co., Ltd., model HMI41T) on each evaluation day.

Example 1
Lemon was harvested by cutting at the infarction. The weight of lemon was 84 to 103 g / piece. The width of the cut surface of the infarction is 3 to 4 mm.
A bag having an inner size of 150 × 180 mm was produced from a biaxially stretched polypropylene film having a thickness of 30 μm. Four holes with an opening area of 1.96 × 10 ⁻⁹ m ² were made in the bag. One lemon was put in this bag, and the opening was sealed with a heat seal. The oxygen transmission rate and moisture permeability per 100 g of lemon were 393 to 482 cc / day · atm and 0.26 to 0.32 g / day (40 ° C., 90% RH). The lemon package was stored at room temperature (7.3 to 24.8 ° C., average temperature 16.1 ° C.) for 98 days to evaluate the quality of the lemon. The results are shown in Table 1. The number of samples was 13 and the test started from the end of November. The same applies hereinafter.
Example 2
The lemon quality was evaluated by storing the lemon in the same manner as in Example 1 except that the storage temperature of the lemon was 8 ° C. The results are shown in Table 1.

<< Comparative Example 1 >>
Lemon was harvested by cutting at the infarction (13 samples). The weight of lemon was 84 to 103 g / piece. The width of the cut surface of the infarction is 6 to 9 m.
A bag having an inner size of 150 × 180 mm was produced from a biaxially stretched polypropylene film having a thickness of 30 μm. Four holes with an opening area of 1.96 × 10 ⁻⁹ m ² were made in the bag. One lemon was put in this bag, and the opening was sealed with a heat seal. The oxygen transmission rate and moisture permeability per 100 g of lemon were 393 to 482 cc / day · atm and 0.26 to 0.32 g / day (40 ° C., 90% RH). The lemon package was stored at room temperature (7.3 to 24.8 ° C., average temperature 16.1 ° C.) for 98 days to evaluate the quality of the lemon. The results are shown in Table 1.
<< Comparative Example 2 >>
Lemon was harvested by cutting at the infarction (13 samples). The weight of lemon was 84 to 103 g / piece. The width of the cut surface of the infarction is 3 to 4 mm.
A bag having an inner size of 150 × 180 mm was produced from a biaxially stretched polypropylene film having a thickness of 30 μm. Four holes of 1.96 × 10 ⁻⁵ m ² were made in the bag. One lemon was put in this bag, and the opening was sealed with a heat seal. Both the oxygen transmission rate and the water vapor transmission rate per 100 g of lemon were too large to measure. The lemon package was stored at room temperature (7.3 to 24.8 ° C., average temperature 16.1 ° C.) for 98 days to evaluate the quality of the lemon. The results are shown in Table 1.

Example 3
Color mandarin was harvested by cutting at the infarction. The weight of color mandarin was 141 to 163 g / piece. The width of the cut surface of the infarction is 2 to 3 mm.
A bag having an inner size of 130 × 160 mm was made of a linear low-density polyethylene film having a thickness of 25 μm. The bag was made with 67 holes with an opening area of 1.96 × 10 ⁻⁹ m ² . One color mandarin was put in this bag, and the opening was sealed with heat seal. The oxygen transmission rate and moisture permeability per 100 g of color mandarin were 3990 to 4610 cc / day · atm and 0.40 to 0.47 g / day (40 ° C., 90% RH). The color mandarin package was stored at room temperature (16.3 to 29.4 ° C., average 23.4 ° C.) for 40 days to evaluate the quality of color mandarin. The results are shown in Table 2. The number of samples was 15 fruits, and the test was started from the middle of April. The same applies hereinafter.
<< Comparative Example 3 >>
The color mandarin was preserved in the same manner as in Example 3 except that the width of the cut surface of the infarction portion was 5.5 to 7 mm, and the quality was evaluated. The results are shown in Table 2.

<< Comparative Example 4 >>
A bag having an inner size of 130 × 160 mm was made of a polylactic acid film having a thickness of 25 μm. The color mandarin was stored in the same manner as in Example 3 except that the bag had ^two holes with an opening area of 1.96 × 10 ⁻⁹ m ² . The results are shown in Table 2.
The oxygen transmission rate and water vapor transmission rate per 100 g of color mandarin are 246 to 285 cc / day · atm and 17.8 to 20.6 g / day (40 ° C., 90% RH).
<< Comparative Example 5 >>
A bag having an inner dimension of 130 × 160 mm was produced from a biaxially stretched polypropylene film having a thickness of 30 μm. The color mandarin was stored in the same manner as in Example 3 except that the bag had ^two holes with an opening area of 1.96 × 10 ⁻⁹ m ² . The results are shown in Table 2.
The oxygen transmission rate and moisture permeability per 100 g of color mandarin are 126 to 145 cc / day · atm and 0.13 to 0.15 g / day (40 ° C., 90% RH).

Example 4
Sudachi was harvested by cutting at the infarction. The weight of Sudachi was 29 to 32 g / piece. The width of the cut surface of the infarction is 2 to 3 mm.
A bag with an inner dimension of 130 × 140 mm was made of a biaxially stretched polypropylene film having a thickness of 25 μm. Six holes with an opening area of 1.96 × 10 ⁻⁹ m ² were made in the bag. Three Sudachi (88 to 96 g) were placed in this bag, and the opening was sealed with heat seal. The oxygen transmission rate and moisture permeability per 100 g of Sudachi were 630 to 688 cc / day · atm and 0.23 to 0.25 g / day (40 ° C., 90% RH). This Sudachi package was stored at 15 ° C. for 11 days to evaluate the quality of Sudachi. The results are shown in Table 3. The number of samples was 5 bags, and the test started from the middle of August. The same applies hereinafter.
<< Comparative Example 6 >>
Sudachi was preserved in the same manner as in Example 4 except that the width of the cut surface of the infarction portion was 5.5 to 6 mm, and the quality was evaluated. The results are shown in Table 3.

An example of cutting at the infarction of the citrus fruit of the present invention Example of cutting at the base of citrus wood

Explanation of symbols

1. Fruit 2. Gag
3. Bunch 4 Cut surface

Claims (5)

A citrus freshness-maintained packaging body, wherein the citrus fruit cut by perilla is packaged with a synthetic resin film, and the moisture permeability of the packaging body per 100 g of the citrus fruit is 0.7 g / day or less. The oxygen permeation rate per 100 g of citrus fruits is 200 cc / 100 g · day · atm or more. The citrus freshness-keeping packaging bag according to claim 1 or 2, wherein the citrus fruits are midnight citrus fruits and / or vinegar citrus fruits. The citrus freshness-keeping package according to claim 1, 2, or 3, wherein the width of the cut portion of the citrus fruit is 5 mm or less. The citrus freshness maintenance method using the citrus freshness maintenance package in any one of Claims 1-4.

Images