JPH0690660A - Method of maintaining quality of cut fruit - Google Patents

Abstract

PURPOSE:To effect seal-packaging of water-rinsed and cut fruits in a low oxygen-permeation pouch to keep the cut fruits good in their qualities without taste deterioration by no use of any chemicals. CONSTITUTION:At first, water-rinsed and cut fruits are placed in pouches made of an oxygen impermeable material. Then, the pouches are deaerated until the inner pressure becomes -60 to 90mmHg lower than the atmospheric pressure, then tightly sealed. The pouched cut fruits are sterilized by irradiation with ultraviolet rays, left to stand at 20 deg.C for 2 to 6 hours. Then, the pouches are preferably stored at 5 to 10 deg.C. The oxygen impermeable material preferably has the oxygen permeation rate of lower than 100ml/1m<2>/24 hours/1atm at 25 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for maintaining the quality of cut fruits. The cut fruit refers to apples, pears, etc., which are obtained by removing the core and peeling the skin.

[0002]

2. Description of the Related Art A knife or the like is required when eating apples, pears, etc., and is inferior in "handiness" to fruits such as mandarin oranges and strawberries. Since this point is considered to be one of the factors that suppress the demand for apples, pears, etc., commercialization of cut fruits that can be eaten immediately after being bought is desired. However, since the surface of cut fruit turns brown when left in the air, it cannot be distributed as a product simply by packaging it with a wrap film or the like. Browning of cut fruits
For a short period of time, it can be controlled by exposure to salt water as is usually done at home. However, since its sustaining effect is limited, it is necessary to further add an antioxidant such as ascorbic acid in order to actually distribute and sell it. In addition, cut fruits are vacuum-packed with a material that has low oxygen permeability (packed in vacuum packaging paper, etc.
A method of sealing and returning to atmospheric pressure) or a method of packaging with nitrogen gas substitution has also been devised. On the other hand, as a method for preventing contamination with bacteria, there are addition of an organic acid solution, high-pressure treatment, and the like.

[0003]

When cut fruits are commercialized, most of them are considered to be eaten as they are. Therefore, considering the current consumer preferences,
Even if the safety of food additives is confirmed, it is desirable not to use them as much as possible. Also, salt and ascorbic acid affect the taste itself. On the other hand, according to the above-mentioned vacuum packaging, it is possible to suppress browning without resorting to chemicals, but since the pulp is placed under reduced pressure during the packaging process, the juice oozes out from the pulp, and the pulp after sealing is considerably Due to force (pressure difference corresponding to atmospheric pressure), some deformation may occur in the soft pulp, and quality deterioration is unavoidable.

In view of the above situation, the present invention uses agents such as food additives as little as possible, and suppresses browning and proliferation of various bacteria without causing deterioration of taste and deformation of pulp.
The purpose is to preserve the quality of cut fruits.

[0005]

Means for Solving the Problems As a result of diligent research on a method for maintaining the quality of cut fruits, the present inventors put the washed cut fruits in a bag with impermeability to oxygen, and the air pressure inside the bag was higher than that of the outside air. Suppress the browning by degassing to a reduced pressure of about -60 to -90 mmHg, then sealing and leaving the cut fruit at about 20 ° C for about 2 to 6 hours, and then storing at low temperature, It has been found that good quality can be maintained. Further, it was found that by irradiating the cut fruits after sealing with ultraviolet rays, the growth of various bacteria was suppressed and the quality retention effect was further improved, and the present invention was completed based on these findings.

That is, according to the present invention, cut fruits washed with water are put in a bag made of a material having poor oxygen permeability, deaerated so that the pressure in the bag is -60 to -90 mmHg lower than that of the outside air, and then sealed. It is a method of maintaining the quality of cut fruits, which is characterized in that The present invention is also the above-mentioned method for maintaining the quality of cut fruits, which comprises irradiating the cut fruits after sealing with ultraviolet rays.

Further, the present invention provides a cut fruit after sealing.
The method for maintaining the quality of cut fruits according to the above, characterized by storing at a temperature of 15 to 20 ° C. for 2 to 6 hours and then storing at a low temperature. The present invention will be described in detail below. Oxygen-impervious material used in the present invention may be a normal film or the like used for packaging vegetables and fruits, because oxygen enters the bag after sealing is a highly oxygen-permeable material, its oxygen permeability 25 ° C., at 1 m ² per 24 hours at 1atm conditions
It is preferably 100 ml or less.

[0008] When the air in the bag is completely removed and the bag is put in a vacuum state, the inconvenience such as the deformation of the pulp occurs as described above. Therefore, it is preferable to degas the bag so that the bag comes into close contact with the surface of the cut fruit. Specifically, it is preferable to perform degassing so that the pressure inside the bag is reduced to about -60 to -90 mmHg as compared with the outside air. It is also possible to enclose a deoxidizer in order to reduce the oxygen concentration in the bag.

For the irradiation of ultraviolet rays, a commonly used ultraviolet germicidal lamp may be used, and the irradiation time may be about 5 minutes, but complete sterilization can be achieved by performing the irradiation for about 2 hours. The cut fruits sterilized by irradiation with ultraviolet rays are preferably stored at a low temperature of 5 to 10 ° C using a refrigerator or the like, but it is particularly preferable to leave them at about 20 ° C for about 2 to 6 hours prior to the low temperature storage. .

The present invention will be described in detail below with reference to examples and experimental examples.

[0011]

[Experimental Example] (Experimental Example 1) The following experiment was performed on the degree of deaeration in the bag. After washing with water, put 100g of cut apple (cultivar'Fuji ') whose surface was lightly wiped into Cowpack NXL-2 (manufactured by Cowpack) and wiped it with a water flow pump equipped with an air pressure regulator inside the bag. -30mmH compared to atmospheric pressure
A bag was prepared which was depressurized to about g, -60 mmHg, -90 mmHg, -125 mmHg, and -150 mmHg. After leaving them at a temperature of 20 ° C. for 24 hours, they were opened, the cut apples were taken out, and the presence or absence of browning, the presence or absence of fruit juice leaching, and the deformation of meat quality were examined by external observation. As a control, a similar test was performed on a sealed apple that was not deaerated. The results are shown in Table 1.

[0012]

[Table 1]

From Table 1, in order to suppress browning of cut apples, it is necessary to reduce the pressure inside the bag to -60 mmHg or less. On the other hand, when the degree of depressurization exceeds -90 mmHg, the juice oozes out from the flesh, and in some cases, the flesh is deformed, so degassing must be performed at a depressurization of about -60 to -90 mmHg. (Experimental Example 2) The following experiment was conducted on the oxygen permeability of the packaging material.

After washing with water, 50 g of cut apples (cultivar'Fuji ') whose surface was lightly wiped off were placed in a bag (17 cm in length × 11 cm in width) made of materials having different oxygen permeability, and a cute sealer V300 (Fuji Impulse Company) The air pressure inside the bag is degassed so that the pressure inside the bag is about -40 mmHg less than the outside air, and the bag is sealed. After leaving them at a temperature of 20 ° C for 24 hours,
The apples were opened and the cut apples were taken out, and the presence or absence of browning, aroma and taste were tested. The presence or absence of browning was determined by external observation, and the scent and taste were evaluated by sensory tests. The results are shown in Table 2.

[0015]

[Table 2]

From Table 2, browning tends to proceed as the oxygen permeability of the packaging material increases, but the fragrance and taste have an oxygen permeability of 100 ml.
The higher the value, the better. In order to completely stop browning, the oxygen permeability is required to be 0.4 ml or less, but even 100 ml does not show browning that impairs the commercial value, so about 100 ml is appropriate considering the aroma and taste. Conceivable. (Experimental Example 3-1) The following experiment was conducted on the temperature treatment after sealing using a variety that easily browns.

After washing with water, 100 g of cut apples (cultivar'Starking Deridas') whose surface water was wiped off lightly
Is placed in Cow Pack NXL-2 (manufactured by Cow Pack), and degassed with a cute sealer V300 (manufactured by Fuji Impulse Co., Ltd.) so that the pressure inside the bag is reduced by about -40 mmHg compared with the outside air, and the bag is sealed. These were left at 20 ° C. and 30 ° C. for 6, 13, 20 and 24 hours, and then stored in a refrigerator at 5 ° C. Four days after the preparation, the apples were opened and the cut apples were taken out, and the presence or absence of browning thereof was examined by external observation. A cut apple chilled immediately after sealing was used as a control. The results are shown in Table 3.

[0018]

[Table 3]

As shown in Table 3, browning is more likely to occur.
It can be seen that in Delicious', the browning treatment is suppressed by the temperature treatment. Although the difference due to the temperature and time of the treatment is not remarkable, a slightly higher effect is recognized by the treatment at 20 ° C. for 6 hours, and thus it is considered that this degree of treatment is sufficient. In order to prevent the deterioration of the quality of cut apples and the propagation of sterilization, it is considered appropriate that the temperature of treatment is low and the time is short. (Experimental example 3-2) The following experiment was performed about the temperature processing after sealing using the variety which is hard to brown.

After washing with water, 50 g of cut apples (cultivar'Fuji ') whose surface was lightly wiped off were dry laminated with polyester and low density polyethylene (oxygen permeability 100 ml / m ² · day · atm at 25 ° C ) Vertical 17c
The bag is placed in a 11 cm wide bag (hereinafter referred to as PET), and is degassed with a cute sealer V300 (manufactured by Fuji Impulse Co., Ltd.) so that the pressure inside the bag is reduced by about -40 mmHg compared with the outside air, and the bag is sealed. These were heated to 20 ° C for 2 hours, 12 hours and
After leaving it for 24 hours, it was placed in a refrigerator at 5 ° C. On the next day and 2 days after the preparation, the apples were opened and the cut apples were taken out, and the presence or absence of browning, the aroma and the taste were tested in the same manner as in Experimental Example 2. A cut apple chilled immediately after sealing was used as a control. The results are shown in Table 4.

[0021]

[Table 4]

According to Table 4, even in the case of "Fuji" which is less likely to be browned, the temperature treatment has an effect of suppressing browning, but the degree thereof is slight. However, the scent was kept good by the temperature treatment for 2 hours, and from the aspect of quality maintenance,
It is preferable to perform temperature treatment at 20 ° C. for about 2 hours. (Experimental Example 4) The following experiment was conducted on the sterilizing effect of the ultraviolet sterilizing lamp.

After washing with water, 100 g of cut apples (cultivar'Fuji ') whose surface water has been wiped off gently is Cowpack NXL-2
Put in (made by Cow Pack), cute sealer V300
(Fuji Impulse Co., Ltd.) degass so that the air pressure inside the bag is about −40 mmHg less than the outside air, and then seal.
These are 40 ℃ under the temperature of 20 ℃ and 40W × 2 UV germicidal lamps.
Each side was left for 5, 30, 60 and 120 minutes. These were kept at 20 ° C until the next day of tonality and then stored in a refrigerator at 5 ° C for 3 days. Then, the container was opened and the viable cell density on the surface of the cut apple was measured by the standard agar plate culture method. A cut apple stored without being irradiated with ultraviolet rays served as a control.
The results are shown in Table 5.

[0024]

[Table 5]

From Table 5, it is sufficient that the irradiation time of the ultraviolet rays is about 5 minutes, but if it is irradiated for 2 hours, the sterilization can be completed.

[0026]

【Example】

(Example 1) After washing with water, 50 g of cut apple (cultivar'Fuji ') whose surface moisture was wiped off was put into PET, and the pressure inside the bag was -40 mmHg compared with the outside air by using Cute Sealer V300 (manufactured by Fuji Impulse). Degas to a moderate vacuum and seal. After irradiating them with UV light at 20 ° C for 1 hour on one side, store them at 5 ° C, open the cut apples on the next day, 2 days and 4 days after the adjustment, and take out the test for browning, scent and taste. The test was conducted in the same manner as in Example 2. The results are shown in Table 6.

[0027]

[Table 6]

(Example 2) After washing with water, 50 g of cut pear (variety'Kosui ') whose surface was lightly wiped off was put in PET, and the pressure inside the bag was compared with the outside air by using the Cute Sealer V300 (manufactured by Fuji Impulse). Degas to a reduced pressure of -40 mmHg and seal. After irradiating ultraviolet rays on one side for 1 hour at a temperature of 20 ° C, they were stored at 5 ° C, opened the next day, 2 days and 4 days after the adjustment, and taken out the cut pear. The test was conducted in the same manner as in 2. The results are shown in Table 7.

[0029]

[Table 7]

[0030]

[Comparative Example] After washing with water, 50 g of cut apples (cultivar'Fuji ') whose surface was lightly wiped off are soaked in a 0.5% ascorbic acid solution containing 0.5% salt for 5 minutes, and then cowpacked.
It is put in NXL-2 (manufactured by Cowpack) and PET, and degassed by a cute sealer V300 (manufactured by Fuji Impulse) so that the pressure inside the bag is reduced by about -40 mmHg compared to the outside air, and the bag is sealed. After irradiating them with UV light at 20 ° C for 1 hour on one side, store them at 5 ° C, open the cut apples on the next day, 2 days and 4 days after the adjustment, and take out the test for browning, scent and taste. The test was conducted in the same manner as in Example 2. The cut apples that were not dipped in the solution served as controls. The results are shown in Table 8.

[0031]

[Table 8]

From Table 8, when a material having low oxygen permeability is used, the effect of dipping the solution is not recognized. When a material having a slight oxygen permeability was used, browning was completely suppressed by the solution immersion treatment, but it was better not to soak the aroma and taste.

[0033]

EFFECTS OF THE INVENTION Since the quality maintaining method according to the present invention uses only materials and machines which are widely used at present, cut fruits can be easily commercialized. In addition, since no chemicals such as food additives are used, the commercialability of cut fruits can be improved without any problem in terms of safety.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location A23B 7/04 9281-4B 9281-4B A23B 7/00 101 9281-4B 7/04 (72) Invention KANEKO Katsuyoshi Iwate Prefecture Morioka City Shimokuragawa 4 Akahira 4 Tohoku Agricultural Test House RC3-15

Claims (3)

[Claims] 1. The washed cut fruits are put in a bag made of a material that is impermeable to oxygen, and the pressure inside the bag is -60 compared to the outside air.
A method for maintaining the quality of cut fruits, which comprises degassing to a pressure of -90 mmHg and then sealing. 2. The method for maintaining the quality of cut fruits according to claim 1, wherein the cut fruits after sealing are irradiated with ultraviolet rays. 3. Cut fruit after sealing at 2 to 15 ° C.
The method for maintaining the quality of cut fruits according to claim 1 or 2, wherein the method is preserved at a low temperature after being left for 6 hours.