JP3130379B2 - Sterilization treatment method of fruit - 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 sterilizing a soft fruit while maintaining the quality of the soft fruit. The present invention relates to a method for treating fresh and soft fruits by high-pressure sterilization, which can maintain nutrient components in a fresh state.

[0002]

BACKGROUND ART Sterilization of fruits, which are acidic foods, is carried out at 85 ° C and 30 ° C.
Minutes processed and marketed as processed food.
When heat-sterilized under these conditions, the soft flesh of the flesh becomes jam-like, so there is no other way to taste the texture of soft fruits such as melons and strawberries than eating fresh fruits. is there. On the other hand, the color and nutrients of the pulp, which indicates the freshness of the fruit, are lost by heat sterilization. Therefore, there is no product that preserves its freshness in the processed food of fruit.

As a method for preserving vegetable tissues in retort foods, a method for producing leafy vegetable retort soup (Japanese Patent Application No. 2-190555) is disclosed in which preheating is carried out in a soup containing calcium before heat sterilization of leafy vegetables. An ultra-high pressure treatment jam obtained by ultra-high pressure treatment without heating the raw material mixture (Japanese Patent Application Laid-Open No. 3-219844) is disclosed.

[0004]

According to the method for sterilizing fruits by high-pressure treatment, the flavor and nutritional components are not damaged as compared with the heat sterilization, but the tissues of soft fruits are destroyed and fresh foods are destroyed. The feeling cannot be maintained and the quality deteriorates. In addition, when heat sterilized, the soft fruit tissue softens, and the color tone and nutrient components are degraded, and the texture and nutrition of fresh fruit,
It will be impossible to obtain the beauty of color.

[0005] Further, in the process of sterilizing retort foods,
As a method of reducing the deterioration of the texture of vegetables, a method of causing water-soluble calcium to act on pectin demethylated by pectin esterase in vegetable tissue to harden the tissue has been disclosed. Is not an effective method for hardening soft fruits. Melon, a soft fruit
When water-soluble calcium is allowed to act on strawberries or the like and heat-treated at 60 ° C. or higher, the soft fruit tissue collapses, and the palatable texture is completely lost.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a high-pressure sterilization method for fruits, which prevents deterioration of the texture and texture of soft fruits and the palatability of fresh fruits. It is an object of the present invention to provide a method for sterilizing fruits which can maintain a certain texture, nutritional components and color tone.

[0007]

Means and Functions for Solving the Problems The present inventor has provided:
After various investigations on the solution of the above-described problems, the inventors focused on performing high-pressure treatment after infiltrating a soft fruit tissue with a calcium aqueous solution.

[0008] That is, the present invention is based on the above idea. The gist of the present invention is to infiltrate a fruit tissue with an aqueous calcium solution and to apply a gauge pressure of 100 to 500 M to the fruit.
A method for sterilizing fruits, comprising a step of performing high-pressure treatment at Pa.

In the present invention, the fruit to be treated is 10
It is a fruit whose texture is degraded due to heat treatment at 0 ° C. or lower, the texture is deteriorated, and the palatability is reduced, and is a so-called soft fruit such as melon, strawberry, peach and the like. An aqueous solution of calcium lactate, calcium acetate, and calcium chloride is used as the aqueous calcium solution to penetrate the soft fruit tissue. The aqueous calcium solution is used to harden fruit tissues, and the aqueous solution preferably has a calcium concentration of 0.05 to 0.50% by weight. If the content is less than 0.05% by weight, the effect of tissue hardening of the soft fruit will not be the desired value. On the other hand, if the concentration exceeds 0.50% by weight, the characteristic taste of the calcium aqueous solution will remain inside the soft fruit, so This is because good palatability is lost.

Next, a method of permeating a calcium aqueous solution into a fruit tissue is a method of immersing in a calcium aqueous solution having a concentration of 0.05 to 0.50% by weight in the case of a melon or a watermelon such as a watermelon. And in this immersed state,
Or take out the fruit after soaking for 10-20 minutes,
Further, high pressure treatment of the next step is performed in a state of being put in the sugar solution. On the other hand, in the case of berries such as strawberry and raspberry, after performing a vacuum replacement treatment in which a calcium aqueous solution is permeated into the fruit tissue in a vacuum state, a high-pressure treatment in the next step is performed to strengthen the soft fruit tissue. can do.

The above-mentioned vacuum replacement method of permeating an aqueous calcium solution into a fruit tissue under a vacuum is based on a method in which soft fruits such as berries are charged into a container previously filled with an aqueous calcium solution, and the berries are transferred into a vacuum container. Absolute pressure inside the vacuum vessel
It is maintained for 5 minutes in a state where the degree of vacuum is 0.01 MPa or less.
Next, after the inside of the vacuum container is returned to the atmospheric pressure, the soft fruits of the berries are taken out to complete the vacuum replacement. The fruits subjected to the vacuum substitution treatment are subjected to high pressure treatment in the next step as they are or in a state where a calcium aqueous solution is separated and separately put in a sugar solution.

[0012] The temperature of the aqueous calcium solution used for immersing the soft fruit is preferably in the range of 0 to 45 ° C. If the temperature is lower than 0 ° C., the tissue of the soft fruit freezes, so that it is difficult to permeate the aqueous calcium solution into the tissue of the fruit.
On the other hand, if the temperature exceeds 45 ° C., softening of the fruit tissue occurs before the tissue of the soft fruit is strengthened, which is not preferable.

In the method for high-pressure treatment of soft fruits in the present invention, for example, a high-pressure tester MS-1 manufactured by Hikari Kogaku Kiki Co., Ltd. is used as a high-pressure treatment device. Then, the soft fruit impregnated with the aqueous calcium solution by the above method is sealed in a flexible plastic container together with the aqueous calcium solution or an appropriate sugar solution, and then put in the high-pressure device container, and then subjected to high-pressure treatment. do. Here, in accordance with the treatment method of the present invention, an object to be treated, a concentration of a calcium aqueous solution, a treatment temperature, a test was performed by changing conditions such as a pressure of a high-pressure treatment, and the resulting product was subjected to a cutting stress, a viable cell count, Table 1 shows the results of measuring the taste evaluation and the like. In this test, the high-pressure processing apparatus used above was used, and the cutting stress was measured by cutting the sample into 1 cm square and using a rheometer NRM-2010J-CW manufactured by Fudo Kogyo Co., Ltd. The stress applied to the flat cutting blade was measured. The number of viable bacteria was measured by a dilution plate culture method. The preference evaluation was carried out by a 25-person expert panel using a five-point evaluation method, out of five. Strawberries and peaches were tested on a sample that was vacuum-substituted for 5 minutes under a vacuum at an absolute pressure of 0.01 MPa.

[0014]

[Table 1]

According to the results of the test shown in Table 1, when the concentration of the aqueous calcium solution is 0% by weight and the high-pressure treatment at a gauge pressure of 300 MPa or more is performed, the viable cell count of any soft fruit is 0 / gram. However, this is not a preferable state because the texture is damaged and the cutting stress is significantly reduced. Therefore, the preference evaluation was a low value. On the other hand, 0.05% by weight or more
It is clear that the texture of soft fruits subjected to high-pressure treatment after immersion in a 0.50% by weight or less aqueous solution of calcium or vacuum displacement treatment is not much different from fresh soft fruits and is sterilized.

As is clear from Table 1, the range of 100 MPa (hereinafter referred to as a gauge pressure) to 500 MPa is required to strengthen the soft fruit tissue. 100M
If it is less than Pa, the action of calcium on soft fruits is insufficient, and tissue strengthening cannot be achieved. On the other hand, 500
By applying a high pressure exceeding MPa, the tissue of soft fruits can be strengthened, but it is necessary to increase the pressure resistance of the high-pressure device, which is not practical because the cost of the device increases. If the pressure is less than 300 MPa, sterilization becomes insufficient, which is not preferable. Therefore, the pressure of high pressure processing is 300MP
It is preferable that the pressure is not less than a and not more than 500 MPa.

Next, if the holding time of the high-pressure treatment is 5 minutes or more, sterilization is sufficiently achieved. On the other hand, if the time is less than 5 minutes, the temperature inside the high-pressure vessel is not stable, so that good reproducible results cannot be obtained. And the temperature at the time of high pressure treatment is 0 ~ 45 ℃
Is preferable. If the temperature is lower than 0 ° C., the action of calcium on the tissue of the soft fruit is insufficient, and it is necessary to mount a cooling device on the high-pressure device, which is expensive and impractical. On the other hand, at a high-pressure treatment temperature exceeding 45 ° C., the texture of soft fruits can be strengthened, but the flavor and color tone deteriorate, which is not preferable.

As described above, according to the present invention, after a calcium aqueous solution is infiltrated into the tissue of a soft fruit, the soft fruit with the calcium aqueous solution or vacuum-substituted is taken out of the calcium aqueous solution in a flexible plastic container. After being poured into a sugar solution containing no calcium, it is sealed in the above-mentioned plastic container and subjected to high pressure treatment, so that a product with excellent flavor can be obtained without damaging the texture of soft fruits and non-heating. A high-pressure sterilization treatment method can be provided. In addition, the soft fruit having a fresh texture and a sterilized state obtained by the present invention can be applied to aseptic packaged fruit dessert food by aseptically combining edible creams and jellies.

[0019]

The present invention will be described below with reference to examples. Embodiment 1 FIG. The edible portion from which the seed portion of the melon was removed was cut into a 2 cm square, and this was immersed in a 0.50% by weight aqueous solution of calcium chloride at 25 ° C. for 30 minutes. ,
The container was sealed and sealed, and the sealed plastic container was subjected to a high-pressure tester MS-1 manufactured by Optical High Pressure Equipment Co., Ltd. at room temperature.
Then, the pressure was increased to 300 MPa, the pressure was maintained for 10 minutes, and then the pressure was released to take out the melon.

The texture of the high pressure treated melon was measured using a rheometer NRM-2010J-CW manufactured by Fudo Kogyo Co., Ltd.
The high-pressure treated melon sample cut into a cm square was measured to have a cutting stress of 4.0 N when cut at 6 cm / min using a 1 mm thick flat blade. This value has a texture equal to or higher than the cutting stress of the untreated melon of 3.0 N. And
The taste of the high-pressure treated melon was evaluated by a 25-person panelist using a 5-point scale, with a perfect score of 5 points, and was evaluated as 5 points equivalent to the untreated product, showing no difference in taste. Did not. When the viable cell count of this high-pressure treated melon was measured, no viable cells were present.

Embodiment 2 FIG. Strawberries are bisected, placed in a 0.20% by weight aqueous solution of calcium chloride, immediately transferred to a vacuum vessel, and maintained at 25 ° C. and an absolute pressure of 0.01 MPa for 5 minutes. , And a vacuum displacement treatment was performed. Next, the strawberry which has been subjected to the vacuum replacement treatment is taken out of the aqueous calcium chloride solution, and the strawberry is 10% by weight.
After putting it in a plastic container together with the sugar solution and sealing it, the sealed plastic container was put into a high-pressure tester MS-1 manufactured by Optical High Voltage Equipment Co., Ltd. at normal temperature, and the pressure was increased to 400 MPa, and the pressure was increased for 10 minutes. After maintaining the pressure, the strawberry was taken out by depressurizing.

Using a rheometer NRM-2010J-CW manufactured by Fudo Kogyo Co., Ltd., the texture of the strawberry subjected to the high pressure treatment was measured for the cutting stress in the same manner as in Example 1, and the stress was 3.0 N. there were. This value was equivalent to the cutting stress of untreated strawberries of 3.5 N, and no difference was observed in terms of flavor. And the taste of this high-pressure treated strawberry was evaluated by a 25-person panelist using a 5-point evaluation method with a perfect score of 5 points.
No difference in palatability was observed. In addition, when the viable cell count of this high-pressure treated strawberry was measured, no viable cells were present and the strawberry was in a sterile state.

[0023]

According to the present invention, an aseptic product free of viable bacteria can be obtained by a simple operation of permeating a calcium aqueous solution into fruit tissue and subjecting the fruit to high-pressure treatment. Deterioration of the texture and texture as soft fruits can be prevented, and the palatable texture, nutritional components, and color tone of fresh fruits can be maintained. That is, even when high-pressure treatment is applied to soft fruits, the tissue is not softened or destroyed, a fresh texture can be maintained, and quality deterioration such as decomposition of color tone and nutrient components occurs. Nothing. And
It can maintain the texture, nutrition and beauty of the color of the fresh fruit.

────────────────────────────────────────────────── ─── Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) A23B 7/153 A23B 7/00 A23L 3/015 JICST file (JOIS) JAFIC file (JOIS)

Claims (3)

(57) [Claims] A step of infiltrating a fruit tissue with an aqueous calcium solution, and compressing the fruit with a gauge pressure of 100 to 500 MPa.
A method for sterilizing fruits, comprising a step of subjecting the fruits to high-pressure treatment. 2. A method of permeating a calcium aqueous solution,
A method of immersing a fruit in an aqueous solution of calcium having a concentration of 0.05 to 0.50% by weight.
2. The method for sterilizing fruits according to claim 1, wherein the method is any one of a method of vacuum substitution at a pressure of 01 MPa or less. 3. A calcium solution Ru was infiltration step and
High pressure treatment to that process, both contact in the temperature range of 0 to 45 ° C.
There is implemented,請 Motomeko 1 or 2 sterilization method of the fruit according to.