JP3135520B2 - How to prevent softening of vegetables - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for preventing softening of vegetables, and more particularly, to a method for preventing softening of vegetables after heat treatment such as retort sterilization or after thawing frozen vegetables.

[0002]

2. Description of the Related Art Conventionally, a wide variety of preserved products such as curries and stews containing vegetables such as carrots, potatoes, onions, mushrooms, and corn as ingredients have been put on the market. In order to sufficiently maintain the temperature, for example, high-temperature and high-pressure treatment such as retort sterilization is performed. As a result, vegetables contained as ingredients in such products are excessively softened and some of them are out of shape. For this reason, various methods for preventing such softening of vegetables have been developed.For example, in retorting root vegetables or fruits and vegetables, the root vegetables or fruits and vegetables are 0.1 to 0.7 in advance. A method for preventing root vegetables or fruits and vegetables from being boiled down by immersing in an aqueous solution of calcium salt of weight% (Japanese Patent Publication No. 3-71102), heating vegetables to an aqueous solution of calcium salt and / or magnesium salt or sugar and / or A method of immersing in an aqueous solution in which a sugar alcohol is dissolved (Japanese Patent Laid-Open No. 4-19)
0756), a method in which vegetables or fruits are preheated at least at a surface temperature of 45 to 75 ° C. for 10 to 180 minutes with any of water, dilute acid water, and sugar solution separately from cooking or high-temperature sterilization (particularly). No. 62-47508) is known.

As described above, various substances are used to prevent the softening of vegetables, but it is generally known that the use of calcium salts or magnesium salts has a high effect of preventing such softening. ing.

However, when a calcium salt or a magnesium salt is used to prevent softening of vegetables, only the surface of the vegetables becomes hard, resulting in an uneven texture. Therefore, the texture was different from the texture of vegetables, and the natural texture of vegetables could not be sufficiently felt.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method using a calcium salt or a magnesium salt.
An object of the present invention is to provide a method for preventing softening of vegetables, which can prevent softening of vegetables caused by heat sterilization or the like without impairing the natural texture of vegetables.

[0006]

Means for Solving the Problems Before impregnating vegetables with an aqueous solution of calcium salt or aqueous solution of magnesium salt, the present inventors preliminarily add at least one of a saline solution, a sugar solution and a sugar alcohol solution to the vegetables. By impregnating, even after heating or thawing the vegetables, it is possible to prevent softening of the vegetables without impairing the original texture of the vegetables, and further, only calcium salts or magnesium salts were used. The present inventors have found that the effect of preventing softening can be enhanced more than in the case, and completed the present invention.

That is, according to the present invention, when heating or freezing vegetables, the vegetables are impregnated with at least one of a saline solution, a sugar solution and a sugar alcohol solution, and then a calcium salt aqueous solution and / or a magnesium salt solution are added. The above object of the present invention can be achieved by impregnating with an aqueous solution.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As vegetables which can be treated in the present invention, any vegetables which can be softened after a heat treatment or a thawing treatment can be used.
For example, as root vegetables, carrot, potato, radish, burdock, and as fruits and vegetables, pumpkin, tomato, other broccoli, Chinese cabbage, onion, cauliflower and the like can be mentioned. For the above vegetables, salt water, sugar solution, sugar alcohol solution, and further, when impregnating with a calcium salt aqueous solution or a magnesium salt aqueous solution, to improve the processing efficiency, or the size of the ingredients included in the product, etc. In consideration of this, it is preferable to perform a cutting process into an arbitrary shape.

In the present invention, when the above-mentioned vegetables are subjected to heat treatment or freezing treatment, the vegetables are previously impregnated with at least one of a saline solution, a sugar solution and a sugar alcohol solution. In this case, these may be used in combination.

When the above-mentioned salt solution is used, its salt concentration is preferably at least 10% by weight or more, and most preferably a saturated concentration.

When the above-mentioned sugar solution or sugar alcohol solution is used, for example, sucrose,
Glucose, trehalose, fructose, xylose, sorbitol and the like can be mentioned. Among them, glucose and sorbitol are preferred in that they do not greatly affect the taste of vegetables, and glucose and trehalose are preferred in that they can sufficiently prevent softening of vegetables.

The sugar concentration of the above sugar solution or sugar alcohol solution is not particularly limited, but is preferably 50% by weight or more. Thereby, the effect of preventing softening of vegetables after the heat treatment or the thawing treatment can be enhanced.

In the present invention, the above-mentioned saline solution, sugar solution,
When impregnating vegetables with a sugar alcohol solution, it is preferable to carry out by immersion treatment. In addition, in performing the immersion treatment, it is preferable to perform the immersion treatment at a temperature of 40 ° C. or less, whereby the destruction of the cellular tissue of the vegetables can be prevented, and the effect of preventing the vegetables from softening after the heat treatment or the thawing treatment is enhanced. Can be.

Regarding the immersion treatment time, the treatment temperature,
It may be arbitrarily adjusted based on the type of vegetables, salt concentration or sugar concentration, pH of the immersion liquid, etc., especially when a high sugar concentration saccharide liquid or sugar alcohol liquid is used, shorten the immersion treatment time. be able to. As another method of shortening the processing time, for example, there is a method of performing the above immersion processing after performing a pressure reduction processing or after repeating the pressure reduction processing and the pressure recovery processing. For example, top 15
mm, lower side 25mm, height 30mm trapezoidal onion pieces (thickness about 3-6mm), processing temperature 25 ° C,
When the immersion treatment is performed under the condition that the sugar concentration is 50% by weight, the immersion liquid pH is 7.0, and the decompression treatment and the decompression treatment are repeated two to three times,
One cycle of the pressure reduction processing and the pressure recovery processing may be performed in about 7 to 8 minutes.

According to the present invention, as described above, vegetables are impregnated with any of a saline solution, a sugar solution, and a sugar alcohol solution,
Impregnating with a calcium salt aqueous solution and / or a magnesium salt aqueous solution. The present invention is characterized by the order of the steps,
This makes it possible to prevent softening of vegetables caused by heat sterilization or the like without impairing the natural texture of vegetables for the first time. Therefore, when the above steps are reversed, that is, when the vegetables are impregnated with an aqueous solution of a calcium salt and / or a magnesium salt and then impregnated with a saline solution, a sugar solution, or a sugar alcohol solution, or these solutions are mixed. When impregnated with vegetables, softening of vegetables cannot be prevented without impairing the natural texture of vegetables.

Examples of the aqueous calcium salt solution that can be used in the present invention include an aqueous solution of calcium lactate, an aqueous solution of calcium chloride, an aqueous solution of calcium carbonate, an aqueous solution of calcium phosphate, and an aqueous solution of calcium sulfate. As the magnesium salt aqueous solution, a magnesium chloride aqueous solution,
Examples thereof include an aqueous solution of magnesium carbonate and an aqueous solution of magnesium sulfate. Among them, an aqueous solution of calcium lactate is most preferred in that it has the least effect on taste. The concentration of the calcium salt and / or magnesium salt is preferably 1 to 3% by weight. When the concentration is low, the effect of preventing softening of vegetables cannot be obtained, while when the concentration is high, the taste of the food becomes bitter, which is not preferable. As a method of impregnating vegetables with the above-mentioned calcium salt aqueous solution or magnesium salt aqueous solution, it is preferable to carry out the immersion treatment. The immersion treatment is preferably performed at 4 to 80 ° C. for 16 hours to 10 minutes, thereby preventing the destruction of the cellular tissue of the vegetables, and softening the vegetables after the heat treatment or the thawing treatment. Can be improved.

The above saline, sugar solution, sugar alcohol solution,
Further, it is desirable that the vegetables subjected to the immersion treatment with the aqueous solution of the calcium salt or the aqueous solution of the magnesium salt be subjected to a water return treatment in the heat treatment or the freeze treatment. This is performed in order to restore the shrinkage of the vegetables, since the vegetables tend to shrink when the saline, sugar solution, or sugar alcohol solution having a high concentration permeates into the vegetables. In addition, by such a water re-treatment, excess bitterness of salty, sweet, calcium, or magnesium salt imparted to vegetables can be removed. The water return treatment may be performed, for example, by a method of water immersion treatment or running water treatment at 20 ° C. for about 8 hours. Alternatively, the heat treatment can be performed by heating vegetables together with the liquid raw material.

As described above, vegetables impregnated with a saline solution, a sugar solution, a sugar alcohol solution, and a calcium salt solution or a magnesium salt solution are filled in a container, and only the vegetables are frozen or sterilized by heat. And can be used as a preservative foodstuff that can be used in a restaurant or at home. Further, it is filled and sealed in a container as an ingredient together with curry, stew and the like, and subjected to a freezing treatment or a heat sterilization treatment to provide a preserved food, for example, a frozen food or a retort food.

[0019]

Embodiment 1 Upper side 15 mm, lower side 25 mm, height 30 m
m trapezoidal onion pieces are put into a sorbitol solution having a sugar concentration of 60% by weight, and immersion treatment is performed at 20 ° C. for 16 hours, and then, a calcium lactate aqueous solution having a calcium salt concentration of 2% by weight is put into the solution. Then, immersion treatment was performed at 60 ° C. for 1 hour.

[0020]

Example 2 Onion pieces similar to those in Example 1 were prepared by adding a sugar concentration of 6
0% by weight of sugar (type: glucose) solution
After performing the immersion treatment at 0 ° C. for 16 hours, it was subsequently poured into an aqueous solution of calcium lactate having a calcium salt concentration of 2% by weight, and the immersion treatment was performed at 60 ° C. for 1 hour.

[0021]

Example 3 An onion piece similar to that of Example 1 was prepared using a salt concentration of 2
After pouring into a 5% by weight saline solution and immersing at 20 ° C. for 16 hours, it was subsequently poured into a 2% by weight calcium lactate aqueous solution of calcium lactate at 60 ° C.
A time immersion treatment was performed.

[0022]

Example 4 An onion piece similar to that in Example 1 was prepared by adding a sugar concentration of 6
0% by weight of a sorbitol solution, and subjected to a immersion treatment at 20 ° C. for 16 hours, followed by a 2% by weight magnesium salt aqueous solution of magnesium chloride,
The immersion treatment was performed at 60 ° C. for 1 hour.

[0023]

Comparative Example 1 The same onion pieces as in Example 1 were introduced into an aqueous solution of calcium lactate having a calcium salt concentration of 2% by weight.
The immersion treatment was performed at 60 ° C. for 1 hour.

[0024]

Comparative Example 2 An onion piece similar to that in Example 1 was prepared by adding a sugar concentration of 6
0% by weight of a sorbitol solution and an aqueous solution of calcium lactate having a calcium salt concentration of 2% by weight.
C. The immersion treatment was performed for 16 hours.

[0025]

Comparative Example 3 The same onion pieces as in Example 1 were introduced into an aqueous solution of calcium lactate having a calcium salt concentration of 2% by weight.
After performing an immersion treatment at 60 ° C. for 1 hour, it was subsequently poured into a sorbitol solution having a sugar concentration of 60% by weight,
C. for 16 hours.

[0026]

EXPERIMENTAL EXAMPLE 1 Each of the onion raw materials obtained in Examples 1 to 4 and Comparative Examples 1 to 3 was subjected to a freezing treatment, and after 7 days, at 20 ° C.
After about 8 hours of thawing and water reversion with water, fill the retort container with curry sauce and seal,
The pressure and heat treatment was performed under the conditions of 121 ° C. and 30 minutes.

In Experimental Example 1, sensory evaluation was conducted by a panel of 10 persons on the hardness after thawing the vegetables and the appearance and texture after the vegetables were subjected to the heat treatment under pressure. Table 1 shows the results. (Evaluation criteria) 5 ... very good, 4 ... good, 3 ... normal, 2 ... bad, 1 ...
Very bad

[0028]

[Table 1]

As is clear from Table 1, according to the present invention, even when a calcium salt or a magnesium salt is used to prevent softening of vegetables after freezing or heat treatment, the natural nature of vegetables is maintained. The texture and taste can be sufficiently exhibited, and the effect of preventing softening of vegetables can be further enhanced as compared with a case where only a calcium salt or a magnesium salt is used.

[0030]

[Experimental Example 2] 15 parts by weight of the onion obtained in Example 1, potato 2 obtained by the same method as in Example 1
0 parts by weight and 15 parts by weight of carrot
Fill and seal 60 parts by weight in a retort container, 121 °
C, heat sterilization under pressure was performed for 30 minutes to obtain a retort curry food. After heating the obtained retort curry food in a container, the container was opened, and a curry dish was poured over rice placed on a curry dish.
The ingredients of such curry dishes were not boiled, had a uniform texture, and could enjoy the natural chewyness of vegetables.

[0031]

According to the present invention, vegetables can be prevented from being softened due to heat treatment or thawing treatment without impairing the natural texture of vegetables.

Claims (2)

(57) [Claims] When heating or freezing vegetables, the vegetables are previously impregnated with at least one of a saline solution, a sugar solution, and a sugar alcohol solution, and then impregnated with a calcium salt aqueous solution and / or a magnesium salt aqueous solution. A method for preventing softening of vegetables. 2. The method for preventing softening of vegetables according to claim 1, wherein the impregnation is performed by immersion treatment.