JP4712656B2 - Method for producing sterilized cucumber and method for producing processed food using the same - Google Patents

Description

The present invention relates to a method for producing sterilized cucumber and a processed food using the obtained sterilized cucumber. More specifically, the present invention relates to a method for producing a sterilized cucumber having a sufficiently reduced initial bacterial count and having a crunchy texture equivalent to that of raw cucumber, and a processed food using the sterilized cucumber obtained by the method.

Potato salad is one of the most classic salads along with vegetable salad. When cooking potato salad at home, it is common to use steamed potatoes that have been cooked, carrots and onions that have been blanched after cutting, and raw cucumbers that have been cut into acidic oil-in-water such as mayonnaise, salad creamy dressings, and French dressings. The potato salad obtained is cooked in combination with the type emulsified food and has a fresh crispy texture of raw cucumber, giving it a fresh feel.

However, in the above-mentioned potato salad cooked at home, foodstuffs other than cucumber have been subjected to heat treatment such as steaming or blanching treatment, so the number of initial bacteria is originally low. On the other hand, since the cucumber used as a foodstuff is generally used after being washed with water and not sterilized, it has a high initial bacterial count. Therefore, the above-mentioned potato salad cooked at home may give off a rotting odor when stored at room temperature (20 ° C), which is required for business lunches, for 2 days. There was a bacterial problem.

Cucumber has a harder outer skin than the inside, thereby having a crispy texture and imparting a fresh feeling to the potato salad. However, it is said that bacteria are attached to the surface of the cucumber skin, and in particular, many bacteria are attached to the warts on the surface.

On the other hand, in the field for business use, conventionally, as a method for sterilizing raw vegetables, a method of immersing in a cold sodium hypochlorite aqueous solution having a concentration of 100 to 500 ppm has been performed. However, when raw cucumber was treated by the above method, although there was an effect of slightly reducing the number of primary bacteria, the number of primary bacteria could not be sufficiently suppressed. Therefore, for example, potato salad using such cucumbers cannot be stored at room temperature (20 ° C.) for 2 days without bacterial problems, as in the case of cooking at home as described above. Bacteriostatic agents such as sodium acetate, lysozyme, protamine, polylysine are added.

However, since the bacteriostatic agent has a peculiar taste, it may affect the taste of the potato salad. In addition, in recent years, while health-consciousness is strong, adding food additives such as a bacteriostatic agent itself impairs commercial value, so processed foods that do not use additives are desired.

Under such circumstances, as a method for sterilizing cucumber, Japanese Patent Application Laid-Open No. 2005-160398 (Patent Document 1) discloses that after processing a hole-like cucumber with warm water (50 to 70 ° C.), the liquid temperature is further 25 ° C. A method of immersing with the following aqueous sodium hypochlorite solution has been proposed. However, the sterilization method of Patent Document 1 is not preferable because the number of primary bacteria is sufficiently suppressed and there is no bacterial problem, but the crunchy texture of cucumber may be impaired.

JP 2005-160398 A

Therefore, an object of the present invention is to use a method for producing a sterilized cucumber having a sufficiently crunchy texture equivalent to that of a raw cucumber, and a sterilized cucumber obtained by the method. Provide processed foods.

As a result of intensive studies to achieve the above object, the present inventors have heated an aqueous sodium hypochlorite solution, which has been used only at low temperatures, to a specific temperature, and the heated aqueous solution has a hole shape. It was found that if the cucumber was treated with the cucumber for a certain period of time and then cooled, the number of primary bacteria was surprisingly sufficiently reduced, and a sterilized cucumber with a crunchy texture equivalent to that of raw cucumber was obtained. The present invention has been completed.

That is, the present invention
(1) After indirect liquid treatment of a hole-like cucumber in an aqueous sodium hypochlorite solution having a liquid temperature of 50 to 65 ° C. and a concentration of 80 to 300 ppm, the hole-like cucumber has a product temperature of A method for producing a sterilized cucumber, which is subjected to a cooling treatment to be 15 ° C. or lower
(2) The method for producing a sterilized cucumber according to claim 1, wherein the temperature of the aqueous sodium hypochlorite solution is 50 to 60 ° C.
(3) The method for producing a sterilized cucumber according to claim 1 or 2, wherein the concentration of the sodium hypochlorite aqueous solution is 100 to 200 ppm.
(4) The method for producing a sterilized cucumber according to any one of claims 1 to 3, wherein the wetted time of the sodium hypochlorite aqueous solution is 3 to 5 minutes.
(5) A method for producing processed food using the sterilized cucumber produced by producing sterilized cucumber according to any one of claims 1 to 4,
(6) Processed food manufacturing method of Claim 5 whose processed food is potato salad,
It is.

According to the present invention, it is possible to obtain a sterilized cucumber having a sufficiently reduced initial bacterial count and having a crunchy texture equivalent to that of raw cucumber. Therefore, by using the obtained sterilized cucumber, further expansion of use to processed foods that use raw cucumbers as raw materials, in particular, the crispness of cucumbers gives a fresh feeling and is likely to affect storage stability. Further expansion of salad usage is expected.

The present invention will be described in detail below.

In the present invention, “sterilized cucumber” refers to a cucumber in which the number of general viable bacteria is reduced by performing a sterilization treatment as compared with an unsterilized cucumber from which mud, dust and the like have been removed by washing. Specifically, an unsterilized cucumber from which mud, dust, and the like have been removed by washing usually has a general viable count of 10 ⁵ cfu / g or more, whereas the sterilized cucumber of the present invention is a sterilizer described later. By treatment, the number of viable bacteria is reduced to 10 ³ cfu / g or less, preferably 10 ² cfu / g or less.

First, the present invention prepares a hole-like cucumber. Hole-shaped cucumbers that have been removed from mud and dust attached to raw cucumbers and have been removed from edible material, or that have been cut into multiple pieces (for example, about 2 to 4 pieces) In addition, it is preferable to use one that is not cut into strips such as slices, strips, sticks, and choppeds. In particular, in the present invention, it is preferable to use the cucumber as it is after removing mud, dust and the like and removing only the unfit food. Microorganisms such as bacteria present in raw cucumber are not present in the contents of cucumber, but are attached to the surface of the cucumber skin. Therefore, the cucumber as it is except for only the above-mentioned cucumber has less exposure of the contents, so there is less bacterial contamination due to reattachment of bacteria to the exposed portion, and the wetted sodium hypochlorite aqueous solution described later This is because the effect of the treatment on the texture is small.

As a method for removing mud, dust and the like adhering to raw cucumber, it is not particularly limited as long as it is a commonly performed method. For example, an aqueous solution containing a detergent such as a neutral detergent It is recommended to use both washing with water and washing with fresh water.

Next, in the present invention, the above-prepared hole-shaped cucumber is subjected to indirect liquid treatment for 2 to 7 minutes in an aqueous sodium hypochlorite solution having a liquid temperature of 50 to 65 ° C. and a concentration of 80 to 300 ppm. Here, “whole cucumber is in contact with sodium hypochlorite aqueous solution” means that the entire surface of the hole cucumber is in contact with the sodium hypochlorite aqueous solution, which is a sterilizing solution. To do. Examples of such a treatment method include a method of immersing a hole-shaped cucumber in the sterilizing solution, or spraying or showering the hole-shaped cucumber with the sterilizing solution.

In the present invention, it is necessary to use an aqueous sodium hypochlorite solution having a liquid temperature of 50 to 65 ° C., preferably 50 to 60 ° C., and a concentration of 80 to 300 ppm, preferably 100 to 200 ppm, as a treatment liquid for sterilization. When the liquid temperature or concentration of the sodium hypochlorite aqueous solution is lower than the above range, the obtained cucumber has a crunchy texture equivalent to that of raw cucumber, but the number of general viable bacteria is not sufficiently reduced. Absent. On the other hand, when the liquid temperature or concentration is higher than the above range, the cucumber obtained is not preferable because the number of general viable bacteria is sufficiently reduced but the crunchy texture of the raw cucumber disappears.

In the present invention, it is necessary to subject the cucumber-like cucumber to an indirect liquid treatment for 2 to 7 minutes, preferably 3 to 5 minutes, with the sterilization treatment liquid. The cucumber obtained when the wetted treatment time is shorter than the above range is not preferable because it has a crispy texture equivalent to that of raw cucumber, but the number of viable bacteria is not sufficiently reduced. On the other hand, when the wetted treatment time is longer than the above range, the cucumber obtained is not preferable because the number of general viable bacteria is sufficiently reduced but the crunchy texture of the raw cucumber disappears.

The ratio of the treatment between the hole-like cucumber and the sodium hypochlorite aqueous solution is not particularly limited as long as the sodium hypochlorite aqueous solution is in contact with the substantially entire surface of the cucumber. When the cucumber is immersed in the sodium hypochlorite aqueous solution and subjected to the liquid contact treatment, the sodium hypochlorite aqueous solution is preferably 3 parts by mass or more and more preferably 5 parts by mass or more with respect to 1 part by mass of the hole-like cucumber. When the ratio of the sodium hypochlorite aqueous solution is less than the above amount, the sodium hypochlorite aqueous solution heated to the above liquid temperature may immerse the hole-like cucumber, so that the liquid temperature may be lower than 50 ° C. This is because a sterilized cucumber with a sufficiently reduced number of general viable bacteria cannot be obtained, which is not preferable.

Next, according to the present invention, a cooling treatment is applied to a hole-like cucumber that has been wetted with a heated aqueous sodium hypochlorite solution. Specifically, the hole-shaped cucumber subjected to the liquid contact treatment is subjected to a cooling treatment so that the product temperature is preferably 15 ° C. or lower, more preferably 10 ° C. or lower. Without cooling, the hole-like cucumber is heated from the heated sodium hypochlorite aqueous solution, and if left as it is, the cucumber can be boiled and the crunchy texture of the raw cucumber disappears, which is not preferable. is there.

As the cooling method, any method can be used, for example, a method of immersing in cooling water such as cold water, ice water or running water, a method of spraying or showering cooling water, and the like. The liquid temperature is preferably 15 ° C. or lower, more preferably 10 ° C. or lower. Of these cooling methods, when the cooling treatment is performed by dipping treatment, it is preferable to use the cooling water at least 3 parts by mass with respect to 1 part by mass of the hole-like cucumber in order to efficiently perform the cooling. It is more preferable to use the above.

The sterilized cucumber treated by the above method has a sufficiently reduced initial bacterial count and a crunchy texture equivalent to that of raw cucumber. And the sterilization cucumber obtained by this invention is cut into strip shape, such as slice shape, strip shape, stick shape, and chopped shape, and can be used as a foodstuff of processed food in a raw state. Examples of processed foods that use cucumbers in their raw state include potato salad, moroccan, vinegar, pickles, and sandwiches. In particular, the potato salad is given a fresh feeling due to the crisp texture of cucumber, and in the field of business, it is required to have a shelf life, so it is preferable to use the sterilized cucumber obtained by the present invention. It is.

Hereinafter, the manufacturing method of the sterilization cucumber of this invention is demonstrated concretely based on an Example and a test example. The present invention is not limited to these.

[Example 1: Sterilized cucumber]
After rinsing 10 cucumbers (approx. 1 kg) with tap water (20 ° C.) for 1 minute, immerse them in 5 minutes while slowly stirring 10 liters of a 0.1% aqueous neutral detergent solution (20 ° C.). Then, it was rinsed with tap water for 1 minute. Next, using a sterilized knife and cutting board, the cucumber sticks were removed to obtain 10 hole-shaped cucumbers. Ten hole-shaped cucumbers thus obtained were immersed in a 10-liter sodium hypochlorite aqueous solution having a liquid temperature of 60 ° C. and a concentration of 200 ppm for 5 minutes while being slowly agitated. Thereafter, the hole-shaped cucumber that was wetted from the aqueous sodium hypochlorite solution was taken out, immersed in 10 liters of ice water, and subjected to cooling treatment until the product temperature reached 10 ° C. or lower to obtain a sterilized cucumber.

In the obtained sterilized cucumber, the number of general viable bacteria is 10 ² cfu / g, whereas the number of whole cucumbers before the wetted treatment is 10 ⁵ cfu / g. It was. Moreover, when the obtained sterilized cucumber was cut into slices and eaten, it had a crunchy texture equivalent to that of raw cucumbers.

[Test Example 1]
In the method for producing the sterilized cucumber of Example 1, the effect on the number of viable bacteria and the texture when the wetted treatment with an aqueous sodium hypochlorite solution is performed under the conditions shown in Table 1 below, or the effect of Example 1 When the cooling treatment after the wetted treatment was not performed (left at normal temperature (20 ° C.)), the influence on the number of general viable bacteria and the texture was examined and evaluated. In addition, the number of general viable bacteria and texture were evaluated by the following methods. Moreover, the hole-shaped cucumber before the liquid contact treatment was on the order of 10 ⁵ cfu / g.

<General viable count>
Put one sterilized cucumber in a sterilized plastic bag and crush it well by stomacher treatment. 10 g of the crushed specimen and 90 g of sterilized physiological saline were put in a sterilized plastic bag, homogenized by a stomacher treatment for 60 seconds, and a 10-fold serial dilution was prepared with further sterilized physiological saline. . 1 ml of this diluted solution was dispensed into a sterilized petri dish, sterilized therein, and an appropriate amount (about 15 ml) of standard agar medium at a temperature of 50 ° C. or less so that the agar did not solidify was dispensed and immediately mixed. When the medium is completely solidified, the petri dish is turned upside down, cultured at 35 ° C. for 48 hours, the number of colonies after 48 hours of culture is counted, and the number of viable bacteria (cfu / g) It was.

<Food texture>
The texture was evaluated after eating after being cut into slices.

<Evaluation of general viable count>
○: 10 ² cfu / g or less Δ: 10 ³ cfu / g or less ×: 10 ⁴ cfu / g or more <Evaluation of texture>
○: Crispy texture.
Δ: Almost crunchy texture.
X: It is not a slightly crunchy texture.
<Comprehensive evaluation>
◎: Both “General viable count” and “Food texture” evaluations are “○”
○: One of the evaluation of “general viable count” and “texture” is “○” and the other is “△”
Δ: “General viable count” and “Eating texture” are both “△”
×: Both the evaluation of “general viable count” and “feel”, or one of them is “×”

As shown in Table 1, the hole-shaped cucumber was subjected to indirect liquid treatment of a sodium hypochlorite aqueous solution having a liquid temperature of 50 to 65 ° C. and a concentration of 80 to 300 ppm, followed by cooling treatment. 1-No. No. 9 sterilized cucumber No. 9 using a sodium hypochlorite aqueous solution whose temperature was outside the above range. 10 and 11 treated cucumbers, No. 1 using a sodium hypochlorite aqueous solution having a concentration outside the above range. No. 12 and No. 13 in which the contact time with the treated cucumber and sodium hypochlorite aqueous solution is outside the above range. Nos. 14 and 15 treated cucumbers and No. It is understood that the number of primary bacteria is sufficiently suppressed as compared with 16 treated cucumbers, and yet has a crunchy texture equivalent to that of raw cucumbers.

No. 1-No. No. 9 of the sterilized cucumber of the present invention. 1-No. 4 and no. From the comparison with 5 and 6, the concentration of the sodium hypochlorite aqueous solution is preferably in the range of 100 to 200 ppm. 1-No. 4 and no. In comparison with No. 7, the temperature of the sodium hypochlorite aqueous solution is preferably in the range of 50 to 60 ° C. 1-No. 4 and no. From the comparison with 8 and 9, it is understood that the contact time with the sodium hypochlorite aqueous solution is preferably in the range of 3 to 5 minutes.

[Example 2: Potato salad]
First, each foodstuff to be used was prepared. That is, the potato (steamed, crushed) was prepared by washing the skinned potato with water, cooking this for 60 minutes, peeling and crushing while hot, and then cooling with vacuum. The cucumber was prepared by cutting the sterilized cucumber obtained in Example 1. Carrots were cut into icing slices, onions were sliced, and all were soaked in boiling water for 3 minutes and then cooled with water.

Potato salad was prepared using the ingredients prepared above at the following blending ratio. That is, mayonnaise (manufactured by QP Corporation), salt, vinegar and white pepper were mixed to make uniform, and then mixed with ingredients to prepare a potato salad. The knives and cutting boards used for the above preparation were sterilized.

<Mixed proportion of potato salad>
Potato (steamed, crush) 550g
Cucumber (ring slice, Example 1) 80g
Carrot (boiled and chopped) 80g
Onion (slicing, branching) 80g
200g mayonnaise
5g salt
Vinegar (acidity 4%) 5g
White pepper 0.3g
――――――――――――――――――――――――――
Total 1000.3g

[Comparative Example 1: Potato salad]
In Example 2, in place of the sterilized cucumber obtained in Example 1, the sterilized cucumber before being subjected to the liquid contact treatment with the sodium hypochlorite aqueous solution of Example 1 was used. A potato salad was prepared according to the above.

[Comparative Example 2: Potato Salad]
In Example 2, in place of the sterilized cucumber obtained in Example 1, No. 1 in Test Example 1 was obtained. A potato salad was prepared using the treated cucumber obtained in No. 10 in the same manner as in Example 2.

[Test Example 2]
The number of general viable bacteria (initial bacterial count) immediately after preparation of each potato salad obtained in Example 2 and Comparative Examples 1 and 2 and the number of general viable bacteria after storage for 48 hours at room temperature (20 ° C.) were measured. The results are shown in Table 2.

From Table 2, the potato salad of Example 2 using the sterilized cucumber of the present invention is generally raw even after storage for 48 hours at room temperature (20 ° C.) compared to the potato salad of Comparative Examples 1 and 2 using cucumbers that are not. It is understood that the number of bacteria is suppressed and preferable.

Claims (6)

After indirect liquid treatment of a hole-like cucumber in a sodium hypochlorite aqueous solution having a liquid temperature of 50 to 65 ° C. and a concentration of 80 to 300 ppm, the hole-like cucumber has a product temperature of 15 ° C. or less. The manufacturing method of the sterilization cucumber characterized by performing cooling processing so that it may become. The method for producing a sterilized cucumber according to claim 1, wherein the temperature of the aqueous sodium hypochlorite solution is 50 to 60 ° C. The method for producing a sterilized cucumber according to claim 1 or 2, wherein the concentration of the sodium hypochlorite aqueous solution is 100 to 200 ppm. The method for producing a sterilized cucumber according to any one of claims 1 to 3, wherein the contact time of the aqueous sodium hypochlorite solution is 3 to 5 minutes. The manufacturing method of the processed food which manufactured the sterilization cucumber by the method in any one of Claims 1 thru | or 4, and uses the manufactured said sterilization cucumber. The method for producing a processed food according to claim 5, wherein the processed food is a potato salad.