JP4381349B2 - Production method of shredded vegetables packed in containers - Google Patents

Description

  The present invention relates to a method for producing high-quality container-packed shredded vegetables with excellent storage stability.

Leafy vegetables such as shredded cabbage are widely used as salads and dishes in homes and restaurants, etc. In recent years, leafy vegetables that have been shredded in advance have been synthesized so that they can be easily served on the table. It is packed in a resin-made bag-like container and marketed at a store such as a supermarket or a convenience store.
By the way, in order to increase the commercial value and reduce the sales loss, it is necessary to keep the quality of such shredded vegetables in a refrigerated environment for several days. Therefore, in order to suppress the growth of bacteria during storage, it is essential to perform sufficient sterilization treatment.

  Here, as a conventional method for sterilizing cut vegetables, a technique (Patent Document 1) in which cut vegetables are sterilized using a mixed solution of sodium chlorite and sodium hypochlorite, or cut vegetables are hypochlorite. A technique (Patent Document 2) that is sterilized with a solution of acid soda, washed with fresh water, and further sterilized with ozone water is known.

JP 2004-65149 A Japanese Patent Publication No. 7-63312

However, leaf vegetables such as cabbage and lettuce are mostly composed of thin leaf parts, and shredded products of leaf vegetables have a large cut surface area in the surface area among cut vegetables. As in the case of sterilization treatment using a solution of a chlorine-based disinfectant such as sodium hypochlorite or sodium chlorite, the leaf vegetable cells are greatly damaged, and the cut surface is browned over time, There is a problem that the quality is lowered, such as the loss of a crunchy texture.
On the other hand, as a sterilization treatment that hardly damages the cells of leafy vegetables, a sterilization treatment by so-called ozone water in which ozone is contained in fresh water is known, but ozone water has a bactericidal power compared to a chlorine-based disinfectant. Since it is weak, it is difficult to sterilize leaf vegetables sufficiently, and it has been said that high-quality shredded leaf vegetables that last for a long time cannot be produced.

  The present invention solves the above-described problems of the prior art, without using a bactericidal agent such as a chlorine-based bactericidal agent in the sterilization treatment of shredded vegetables, and sufficient sterilization An object of the present invention is to provide a method for producing containerized shredded leaf vegetables that can be refrigerated for several days while maintaining high quality.

  As a result of intensive research to achieve the above object, the present inventor has produced a sterilization treatment by washing leafy vegetables in a specific method before the sterilization treatment, even in a sterilization treatment with ozone water having a weak sterilization power. The present inventors have found that the number of bacteria remaining in the chopped leaf vegetables can be greatly reduced to suppress the bacterial growth over time, and the present invention has been completed.

That is, the present invention
(1) A method for producing containerized shredded vegetables,
A first washing step for washing the leafy vegetables in the hall with fresh water of 10 ° C. or lower;
A cutting process for cutting leaf vegetables into 2 to 8 parts after the first washing,
A second washing step of washing the leaf vegetables after cutting with fresh water of 10 ° C. or less,
Shredding process for shredding the leaf vegetables after the second washing into 1 mm width or less ,
A third washing step of washing the leafy vegetables after shredding with fresh water of 10 ° C. or lower,
An ozone water sterilization process for sterilizing the leaf vegetables after the third washing process using ozone water having an ozone concentration of 5 to 20 ppm and 10 ° C. or less in a mass ratio of 8 times or more with respect to the leaf vegetables;
Dehydration step of dehydrating leafy vegetables after sterilization with ozone water, and
Provided is a production method including a housing step of housing leaf vegetables after dehydration in a synthetic resin container.

  Moreover, this invention provides the manufacturing method of the container stuffed shredded vegetable as described in said (1) characterized by cutting a leaf vegetable into the width of 1 mm or less in (2) shredding process.

  Furthermore, the present invention provides (3) the method for producing chopped leafy vegetables according to (1) or (2) above, wherein in the ozone water sterilization step, the ozone concentration of ozone water is 5 to 20 ppm. I will provide a.

The present invention also provides (4) a packaged shredded leafy vegetable having a general viable count of less than 2.0 × 10 ⁵ cells / g when stored at 0 to 10 ° C. for 4 days after production. Such container-stuffed shredded vegetables can be produced by the production method described in any one of (1) to (3) above.

According to the method for producing containerized shredded leaf vegetables of the present invention, the leaf vegetables can be sufficiently sterilized and sterilized without using a chlorine-based disinfectant that damages the leaf vegetables. However, it is possible to produce a container-packed shredded vegetable with a sufficiently reduced number of viable bacteria immediately after production (hereinafter also referred to as “the number of first bacteria”). Therefore, the produced packed chopped leafy vegetables are less prone to bacteria growth when stored in a refrigerated environment at 0 to 10 ° C., and the number of viable bacteria is 2.0 × 10 ⁵ when stored for 4 days after production. Since it can be suppressed to less than / g, it is extremely hygienic and there is no worry of causing food poisoning or the like. In addition, the fresh flavor of the leafy vegetables can be maintained over a period of several days, and the vivid color of the leafy vegetables and the plump and voluminous appearance peculiar to shredded products must be maintained. It is something that can be done.

  In particular, the method for producing chopped leafy vegetables in a container of the present invention is particularly effective in producing leafy vegetables that are chopped into pieces having a width of 1 mm or less that are easily damaged by a bactericide.

  Hereinafter, the present invention will be described in detail. In the present invention, “%” means “mass%” unless otherwise specified.

In the present invention, leafy vegetables refer to all vegetables having relatively thin leaf parts such as cabbage, purple cabbage, lettuce, Chinese cabbage and the like as edible parts. In the present invention, these leafy vegetables are raw and about 5 mm or less. A processed product that is chopped into widths and packed in a plastic bag-like container or the like is called a container-packed chopped leaf vegetable.
Next, this invention is demonstrated for every process.

<First cleaning step>
This is a step of washing leaf vegetables before being cut (in a round state) with fresh water at 10 ° C. or lower. By washing in the state of the hole with the largest number of bacteria, many bacteria attached to the surface of leafy vegetables are efficiently removed to reduce the number of bacteria and prevent bacterial contamination in the next cutting process . In addition, by using fresh water at 10 ° C. or lower, it is possible to prevent the temperature of vegetables from rising and to suppress the growth of bacteria.
As the washing method, a method of immersing leaf vegetables in a water tank overflowing with fresh water, a method of showering fresh water on leaf vegetables, or the like can be arbitrarily selected, but washing with running water is desirable.

<Cut process>
In order to make it easier to handle the leaf vegetables after the first washing in the subsequent shredding process, and to make it easier to remove bacteria that have entered and adhered between the leaf parts in the next second washing process, It is a process of cutting into 2 to 8 parts, and further removing outer leaves and cores which are inedible parts. The number of bacteria is reduced in the first washing process, and it is important to keep the kitchen knife, cutting board, etc. clean in this process and prevent bacterial contamination.

<Second cleaning step>
It is the process of washing the leafy vegetables after being cut in the cutting process using fresh water of 10 ° C. or lower. The number of bacteria is reduced in the first washing process, but in the second washing process, the bacteria that enter and adhere between the leaf parts are efficiently removed to reduce the number of bacteria, and the bacterial contamination in the next shredding process. To prevent. In addition, by using fresh water at 10 ° C. or lower, it is possible to prevent the temperature of vegetables from rising and to suppress the growth of bacteria.
The washing method can be arbitrarily selected from a method of immersing leafy vegetables in a water tank overflowing with fresh water, a method of showering fresh water on leafy vegetables, etc., as in the first washing step. It is desirable.

<Chopping process>
This is a step of cutting the leaf vegetables after the second washing into strips by means of a slicer or the like. At the time of shredding, it is desirable to take measures such as washing the blade part of a slicer etc. under running water in order to remove the vegetable juice containing organic matter flowing out from the cut surface of leafy vegetables and prevent the growth of bacteria. . In addition, the shredded width of leafy vegetables is generally about 5 mm or less, but in the present invention, since the damage given to leafy vegetables is small, even when the shredded width is narrowed to 1 mm or less, the flavor remains for several days. It can maintain a fresh and crunchy texture, and can be applied to all shredded leafy vegetables.

<Third cleaning step>
This is a step of washing the shredded leafy vegetables using fresh water of 10 ° C. or lower. The vegetable juice containing organic matter flows out from the cut surface of the shredded leafy vegetables, but this organic matter promotes the growth of bacteria and reduces the bactericidal effect of ozone water in the next process. The organic matter is sufficiently removed in In addition, the bacteria left in the first and second washing steps are also removed.
As for the washing method, as in the first and second washing steps, a method of immersing leafy vegetables in a water tank overflowing with fresh water, a method of showering fresh water on leafy vegetables, and the like can be arbitrarily selected. It is desirable to use running water.

<Ozone water sterilization process>
This is a step of sterilizing the chopped leaf vegetables after the third washing using ozone water. As a sterilization method, the shredded leafy vegetable and ozone water are sufficiently brought into contact with each other by a method of immersing shredded leafy vegetable in ozone water or a method of showering ozoned water into shredded leafy vegetable. If the ozone concentration of ozone water is too low, or if the amount of ozone water used for leafy vegetables is small, a sufficient bactericidal effect cannot be obtained, so the ozone concentration of ozone water is 5 ppm or more, and the amount of ozone water used is leafy vegetables. On the other hand, it is necessary to use 8 times or more in mass ratio.

It should be noted that if the ozone concentration of the ozone water is too high, the ozone concentration of the ozone water is preferably 20 ppm or less because it may be damaged depending on the type of vegetables. Moreover, if the amount of ozone water used is 8 times or more the mass of leaf vegetables, it is too much for quality of shredded leaf vegetables, but this is not a problem. It is enough if we put it in quantity.
Ozone water may be produced by a conventional method. For example, ozone water can be easily produced by electrolyzing water using a commercially available ozone water generator. The ozone concentration of ozone water may be measured by a conventional method such as an ultraviolet absorption method. In addition, when the ozone water generator generally marketed is used, since ozone concentration of ozone water can be set arbitrarily, ozone water with a desired ozone concentration can be easily produced in large quantities.

<Dehydration process>
This is a process of removing moisture from the chopped leaf vegetables sterilized with ozone water. A lot of water remains in the leafy vegetables, and when water drops drips from the leafy vegetables, it becomes an environment where bacteria can easily grow during storage, and the fluffy volume peculiar to shredded cabbage is lost. Since it has a sticky appearance and looks bad and the product value decreases, it is necessary to dehydrate it appropriately. However, excessive removal of water from the leafy vegetables in this step results in a state of deflation during storage, which eliminates the crispness and is not preferable.
This dehydration treatment can be carried out using a general centrifugal vegetable dehydrator or the like as appropriate.

<Containment process>
This is a step of storing leafy vegetables from which moisture has been removed in the dehydration step in a synthetic resin container. Here, the synthetic resin container may be of any material and form that can keep the stored leafy vegetables clean, for example, polypropylene, polyethylene, polyamide, PET, etc. It is possible to use a bag-like container made of a single layer or a multi-layer film, a container in which a tray molded with PET, polystyrene or the like is enclosed in these bag-like containers. In addition, such a synthetic resin container may be provided with a small hole or the like so that carbon dioxide generated by respiration of the stored leafy vegetables can be discharged out of the container.
Moreover, what is necessary is just to perform filling of the leaf vegetable to a synthetic resin container using a general filling machine.

Container-packed shredded vegetables produced by the above process can suppress the number of viable bacteria to less than 2.0 × 10 ⁵ / g when stored at 0 to 10 ° C. for 4 days after production. In general, a cut vegetable having a general viable count of 1.0 × 10 ⁶ / g or more is not preferable in terms of hygiene because the number of bacteria is excessive.
In addition, the number of general viable bacteria is the most representative index indicating the degree of microbial contamination of foods, also called the standard plate bacteria count, and “Food Hygiene Inspection Guidelines” (Japan Food Sanitation Association, June 30, 2004) Issue, supervised by the Ministry of Health, Labor and Welfare).

<Example 1>
The cabbage of the hole was washed by immersing it in a water bath that was flushed with 10 ° C. fresh water for 1 minute (first washing step). Next, the outer leaf of the cabbage was removed, and the core part was removed by cutting into four pieces with a clean knife (cutting process). The resulting four-part cabbage was washed by immersing it for 1 minute in a water bath that was flushed with 10 ° C. fresh water (second washing step). Next, the cabbage was cut into 0.8 mm widths using a slicer (manufactured by Yoshizumi Sangyo Co., Ltd.). The obtained shredded cabbage was washed by immersing it in a water bath that was flushed with 10 ° C. fresh water for 1 minute (third washing step). Next, lightly drained shredded cabbage is put into a vegetable washing machine (trade name WA-300, manufactured by Kobe Steel, Ltd.), and ozone water with an ozone concentration of 15 ppm and 10 ° C. is 10 times the mass of cabbage. Was sterilized for 1 minute while stirring cabbage and ozone water (ozone water sterilization step). Thereafter, the shredded cabbage sterilized with ozone water was put into a dehydrator (manufactured by Daiei Seisakusho Co., Ltd.) and dehydrated for 1 minute at a rotation speed of 1000 rpm (dehydration step). The obtained dehydrated shredded cabbage was housed in a bag-like container made of a laminated sheet of polypropylene resin and sealed (accommodating step) to produce a container-packed shredded cabbage (implemented product 1).

<Example 2>
The cabbage of the hole was washed by immersing it in a water bath that was flushed with 10 ° C. fresh water for 1 minute (first washing step). Next, the outer leaf of the cabbage was removed, and the core portion was removed by cutting it in half with a clean knife (cutting process). The obtained split cabbage was washed by immersing it for 1 minute in a water bath which was flushed with 10 ° C. fresh water (second washing step). Next, the cabbage was chopped into 1.0 mm widths using a slicer (same as Example 1) (chopping step). The obtained shredded cabbage was washed by immersing it in a water bath that was flushed with 10 ° C. fresh water for 1 minute (third washing step). Next, lightly drained shredded cabbage is put into a vegetable washing machine (same as in Example 1), and ozone water with an ozone concentration of 5 ppm and 10 ° C. is used at a mass 8 times the cabbage mass. And ozone water were stirred for 1 minute (ozone water sterilization step). Thereafter, the shredded cabbage sterilized with ozone water was put into a dehydrator (same as in Example 1) and dehydrated at a rotation speed of 1000 rpm for 1 minute (dehydration step). The resulting dehydrated shredded cabbage is housed in a bag-like container (same as in Example 1) made of a polypropylene resin laminate sheet (same as in Example 1) and sealed (accommodating step). 2) was produced.

<Comparative Example 1>
The outer leaves of the cabbage in the hole were removed, and the core was removed by cutting into four pieces with a clean knife (cutting process). Next, the cabbage was cut into 0.8 mm widths using a slicer (same as in Example 1) (chopping step). The obtained shredded cabbage was washed by immersing it for 3 minutes in a water bath overflowed with 10 ° C. fresh water (cleaning step before sterilization). Next, lightly drained shredded cabbage is put into a vegetable washing machine (same as in Example 1), and ozone water having an ozone concentration of 15 ppm and 10 ° C. is used at a mass 10 times that of cabbage. And ozone water were stirred for 1 minute (ozone water sterilization step). Thereafter, the shredded cabbage sterilized with ozone water was put into a dehydrator (same as in Example 1) and dehydrated for 1 minute at a rotation speed of 1000 rpm (dehydration step). The resulting dehydrated shredded cabbage is housed in a bag-like container (same as in Example 1) made of a polypropylene-based resin laminate (same as in Example 1) and sealed (accommodating step). 1) was produced.

<Comparative example 2>
The outer leaves were removed from the cabbage of the hole, and the core was removed by cutting into four pieces with a clean knife (cutting process). Next, the quarter cabbage was cut into 0.8 mm widths using a slicer (same as in Example 1) (chopping process). The obtained shredded cabbage was washed by immersing it for 3 minutes in a water bath overflowed with 10 ° C. fresh water (cleaning step before sterilization). Next, the cabbage drained lightly was immersed in a water tank filled with a sterilizing solution containing sodium hypochlorite and sodium chlorite at a concentration of 150 ppm each (chlorine-based sterilization step). Thereafter, the sterilized shredded cabbage was immersed for 3 minutes in a water bath which was flushed with 10 ° C. fresh water to wash away the sterilizing solution (cleaning step after sterilization). Further, it was put into a dehydrator (same as Example 1) and dehydrated for 1 minute at a rotation speed of 1000 rpm (dehydration step). The resulting dehydrated shredded cabbage is housed in a bag-like container (same as in Example 1) made of a polypropylene-based resin laminate (same as in Example 1) and sealed (accommodating step). 2) was produced.

<Test example>
For each sample of the above-mentioned product 1, product 2, comparative product 1 and comparative product 2, the number of general viable bacteria (SPC) was measured immediately after production and after storage for 4 days in a refrigerator at 10 ° C. The flavor was evaluated. The number of general viable bacteria was measured by the method described in the “Food Sanitation Inspection Guidelines” above. The appearance was evaluated by visual observation, and the flavor was evaluated by tasting. The results are shown in Table 1.

Meaning of terms in Table 1
Appearance evaluation A: The original color tone of the cabbage is maintained and is good.
B: Partial discoloration is observed.
Evaluation of flavor A: The original flavor of cabbage is strongly felt and good.
B: The original flavor of cabbage is weak and slightly poor.
C: An unpleasant odor such as a chlorine odor is felt and is bad.

  From Table 1, it can be understood that in Examples 1 and 2, the general viable count of shredded cabbage is sufficiently suppressed even after storage for 4 days, the appearance and flavor are good, and the quality is excellent. On the other hand, Comparative Product 1 has a high number of general viable bacteria after storage for 4 days, and Comparative Product 2 has deteriorated in appearance and flavor after storage for 4 days, both of which have difficulty in quality. Is understood.

Claims (1)

A method for producing shredded vegetables in a container,
A first washing step for washing the leafy vegetables in the hall with fresh water of 10 ° C. or lower;
A cutting process for cutting leaf vegetables into 2 to 8 parts after the first washing,
A second washing step of washing the leaf vegetables after cutting with fresh water of 10 ° C. or less,
Shredding process for shredding the leaf vegetables after the second washing into 1 mm width or less ,
A third washing step of washing the leafy vegetables after shredding with fresh water of 10 ° C. or lower,
An ozone water sterilization process for sterilizing the leaf vegetables after the third washing process using ozone water having an ozone concentration of 5 to 20 ppm and 10 ° C. or less in a mass ratio of 8 times or more with respect to the leaf vegetables;
Dehydration step of dehydrating leafy vegetables after sterilization with ozone water, and
The manufacturing method characterized by including the accommodation process which accommodates the leaf vegetable after dehydration in a synthetic resin container.