CN103747685B - The manufacture method of Cut vegetables - Google Patents

Abstract

The manufacturing method of cut vegetables comprises: the 1st sterilizing process that makes vegetables contact with the alkaline liquid of pH11～13.5; The process of cutting above-mentioned vegetables after above-mentioned 1st sterilizing process; The second sterilization step of contacting with one or more liquids selected from fatty acid ester-containing surfactants and fatty acid salts.

Description

Method of making cut vegetables

technical field

The invention relates to a method for manufacturing cut vegetables.

Background technique

Cut vegetable products in which cut vegetables are sealed in polypropylene bags with nitrogen gas are widely sold in the fresh vegetable section of supermarkets. As an industrialized method for producing such cut vegetables, for example, a method has been proposed in which cut vegetables are treated in a chlorite solution, then dehydrated and directly stored without washing (Japanese Patent Laying-Open No. 11-196763 ).

Contents of the invention

However, in the cut vegetables produced by the method of JP-A-11-196763, depending on the type of vegetables, the peculiar astringency of the vegetables can be sensed. There are many consumers who do not like such astringent taste, centering on young people including infants and children.

Therefore, in order for consumers to accept cut vegetable products, it is required not only to exhibit good storage stability, but also to be able to industrially produce cut vegetables with greatly reduced astringency or no astringency. In addition, in order to industrially produce cut vegetable products exhibiting good storage stability, the cut vegetables are usually immersed in water or a chlorite solution, followed by washing and sterilization. In this case, bubbles from lime juice and additives are often generated on the liquid surface of the immersion tank, and overflow of bubbles from these immersion tanks hinders concentration control of the immersion liquid, so it is not preferable in terms of quality control. Therefore, it is required to produce cut vegetable products with stable quality without bubbles overflowing from the dipping tank.

The invention provides a method for producing cut vegetables. The method can produce cut vegetables whose unique astringent taste is greatly reduced or does not feel astringent, and has good storage stability. The dipping tank for vegetables overflows to produce cut vegetables with good storage stability and stable quality.

A method for producing cut vegetables according to an aspect of the present invention includes: a first sterilization step of bringing the vegetables into contact with an alkaline liquid having a pH of 11 to 13.5; a step of cutting the vegetables after the first sterilization step; The second sterilizing step in which the obtained cut vegetables are brought into contact with a liquid containing ozone and one or two or more types selected from fatty acid ester-containing surfactants or fatty acid salts.

In the method for producing cut vegetables, the alkaline liquid may be an aqueous solution of an alkali metal salt or an alkaline earth metal salt, or any of them. In this case, the total concentration of the alkali metal salt and the alkaline earth metal salt in the alkaline liquid may be 10 to 30000 mg/L.

In addition, in the method for producing cut vegetables, the concentration of chloride ions in the liquid containing the ozone and one or more selected from fatty acid ester-containing surfactants and fatty acid salts may be less than 100 mg/L.

In addition, in the above-mentioned method for producing cut vegetables, in the above-mentioned liquid containing one or more kinds selected from surfactants or fatty acid salts containing the above-mentioned fatty acid esters, surfactants selected from the group consisting of the above-mentioned fatty acid esters The total concentration of one or two or more of the agents or fatty acid salts may be 10 to 1000 mg/L.

Moreover, in the manufacturing method of the said cut vegetable, the surfactant containing the said fatty acid ester may be glycerin fatty acid ester.

According to the above-mentioned method for producing cut vegetables, by performing the treatment in the order of the above-mentioned first sterilization step, the above-mentioned cutting step, and the above-mentioned second sterilization step, it is possible to produce vegetables whose unique astringent taste is greatly reduced or does not feel astringent, Moreover, the cut vegetables having good storage stability can be produced with stable quality without bubbles overflowing from the immersion tank of the cut vegetables during production.

detailed description

Hereinafter, the manufacturing method of the cut vegetables which concerns on one Embodiment of this invention is demonstrated in detail. In addition, unless otherwise specified, "part" means a mass part, and "%" means a mass %.

1. Manufacturing method of cut vegetables

The method for producing cut vegetables according to this embodiment includes: a first sterilization step (hereinafter, also simply referred to as "first sterilization step") in which vegetables are brought into contact with an alkaline liquid having a pH of 11 to 13.5; The process of the above-mentioned vegetables (hereinafter also simply referred to as "cutting process"); The second sterilization step in which more than one liquid is in contact (hereinafter, also simply referred to as "the second sterilization step").

1.1. The first sterilization process

In the 1st disinfection process, vegetables are brought into contact with the alkaline liquid (henceforth abbreviated as "alkaline liquid") of pH11-13.5. For example, in the first sterilization step, vegetables can be brought into contact with the alkaline liquid by immersing the vegetables in an alkaline liquid of pH 11 to 13.5, or by spraying the alkaline liquid on the vegetables. The pH is the pH at 25° C., and the measurement can be performed using, for example, HM-30P manufactured by DKK Toa Co., Ltd. or the like. The pH described below can also be adjusted by the same method.

When the pH of the alkaline liquid exceeds 13.5, an astringent taste may be produced in the vegetables, and on the other hand, if the pH is less than 11, the vegetables may not be sufficiently sterilized. The pH of the alkaline liquid is preferably 12.0 to 13.0 from the viewpoint of sufficiently performing sterilization and more reliably reducing the astringent taste of vegetables.

The alkaline liquid is preferably an aqueous solution of an alkali metal salt and an alkaline earth metal salt, or an aqueous solution of either of them, from the viewpoint of the astringent taste of the obtained cut vegetables. At this time, the concentration of the alkali metal salt and the alkaline earth metal salt in the alkaline liquid is such that the pH of the alkaline liquid becomes the above-mentioned pH. The specific concentration also depends on the type of the alkali metal salt and the alkaline earth metal salt, but is preferably 10 to 100%. 30000mg/L, more preferably 100-10000mg/L, still more preferably 100-6000mg/L. In addition, at this time, the alkaline liquid is preferably an aqueous solution of at least one selected from, for example, calcined calcium, sodium hydroxide, potassium hydroxide, and calcium hydroxide, particularly from the viewpoint of the astringent taste of the obtained cut vegetables. Moreover, in consideration of the taste of the obtained cut vegetables, an aqueous solution of roasted calcium is more preferable.

As the water used for the alkaline liquid, tap water or groundwater to which a fungicide such as sodium hypochlorite has been added can be used for the sake of convenience or low cost in the production of cut vegetables. In addition, in order to increase the bactericidal effect, a small amount of chlorine-based bactericides such as hypochlorite and chlorite can be added to the alkaline liquid, but this may have an adverse effect on the astringent taste of cut vegetables. Therefore, in the method for producing cut vegetables according to the present embodiment, the concentration of chloride ions in the alkaline liquid is preferably less than 100 mg/L, more preferably 50 mg/L or less, further preferably 10 mg/L or less, as the lower limit, 0mg/L.

The temperature of the alkaline liquid when immersing vegetables in the alkaline liquid is preferably 0 to 50°C, more preferably 0 to 15°C. Here, if the immersion temperature is lower than 0°C, freezing damage to plant bacteria may occur, and on the other hand, if the immersion temperature exceeds 50°C, the texture of cut vegetables may deteriorate.

When immersing vegetables in an alkaline liquid, the immersion time is preferably 1 to 20 minutes, more preferably 2 to 20 minutes. Here, if the immersion time is less than 1 minute, the bactericidal effect may become insufficient. On the other hand, if the immersion time exceeds 20 minutes, browning tends to be accelerated.

Various additives may be contained in the alkaline liquid within a range that does not inhibit the astringent taste reducing effect. For example, acidic components such as organic acids, inorganic acids, and water-soluble chelating agents having acidic groups, surfactants, thickeners, dispersants, inorganic salts, alcohols, sugars, and the like may be contained.

In addition, you may cut vegetables before performing a 1st sterilization process. That is, the vegetables to be subjected to the first sterilization process may be uncut full-sized vegetables, or may remove inedible parts such as skins and cores from uncut full-sized vegetables, or may cut uncut full-sized vegetables Into about 1/2 ~ 1/4.

Moreover, when a vegetable is a leafy vegetable, the vegetable which piled up the leaf cut out from a core can also be applied. In addition, known methods can be used as the method of dicing. In addition, before performing the 1st sterilization process, you may wash vegetables beforehand.

Vegetables for carrying out the method for producing cut vegetables according to the present embodiment are not particularly limited. As the raw vegetable salad, commonly eaten vegetables can be used, such as leafy vegetables such as cabbage and lettuce, root vegetables such as radish and carrot, green pepper, onions etc. Among these vegetables, since leafy vegetables and onions tend to have an astringent taste, the method for producing cut vegetables according to this embodiment is preferably performed on at least one selected from leafy vegetables and onions.

1.2. Cutting process

Next, the above-mentioned vegetables after the above-mentioned first sterilization step are cut. Thus, cut vegetables can be obtained. For example, the vegetables subjected to the first sterilization step are cut into edible sizes using a commercially available food cutter. Here, the method of cutting vegetables depends on the type of vegetables, the cutting method (shredded, diced, square-cut, random cut, etc.), the type of dishes using cut vegetables (raw vegetable salad, cooked vegetable salad, etc.), etc. Decide appropriately. In this way, by performing the first sterilization step on the vegetables and cutting the vegetables before the second sterilization step, it is possible to suppress the astringency of the cut vegetables.

The cutting width in the cutting step is preferably 0.5 to 80 mm, more preferably 0.5 to 30 mm, even more preferably 0.5 to 3 mm. If the cutting width is less than 0.5 mm, astringent taste is likely to occur, and on the other hand, if the cutting width exceeds 80 mm, it is difficult to obtain a good taste of cut vegetables. These cutting widths are appropriately determined in accordance with cutting methods such as shredding, dicing, square column cutting, random cutting, and the like.

1.3. The second sterilization process

In the 2nd sterilization process, the cut vegetables obtained by the said cutting process are brought into contact with the liquid containing ozone and the following (a) component.

(a) Component: 1 or more selected from fatty acid ester-containing surfactants or fatty acid salts

By bringing the cut vegetables obtained by the above cutting step into contact with a liquid containing ozone and the above-mentioned component (a), it is possible to manufacture cut vegetables with a sharply reduced or no bitter taste unique to vegetables and good storage stability. Vegetables, and further cut vegetables with good storage stability can be produced with stable quality without air bubbles overflowing from the immersion tank of the cut vegetables during production.

1.3.1. Conditions

When immersing cut vegetables in the liquid containing ozone and (a) component, the temperature of the liquid is preferably 0 to 30°C, more preferably 0 to 10°C. Here, if the immersion temperature is lower than 0°C, freezing damage to plant bacteria may occur, and on the other hand, if the immersion temperature exceeds 30°C, damage to plant cells tends to increase.

When immersing cut vegetables in the liquid containing ozone and (a) component, the immersion time is preferably 1 to 30 minutes, more preferably 2 to 10 minutes. Here, if the immersion time is less than 1 minute, the bactericidal effect may become insufficient. On the other hand, if the immersion time exceeds 30 minutes, the damage to plant cells tends to increase.

By performing the second sterilization process on the cut vegetables, it is possible to sterilize and sufficiently suppress the occurrence of vegetable astringency. That is, at this time, by performing the second sterilization step on the cut vegetables obtained in the cutting step, the cut vegetables can be brought into contact with the liquid after increasing the surface area in contact with the liquid containing ozone and component (a). Furthermore, by using the liquid containing the component (a) in addition to ozone having a bactericidal effect, the wettability of the surface of the cut vegetables is improved, and the cleaning performance is improved, so it is possible to remove microorganisms such as pollution and bacteria adhering to the surface of the cut vegetables , It is possible to produce cut vegetables that are safe to use, and to remove the astringent taste. In addition, in the immersion tanks for cleaning and sterilizing cut vegetables, bubbles from lime juice and additives are often generated on the liquid surface of the immersion liquid. Therefore, even if cut vegetables are immersed in the dipping liquid, bubbles can be prevented from overflowing from the dipping tank, and stable quality can be produced without interfering with concentration management of the dipping liquid.

1.3.2. Liquids containing ozone and component (a)

The liquid containing ozone and (a) component can be comprised from the mixture of ozone, (a) component, and water, for example.

＜Ozone＞

Ozone used in the present invention may be used as a gas by aeration or may be used by dissolving it.

Aeration can be performed, for example, by storing to-be-processed water containing an object to be treated (cut vegetables) in a container, and supplying a gas (aeration gas) containing at least ozone to the to-be-processed water. In addition, the component (a) may be added to the water to be treated while supplying the aeration gas to the water to be treated.

In addition, in this step, when aeration is performed, a stirring device or the like may be used in combination in order to stir the water to be treated.

As a container (processing container) that holds the water to be treated and aerates it, since the oxidizing power of ozone is strong, it is preferable that the material of the surface in contact with the water to be treated is glass, Teflon (registered trademark), titanium, or ozone-treated (A strong oxide film is formed by high-concentration ozone) aluminum or stainless steel container. When using a container made of nitrile rubber, silicon, or polyurethane, which has low resistance to ozone, it is necessary to pay sufficient attention to the deterioration of the container.

As the aeration gas, the generated ozone can be directly used, or it can be diluted with a diluent gas and supplied.

The method of generating ozone is not limited, and there are methods of irradiating oxygen with high-energy light such as electron beams, radiation, and ultraviolet rays, chemical methods, electrolysis methods, discharge methods, and the like. Industrially, the silent discharge method is often used from the viewpoint of production cost and production volume.

For generation of ozone, a commercially available ozone generator can be used, for example, OZSD-3000A (trade name) manufactured by Ebara Industrial Co., Ltd. is commercially available.

Since ozone is self-decomposing, it is preferably used immediately after preparation.

As the diluent gas for diluting ozone, a gas inactive or low in reactivity to ozone is preferable, and examples thereof include helium, argon, carbon dioxide, oxygen, air, nitrogen, and the like.

The ozone concentration in the ventilation gas is not particularly limited, but is preferably 7500 volume ppm or less, more preferably 5000 volume ppm or less in consideration of operational safety. The lower limit is not particularly limited, but considering the efficiency of ozone treatment, etc., it is preferably 1 volume ppm or more, more preferably 10 volume ppm or more. In particular, in the present invention, since component (a) is used in combination in the first sterilization step and the second sterilization step, the sterilization effect can be effectively obtained when the concentration of ozone is low, for example, in the range of 10 to 5000 volume ppm. , and thus useful.

The method of aerating the aeration gas into the water to be treated is not particularly limited, and conventionally used methods such as diffusers, diffusers, diffusers, and injectors can be used.

In addition, in this process, in order to make bleaching, decomposition|disassembly of a refractory substance, etc. progress rapidly, an accelerated oxidation process (AOP) can be performed together with an aeration process.

AOP is a treatment that further promotes the oxidation reaction by actively decomposing ozone to generate hydroxyl radicals with high oxidizing power. As a method for positively decomposing ozone, ultraviolet irradiation, addition of H ₂ O ₂ , addition of an inorganic catalyst, and the like are generally used.

＜(a) Ingredients＞

Since the present invention relates to a method for producing cut vegetables, it is preferable to use components that are not subject to usage restrictions in food additives in consideration of residues in vegetables. In addition, since ozone is used for sterilization, compounds that react violently with ozone may reduce the bactericidal effect and lower the preservability, so it is not suitable. In view of these factors, as the fatty acid ester-containing surfactant of the (a) component, glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, etc. are preferably used. esters, sucrose fatty acid esters, propylene glycol fatty acid esters, and glycerin fatty acid esters are more preferred in consideration of storage stability. In this specification, "surfactant containing fatty acid ester" means "surfactant having a fatty acid ester moiety in the molecule".

Moreover, in order to suppress overflow of bubbles from a vegetable washing machine, it is preferable to be low-foaming. Taking the above into consideration, it is preferable that the carbon chain length of the hydrocarbon group derived from the (ester bonded) fatty acid of the fatty acid ester-containing surfactant is 1-9. In addition, in the fatty acid ester-containing surfactant, the carbon chain lengths of the hydrocarbon groups derived from the fatty acid bonded to the ester bond may be all the same or different. When the carbon chain length of the hydrocarbon group of the fatty acid ester is less than 1, the wettability of the vegetable surface may not be improved, and the bactericidal property may be significantly lowered. In addition, it is considered that it is difficult to obtain a fatty acid ester having a hydrocarbon group having a carbon chain length of less than 1 industrially, so it is not suitable for industrial use. When the carbon chain length of the hydrocarbon group of the fatty acid ester exceeds 9, the stability of generated air bubbles becomes high, and the air bubbles may overflow from the vegetable washing machine. From the above, it is more preferable to use a fatty acid ester of glycerol in which the hydrocarbon group of the fatty acid ester has a carbon chain length of 1 to 9.

Among glycerol fatty acid esters in which the hydrocarbon group of the fatty acid ester has a carbon chain length of 1 to 9, triacetin, diacetin, monoacetin, and monocaprylin are preferred. Among these, glyceryl triacetate and glyceryl monocaprylate are more preferable from the viewpoint of excellent effect of suppressing bubble overflow. Furthermore, it is most preferable to use glyceryl triacetate and glyceryl monocaprylate in combination from the viewpoint of obtaining an excellent bactericidal effect at a low concentration in a short time. In addition, the usage ratio of triacetin to monocaprylin (ratio of monocaprylin/triacetin) is preferably 2 to 5.5. In addition, examples of industrially available products include glyceryl triacetate (manufactured by Azuchi Sangyo Co., Ltd.), glyceryl monocaprylate (manufactured by Sun Chemical Co., Ltd., Sunsoft 700P-2), and the like.

In the case of triacetin, although the absolute value of the lowered surface tension (the amount of change to the equilibrium surface tension) is small, the rate of dynamic surface tension reduction is fast, allowing faster and easier wetting of cut vegetables surface. On the other hand, glyceryl monocaprylate lowers the dynamic surface tension more slowly than glyceryl triacetate, but the absolute value of the reduced surface tension is greater than that of glyceryl triacetate. It is possible to improve the wettability of the surface of the cut vegetables. Therefore, using the synergistic effect of monocaprylycerin and triacetin, the wettability of the surface of cut vegetables can be improved more quickly with less chemical dosage. Since triacetin is superior in water solubility and inexpensive compared to monocaprylin, compared with the case of using only monocaprylin, it is possible to further reduce the cost while maintaining the same pollution and microorganism removal effect. In addition, since triacetin has less bitterness than glyceryl monocaprylate, it is easy to suppress a change in the sense of taste of vegetables accompanying washing.

As the fatty acid salt of the component (a), it is preferable to use a fatty acid salt having a carbon chain length of 7 to 9 in the hydrocarbon group in consideration of remaining in vegetables and low foaming properties so as not to suppress bubbles from overflowing from the vegetable washing machine. Among them, caprylic acid salts are more preferred, and sodium salts are further preferred, from the viewpoint of excellent effect of suppressing bubble overflow.

The concentration of component (a) in the treated aqueous solution varies depending on the substance used, but is preferably 10 to 1000 mg/L, more preferably 10 to 100 mg/L, and still more preferably 15 to 95 mg/L. If the concentration of component (a) is 10mg/L or more, the effect of reducing the astringency of vegetables is easy to be obtained, and if the concentration of component (a) is 1000mg/L or less, the overflow of air bubbles is greatly reduced. Worry about residues in vegetables.

When preparing an aqueous solution containing ozone and (a) component, the above-mentioned (a) component, in other words, fatty acid ester-containing surfactant or fatty acid salt, can be prepared by diluting multiple components from a single raw material, or by combining multiple Concentrate each component into 1 or 2 or more formulations, and dilute the resulting formulations to prepare.

The water used for the aqueous solution containing ozone and component (a) is usually tap water or groundwater to which a fungicide such as sodium hypochlorite has been added for convenience or in view of the desire for low cost. Therefore, tap water or sodium hypochlorite may be used as water. fungicides in groundwater.

In addition, in order to enhance the bactericidal effect, a small amount of chlorine-based bactericides such as hypochlorite and chlorite may be added to the aqueous solution containing ozone and component (a), but this may adversely affect the astringent taste of the obtained cut vegetables. Therefore, in the method for producing cut vegetables according to this embodiment, the concentration of chloride ions is preferably less than 100 mg/L, more preferably 50 mg/L or less, even more preferably 10 mg/L or less, and the lower limit is 0 mg/L. .

As for cut vegetables, pH of the liquid containing ozone and (a) component becomes like this. Preferably it is 3.5-8.0, More preferably, it is 4.0-6.8. If pH is less than 3.5, damage to vegetables may become large and quality may be impaired. In addition, when the pH exceeds 8.0, the consumption of ozone may increase remarkably, and sufficient sterilization may not be possible.

The pH of the liquid containing ozone and component (a) can be adjusted with an alkaline agent such as an acid component or sodium hydroxide. The acid component is a water-soluble compound whose pH is less than 7.0 when about 0.5% is dissolved in pure water (pH 7.0), and is a hydrophilic compound that exhibits water solubility even at a weakly acidic pH of 6 or less. For example, an organic acid, an inorganic acid, a water-soluble chelating agent which has an acidic group, etc. are mentioned. In consideration of the preservability of the obtained cut vegetables, acetic acid, citric acid, phosphoric acid, or mixtures thereof are preferred, and acetic acid is more preferred at a concentration of 100 to 500 mg/L.

The liquid containing ozone and the component (a) may contain various additives within the range of ensuring the reduction effect of astringent taste, suppressing the overflow of air bubbles from the vegetable washing machine, and not hindering the ozone oxidation reaction. For example, surfactants, thickeners, dispersants, inorganic salts, alcohols, sugars, etc. other than the component (a) may be contained.

If necessary, the cut vegetables subjected to the second sterilization process are dehydrated using a known centrifugal dehydrator, and the obtained cut vegetables (with an inert gas such as nitrogen as necessary) are filled and sealed in a thermoplastic resin bag such as polypropylene, Thereby, a cut vegetable product can be obtained.

1.4. Features

According to the method for producing cut vegetables according to the present embodiment, by performing the treatment in the order of the first sterilization step, the cutting step, and the second sterilization step, it is possible to produce vegetables with a sharply reduced astringent taste or no astringent taste. , and have good storability cut vegetables, and furthermore, the cut vegetables with good storability can be produced with stable quality without bubbles overflowing from the immersion tank of the cut vegetables during production.

That is, sufficient sterilization can be performed by performing the first sterilization step. And, by processing in the order of the first sterilizing process, the cutting process, and the second sterilizing process, it is possible to sterilize with a specific bactericide before cutting, and to make the cut vegetables and the vegetables with the surface area increased after cutting. Since the liquid containing ozone and (a) component contacts, sufficient sterilization can be performed, and the generation of astringent taste of vegetables can be suppressed. In addition, since the liquid containing component (a) with low foam stability is used, even if the cut vegetables are immersed in the dipping liquid, bubbles can be prevented from overflowing from the dipping tank, and the concentration control of the dipping liquid, etc., can be maintained with stable quality. to manufacture.

2. Example

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following Example.

2.1. Embodiment 1

Divide 1,000 g of the whole cabbage without the core and contaminated outer leaves into quarters to obtain cabbage pieces, wash the cabbage pieces (vegetables) with clean water, and immerse them in 4,000 mL of alkaline liquid of pH 12 at 20°C 5 minutes. The above-mentioned alkaline liquid was adjusted by adding calcined calcium to tap water, and the calcined calcium concentration was adjusted to 1000 mg/L. Furthermore, a sodium hypochlorite solution was added to adjust the chloride ion concentration to 1 mg/L (the first sterilization step). Next, the cabbage pieces subjected to the first sterilization step were cut into 1 mm width with a shredding slicer (cutting step). The shredded cabbage (cut vegetables) enters the sieve located below the julienne slicer.

Next, the shredded cabbage was immersed in 40 L of aqueous solution at a liquid temperature of 10° C. for 5 minutes, and aeration treatment was performed by spraying air containing 5,000 volume ppm of ozone at a flow rate of 0.8 L per minute using an injector. .

The aqueous solution subjected to the ozone aeration was adjusted by adding component (a1) glyceryl monocaprylate (Sunsoft 700P-2 manufactured by Sun Chemical Co., Ltd.) and component (a2) glyceryl triacetate (manufactured by Azuchi Kogyo Co., Ltd.) to tap water. The concentration of glyceryl monocaprylate was adjusted to 40 mg/L, and the concentration of glyceryl triacetate was adjusted to 15 mg/L. Next, acetic acid (high-quality acetic acid manufactured by Daicel Industries) was added to the above-mentioned aqueous solution containing the above-mentioned (a1) and (a2), and the concentration of acetic acid was adjusted to 300 mg/L. Furthermore, an aqueous sodium hypochlorite solution was added to adjust the chloride ion concentration to 1 mg/L and the pH to 4.5, and the resulting solution was used in the second sterilization step (second sterilization step). The aqueous solution subjected to the above-mentioned ozone aeration is in a preferred state with few bubbles on the liquid surface and no overflow of bubbles from the immersion tank. Next, the shredded cabbage subjected to the second sterilization step was dehydrated using a centrifugal dehydrator (processing conditions: 1100 rpm, 1 minute) to obtain shredded cabbage (cut vegetables).

Shredded cabbage products were produced by putting the obtained shredded cabbage into a stretched acrylic bag with a thickness of 40 μm, and heat-sealing the opening of the bag, and kept in refrigeration at 10° C. for 4 days.

2.2. Embodiment 2

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, in the 2nd sterilization process of Example 1, except having added sodium hydroxide and adjusted pH to 6.8, the shredded cabbage product was manufactured similarly.

2.3. Embodiment 3～5

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were produced in the same manner except that the pH and composition of the alkaline liquid were changed in the first sterilization step of Example 1.

2.4. Embodiment 6

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, in the 1st sterilization process of Example 1, except having changed the composition of alkaline liquid, the shredded cabbage product was manufactured similarly.

2.5. Embodiment 7

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were manufactured in the same manner except that the composition of the alkaline liquid was changed in the first sterilization step of Example 1, and the concentration of chloride ions was changed in the second sterilization step. Here, the chloride ion concentration was adjusted by increasing the amount of sodium hypochlorite aqueous solution added.

2.6. Embodiment 8

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, in the first sterilization step of Example 1, shredded cabbage products were produced in the same manner except that the composition of the alkaline liquid and the concentration of chloride ions were changed. Here, the concentration of chloride ions was adjusted by increasing the amount of sodium hypochlorite added.

2.7. Embodiments 9-10

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were manufactured in the same manner except that the liquid used in the second sterilization step of Example 1 was changed.

As components added to the liquid used in the second sterilization process, component (a3) sorbitan caprylate (Rikemal C-250 manufactured by RikenVitamin Co., Ltd.) and component (a4) decaglyceryl monocaprylate were used respectively. (MCA-750 manufactured by Sakamoto Pharmaceutical Co., Ltd.).

2.8. Embodiment 11

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were produced in the same manner except that the liquid used in the second sterilization step of Example 1 was changed, and hydrochloric acid was added to adjust the pH to 6.7. As a component added to the liquid used in the second sterilization step, component (a5) sodium octanoate (Tokyo Chemicals) was used.

2.9. Examples 12-13

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were manufactured in the same manner except that the addition concentrations of (a1) glyceryl monocaprylate and (a2) glyceryl triacetate in the liquid used in the second sterilization step of Example 1 were changed.

2.10. Comparative example 1

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were produced in the same manner except that the first sterilization step of Example 1 (instead of the alkaline liquid, immersing the cabbage pieces in water) was not performed.

2.11. Comparative Example 2

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were produced in the same manner except that the second sterilization step (washing of shredded cabbage with water instead of ozone and liquid) in Example 1 was not performed.

2.12. Comparative example 3

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were manufactured in the same manner except that the first sterilization step and the second sterilization step in Example 1 were replaced.

2.13. Comparative Examples 4 and 5

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, shredded cabbage products were produced in the same manner except that the pH of the alkaline liquid used in the first sterilization step of Example 1 was changed. Here, in Comparative Examples 4 and 5, sodium hydroxide was added, and pH adjustment was performed by increasing or decreasing the added amount.

2.14. Comparative example 6

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, in the first sterilization process of Example 1, a hydrochloric acid solution (pH2) was used instead of the alkaline liquid, and the second sterilization process of Example 1 was not performed (that is, the cabbage pieces obtained by washing the cabbage pieces with clean water and then shredded). Shredded cabbage was washed with water), and a shredded cabbage product was produced in the same manner.

2.15. Comparative Example 7

In Example 1, shredded cabbage products were manufactured in the same manner as in Example 1 except that various conditions were changed to those shown in Table 1. That is, except that the liquid used in the second sterilization process of Example 1 was adjusted with a surfactant ((a'1) sodium dodecylbenzenesulfonate (Tokyo Chemical Industry Co., Ltd. reagent)), the same procedure was carried out. Make shredded cabbage products.

2.16. Test example 1

When the cut vegetables of Examples 1 to 11 and Comparative Examples 1 to 7 were produced, the degree of generation of air bubbles on the surface of the immersion liquid in the dipping tank in which the cut vegetables were dipped in the second sterilization step was evaluated by the following evaluation method. Moreover, about the cut vegetables of each example manufactured in Examples 1-11 and Comparative Examples 1-7, the number of bacteria and astringent taste after storage at 10 degreeC for 4 days were evaluated by the following evaluation methods. These results are shown in Table 1, respectively. In addition, since the evaluation of the astringency evaluation was not performed about the sample whose storage stability evaluation result was "x", it described it as "-" in a table|surface.

[Generation of air bubbles on the surface of the dipping liquid when dipping cut vegetables]

The degree of generation of air bubbles on the liquid surface during immersion was visually evaluated according to the following evaluation criteria.

"◎": Generation of air bubbles on the immersion liquid surface is less than 30% of the entire liquid surface.

"◯": Generation of air bubbles on the immersion liquid surface is 30% or more and less than 70% of the entire liquid surface.

"x": Generation of air bubbles on the immersion liquid surface is 70% or more of the entire liquid surface.

[Number of bacteria after preservation]

According to the food sanitation inspection guidelines, the general microbial count (SPC) of cut vegetables after storage is investigated, and the evaluation is carried out according to the following evaluation criteria.

"◎": less than 1×10 ⁴ CFU/g.

"○": 1×10 ⁴ CFU/g or more to less than 1×10 ⁶ CFU/g.

"×": 1×10 ⁶ CFU/g.

[Evaluation results of astringency]

The preserved cut vegetables were eaten and evaluated according to the following evaluation criteria.

"⊚": No astringency can be sensed at all.

"○": Astringent taste not to be minded.

"x": Astringent taste is sensed.

Table 1

Claims (20)

1. A method for producing cut vegetables, comprising: a first sterilization step of contacting the vegetables with an alkaline liquid of pH 11 to 13.5; a step of cutting the vegetables after the first sterilization step; and making the cut vegetables A second sterilization step in which the cut vegetables obtained in the step are contacted with a liquid containing ozone and one or two kinds of surfactants selected from fatty acid ester-containing surfactants and fatty acid salts, Wherein, the chloride ion concentration of the liquid containing the ozone and one or two selected from fatty acid ester-containing surfactants and fatty acid salts is less than 100 mg/L. 2. The method for producing cut vegetables according to claim 1, wherein the alkaline liquid is an aqueous solution of an alkali metal salt and/or an alkaline earth metal salt. The method for producing cut vegetables according to claim 2, wherein the total concentration of the alkali metal salt and the alkaline earth metal salt in the alkaline liquid is 10 to 30000 mg/L. 4. The method for producing cut vegetables according to claim 1, wherein in the liquid containing one or two selected from surfactants containing the fatty acid esters and fatty acid salts, selected from The total concentration of one or both of the fatty acid ester-containing surfactant and the fatty acid salt is 10 to 1000 mg/L. 5 . The method for producing cut vegetables according to claim 1 , wherein the alkaline liquid is an aqueous solution of at least one selected from calcined calcium, sodium hydroxide, potassium hydroxide, and calcium hydroxide. 6. The manufacturing method of cut vegetables according to claim 1, wherein the alkaline liquid contains calcined calcium. 7. The method for producing cut vegetables according to claim 1, wherein the chloride ion concentration of the alkaline liquid is less than 100 mg/L. 8 . The method for producing cut vegetables according to claim 1 , wherein in the first sterilization step, the temperature of the alkaline liquid when the vegetables are immersed in the alkaline liquid is 0 to 50° C. . 9. The method for producing cut vegetables according to claim 1, wherein the vegetables are at least one selected from leaf vegetables, root vegetables, green peppers, and onions. 10 . The method for producing cut vegetables according to claim 1 , wherein the cutting width of the vegetables in the cutting step is 0.5 to 80 mm. 11 . 11 . The method for producing cut vegetables according to claim 1 , wherein in the second sterilization step, the temperature of the liquid when the cut vegetables are immersed in the liquid is 0 to 30° C. 11 . 12. The manufacturing method of cut vegetables according to claim 1, wherein, the surfactant containing fatty acid ester is selected from glycerin fatty acid ester, polyglycerol fatty acid ester, sorbitan fatty acid ester, poly At least one of oxyethylene sorbitan fatty acid ester, sucrose fatty acid ester and propylene glycol fatty acid ester. 13. The method for producing cut vegetables according to claim 1, wherein the fatty acid ester-containing surfactant is glycerin fatty acid ester. 14. The method for producing cut vegetables according to claim 12 or 13, wherein the glycerin fatty acid ester is a glycerol fatty acid ester in which the carbon chain length of the hydrocarbon group of the fatty acid ester is 1-9. 15. The manufacturing method of cut vegetables according to claim 14, wherein, the fatty acid ester of glycerol whose carbon chain length of the hydrocarbon group of the fatty acid ester is 1 to 9 is selected from glyceryl triacetate, glyceryl diacetate, At least one of glyceryl monoacetate and glyceryl monocaprylate. 16 . The method for producing cut vegetables according to claim 15 , wherein the ratio of glyceryl triacetate to glyceryl monocaprylate is 2 to 5.5. 17 . The method for producing cut vegetables according to claim 1 , wherein the fatty acid salt is a fatty acid salt having a hydrocarbon group with a carbon chain length of 7-9. 18. The method for producing cut vegetables according to claim 1, wherein the fatty acid salt is caprylate. 19. The method for producing cut vegetables according to claim 1, wherein the fatty acid salt is a sodium salt. 20. The method for producing cut vegetables according to claim 1, wherein in the second sterilization step, the pH of the liquid is 3.5 to 8.0.