JP7153614B2 - Method for producing cut vegetables - Google Patents

Description

The present invention relates to a method for producing cut vegetables.

Recently, for the purpose of facilitating cooking at home, the number of cases where fruits and vegetables are sold in a form such as cut vegetables that can be cooked immediately is increasing. In addition, such cut vegetables and the like are treated with sterilized water containing hypochlorous acid for the purpose of avoiding the problem of discoloration or coloring during storage or the occurrence of food poisoning.

In Patent Document 1, cut vegetables are container-packed cut vegetables packed in a packaging container, and are stored at a temperature of 0 to 15 ° C. for one day after production and are removed from the packaging container. The amount of organic matter contained in the cut vegetables is 40 ppm or less as the COD of washing water obtained by soaking and washing 50 g of the cut vegetables in 500 mL of water, and the normal viable cell count of the cut vegetables is 1 × 10 ² to 1 × 10 ⁶ CFU/g of packaged cut vegetables are disclosed.
Patent Document 2 discloses a method for producing container-packed cut vegetables in which sterilized cut vegetables are packed in a packaging container, wherein the cut surfaces of the raw vegetables are sterilized with a sterilizing liquid at the time of harvest within 12 hours after harvesting. Disclosed is a method for producing container-packed cut vegetables in which the cut vegetables are processed and sterilized with an alkaline sterilizing solution after the sterilization, before cutting and/or after cutting.
Patent Document 3 discloses container-packed cut vegetables in which sterilized cut vegetables are packed in a packaging container, and the cut surfaces of the raw vegetables are sterilized with a sterilizing liquid within 12 hours after harvesting. The amount of organic matter adhering to the surface of the cut vegetables stored in containers at a temperature of 0 to 15 ° C. for 1 day after production and removed from the packaging container is 50 g of the cut vegetables in 500 mL of water. Disclosed is a container-packed cut vegetable whose COD of washing water obtained by immersion washing is 40 ppm or less, and a method for producing the same.
In Patent Document 4, in a method for producing container-packed cut vegetables in which sterilized cut vegetables are packed in a packaging container, the cut surface of the raw material vegetables at harvest within 12 hours after harvesting is sterilized with a sterilizing liquid. Disclosed is a method for producing container-packed cut vegetables in which the vegetables are sterilized with a sterilizing liquid before being cut into a size for packaging.

WO2013/179378 JP 2014-100101 A JP 2013-243988 A JP 2013-243987 A

As a conventional industrial production method for cut vegetables, the edible parts of vegetables are cut into edible sizes, washed, and sterilized using a hypochlorous acid aqueous solution such as electrolytic hypochlorite. was common. However, the present inventors have found that the cut vegetables obtained by the above production method have a problem that the growth of the number of viable bacteria adhering to the cut vegetables after storage cannot be sufficiently suppressed.

The present invention provides a method for producing cut vegetables that can suppress the growth of the number of viable bacteria adhering to the cut vegetables and the discoloration of the cut vegetables even after storage.

The present invention relates to a method for producing cut vegetables, including the following steps A to D.
Step A: Step of cutting the harvested vegetables in the vicinity of the separated part at the time of harvesting to expose a new cut surface Step B: After step A, on the new cut surface of the vegetables, (a) a fungicide (hereinafter referred to as component (a)) and a step of contacting a treatment liquid I containing water Step C: After step B, a step of cutting vegetables into eating sizes Step D: After step C, cut vegetables (a) A step of washing with a treatment solution II containing components and water

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the cut vegetables which can suppress the growth of the number of viable bacteria adhering to cut vegetables, and the discoloration of cut vegetables even after preservation is provided.

[Method for producing cut vegetables]
The reason why the method for producing cut vegetables of the present invention can suppress the growth of the number of viable bacteria adhering to cut vegetables and the discoloration of cut vegetables even after storage is not necessarily clear, but is presumed as follows.
The present inventors have found that the cause of the growth and discoloration of currently distributed cut vegetables is not only the fungi adhering to the surface of the cut vegetables, but also the fungi that have entered the interior of the cut vegetables through the vessels and the like. I found out that there is It is thought that the fungi present inside the cut vegetables of the product entered through the vegetable pipes, etc. from the equipment and washing water during the cutting of the vegetables and the subsequent sterilization, washing, and rinsing. In addition, it is conceivable that fungi attached to the cut vegetable surfaces and cut surfaces that have become products may migrate inside the cut vegetables during storage. In fact, it is often observed that the longer the water rinsing time after the sterilization and washing, the more fungal growth and discoloration of the cut vegetables. In the present invention, the harvested vegetables are newly cut to form a new cut surface including, in particular, a vessel portion, and the cut surface is brought into contact with a treatment liquid containing a bactericide, thereby preliminarily permeating the inside of the vegetables with a bactericide. By doing so, it is possible to sterilize the fungi that enter the interior through the cut surfaces of the vegetables when the vegetables are cut and thereafter. In particular, a remarkable effect can be obtained by cutting near the separated portion at the time of harvesting to expose a new cut surface and bringing it into contact with a treatment liquid containing a fungicide. As a result, after the pretreatment of the present invention, even if a conventional production process for cut vegetables is performed, the initial number of bacteria in the cut vegetables produced as a product can be significantly reduced, and the growth of bacteria during storage is also small. It is considered that the level could be maintained. In addition, most of the cut/separated parts of the harvested vegetables at the time of harvesting are clogged with drying and secretion substances of the vegetables themselves in the distribution process of the vegetables before cutting. It is considered necessary to expose a new cut surface before cutting in order to allow the disinfectant to penetrate efficiently.
In addition, the mechanism of action of the present invention is not limited to these.

Vegetables targeted by the present invention include leafy stem vegetables, fruit vegetables, root vegetables and the like. More specifically, one or more leafy and stem vegetables selected from cabbage, lettuce, Chinese cabbage, salad greens, green leaves, sunny lettuce, spinach, mizuna, Japanese mustard spinach, garland chrysanthemum, and onion, fruit vegetables such as green pepper, cucumber, and tomato, and radish. , Carrots, root vegetables such as taro, and the vegetables of the present invention include cabbage, lettuce, Chinese cabbage, salad greens, green leaves, sunny lettuce, spinach, mizuna, Japanese mustard spinach, from the viewpoint of expanding the range of application of distribution time and temperature. , garland chrysanthemum, and onion.

<Process A>
Step A is a step of cutting the harvested vegetables in the vicinity of the separation portion at the time of harvesting to expose a new cut surface.
Since it often takes time for harvested vegetables to be transported to a factory for manufacturing cut vegetables, the separation surface formed at the time of harvesting the vegetables is discolored and contaminated with secretions and the like. In addition, the cross section of the vessel on the separation surface of the vegetables is blocked by air drying, and even if the separation surface at the time of harvesting is brought into contact with the treatment liquid I in the process B without performing the process A, The component (a) of does not permeate the interior of the vegetables, and the effect of the present invention cannot be obtained. Therefore, in step A, it is preferable that the vegetable is cut in the vicinity of the separated portion at the time of harvesting to expose a new cut surface and newly expose a cross section of one or more vessels of the vegetable. The separated portion and the new cut surface at the time of harvesting the vegetables can be formed by selecting, for example, the portion that was in contact with the soil when the vegetable was growing and the portion that was in the vicinity of the soil. In addition, the separation part and the cut surface can be formed by selecting from a part where vessels gather and a part connected to vessels. The position of the new cut surface can be set appropriately depending on the type of vegetables, etc. As an example, the new cut surface is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 1 mm or more from the separated portion at harvest. It is preferable to expose at a distance of 10 mm or less, more preferably 5 mm or less.

In the cutting of the vegetables in step A, as long as the vegetables are cut and new cut surfaces are exposed, the cut parts may remain in the vegetables or may be separated from the vegetables. The separation method is convenient in terms of work.
When newly exposing the cut surface of the vegetable, it is preferable to cut the cut surface without leaving the separated surface at the time of harvesting. Moreover, when a new cut surface is exposed, it is preferable that the new cut surface does not cover edible parts such as leaves.
As a method for newly exposing the cut surface to the vegetables, from the viewpoint of preventing contamination by bacteria, a method such as cutting with a knife or making a notch is preferable. Furthermore, excision, and excision using a clean knife or other edged tool is preferable. One way to clean the blade is to disinfect it with a disinfectant. Ethanol, chlorate aqueous solution, etc. can be used as a disinfectant.

Step A is preferably a step of excising the harvested vegetables in the vicinity of the separation portion at the time of harvesting to expose a new separation surface.
In step A, from the viewpoint of efficiently contacting and permeating the new separation surface with the treatment liquid I in step B, the neighboring portion including the separated portion of the vegetables at the time of harvesting is excised to expose the new separation surface. is more preferred.

When the vegetables targeted by the present invention are one or more kinds of leafy stem vegetables selected from cabbage, lettuce, Chinese cabbage, salad greens, green leaves, sunny lettuce, spinach, mizuna, Japanese mustard spinach, edible chrysanthemum, and onion, separation at the time of harvest Since the portion is formed in the core of the leafy stem vegetable, in that case, step A includes cutting, preferably excising, the neighboring portion including the separated portion formed in the core at the time of harvesting the leafy stem vegetable. It is preferable to expose a new cut surface, preferably a separation surface, on the core.

<Process B>
Step B is, after step A, a step of contacting a new cut surface of the vegetable with a treatment liquid I containing the component (a) and water. In step B, the new cut surface of the vegetable formed in step A is brought into contact with the treatment liquid I, thereby spreading the component (a) contained in the treatment liquid I through the vessel of the vegetable to the entire inside of the vegetable. It may be a permeation step.

The treatment liquid I contains a bactericide as the component (a).
Examples of disinfectants include chlorine-based disinfectants and oxygen-based disinfectants. Component (a) specifically includes hypochlorous acid or its salts, organic peracids, ozone, and hydrogen peroxide. Alkali metal salts such as sodium salts are preferred as the hypochlorite from the standpoints of availability and sterilization. Organic peracids include organic peracids having 2 to 12 carbon atoms, and peracetic acid, perlauric acid, and peroctanoic acid are preferred from the viewpoint of availability and sterilization. Hydrogen peroxide is also a disinfectant that can be suitably used. Component (a) is preferably hypochlorous acid or a salt thereof from the viewpoint of availability and sterilization.

As the treatment liquid I, a weakly alkaline treatment liquid containing hypochlorous acid or its salt and water (hereinafter referred to as treatment liquid Ia), a neutral to weak solution containing hypochlorous acid or its salt and water An acidic processing liquid (hereinafter referred to as processing liquid Ib) can be used.

The treatment liquid Ia can be obtained by diluting a concentrated hypochlorite aqueous solution to make it slightly alkaline. Further, the treatment liquid Ib can be obtained as a neutral to weakly acidic liquid by electrolyzing saline or hydrochloric acid to generate hypochlorous acid. The treatment liquid Ib is available as electrolyzed water, slightly acidic electrolyzed water, or the like.

In the treatment liquid I, the component (a) is preferably 0.1 ppm or more, more preferably 0.5 ppm or more, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage, and from the viewpoint of influence on odor and appearance. , preferably 500 ppm or less, more preferably 250 ppm or less.
The treatment liquid Ia contains component (a) preferably at 10 ppm or more, more preferably 50 ppm or more, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage, and preferably at 500 ppm from the viewpoint of the effect on odor and appearance. below, more preferably below 250 ppm.
In the treatment liquid Ib, the component (a) is preferably 0.1 ppm or more, more preferably 0.5 ppm or more, still more preferably 1 ppm or more, and even more preferably 2 ppm, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. Above, more preferably 5 ppm or more, and from the viewpoint of influence on odor and appearance, preferably 100 ppm or less, more preferably 50 ppm or less, still more preferably 30 ppm or less, and even more preferably 25 ppm or less.
When the component (a) is a salt, the content is calculated based on the amount converted to the acid form of the component. The same applies to quantitative ratios involving the component (a), such as mass ratios described later.

The treatment liquid I preferably contains a surfactant as the component (b) from the viewpoints of improving bactericidal properties, suppressing discoloration after storage, and shortening the time required for the step B. As the component (b), a nonionic surfactant is preferable from the viewpoint of shortening the time of the step B and reducing foam.

Examples of nonionic surfactants include alkyleneoxy groups such as glycerin fatty acid esters, polyglycerin fatty acid esters, propylene glycol fatty acid esters, polyethylene glycol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, and polyoxyethylene sorbitan fatty acid esters. and polyhydric alcohol fatty acid esters. Further, polyoxyethylene alkyl ether, polyoxyethylene dialkyl ether, polyoxyethylene glycol, polyoxyethyleneoxypropylene glycol, polyoxypropyleneoxyethyleneoxypropylene glycol and the like are included.

When glycerin fatty acid ester is used, the average degree of esterification is preferably 0.8 or more, more preferably 1 or more, and preferably 3 or less, more preferably 1, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. 0.5 or less, more preferably 1, ie, a monoester. The number of carbon atoms in the fatty acid is preferably 6 or more, more preferably 8 or more, and preferably 12 or less, more preferably 10 or less, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. The average number of added moles of glycerin is preferably 1 mol or more, preferably 5 mol or less, more preferably 2 mol or less, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. In addition, the 1 mol adduct in the glycerin fatty acid ester is preferably 40% or more, more preferably 50% or more, still more preferably 70% or more, and 100%, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. It is preferable to have:
When sorbitan fatty acid ester is used, the average degree of esterification is preferably 0.8 or more, more preferably 1 or more, and preferably 3 or less, more preferably 3 or less, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. It is 1.5 or less, more preferably 1, that is, a monoester. The carbon number of the fatty acid is preferably 8 or more, more preferably 12 or more, still more preferably 16 or more, and preferably 20 or less, more preferably 18 or less, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. Fatty acids are saturated or unsaturated fatty acids, preferably unsaturated fatty acids.

From the viewpoint of food safety, the component (b) is one or more selected from glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and sucrose fatty acid esters, which are also food additives. is preferred.
Component (b) is preferably one or more selected from glycerin fatty acid esters and sorbitan fatty acid esters, from the viewpoint of further improving bactericidal properties and suppressing discoloration after storage.
The treatment liquid I preferably contains a glycerin fatty acid ester as the component (b).

When the treatment liquid I contains the (b) component, the (b) component is preferably 1 ppm or more, more preferably 5 ppm or more, from the viewpoint of improving bactericidal properties, suppressing discoloration after storage, and shortening the time of step B, More preferably 10 ppm or more, and from the viewpoint of shortening the time of step B and low foaming, preferably 1000 ppm or less, more preferably 100 ppm or less, and still more preferably 50 ppm or less.

When the treatment liquid I contains the component (b), the mass ratio (a)/(b) of the content of the component (a) to the content of the component (b) is determined to improve sterilization properties and discoloration after storage. From the viewpoint of suppression and time reduction of step B, it is preferably 0.01 or more, more preferably 0.1 or more, and preferably 20 or less, more preferably 15 or less. In addition, when the (a) component is a chlorine-based disinfectant, the effective chlorine concentration / (b), which is the mass ratio between the effective chlorine concentration and the content of the (b) component, is the above (a) / (b). A range is preferred.

From the viewpoint of obtaining physical properties of low foaming and low viscosity, the treatment liquid I preferably contains a water-soluble solvent as the component (c). Examples of water-soluble solvents include ethylene glycol, propylene glycol, ethanol, diethylene glycol monobutyl ether and the like.

The pH of the treatment liquid Ia is preferably 8 or more, more preferably 9 or more, and preferably 11 or less, more preferably 10, from the viewpoints of improving bactericidal properties, suppressing discoloration after storage, safety, and affecting appearance. It is below.
The pH of the treatment liquid Ib is preferably 4 or more, more preferably 5 or more, and preferably less than 8, more preferably 7, from the viewpoints of improving bactericidal properties, suppressing discoloration after storage, safety, and affecting appearance. It is below.

In step B, as a method of contacting and permeating the new cut surfaces of the vegetables with the treatment liquid I, there is a method of immersing the vegetables in the treatment liquid I so that the treatment liquid I contacts at least the new cut surfaces of the vegetables. preferable. In addition to the method of immersing the vegetables in the treatment liquid I, as a method of bringing the new cut surfaces of the vegetables into contact with the treatment liquid I, there is a method of applying, spraying, or compressing the treatment liquid I onto the new cut surfaces of the vegetables. mentioned.

In step B, the time for contacting and permeating the newly cut surface of the vegetable with the treatment liquid I is preferably 1 second or longer, more preferably 60 seconds or longer, and still more preferably 60 seconds or longer, from the viewpoint of improving sterilization properties and suppressing discoloration after storage. is 180 seconds or more, and from the viewpoint of workability, it is preferably 1 day or less, more preferably 3 hours or less, and even more preferably 30 minutes or less.

In step B, when the vegetables are immersed in the treatment liquid I so that the treatment liquid I comes into contact with and permeates at least the new cut surface of the vegetables, the time for immersing the vegetables in the treatment liquid I depends on the sterilization improvement and after storage. From the viewpoint of suppressing discoloration, preferably 1 second or more, more preferably 60 seconds or more, and still more preferably 180 seconds or more, and from the viewpoint of workability, preferably 6 hours or less, more preferably 3 hours or less, and more preferably is less than 30 minutes.

<Process C>
Step C is a step of cutting vegetables into eating size after step B. Step C may be a step of cutting the vegetables permeated with the component (a) in step B into eating sizes.

As a mode of cutting vegetables into eating size, after removing the outer leaves, skin and core in advance, cutting with a knife such as square cutting, julienne, strip cutting, ginkgo cutting, beat cutting, round cutting, etc. "Chigiri" etc. can be mentioned. As for the eating size, shreds with a width of 0.2 to 5.0 mm or diced with a width of 1 to 8 cm are preferable in terms of meeting consumer demand and ease of eating.

In step C, when cutting the vegetables into eating sizes, the vegetables are cut while pouring a treatment liquid containing the component (a) (hereinafter referred to as a water injection treatment liquid), for example, an aqueous solution containing the component (a) into the cut portion of the vegetables. You may perform processing to do. As the water injection treatment liquid, for example, an aqueous solution containing chlorite (preferably sodium salt), ozone, acetic acid, ethanol, etc., and electrolytic hypochlorite may be used.

As the water injection treatment liquid, the treatment liquid I described above, preferably the treatment liquid Ia or the treatment liquid Ib can be used. For the treatment liquid to be injected, the treatment liquid I, preferably the treatment liquid Ia, or the treatment liquid Ib can be appropriately applied.
When treatment liquid I is used as the water treatment liquid, the concentration of component (a) is preferably 0.1 ppm or more, more preferably 0.5 ppm or more, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage, and From the viewpoints of shortening the time of Step C and reducing foaming, it is preferably 500 ppm or less, more preferably 250 ppm or less.
When treatment liquid Ia is used as the water injection treatment liquid, the concentration of component (a) is preferably 10 ppm or more, more preferably 50 ppm or more, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. from the viewpoint of the influence of , it is preferably 500 ppm or less, more preferably 250 ppm or less.
When the treatment liquid Ib is used as the water treatment liquid, the concentration of the component (a) is preferably 0.1 ppm or more, more preferably 0.5 ppm or more, and still more preferably from the viewpoint of improving sterilization properties and suppressing discoloration after storage. is 1 ppm or more, more preferably 2 ppm or more, still more preferably 5 ppm or more, and from the viewpoint of the effect on odor and appearance, preferably 100 ppm or less, more preferably 50 ppm or less, still more preferably 30 ppm or less, and even more preferably is 25 ppm or less.

As a specific method of cutting vegetables into eating size while pouring water, when using a commercially available food slicer to cut vegetables, it is possible to cut while pouring water treatment liquid into the cut part of vegetables. A hose, a shower head, or the like may be used to supply the water treatment liquid.

The water injection amount of the water injection treatment liquid is preferably 0.1 L/min or more, more preferably 0.2 L/min or more, and preferably 10 L/min or less when the vegetable cutting process is performed at, for example, 1 kg/min. , more preferably 5 L/min or less, still more preferably 3 L/min or less. The temperature of the water treatment liquid is preferably 0 to 10°C.

<Process D>
Step D is a step of washing the cut vegetables after Step C with a treatment liquid II containing the component (a) and water. In step D, the cut vegetables impregnated with the component (a) in step B are further washed with treatment liquid II to sterilize the outer surface of the cut vegetables and increase the number of viable bacteria adhering to the cut vegetables after storage. And discoloration of cut vegetables can be suppressed.

In step D, the method of washing the cut vegetables with the treatment liquid II may be any method as long as the cut vegetables are brought into contact with the treatment liquid II. Specifically, the cut vegetables are immersed in the treatment liquid II, A method of air bubbling is mentioned.

In step D, the time for washing the cut vegetables with the treatment solution II is preferably 1 second or longer, more preferably 5 seconds or longer, and still more preferably 30 seconds, from the viewpoint of sterilization, suppression of bacterial growth, and suppression of discoloration. From the viewpoint of the above and the effect on the appearance, the time is preferably 60 minutes or less, more preferably 30 minutes or less, and even more preferably 10 minutes or less.

In step D, the time for immersing the cut vegetables in the treatment solution II for washing is preferably 10 seconds or longer, more preferably 30 seconds or longer, and even more preferably 1 second or longer, from the viewpoint of sterilization, suppression of bacterial growth, and suppression of discoloration. minutes or more, and preferably 60 minutes or less, more preferably 30 minutes or less, and even more preferably 10 minutes or less from the viewpoint of the influence on the appearance.

The treatment liquid II contains a bactericide as the component (a). The component (a) is the same as the component (a) of the treatment liquid I described above, and the preferred embodiments are also the same.

As the treatment liquid II, a weakly alkaline treatment liquid containing hypochlorous acid or its salt and water (hereinafter referred to as treatment liquid IIa), a neutral to weak solution containing hypochlorous acid or its salt and water An acidic processing liquid (hereinafter referred to as processing liquid IIb) can be used. The treatment liquids IIa and IIb can be obtained in the same manner as the treatment liquids Ia and Ib.

Treatment liquid II contains component (a) preferably at 0.1 ppm or more, more preferably 0.5 ppm or more, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage, and from the viewpoint of effect on odor and appearance. , preferably 500 ppm or less, more preferably 250 ppm or less.
Treatment liquid IIa contains component (a) preferably at 10 ppm or more, more preferably 50 ppm or more, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage, and preferably at 500 ppm from the viewpoint of influence on odor and appearance. below, more preferably below 250 ppm.
In the treatment liquid IIb, the component (a) is preferably 0.1 ppm or more, more preferably 0.5 ppm or more, still more preferably 1 ppm or more, and even more preferably 2 ppm, from the viewpoint of improving bactericidal properties and suppressing discoloration after storage. Above, more preferably 5 ppm or more, and from the viewpoint of influence on odor and appearance, preferably 100 ppm or less, more preferably 50 ppm or less, still more preferably 30 ppm or less, and even more preferably 25 ppm or less.

Treatment liquid II preferably contains a surfactant as component (b) from the viewpoints of improving bactericidal properties, suppressing discoloration after storage, and shortening the time required for step B. The component (b) is the same as the component (b) of the treatment liquid I described above, and the preferred embodiments are also the same.

When the treatment liquid II contains the (b) component, the (b) component is preferably 1 ppm or more, more preferably 5 ppm or more, from the viewpoint of improving bactericidal properties, suppressing discoloration after storage, and shortening the time of step B, More preferably 10 ppm or more, and from the viewpoint of shortening the time of step B and low foaming, preferably 1000 ppm or less, more preferably 100 ppm or less, and still more preferably 50 ppm or less.

When the treatment liquid II contains the component (b), the mass ratio (a)/(b) of the content of the component (a) to the content of the component (b) is determined to improve sterilization and discoloration after storage. From the viewpoint of suppression and time reduction of step B, it is preferably 0.01 or more, more preferably 0.1 or more, and preferably 20 or less, more preferably 15 or less. However, when the (a) component is a chlorine-based disinfectant, the content of the (a) component is a value converted to the effective chlorine concentration.

The treatment liquid II preferably contains the water-soluble solvent of the component (c) described for the treatment liquid I from the viewpoint of obtaining low-foaming and low-viscosity physical properties.

The pH of the treatment liquid IIa is preferably 8 or more, more preferably 9 or more, and preferably 11 or less, more preferably 10, from the viewpoints of improving bactericidal properties, suppressing discoloration after storage, safety, and affecting appearance. It is below.
The pH of the treatment solution IIb is preferably 4 or more, more preferably 5 or more, and preferably 8 or less, more preferably 7, from the viewpoints of improving bactericidal properties, suppressing discoloration after storage, safety, and affecting appearance. It is below.

The treatment liquid II may have the same composition (components and contents) as the treatment liquid I described above from the viewpoint of workability and availability. For the treatment liquid II, the aspects described for the treatment liquid I can be applied as appropriate.

<Process E>
The method for washing cut vegetables of the present invention preferably includes the following step E from the viewpoint of removing foreign substances and dirt components adhering to vegetables and removing treatment liquid I and treatment liquid II in which they are dissolved and dispersed.
Step E: After step D, a step of exposing the cut vegetables to water or hypochlorous acid or its salt, and a neutral or weakly acidic treatment solution containing water (hereinafter collectively referred to as a water treatment solution).

In step E, the method of exposing the cut vegetables to the water treatment liquid includes a method of immersing the cut vegetables in the water treatment liquid, a method of blowing air into the immersion tank for bubbling treatment, and a method of rinsing the cut vegetables with the water treatment liquid. method.
As the water of the water treatment liquid used in step E, tap water and fresh water are desirable. The water treatment liquid may be an aqueous solution of a sterilant with weak sterilization power, such as an aqueous solution containing chlorite (preferably sodium salt), ozone, acetic acid, ethanol, etc., and electrolytic hypochlorite water, which may be used for sterilization. From the viewpoint of improving properties and suppressing discoloration after storage, it is possible to use a neutral or weakly acidic treatment solution containing water, hypochlorous acid or its salt, and water, and the above-described treatment solutions Ib to IIb. preferable. Specific examples and preferred examples of the treatment liquids Ib to IIb are as described above.

In step E, when the cut vegetables are immersed or rinsed in the water treatment liquid, the time for immersing the cut vegetables in the water treatment liquid is the removal of foreign matter and dirt components attached to the vegetables and the treatment liquid I in which they are dissolved and dispersed. From the viewpoint of removal of the treatment liquid II, the time is preferably 1 second or longer, more preferably 3 seconds or longer, and preferably 10 minutes or shorter, more preferably 5 minutes or shorter. Especially when rinsing with a water treatment liquid, from the viewpoint of suppressing new bacterial contamination and reducing the number of bacteria before storage, it is preferably 1 second or longer, more preferably 3 seconds or longer, and preferably 5 minutes or shorter, more preferably 5 minutes or shorter. It is 10 seconds or less, more preferably 5 seconds or less.

After step E, in order to remove water containing trace amounts of organic matter from the cut vegetables, a centrifugal separator may be used to drain water if necessary. The produced cut vegetables are hermetically filled in packaging containers.

<Preparation of treatment liquid>
(1) Treatment liquid a
Using tap water (pH 7.5, hardness 2.1 ° dH) as a raw material, 15 ppm of electrolytic hypochlorite was obtained using Pure Star Mu-Clean II (slightly acidic electrolyzed water generator, manufactured by Morinaga Milk Industry Co., Ltd.). (Sodium hypochlorite concentration of 15 ppm). Using this, as the component (b), a glycerin fatty acid ester (Sunsoft No. 700H, manufactured by Taiyo Kagaku Co., Ltd.) was added to 20 ppm to prepare a treatment liquid a (mass ratio (a)/ (b) = 0.75). The temperature of the treatment liquid a was adjusted to 20°C. The concentrations of electrolytic hypochlorite and sodium hypochlorite are concentrations converted to acid-type compounds.

(2) Treatment liquid b
Using tap water (pH 7.5, hardness 2.1 ° dH) as a raw material, 15 ppm of electrolyzed hypochlorite was obtained using Purestar Muclean II (slightly acidic electrolyzed water generator, manufactured by Morinaga Milk Industry Co., Ltd.) ( concentration of sodium hypochlorite is 15 ppm). This was used as the treatment liquid b. The temperature of the treatment liquid b was adjusted to 20°C. The concentrations of electrolytic hypochlorite and sodium hypochlorite are concentrations converted to acid-type compounds.

<Example 1 and Comparative Example 1>
Example 1-1
A few outer leaves, which are the non-edible parts of the harvested lettuce, were removed. The neighboring part including the separated part formed in the core at the time of harvesting was cut with a kitchen knife almost perpendicular to the vessel to expose a new separated surface in the core (step A). Next, the lettuce core was immersed in the treatment liquid a for 10 minutes so that the treatment liquid a was in contact with the new separation surface formed on the core of the lettuce ( Step B). After the immersion, the lettuce core was removed and cut into approximately 3 cm squares with a kitchen knife (step C). 30 g of cut lettuce was placed in a 3 L beaker with a handle (made of SUS304, manufactured by AS ONE Co., Ltd.) containing 1.8 liters of treatment liquid a, and a bubbling operation (an operation of injecting air at a rate of 60 liters/minute) was performed for 5 times. minutes, and the washed lettuce was pulled up using a colander (step D). The washed lettuce was placed in a basket of a salad spinner, soaked in a bowl containing 1800 g of water for 3 seconds, and then pulled out for rinsing (step E). Tap water (pH 7.5, hardness 2.1°dH, 20°C) was used as rinsing water. After rinsing, the salad spinner was spun to dehydrate the lettuce for 30 seconds.
20 g of dehydrated lettuce was weighed, placed in a zippered plastic bag (Unipack H-4, manufactured by Seisan Nippon Co., Ltd.), and stored at 10° C. for 3 days.

Example 1-2
Cut lettuce was produced and stored in the same manner as in Example 1-1, except that in step B, treatment liquid b was used instead of treatment liquid a.

Comparative Example 1-1
Cut lettuce was produced and stored in the same manner as in Example 1-1, except that Step A and Step B were not performed.

Comparative Example 1-2
Cut lettuce was produced and stored in the same manner as in Example 1-1, except that step A was not performed.

Comparative Example 1-3
Cut lettuce was produced and stored in the same manner as in Example 1-1, except that step B was not performed.

Comparative Example 1-4
Cut lettuce was produced and stored in the same manner as in Example 1-1, except that tap water (pH 7.5, hardness 2.1°dH, 20°C) was used in step B instead of treatment liquid a. did.

Comparative Example 1-5
Cut lettuce was produced and stored in the same manner as in Example 1-1, except that step D was not performed.

Comparative Example 1-6
Cut lettuce was produced and stored in the same manner as in Example 1-1, except that the order of steps A and B was reversed.

[Measurement of viable count]
10 g of lettuce before storage and after storage for 3 days are each weighed, placed in a sample bag for stomacher (Sanispec filter test bag, AS ONE Corporation), 10 g of physiological saline is added, and homogenizer (SH-II M , Elmex Co., Ltd.) for 60 seconds to collect an extract. Thereafter, the cells were inoculated on a standard agar medium by the agar plate surface smearing method, and after culturing at 37°C for 48 hours, the number of viable cells was measured. In addition, as a standard, several outer leaves, which are the inedible parts of the harvested lettuce, are removed, the core is removed, and the lettuce is cut into 3 cm squares with a kitchen knife (only in process C, processes A, B, D, The viable count of lettuce without E) (also referred to as reference cut lettuce) was measured in the same manner as above.
Table 1 shows the difference between the obtained viable count and the viable count of the reference cut lettuce as the general viable count. The general viable cell count is the difference from the standard cut lettuce, and a negative value and a smaller value (larger absolute value) are preferable in terms of growth suppression of the viable cell count. The absolute value of viable count of standard cut lettuce is 4.8 to 5.9 (logcfu/g) before storage.

[Discoloration evaluation]
The degree of discoloration of the lettuce after storage for 3 days was evaluated according to the following criteria. Table 1 shows the results. For lettuce, 2 or more is preferred. In addition, the score is a value obtained by rounding off the average value given by three researchers who have been conducting research on the freshness of vegetables for 5 years or more according to the following criteria.
5: There was no discoloration at all.
4: Discolored (pink).
3: Discolored (red).
2: Discolored (brown).
1: Corrupted.

<Example 2 and Comparative Example 2>
Example 2-1
A few outer leaves, which are the non-edible parts of the harvested lettuce, were removed. The neighboring portion including the separated portion formed in the core during harvesting was excised with a kitchen knife to expose a new separated surface in the core (step A). Next, put 13 liters of the treatment solution a into a 30-liter pot (made of SUS), put 5 heads (about 1.3 kg) of whole lettuce with a new separation surface exposed at the core, and put the lettuce core. A new separation surface formed in the part was brought into contact with the treatment liquid a, and a lid with a weight placed thereon was placed on the lid to immerse the lettuce for 10 minutes (step B). After soaking, the lettuce was cut into quarters with a kitchen knife, the core was removed, and the lettuce was cut into approximately 3 cm squares with a food slicer (ECD-702, manufactured by Emura Co., Ltd.) (step C). Put 1.3 kg of cut lettuce in a 100 L pan (made of SUS) containing 80 liters of treatment liquid a, perform a bubbling operation (an operation of injecting air at a rate of 60 liters/minute) for 5 minutes, and use a colander. The washed lettuce was pulled up (step D). The washed lettuce was immersed in a polypropylene 90-liter bucket containing 75 liters of water for 3 seconds, and then pulled up using a colander to rinse (step E). Tap water (pH 7.5, hardness 2.1°dH, 20°C) was used as rinsing water. After rinsing, the lettuce was dehydrated for 30 seconds using a high-speed dehydrator for food (TDS-FZ, manufactured by Emura).
20 g of dehydrated lettuce was weighed, placed in a zippered plastic bag (Unipack H-4, manufactured by Seisan Nippon Co., Ltd.), and stored at 10° C. for 3 days.

Example 2-2
In step E, cut lettuce was produced and stored in the same manner as in Example 2-1, except that the rinsing time (immersion time) was set to 1 minute.

Example 2-3
Cut lettuce was produced and stored in the same manner as in Example 2-1, except that in step E, treatment liquid b was used instead of tap water for rinsing for 1 minute.

Comparative Example 2-1 (treatment process assuming the site)
A few outer leaves, which are the non-edible parts of the harvested lettuce, were removed. 7 heads of lettuce (approximately 1.3 kg) were cut into 4 pieces with a kitchen knife, removed the core, and cut into 3 cm squares with a food slicer (ECD-702, manufactured by Emura Co., Ltd.). At that time, the blade (30×30 mm square cut leafy vegetable disc) was cut while pouring the treatment liquid b over it (there is a hole for a hose connected to the machine). 1.3 kg of cut lettuce is placed in a 45-liter bucket (made of polypropylene) containing 26 liters of treatment liquid (10 ppm aqueous solution of Softanol EP7045 (manufactured by Nippon Shokubai Co., Ltd.)), soaked for 5 minutes, and washed with a colander. pulled up lettuce. Put the washed lettuce in a 90-liter bucket (made of polypropylene) containing 80 liters of water, perform a bubbling operation (an operation of injecting air at a rate of 60 liters/minute) for 10 minutes, and pull up the lettuce using a colander. Rinsing was performed with Put the lettuce after rinsing into a 90-liter bucket (made of polypropylene) containing 80 liters of treatment liquid b, perform a bubbling operation (an operation of injecting air at a rate of 60 liters/minute) for 10 minutes, and lettuce using a colander. Sterilization was performed by pulling up the Put the sterilized lettuce in a 90 liter bucket (made of polypropylene) containing 80 liters of tap water (pH 7.5, hardness 2.1°dH, 20°C), soak for 5 minutes, and pull up the lettuce using a colander. Rinsing was performed by After rinsing, the lettuce was dehydrated for 30 seconds using a high-speed dehydrator for food (TDS-FZ, manufactured by Emura).
20 g of dehydrated lettuce was weighed, placed in a zippered plastic bag (Unipack H-4, manufactured by Seisan Nippon Co., Ltd.), and stored at 10° C. for 3 days.

[Measurement of viable count]
In the same manner as in [Measurement of viable cell count] described in Example 1 and Comparative Example 1, the viable count of lettuce before storage and after storage for 3 days was measured. Table 2 shows the results.

[Discoloration evaluation]
The discoloration condition of the lettuce after storage for 3 days was evaluated according to the same criteria as in [Evaluation of discoloration] described in Example 1 and Comparative Example 1. Table 2 shows the results.

<Example 3 and Comparative Example 3>
Example 3-1
Several outer leaves, which are non-edible parts of the harvested cabbage, were removed. The neighboring portion including the separated portion formed in the core during harvesting was excised with a kitchen knife to expose a new separated surface in the core (step A). Next, put 13 liters of treatment solution a into a 30-liter size pot (made of SUS), put 5 whole cabbages (about 1.3 kg) in which a new separation surface is exposed at the core, and put the cabbage cores. A new separation surface formed in the portion was made to come into contact with the treatment liquid a, and a lid with a weight placed thereon was placed to immerse the cabbage for 10 minutes (step B). After immersion, the cabbage was cut crosswise into four parts with a kitchen knife, the core part was removed, and the cabbage was cut into 1.3 mm widths with a slicer (step C). 60 g of the cut cabbage was placed in a 3-liter beaker with a handle (made of SUS304, manufactured by AS ONE Co., Ltd.) containing 2.7 liters of treatment liquid a, and a bubbling operation (an operation of injecting air at a rate of 60 liters/minute) was performed. After 5 minutes, the washed cabbage was pulled up using a colander (step D). The washed lettuce was placed in a basket of a salad spinner and rinsed by immersing it in a bowl containing 2.7 L of water for 3 seconds and pulling it out (step E). Tap water (pH 7.5, hardness 2.1°dH, 20°C) was used as rinsing water. After rinsing, the salad spinner was spun to dehydrate the lettuce for 30 seconds.
20 g of dehydrated lettuce was weighed, placed in a zippered plastic bag (Unipack H-4, manufactured by Seisan Nippon Co., Ltd.), and stored at 10° C. for 3 days.

Comparative Example 3-1
Several outer leaves, which are non-edible parts of the harvested cabbage, were removed. Two heads of cabbage were cut into quarters with a kitchen knife per head, the core part was removed, and the cabbage was cut into 1.3 mm widths with a slicer. At that time, the cutting was performed while pouring the treatment liquid b over the blade. 60 g of cut cabbage is placed in a 1 liter cup (made of polypropylene) containing 900 ml of a treatment solution (10 ppm aqueous solution of Softanol EP7045 (manufactured by Nippon Shokubai Co., Ltd.)) and immersed for 5 minutes. pulled up. Put the washed cabbage in a polypropylene 5-liter bucket containing 2.7 liters of water, perform a bubbling operation (an operation of injecting air at a rate of 60 liters/minute) for 10 minutes, and pull up the cabbage using a colander. Rinsing was performed with Put the rinsed cabbage in a 5-liter bucket (made of polypropylene) containing 2.7 liters of the treatment liquid b, perform a bubbling operation (an operation of injecting air at a rate of 60 liters / minute) for 10 minutes, and use a colander. Sterilization was performed by pulling up the cabbage. The sterilized cabbage was soaked in a 5-liter bucket (made of polypropylene) containing 2.7 liters of water for 5 minutes, and rinsed by pulling up the cabbage using a colander. The rinsed cabbage was placed in a salad spinner basket, and the salad spinner was spun to dehydrate the cabbage for 30 seconds.
20 g of the dehydrated cabbage was weighed, placed in a zippered plastic bag (Unipack H-4, manufactured by Seisan Nippon Co., Ltd.), and stored at 10° C. for 3 days.

[Measurement of viable count]
10 g of cabbage before storage and after storage for 3 days were each weighed, placed in a stomacher sample bag (Sanispec filter test bag, AS ONE Co., Ltd.), 10 g of physiological saline was added, and homogenizer (SH-II M) was added. , Elmex Co., Ltd.) for 60 seconds to collect an extract. Thereafter, the cells were inoculated on a standard agar medium by the agar plate surface smearing method, and after culturing at 37°C for 48 hours, the number of viable cells was measured. In addition, as a standard, a few outer leaves, which are the inedible parts of the harvested cabbage, were removed, the core was removed, and the cabbage was cut into 1.3 mm widths with a slicer (only in process C, processes A, B, D and E were not performed) (also referred to as reference cut cabbage) was also measured in the same manner as above.
Table 3 shows the difference between the obtained viable cell count and the viable count of the reference cut cabbage as the general viable count. It is preferable that the difference between the general viable cell count and the value of the viable count of the reference cut cabbage be a negative value and be smaller from the viewpoint of suppressing the growth of the viable count. The absolute value of viable cell count of standard cut cabbage is 5.4 to 5.8 (log cfu/g) before storage.

[Discoloration evaluation]
The degree of discoloration of the cabbage after storage for 3 days was evaluated according to the following criteria. Table 3 shows the results. For cabbage, 5 is preferred. In addition, the score is a value obtained by rounding off the average value given by three researchers who have been conducting research on the freshness of vegetables for 5 years or more according to the following criteria.
5: There was no discoloration at all.
4: Discolored (green faded).
3: Discolored (pale yellow).
2: Discolored (brown).
1: Discolored (dark brown).
0: Corrupted.

Claims (12)

A method for producing cut vegetables, comprising the following steps A to D,
The following (a) component is hypochlorous acid or a salt thereof,
The following treatment liquid I and treatment liquid II contain 1 ppm or more and 100 ppm or less of the component (a) and have a pH of 5 or more and 11 or less,
The vegetables are one or more leafy stem vegetables selected from cabbage, lettuce, Chinese cabbage, salad greens, green leaves, sunny lettuce, spinach, mizuna, Japanese mustard spinach, garland chrysanthemum, and onion.
A method for producing cut vegetables.
Step A: A step of cutting the harvested vegetables near the core, which is the separated part at the time of harvesting, to expose a new cut surface on the core Step B: After Step A, a new cut surface is made on the core of the vegetable. A step of contacting the cut surface formed in (a) with a treatment liquid I containing a fungicide (hereinafter referred to as component (a)) and water for 60 seconds or more to permeate the vegetables with the treatment liquid I. Step C: After step B, a step of cutting the vegetables into eating sizes. Step D: After step C, a step of washing the cut vegetables with a treatment liquid II containing the component (a) and water. 2. The method for producing cut vegetables according to claim 1, wherein step A is a step of cutting the harvested vegetables in the vicinity of the core portion, which is the portion separated at the time of harvesting, to expose a new separation surface. 3. The method for producing cut vegetables according to claim 2, wherein step A is a step of exposing a new separation surface by excising the neighboring portion including the core, which is the separated portion of the vegetable at the time of harvesting. 4. The method for producing cut vegetables according to any one of claims 1 to 3, wherein step A newly exposes one or more vessel cross-sections of the vegetables. 5. The method for producing cut vegetables according to any one of claims 1 to 4, wherein in the step B, the treatment liquid I is brought into contact with the newly cut surface of the vegetable for 180 seconds or more. 6. Production of cut vegetables according to any one of claims 1 to 5, wherein step B is a step of immersing the vegetables in the treatment liquid I so that the treatment liquid I contacts at least the newly cut surfaces of the vegetables. Method. 7. The method for producing cut vegetables according to claim 6, wherein in the step B, the vegetables are immersed in the treatment liquid I for 60 seconds or longer. 8. The method for producing cut vegetables according to any one of claims 1 to 7, wherein step B is a step of allowing component (a) to permeate the entire interior of the vegetable through the vessel of the vegetable. 9. The method for producing cut vegetables according to any one of claims 1 to 8 , wherein in step C, the vegetables permeated with the component (a) in step B are cut into eating sizes. The method for producing cut vegetables according to any one of claims 1 to 9 , wherein the treatment liquid I further contains (b) a surfactant (hereinafter referred to as component (b)). The method for producing cut vegetables according to any one of claims 1 to 10 , wherein the treatment liquid II further contains component (b). 12. The cut vegetable according to claim 10 or 11 , wherein the component (b) is one or more selected from glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and sucrose fatty acid esters. manufacturing method.