JP2008193926A - Processed green vegetable and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide processed green vegetables capable of retaining fresh green color which green vegetables naturally have. <P>SOLUTION: A method for producing the processed green vegetables comprises giving alkali treatment and a membrane-making substance to the surface of green vegetables and performing heat treatment to form a membrane of the membrane-making substance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a processed green vegetable that retains a vivid green color while preventing discoloration and fading, a method for producing the same, and a processed food containing the processed green vegetable.

It is known that chlorophyll contained naturally in green vegetables is decomposed by the action of enzymes, heat, acid, etc., and the central metal magnesium (Mg) is removed, and it is converted to more stable pheophytin. In particular, in processed foods for preservation such as chilled foods and retort foods that contain green vegetables, not only in the cooking process, but also in the process of heat sterilization after cooking and in the preservation process, chlorophyll decomposes and discoloration of the green vegetables There is a problem that discoloration proceeds.
As a method for preventing such discoloration and discoloration of green vegetables, magnesium, which is the central metal of chlorophyll originally contained in green vegetables, is replaced with metal ions such as copper (Cu), zinc (Zn), and iron (Fe). It is considered to change to more stable copper chlorophyll, zinc chlorophyll, iron chlorophyll and the like. As a specific method, a method of heating green vegetables by immersing them in an aqueous solution of copper chlorophyll and / or copper chlorophyllin alkali metal salt (Patent Document 1), copper-containing yeast, zinc-containing yeast, iron-containing yeast in green vegetables There are a method of heating by adding a mineral yeast such as (Patent Document 2), a method of mixing a strip-like or powdered green vegetable and a food material powder containing a large amount of copper and zinc (Patent Document 3).
However, these metal-substituted chlorophylls are a kind of synthetic colorant and have image problems for consumers.
In order to deal with such problems, a method of stabilizing the green color of green vegetables by branching green vegetables with an alkaline solution using the stabilization of chlorophyll in an alkaline state is also considered. (Patent Documents 4 to 6).
However, there is a problem that the alkaline solution is dispersed by being heated in the cooking process or the heat sterilization process after blanching, resulting in a decrease in the pH of the green vegetable portion and a brown color change. It was.
Therefore, there is still a need for a method that can keep the green color of chlorophyll that green vegetables originally contain without using a synthetic colorant and after cooking and heat sterilization treatment and after storage.

JP-A-6-217732 JP 2004-201553 A JP 2005-102618 A Japanese Patent Laid-Open No. 10-229816 JP 2000-4821 JP 2006-158293 A

An object of this invention is to provide the process green vegetable which can hold | maintain the vivid green which a green vegetable has naturally. Moreover, it aims at providing the manufacturing method of the processed green vegetable for providing this processed green vegetable.
Another object of the present invention is to provide a processed food containing, as an ingredient, processed green vegetables that can be preserved after heat sterilization treatment and / or after storage for a certain period of time in a heat sterilized food after packaging. And

The present inventors apply alkali treatment to the surface of green vegetables, apply a film-forming substance to the vegetable surface, heat-treat it to form a film, and thereby process cooking, heat sterilization, and long-term During storage, etc., it is possible to maintain the environment of the green vegetable surface in an alkaline state, stabilize the chlorophyll whose central metal ion is naturally contained in the green vegetable, prevent fading and discoloration, and vivid green It was found that processed green vegetables capable of holding
Such a processed green vegetable and its manufacturing method are specifically as follows.

The method for producing a processed green vegetable of the present invention is characterized in that an alkali treatment and a film-forming substance are applied to the surface of the green vegetable, and a heat treatment is performed to form a film of the film-forming substance.
Preferably, blanching may be performed before the alkali treatment.
The alkali treatment is selected from the group consisting of mixing powdery alkali with green vegetables, attaching powdery alkali, injecting alkali, and immersing green vegetables in an alkaline solution. It is preferable to include a treatment.
Preferably, applying the film-forming substance includes depositing it as a powder or as a dispersion.
The heat treatment preferably includes a treatment selected from the group consisting of immersion in hot water, spraying of steam, stir-fry or frying, treatment with microwaves, and spraying of hot air.
In addition, the processed green vegetable provided by the present invention has a film-forming substance starch coating on the surface, and the color tone of the surface is a hue of 10 GY to 10 G, lightness: 3 to 7 in the color sample of the JIS standard color chart. Saturation: It is a color tone of 6 to 10, and has a shelf life of at least 2 weeks in chilled.
Alternatively, the processed green vegetable provided by the present invention has a film-forming substance starch coating on the surface, and the chlorophyll whose central metal is magnesium contains more magnesium than other metal cations, at least in chilled It has a shelf life of 2 weeks.
The processed food of the present invention includes a processed green vegetable obtained by the above-described manufacturing method or a processed green vegetable having the above-described characteristics, and is subjected to heat sterilization treatment so as to have a shelf life of at least 2 weeks in a chilled state. It is preferable.

The present invention is suitable for ingredients of chilled foods, retort foods and other processed foods that are not discolored or discolored by heating or oxidation, and are subjected to heat sterilization, while maintaining the vivid green color that green vegetables naturally have. Processed green vegetables can be provided.
Moreover, this invention can provide the processed food which contains the processed green vegetable which has kept the vivid green which a green vegetable has naturally as an ingredient.

Specific examples of the green vegetables used in the method of the present invention include, but are not limited to, green beans, spinach, broccoli, green peas, green pepper, basil, and green vegetables, but the central metal is magnesium (Mg). Any green edible plant containing chlorophyll may be used. In the present invention, chlorophyll whose central metal is magnesium (Mg) includes both chlorophyll a and chlorophyll b that can be detected by HPLC measurement described later.
The green vegetable can be used in any size, but it is preferable that the green vegetable is cut into an appropriate size as an ingredient for cooking to be performed later.
In the production method of the present invention, blanching may be performed before alkali treatment is performed on the surface of the green vegetable. By blanching, an enzyme such as a chlorophyll-degrading enzyme contained in green vegetables can be inactivated. The blanching differs in temperature and time depending on the type and size of the green vegetable, and the setting of appropriate blanching conditions is within the scope of common technical knowledge of those skilled in the art. For example, it is sufficient to pour water at 80 to 100 ° C. for about 5 minutes.

In the production method of the present invention, after the blanching as an optional step, the surface of the green vegetable is subjected to alkali treatment.
As the alkali used for the alkali treatment of the present invention, any alkali can be used as long as it exhibits alkalinity when dissolved in water. For example, an alkali such as an alkali metal / alkaline earth metal hydroxide, a salt thereof with a weak acid, specifically, an alkali metal salt or a substance containing an alkaline earth metal salt is exemplified. More specifically, for example, the following substances can be used.

  Examples of the alkali that can be used in the production method of the present invention include hydroxides such as alkali metal hydroxides (sodium hydroxide, potassium hydroxide, etc.), alkaline earth metal hydroxides (calcium hydroxide, etc.), water Examples thereof include magnesium oxide. Moreover, the alkali metal carbonate which is carbonate, alkaline-earth metal carbonate, magnesium carbonate, etc. are illustrated. Further, examples include alkali metal hydrogen carbonates (bicarbonate (sodium hydrogen carbonate), etc.), alkaline earth metal hydrogen carbonates and the like, which are hydrogen carbonates. Organic acid salts such as alkali metal organic acid salts (sodium acetate, trisodium citrate, disodium succinate, sodium tartrate, sodium hydrogen tartrate, disodium malate, sodium ascorbate, sodium gluconate, etc.), alkaline earth metals Examples include organic acid salts (such as calcium lactate) and magnesium organic acid salts. Examples of the phosphate include alkali metal phosphates, alkaline earth metal phosphates, and magnesium phosphates. Of these, carbonates and bicarbonates, particularly sodium bicarbonate, and organic acid salts, particularly trisodium citrate are preferred. By maintaining the green vegetable at the above pH by the alkali, it becomes possible to stabilize the chlorophyll whose central metal originally contained in the green vegetable is magnesium.

In the present invention, the amount of alkali added is not particularly limited, but it is desirable that the pH of the surface of the green vegetable when alkali-treated is 7 to 11, preferably 7 to 9. It is preferable for obtaining a chlorophyll stabilizing effect. For this purpose, generally, alkali can be used in an amount of 0.1 to 5% by mass (hereinafter abbreviated as%), preferably 0.5 to 2%, based on green vegetables.
In this case, if the pH is too lower than the above range, the desired chlorophyll stabilizing effect may not be obtained. On the other hand, if the pH is too high, the bitterness, agitation and off-flavor peculiar to alkali are generated, and the flavor is impaired. There is a case. In addition, said pH is calculated | required by shaving off about 1 mm of the surface of a green vegetable, and making it into paste form (in the case of a leaf thing, crushing as it is), and measuring this with a handy pH meter. As the pH meter, “ISFET pH Meter KS723” manufactured by Shindengen Electric Industry Co., Ltd. may be used.

As a method of performing the alkali treatment, any method that a person skilled in the art can think of as technical common sense can be used. For example, a green vegetable is mixed with a powdered alkali, and a powdered alkali is attached. It is preferable to use any one of the above, injecting the alkaline solution, and immersing the green vegetable in the alkaline solution.
The powdery alkali means a particle having a particle size of 20 μm or more, and the alkali of the present invention can have a particle size of 20 to 500 μm. As the alkali, a pulverized product after crystallization can be suitably used.
Moreover, in the manufacturing method of this invention, it is preferable to perform an alkali treatment, after damaging the surface structure of green vegetables. As a method of damaging the surface of vegetables, any method that can be considered as technical common knowledge by those skilled in the art can be used. For example, freezing and thawing, tools such as mortars and mixers, and processing using ultrasound Etc.
In particular, it is preferable to attach alkali to the surface structure of the damaged green vegetable, for example, a method of attaching the alkali after damaging the surface structure of the green vegetable with a mortar or the like, or a powdered alkali and green vegetable A method of mixing and kneading the surface of the green vegetable with the alkali, a method of mixing green vegetables and spices other than alkali such as spices in the same manner, kneading the vegetable surface, and then attaching the alkali. Among them, a method in which powdery alkali and green vegetable are mixed and the surface of the green vegetable is rubbed with the alkali is particularly preferable.
Such mixing can also be performed using a mixer or the like.

In the alkali treatment, it is preferable that the alkali is sufficiently infiltrated into the green vegetable by holding it for a certain time or more. For example, when powdery alkali is used for the alkali treatment, it may be allowed to stand at 0 to 30 ° C. for 10 minutes or longer after adhering or mixing with green vegetables, and it is more preferably left for 10 minutes to 2 hours. When an alkali solution is used for the alkali treatment, it may be immersed in the alkali solution at 0 to 30 ° C. for 10 minutes or more, and more preferably 30 minutes to 2 hours. Moreover, you may make a vacuum state and infiltrate a green vegetable with an alkali. In this case, the normal standing or immersion time can be shortened.
Moreover, you may perform blanching in an alkaline solution, after giving an alkali treatment to green vegetables. The temperature and time for performing blanching in an alkaline solution can be arbitrarily selected according to technical common knowledge of those skilled in the art, as described above.

In the production method of the present invention, the alkali treatment is performed as described above, and the film-forming substance is applied to the surface of the green vegetable. The treatment for applying the film-forming substance can be performed after the alkali treatment or simultaneously with the alkali treatment, and the former is desirable.
The film-forming substance that can be used in the present invention is edible, and includes, for example, carrageenan, agar, alginic acid and its salts, locust bean gum, tara gum, tamarind seed polysaccharide, gum arabic, caraya gum, tragacanth gum, pullulan. , Gellan gum, curdlan, starch, modified starch and the like. As starch, starch, such as potato starch, wheat starch, corn starch, tapioca starch, and brown rice starch, and modified starches thereof, wheat flour, and the like can be used as long as they contain starch. In the present invention, the effect can be exhibited by using one kind of film-forming substance among these, but it is also possible to use two or more kinds of film-forming substances in combination. In particular, potato starch and corn starch are preferred. According to these starches, the film formation effect is better, the yield on the green vegetable surface is good, and even when the green vegetable is heat-treated at a high temperature such as retort food, the film formation is good Has an effect.

The film-forming substance may be attached in the form of a powder to the surface of the green vegetable, or may be deposited on the surface of the green vegetable as a dispersion using water or a seasoning liquid.
The film forming material is preferably applied so that the film forming material is thinly and uniformly attached to the surface of the green vegetable. When practicing the present invention, if the film-forming substance is thick, or if it is formed into a film, the original texture and taste of the vegetable may be impaired. This is because the processed green vegetables with the original texture and taste can be achieved by adhering.
The amount of the film-forming substance applied to the surface of the green vegetable is not particularly limited as long as a film can be formed on the vegetable surface by the subsequent heat treatment, but the film-forming substance is dry mass with respect to the green vegetable. 0.2 to 10%, preferably 1 to 5%. When the film-forming substance is applied as a dispersion, the concentration of the film-forming substance can be 20 to 60%, and preferably 40 to 50%.

When applying the film-forming substance, the film-forming substance may be applied alone to the surface of the green vegetable, or the film-forming substance and the alkali can be applied together.
For example, when the film-forming substance is applied as a dispersion, the green vegetable may be immersed in a dispersion containing the film-forming substance and an alkali, or the dispersion may be applied to the surface of the green vegetable. May be applied.
In addition, when the film-forming substance is applied in the form of powder, a mixture of the film-forming substance and powdered alkali can be attached to the surface of the green vegetable.

In the production method of the present invention, heat treatment such as hot water, steam, hot air, frying and frying is performed on the green vegetables subjected to the alkali treatment and the film-forming substance, and the green vegetables adhere to part or all of the surface of the green vegetables. The food is placed in an atmosphere in which the film-forming substance becomes viscous and forms a film, and a film of the film-forming substance is formed on the surface of the food. The method and means of heat treatment, the conditions thereof, and the like are not particularly limited as long as film formation can be achieved and the film is not peeled off, and can be arbitrarily selected or set. Note that the heat treatment can be performed under a temperature condition that allows the film-forming substance to form a film. For example, it is preferable to perform the film-forming substance under a condition of 65 to 160 ° C.
For example, when boiled using starch as a film-forming substance, it is necessary to put green vegetables in hot water at a temperature equal to or higher than the gelatinization temperature of starch. If the temperature is lower than this, the starch adhering to the surface of the green vegetable during boiling will be dispersed in the hot water before gelatinizing, so a film is formed on the surface of the green vegetable, that is, a film is formed. I can't.

The processed green vegetable of the present invention thus obtained may be further subjected to a heat sterilization treatment.
In the present invention, “heat sterilization treatment” means heat sterilization treatment of food in a sealed or open state, for example, medium temperature heat sterilization treatment for chilled commercial distribution, pressure heat sterilization treatment for retort, etc. That means. “Sealed state” means that food is sealed in a sealed container and heat sterilized, or food is not filled in a container and heat sterilized using a closed heat sterilizer (so-called aseptic filling process). The case), which is preferable for imparting a desired preservability improving effect.
The processed green vegetable of the present invention can be heat sterilized under the condition that the central temperature of the green vegetable is 95 ° C to 135 ° C and heated for about 1.5 minutes to 60 minutes. For example, in the case of chilled food, it corresponds to 15 minutes at 105 ° C or more, in the case of retort food, it corresponds to 20 minutes at 122 ° C, and in the case of aseptic filling food, it corresponds to 1.5 minutes at 130 ° C. The desired sterilizing effect can be achieved by heat treatment under the conditions. In particular, in the case of chilled food, fading and discoloration of green during heat sterilization treatment and storage are suppressed, and it becomes possible to provide a high-quality processed food containing green vegetables.

The processed green vegetable obtained by the production method of the present invention is characterized by having a film of a film-forming substance on its surface.
The film of the film-forming substance present on the surface of the processed green vegetable of the present invention can be detected using various methods depending on the type of the film-forming substance. For example, when the film-forming substance contains starch, the presence of the film of the film-forming substance can be detected by positively reacting iodine starch on the surface of the processed green vegetable, that is, blue-violet color. Selection of such an appropriate detection method and setting of conditions for the detection method are within the scope of technical common knowledge of those skilled in the art.
In the processed green vegetable of the present invention, the film of the film-forming substance only needs to cover part or all of the vegetable surface, but it is preferable that most or all of the surface of the processed green vegetable is covered with the film.

The processed green vegetable of the present invention is characterized in that the color tone of the surface is a hue of hue: 10 GY to 10 G, lightness: 3 to 7, saturation: 6 to 10 in the color sample of the JIS standard color chart.
The color tone can be determined by comparing the color tone of the green vegetable surface with the color sample of the JIS standard color chart according to the method of using the standard color chart of JIS (JIS Z 8721).

The processed green vegetable of the present invention can maintain the pH of the green vegetable surface by the film of the film-forming substance, and the chlorophyll originally contained in the green vegetable is prevented from decomposing and magnesium from flowing out, It is characterized in that chlorophyll containing magnesium as a central metal is stably held in green vegetables. On the other hand, as a conventional method for preventing discoloration or discoloration of green vegetables, magnesium, which is the central metal of chlorophyll originally contained in green vegetables, is replaced with metal ions such as copper (Cu), zinc (Zn), and iron (Fe). There may be.
Chlorophyll containing magnesium as the central metal, and chlorophyll in which the central metal is replaced by other metal cations (copper, zinc, iron, etc.) Based on this, different precipitation peaks can be detected.

Specifically, green vegetables are ground finely in a mortar, an extraction solvent (a mixture of methyl alcohol 3: acetone 1) is added to and mixed with this, and the mixture is allowed to stand, then filtered through filter paper, and twice the amount of petroleum ether is added. In addition, shake well and leave. A chlorophyll liquid is obtained by separating the upper layer petroleum ether tank.
Prepare a mixed solution containing chlorophyll containing magnesium (a and b), chlorophyll containing each other metal cation (a and b of the metal cation), pheophytin a, pheophytin b, etc. at known concentrations, and a standard solution And The content and ratio of each of the standard solution and the extract can be determined by separating and evaluating the peak under the extraction conditions by HPLC.

Based on the precipitation peaks of chlorophyll containing magnesium (a and b) and chlorophyll containing other metal cations (a and b of the metal cation) obtained as described above, the magnitude relationship between the contents of both is detected. To do.
As described above, as a conventional method for preventing discoloration and discoloration of green vegetables, magnesium, which is a central metal of chlorophyll contained in green vegetables, is used as copper (Cu), zinc (Zn), iron (Fe) using synthetic additives. When the metal ions such as chlorophyll are substituted, the chlorophyll in which the central metal in the green vegetable is substituted with a metal ion other than magnesium is more than the chlorophyll whose central metal is magnesium. According to the present invention, it is possible to prevent discoloration and discoloration of green vegetables even when no synthetic additive is used, and this point has an important significance as a technique for producing processed foods. And the green vegetable of this invention and the green vegetable of the conventional method using a synthetic additive can be discriminate | determined by using the said precipitation method. The present invention does not completely exclude the use of synthetic additives.

Using the processed green vegetables obtained by the present invention as an ingredient, processed foods for storage subjected to heat sterilization treatment such as chilled foods and retort foods can be produced. Examples of such processed foods include, but are not limited to, stew, cooked rice, Happo vegetables, and steamed rice bowls.
When the processed green vegetables of the present invention are used as ingredients for processed foods, spices and seasonings can be applied in any step of the method for producing processed green vegetables, or a film-forming substance coating on the surface After forming, spices and seasonings may be applied alone or together with other ingredients.
The processed green vegetable of the present invention is not only after heat sterilization treatment but also at least after storage for 2 weeks in a chilled state, the specific green characteristics of the present application (specific color and magnesium-containing chlorophyll and other metal ion-containing chlorophylls). Ratio) can be maintained.
In the present invention, the processed food containing the processed green vegetable having the above characteristics as an ingredient is combined with other foods such as cooked rice, sauce, soup, etc., using the green vegetable appropriately subjected to the above-mentioned treatment, and heat sterilization processing, etc. It can be served. Whether the green vegetables are used alone or in combination with other foods, it is possible to provide a high-quality product including the green vegetables having the above characteristics. It can also be tailored to have a shelf life of at least 2 weeks in chilled.
The following examples further illustrate the present invention, but the scope of the present invention is not limited to the examples.

<Example 1>
Sayaingen was salted with sodium bicarbonate having a mass ratio of 100: 3, and then allowed to stand at room temperature for 4 hours to immerse the soybeans in alkali. As the baking soda, a pulverized product after crystallization having a particle size of about 30 μm was used. On the surface of the soy beans treated in this way, potato starch powder was sprinkled and adhered at a weight ratio of soy beans: potato starch = 100: 2. This was boiled at 95 ° C. for 1 minute to form a film on the surface of the soybean.
The processed soya beans (20 g) thus obtained are filled into a container together with rice (80 g), seasoning liquid (112 g), boiled chicken (30 g), boiled shiitake (20 g), boiled carrot (20 g) and sealed. Then, heat sterilization treatment was performed at 105 ° C. for 15 minutes with a retort sterilizer. The soya beans in the container-cooked rice prepared in this way exhibited a bright green color immediately after the heat sterilization treatment and after storage for 2 weeks in a tilde.
The characteristics (green characteristics, presence / absence of film-forming substance) of the above-mentioned pods were as shown in the table below.

[Table 1]
Immediately after heat sterilization and after storage for 2 weeks
Matching JIS hue: 5G Hue: 2.5G
Color tone of standard color chart Lightness: 4 Lightness: 4
Saturation: 6 Saturation: 6

HPLC * 1 A> B * 2 A> B * 2

Iodine starch reaction Positive Positive

* 1: The size of the precipitation peak of A: Chlorophyll a and b containing magnesium and B: Chlorophyll a and b containing other metal cations was examined by HPLC under the following conditions.
* 2: No precipitation peak of B was detected.

<Dye extraction>
Vegetables were finely ground in a mortar, and an extraction solvent (a mixture of methyl alcohol 3: acetone 1) was added and mixed with this, and left for 5 minutes. Then, it filtered with the filter paper.
The above extract was put in a test tube, and twice this amount of petroleum ether was added and shaken well and allowed to stand. A chlorophyll liquid is obtained by separating the upper layer petroleum ether tank.
<Separation by HPLC>
The HPLC apparatus was implemented using Shimadzu LC-10A (SPD-M10A detector).
Column for analysis Tosoh TSKgel ODS-80TM (4.6mmφ × 15cm)
Guard column Tosoh TSKguardgel ODS-80TM (3.2mmφ × 1.5cm)
Mobile phase gradient (gradient elution method)
Solvent A (95% ethanol solution containing 0.005N Nacl):
Solution B (80% ethanol solution containing 0.005N Nacl) =
Gradient linearly in 10 minutes from 5:95 (v / v) to A: B = 95: 5,
Then run 95: 5 for 25 minutes.
Detection wavelength 405 or 425nm Temperature 40 ℃ Flow rate 0.8ml / min
<Identification of compound>
The substance and the amount thereof were identified by the elution time and the peak area on the HPLC chart.
Specifically, the mixed liquid of chlorophyll a, chlorophyll b, pheophytin a, pheophytin b, copper chlorophyll a, copper chlorophyll b, iron chlorophyll a, iron chlorophyll b, zinc chlorophyll a, zinc chlorophyll b, whose concentration was known was adjusted. Standard solutions were used.
This standard solution and the above extract were separated under the above extraction conditions by HPLC, and the peak was evaluated to determine the respective contents and ratios.
Here, chlorophyll a refers to a chlorophyll reduced form, and chlorophyll b refers to a chlorophyll oxidized form. The same applies to pheophytin, copper chlorophyll, iron chlorophyll, and zinc chlorophyll.

<Comparative Example 1>
Cooked rice in a container was prepared and stored in the same manner as in Example 1 except that potato starch powder was applied and the treatment for adhesion was not performed. The green beans that had entered this were discolored and browned immediately after the heat sterilization treatment, and the green color was further discolored and browned after storage in chilled for 2 weeks.

[Table 2]
Immediately after heat sterilization and after storage for 2 weeks
Matching JIS Hue: 10Y Hue: 5Y
Color tone of standard color chart Lightness: 5.5 Lightness: 6
Saturation: 6 Saturation: 6

HPLC * 1 A> B * 3 A> B * 3

Iodine starch reaction Negative Negative

* 1: The size of the precipitation peak of A: chlorophyll a, b containing magnesium and chlorophyll a, b containing other metal cations was examined by HPLC under the above-mentioned conditions.
* 3: A precipitation peak of A smaller than that in Example 1 was detected, but no precipitation peak of B was detected.

Claims (9)

  A method for producing a processed green vegetable, comprising subjecting a surface of a green vegetable to an alkali treatment and a film-forming material, and performing a heat treatment to form a film of the film-forming material.   The method according to claim 1, wherein the blanching is performed before the alkali treatment.   The alkali treatment is selected from the group consisting of mixing powdery alkali with green vegetables, attaching powdery alkali, injecting alkaline solution, and immersing green vegetable in alkaline solution The method of Claim 1 or 2 including the process processed.   4. The method of any one of claims 1 to 3, wherein applying the film-forming material comprises depositing the film-forming material as a powder or as a dispersion.   The heat treatment includes any one selected from the group consisting of immersion in hot water, spraying of steam, stir-fry or deep-fried, treatment with microwaves, and spraying of hot air. the method of.   It has a film of a film-forming substance on the surface, and the color tone of the surface is a hue of 10 GY to 10 G, lightness: 3 to 7, chroma: 6 to 10 in the color sample of the JIS standard color chart, Processed green vegetable with chilled storage for 2 weeks.   A processed green vegetable having a film of a film-forming substance on the surface, containing more chlorophyll containing magnesium than chlorophyll containing other metal cations, and having a shelf life of at least 2 weeks in a chilled form.   Processed food containing the processed green vegetable manufactured by the method of any one of Claims 1-5, or the processed green vegetable of Claim 6 or 7.   The processed food according to claim 8, which has been subjected to heat sterilization treatment so as to have a shelf life of at least 2 weeks in a chilled state.