JP2018033425A - Dried green vegetable for instant food and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide dried green vegetables for instant food and its production method that can prevent color fading or discoloration during storage.SOLUTION: A production method of dried green vegetables for instant food is provided in which at least one or two or more kinds of saccharide selected from lactose, maltose and malt starch syrup are added to the green vegetables subjected to the blanching after the blanching processing of green vegetables, and are dried by hot air at 100°C or less. The dried green vegetables obtained by the production method contains the maltose and/or the lactose of 10 wt% or more. The water content is 14 wt% or less, all sugar content is 55-80 wt%, and the pH of the 20 times diluted solution of the dried green vegetables is 7-8, and thereby the problem is solved.SELECTED DRAWING: None

Description

  The present invention relates to a dried green vegetable for instant food and a method for producing the same.

  At present, a large number of products such as instant noodles, instant soup, instant miso soup, and instant cooked rice are on the market as instant foods, such as hot water cooking, hot pot cooking, and microwave cooking.

  Examples of ingredients for instant food include dried meats, dried eggs, and dried vegetables. Of these, dried vegetables are generally dried by a drying method such as ventilation drying, hot air drying, vacuum freeze drying, and microwave drying after branching the vegetables.

  Conventionally, green vegetables have a problem that the color is faded or discolored by an enzyme or heat, and a blanching treatment is generally performed under alkaline conditions as a method for preventing the discoloration or discoloration of green vegetables. However, when drying green vegetables, this alone is insufficient to prevent fading or discoloration.

  As a method for producing dried vegetables with good storage stability and quality, Patent Document 1 discloses that a vegetable is pH 7-10, blanched in an aqueous solution containing 0.01-20 g / L of magnesium ions, and then dried. A method for producing dried vegetables is described. However, this method can maintain the color tone of the green vegetable after drying more than the blanching treatment under normal alkaline conditions, but for long-term storage, it is treated with nitrogen using a highly airtight pouch. There is a problem that it needs to be stored together with an oxygen scavenger, and when stored normally, there is a problem of discoloration immediately.

  In addition, as a technique for maintaining the fresh color of green-yellow vegetables, Patent Document 2 discloses that brunched vegetables are adjusted to pH 8.0-9.0, immersed in a solution such as reduced starch syrup, and then lyophilized. The technology is described. However, this method has a problem that the texture is remarkably deteriorated depending on the kind of vegetables because ice crystals generated at the time of freezing destroy the vegetable tissue due to the step of freezing. In addition, if a large amount of reduced starch syrup is included in vegetables, excessive foaming occurs during drying, or it takes time to freeze and dry, so it takes a lot of money to produce dried vegetables, and the amount that can contain reduced starch syrup, etc. There were limits.

JP 60-58033 A Japanese Patent No. 2926691

  It is an object of the present invention to provide a dried green vegetable for instant food that can prevent fading or discoloration during storage and a method for producing the dried green vegetable.

  As a result of intensive research on the cause of fading or discoloration during storage, the inventors have found that it is not sufficient to control the pH of green vegetables during blanching, reducing the free water of dried vegetables, and contact with oxygen I thought that it was important to suppress. Therefore, by adding saccharides to green vegetables whose pH was controlled by branching, we tried not only to cover the vegetables with saccharides but also to suppress free water in the dried vegetables. However, depending on the type of saccharide used, it was found that the color change was promoted on the contrary rather than suppressing the color change during storage, and as a result of further intensive research, it was found that the type and content of the added saccharide was important. It came to.

That is, it is a dried green vegetable for instant food, containing 10% by weight or more of maltose and / or lactose, having a moisture content of 14% by weight or less, and having a total sugar content of 55 to 80% by weight, A dried green vegetable for instant food, characterized in that the pH of a 20-fold diluted solution of the dried green vegetable for food is 7-8, and a blanching step for branching the green vegetable;
A saccharide addition step of adding at least one or two or more saccharides selected from lactose, maltose and malt syrup to the green vegetable blanched in the blanching step, and the green vegetable added with a saccharide in the saccharide addition step A hot-air drying step of drying with hot air of 100 ° C. or less, and a method for producing a dried green vegetable for instant food, wherein the dried green vegetable for instant food obtained by the production method is maltose and / or lactose 10% by weight or more, the water content is 14% by weight or less, the total sugar content is 55 to 80% by weight, and the pH of the 20-fold diluted solution of dried green vegetables for instant food is 7 to 8 It is the manufacturing method of the dry green vegetable for instant foods characterized by the above-mentioned.

  Furthermore, in the saccharide addition step, it is preferable to add a magnesium salt so as to include the magnesium salt so as to improve the green coloring just after drying.

  Furthermore, it is preferable to adjust the pH of the 20-fold diluted solution of dried green vegetables to 7.2 to 7.8.

  ADVANTAGE OF THE INVENTION By this invention, the dry green vegetable for instant foods which can prevent discoloration or discoloration at the time of a preservation | save, and its manufacturing method can be provided.

  Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following description.

  The green vegetables in the present invention are chlorophyll-derived green-colored vegetables, and examples include spinach, komatsuna, cabbage, broccoli, peppers, bitter gourd, green onions, leek, bamboo shoots, green beans, peas, silk radish, and bean seedlings. .

  If necessary, the green vegetables are washed and sterilized with hypochlorous acid, and then cut into an appropriate size. The cut green vegetables may be immersed in an aqueous solution containing lime water or bittern.

  Then brunch the cut green vegetables. When green vegetables are dried raw, chlorophyll is decomposed to become pheophytin and discolored, so that blanching is generally performed. There is no particular limitation on the blanching method, and the time may be adjusted by boiling or steam according to the green vegetables to be used.

  In addition, when blanching is performed by boiling, the pH of the blanching solution is not particularly limited, but when it becomes acidic, chlorophyll is decomposed, and when the alkalinity is too strong, the green vegetable fiber is softened and the texture becomes too soft. Therefore, neutral to weak alkalinity is preferable, and it is preferable to perform branching while adjusting with carbonate or the like so that the pH is about 7 to 8.5.

  Next, the blanched green vegetables are dehydrated if necessary, and sugars are added. The purpose of adding sugar is to cover dry green vegetables, block oxygen and reduce free water to prevent discoloration and discoloration during storage, as well as to make vegetables flexible during drying. This is to prevent breakage of the vegetables inside, to prevent damage during transportation by curing after drying, and to ensure the resilience when used as an ingredient for instant food.

  Usually, saccharides are said to react with free amino acids to cause a Maillard reaction and turn brown. This reaction is said to occur more easily as saccharides exhibiting reducibility, and by using saccharides exhibiting reducibility, the Maillard reaction proceeded during storage, and discoloration (browning) during storage proceeded. Therefore, it was thought that discoloration during storage could be suppressed by using sucrose, trehalose, reduced starch syrup, etc. that did not exhibit reducing ability, but it is surprisingly preserved even when saccharides that do not exhibit reducing ability are used. It turned out that the discoloration of the color progressed, and that the Maillard reaction was not necessarily the cause of the discoloration during storage. Thus, as a result of verification using various saccharides, the cause was unknown, but it was found that lactose and maltose are preferable for suppressing discoloration during storage in order to suppress discoloration during storage.

  The saccharide to be added in the present invention is at least one selected from malt syrup containing at least lactose, maltose and maltose, and the content of lactose and / or maltose in the dried green vegetable is in the dried green vegetable. It is preferable to add to 10 wt% or more, more preferably 22 wt% or more. What is necessary is just to perform the measuring method of a lactose and maltose content by HPLC method. Moreover, the malt starch syrup in this invention is the thing which decomposed | disassembled starch with the acid or the enzyme, and does not contain the reduced starch syrup which reduced this with hydrogen. The content of lactose or / and maltose after drying is as high as possible, but as will be described later, the total amount of sugar in the dried green vegetable is more than 80% by weight based on the weight of the dried green vegetable. Since it is substantially difficult to do, it is at most 80% by weight or less in dry green vegetables, and is 70% by weight or less in view of the original sugar content of the vegetables.

  Moreover, it is preferable to add so that the total amount of sugar in dry green vegetables may be 55 to 80 weight% with respect to the weight of dry green vegetables. The analysis method of the total sugar amount may be calculated by adding each monosaccharide analysis by the HPLC method when only monosaccharides, disaccharides and reducing sugars are added. When the added sugar contains a sugar of three or more sugars such as maltose starch syrup or reduced starch syrup, it may be calculated by the phenol-sulfuric acid method. When the total amount of sugar in the dried green vegetable is less than 55% by weight with respect to the weight of the dried green vegetable, the coating of the dried green vegetable with sugar is incomplete, and fading and discoloration are likely to occur. In addition, green vegetables lack flexibility during drying and are easily cracked during production. Further, they become brittle after drying and are easily cracked during transportation, and the restorability deteriorates. Conversely, if the total amount of sugar in the dried green vegetable is more than 80% by weight based on the weight of the dried green vegetable, the actual solid content of the vegetable and the moisture content of the dried green vegetable are real. Is difficult. A more preferred range is 65 to 75% by weight.

  In addition to lactose, maltose, and malt syrup, saccharides to be added in the present invention can be mixed with reducing sugars such as glucose, trehalose, sorbitol, reduced starch syrup, starch degradation products, and reduced starch degradation products. The saccharide to be added is preferably added so that lactose and / or maltose is contained as much as possible.

  Moreover, fructose and sucrose were mentioned as saccharides which promote discoloration during storage. Therefore, it is preferable that saccharides to be added do not contain fructose and sucrose as much as possible, but fructose and sucrose are often originally contained in green vegetables, and the content of fructose in dry green vegetables is 10 wt. % Or less, more preferably 5% by weight or less. The analysis method of fructose and sucrose content may be performed by HPLC method.

  As a method for adding saccharides, they may be added by powder mixing or may be added by immersing them in an aqueous saccharide solution.

  Moreover, it is preferable to add magnesium salts, such as magnesium carbonate and magnesium chloride, simultaneously with the addition of saccharides. By adding the magnesium salt, the green condition after drying is easily maintained as compared with the case where the magnesium salt is not added. Moreover, the pH of the green vegetable after drying can also be adjusted to a predetermined range by adding alkaline agents, such as sodium carbonate and lime water, at the time of saccharide addition.

  Next, the green vegetables to which saccharides are added are dried so that the water content is 14% by weight or less. The drying method is not particularly limited, however, in order to add a large amount of sugar and dry at low cost, ventilation drying or hot air drying is preferable. When hot air drying is performed, a temperature higher than 100 ° C. is not preferable because discoloration proceeds during drying. More preferably, drying is performed at 80 ° C. or less, and more preferably 60 ° C. or less. The water content of the green vegetable after drying is preferably small, more preferably 10% by weight or less, and further preferably 7% by weight or less. The moisture measurement method may be performed under the drying conditions of 105 ° C. for 4 hours by the atmospheric pressure drying method.

  Moreover, as for the pH of the green vegetable after drying, it is preferable that the pH of the 20 times dilution liquid of a dry green vegetable is 7-8. For example, 190 g of pure water is added to 10 g of dried green vegetables, pulverized and stirred with a mixer, and measured with a pH meter (electrode type) while stirring the 20-fold diluted solution. If the pH is less than 7, green fading is observed at the stage after drying, and if the pH is higher than 8, discoloration tends to proceed during storage. More preferably, it is preferable to adjust the pH at the time of blanching or addition of saccharides so that the pH of a 20-fold diluted solution of dried green vegetables is in the range of 7.2 to 7.8.

  The dried green vegetables for dried instant food are condensed by hot water cooking, cooking in a pot, cooking in a microwave oven, etc., and used as ingredients for instant food.

Hereinafter, the present embodiment will be described in more detail with reference to examples.
<Preliminary test>
It was verified in a preliminary test how the type of sugar affects the fading or discoloration during storage. Glucose, fructose, lactose, maltose, sucrose, trehalose, sorbitol, malt starch syrup (maltose content 33%, solid content 75%), and reduced starch syrup (solid content 75%) were used.

  As dry green vegetables, cabbage dried with hot air was used as an index.

  As a method for producing a dried cabbage, the leaves of the outer cabbage having a green color are cut into a size of about 30 × 25 mm, blanched with a 0.1% aqueous sodium bicarbonate solution at 98 ° C. for 2 minutes, and the blanched cabbage is taken out. After cooling and washing with running water, centrifugal dehydration was performed until the weight became 60% by weight of the raw cabbage. Next, 20% by weight of the above saccharides as a solid content is added to 100% by weight of the dehydrated cabbage, and mixed and allowed to stand so that the total weight of the saccharides contained in the dried cabbage is about 70% by weight. After removing excess drip, drying at 80 ° C. for 2 hours, further drying at 70 ° C. for 2 hours, and drying at 60 ° C. for 4 to 6 hours to adjust the water content to 7% by weight A dried cabbage sample was prepared. The pH of the 20-fold diluted solution of the dried cabbage sample was adjusted to be about 7.5.

  As a method of simply confirming the change in color tone during storage of the prepared dried cabbage sample, 10% by weight of moisture is humidified in the dried cabbage, and the humidified dried cabbage is heated at 60 ° C. for 48 hours to force The color tone was evaluated. The evaluation is conducted by five skilled panelists, and when the color tone after drying is 5 points, 5 items that are equivalent in appearance and 4 points that are slightly faded or discolored but are good In general, there were 3 points where fading or browning was possible, but 2 points where discoloration or browning was conspicuously impossible as a product, and 1 point where discoloration or discoloration was remarkably impossible as a product.

  The preliminary test results are shown in Table 1 below.

  From the above results, it was found that malt starch syrup containing a large amount of lactose, maltose and maltose is preferable as the saccharide having the effect of preventing fading and discoloration during storage. Conversely, it was found that fructose and sucrose are highly likely to promote discoloration during storage. For other saccharides, discoloration during storage proceeds to some extent, but the degree of discoloration is less than that of fructose and sucrose. From the results of malt varieties (solid content 75%, sugar composition maltose 33% by weight), lactose and If a large amount of maltose was contained, the effect on fading and discoloration during storage was considered to be small even if some other sugars were contained. In addition, when sucrose, trehalose, sorbitol, and reduced starch syrup, which do not exhibit reducibility, may exhibit discoloration during storage, it was suggested that only the Maillard reaction is not the cause of discoloration during storage.

<Experiment 1> About sugar content and lactose or / and maltose content (Example 1-1)
Dried according to the method of the preliminary test, except that maltose is 4% by weight and glucose is 6% by weight with respect to 100% by weight of dehydrated cabbage, and the saccharide is thoroughly mixed and allowed to stand for 1 hour at 25 ° C. A cabbage sample was prepared.

(Example 1-2)
Dried according to the method of the preliminary test, except that maltose was 8% by weight and glucose was 12% by weight with respect to 100% by weight of dehydrated cabbage, and the saccharide was mixed thoroughly and allowed to stand for 1 hour at 25 ° C. A cabbage sample was prepared.

(Example 1-3)
A dry cabbage sample was prepared according to the method of the preliminary test, except that the addition of sugar was 20% by weight of maltose with respect to 100% by weight of cabbage, the sugar was sufficiently mixed, and then allowed to stand at 25 ° C. for 1 hour for permeation.

(Example 1-4)
Dried cabbage sample according to the method of the preliminary test, except that the addition of sugar is 4% by weight lactose and 6% by weight glucose with respect to 100% by weight cabbage, and the sugar is thoroughly mixed and then allowed to stand at 25 ° C. for 1 hour for permeation. Was made.

(Example 1-5)
Dried cabbage sample according to the method of the preliminary test, except that the sugar addition is 8 wt% lactose and 12 wt% glucose with respect to 100 wt% cabbage, and the saccharide is thoroughly mixed and then allowed to stand at 25 ° C for 1 hour to infiltrate. Was made.

(Example 1-6)
A dry cabbage sample was prepared according to the method of the preliminary test, except that the addition of sugar was 20% by weight of lactose with respect to 100% by weight of cabbage, and the sugar was sufficiently mixed and then allowed to stand at 25 ° C. for 1 hour for permeation.

(Example 1-7)
The preliminary test was performed except that the addition of saccharide was 4% by weight of lactose, 4% by weight of maltose and 12% by weight of glucose with respect to 100% by weight of cabbage, and the saccharide was sufficiently mixed and then allowed to stand for 1 hour at 25 ° C. Dry cabbage samples were made according to the method.

(Example 1-8)
According to the method of the preliminary test, except that the addition of sugar was 30% by weight of malt starch syrup (maltose content 33% by weight) with respect to 100% by weight of cabbage, and the saccharide was sufficiently mixed and then allowed to stand at 25 ° C. for 1 hour for permeation. A dried cabbage sample was prepared.

(Comparative Example 1-1)
The dried cabbage sample was prepared according to the method of the preliminary test, except that the addition of sugar was 3% by weight of maltose and 7% by weight of glucose with respect to 100% by weight of cabbage, and the saccharide was mixed thoroughly and then allowed to stand for 1 hour at 25 ° C. Produced.

(Comparative Example 1-2)
The dry cabbage sample was prepared according to the method of the preliminary test except that the addition of sugar was 4% by weight of maltose and 4% by weight of glucose with respect to 100% by weight of cabbage, and the sugar was thoroughly mixed and then allowed to stand for 1 hour at 25 ° C. Produced.

(Comparative Example 1-3)
The dried cabbage sample was prepared according to the method of the preliminary test, except that the sugar was added to 3% by weight of lactose and 7% by weight of glucose with respect to 100% by weight of cabbage, and the saccharide was sufficiently mixed and then allowed to stand at 25 ° C for 1 hour to infiltrate. Produced.

  Each dried cabbage sample was analyzed for total sugar content and sugar content. In addition, except for Example 1-8, since saccharides to be added were 2 sugars or less, each sugar was individually analyzed by the HPLC method and then integrated to calculate the total sugar amount. Moreover, about Example 1-8, while measuring the maltose content by HPLC method, the total amount of sugars was measured by the phenol sulfuric acid method. Moreover, in addition to the appearance evaluation about the deterioration test performed by the preliminary test, it evaluated also the difficulty of breaking of the cabbage during drying and after drying. Excellent softness during drying, hardness after drying, strength, excellent resistance to breakage ◎, softness during drying, hardness after drying, strength and strength are also good. ◯ for things, softness during drying, hardness after drying, lack of strength, fragile △, flexibility during drying, hardness after drying, hardness, lack of strength, fragile and fragile × did. The results are shown in Table 2.

  As for the fragility, it can be seen that if the total sugar amount is 55% by weight or more, the higher the total sugar amount, the better, and particularly 65% by weight or more is very good. Further, it can be seen that when the total sugar amount is less than 55% by weight, not only is it easily broken, but even when maltose is contained, the color is easily changed. It was shown that discoloration during storage can be suppressed when the maltose or / and lactose content is 10 wt% or more and the total sugar content is 55 wt% or more.

  In addition, maltose can suppress changes in color tone during storage compared to lactose, but sugar is easy to stick, and by adding lactose, the stickiness caused by sugar can be reduced. The aptitude is improved. Since lactose has a unique sweetness, it is preferable to add lactose mainly for maltose in order to improve the production suitability.

<Experiment 2> pH adjustment and magnesium salt addition (Example 2-1)
A dried cabbage sample was produced according to the method of Example 1-7, except that it was blanched at 98 ° C. for 2 minutes and the pH of the 20-fold diluted solution of the dried cabbage sample after drying was 7.0.

(Example 2-2)
A dried cabbage sample according to the method of Example 1-7, except that it was blanched with a 0.05% aqueous sodium bicarbonate solution at 98 ° C. for 2 minutes, and the pH of a 20-fold diluted solution of the dried cabbage sample after drying was 7.2. Manufactured.

(Example 2-3)
A dried cabbage sample according to the method of Example 1-7, except that it was blanched in a 0.15% aqueous sodium bicarbonate solution at 98 ° C. for 2 minutes, and the pH of a 20-fold diluted solution of the dried cabbage sample after drying was 7.8. Manufactured.

(Example 2-4)
A dried cabbage sample according to the method of Example 1-7, except that the blanching treatment was performed at 98 ° C. for 2 minutes in a 0.30% aqueous sodium bicarbonate solution, and the pH of the 20-fold diluted solution of the dried cabbage sample after drying was 8.0. Manufactured.

(Example 2-5)
Example 1 except that 0.1% by weight of magnesium carbonate is added to the weight of the cabbage after dehydration when the saccharide is added, and the pH of the 20-fold diluted solution of the dried cabbage sample after drying is 7.7. Dry cabbage samples were prepared according to the method of 7.

(Example 2-6)
Hot water at 98 ° C., 2 minutes blanching treatment, magnesium carbonate is added at 0.1% by weight with respect to the weight of cabbage after dehydration, and 0.1% by weight of sodium carbonate is added after drying. A dried cabbage sample was produced according to the method of Example 1-7, except that the pH of the 20-fold diluted solution of the dried cabbage sample was 7.5.

(Comparative Example 2-1)
Dry cabbage according to the method of Example 1-7, except that a 20-fold dilution of the dried cabbage sample after drying was performed with a 0.05% citric acid aqueous solution at 98 ° C. for 2 minutes and the pH of the 20-fold diluted solution of the dried cabbage sample was 6.5. Samples were manufactured.

(Comparative Example 2-2)
A dried cabbage sample according to the method of Example 1-7, except that the blanching treatment with a 0.50% aqueous sodium bicarbonate solution at 98 ° C. for 2 minutes and the pH of a 20-fold diluted solution of the dried cabbage sample after drying was 8.5. Manufactured.

  The appearance evaluation of the deterioration test performed in the preliminary test was also performed in Experiment 2. The results are shown in Table 3.

  By adjusting the pH to the alkali side during blanching, fading during blanching can be suppressed, but when the pH of 20-fold dilution after drying is higher than 8, discoloration during forced deterioration proceeds. Conversely, if the pH is adjusted to the acidic side during blanching and the pH of the 20-fold diluted after drying is less than 7, fading will proceed during blanching and drying. Therefore, it is preferable to adjust the pH at the time of blanching treatment or addition of saccharides so that the 20-fold diluted pH after drying is 7 to 8, more preferably 7.2 to 7.8.

  Further, by adding a magnesium salt at the time of sugar addition after blanching and adjusting the pH as necessary, the green color tone after drying becomes more vivid and the color tone is maintained even after forced deterioration.

Claims (5)

Dried green vegetables for instant food,
Containing 10% by weight or more of maltose and / or lactose,
The water content is 14% by weight or less,
The total sugar content is 55-80% by weight;
A dry green vegetable for instant food, wherein the pH of the 20-fold diluted solution of the dried green vegetable for instant food is 7-8.   The dried green vegetable for instant food according to claim 1, wherein the dried green vegetable contains a magnesium salt. Blanching process of blanching green vegetables;
A saccharide addition step of adding at least one saccharide selected from lactose, maltose and malt syrup to the green vegetable blanched in the blanching step;
A hot air drying step of drying the green vegetable to which saccharide has been added in the saccharide addition step with hot air of 100 ° C. or less, and a method for producing dried green vegetables for instant foods,
The dried green vegetable for instant food obtained by the production method is
Containing 10% by weight or more of maltose and / or lactose, having a water content of 14% by weight or less, and having a total sugar content of 55-80% by weight;
A method for producing a dried green vegetable for instant food, wherein the pH of the 20-fold diluted solution of the dried green vegetable for instant food is 7-8.   The method for producing a dried green vegetable for instant food according to claim 3, wherein a magnesium salt is added in the saccharide addition step. 5. The method for producing instant dried green vegetables according to claim 3, wherein the 20-fold diluted solution of dried green vegetables for instant food has a pH of 7.2 to 7.8.