JP7234441B1 - Dry food manufacturing method - Google Patents

Abstract

An object of the present invention is to provide a dried green vegetable food that is resistant to browning. A dry food is produced by a method including the following steps i) to iv). i) step of blanching green vegetables; ii) step of dehydrating green vegetables in i); mixing; and iv) drying the green vegetables. Here, the amount of sugar alcohol in the externally added saccharide is 10% by weight or more. [Selection figure] None

Description

TECHNICAL FIELD The present invention relates to a dried food obtained by drying green vegetables and a method for producing the same.

Dried foods are widely used as one of the forms of preserved foods and instant foods. Dried vegetables are often used, especially in ready-to-eat foods. Dried vegetables are usually produced by heat-treating vegetables and then drying them by a method such as hot air drying or vacuum freeze drying. For some instant foods, it is desirable to maintain the texture of the vegetables themselves. For the purpose of improving and adjusting the taste, it is produced by drying in a state where sugars such as glucose are added to the surface. Among such dried vegetables, green vegetables in particular are prone to browning with the passage of time after drying, which leads to deterioration of the appearance of food.

In Patent Document 1, in producing a dried vegetable food, in order to maintain the original appearance color tone of the vegetables, the blanched vegetable material is adjusted to pH 8.0 to 9.0, and this is It is disclosed that the material is lyophilized after being immersed in an aqueous solution containing one or more of reduced starch syrup, reduced malt starch syrup, reduced starch, starch hydrolyzate and disaccharide. Patent Document 2 describes a method of adding at least a sugar selected from lactose, maltose and malt starch syrup to blanched green vegetables and drying with hot air at 100°C or less in order to maintain the appearance color tone of green vegetables. disclosed. In this method, the dried green vegetables after production have a pH of 7 to 8 in a 20-fold dilution, contain 10% by weight or more of maltose and/or lactose, and have a total sugar content of 65. It contains up to 80% by weight, and the water content is 14% by weight or less. Both of the methods described in Patent Documents 1 and 2 include a step of adjusting the pH of the food to be weakly basic to basic.

JP-A-6-233651 JP 2018-033425 A

An object of the present invention is to provide a dried green vegetable food that is less prone to browning. Another object of the present invention is to provide a method for producing a dried green vegetable food that is resistant to browning.

As a result of intensive studies, the present inventors found that browning over time can be suppressed by substituting a sugar alcohol for part or all of the sugars added to green vegetables. I came to complete it.

That is, the present invention provides the following.
(1) A dried food product obtained by drying green vegetables, wherein the total carbohydrate content is 60 to 85% by weight and the sugar alcohol content is 7 to 70% by weight.
(2) The dry food according to (1), wherein the carbohydrate contains glucose, and the glucose content is 15 to 65% by weight.
(3) the following steps i) to iv):
i) blanching green vegetables;
ii) dehydrating the green vegetables of i);
iii) a step of mixing the green vegetables and the externally added saccharide of ii) in a weight ratio of 80:20 to 90:10; and iv) a step of drying the green vegetables;
A method for producing a dry food, wherein the sugar alcohol accounts for 10% by weight or more of the externally added saccharide.
(4) The production method according to (3), wherein the externally added saccharide contains saccharides, and the amount of saccharides in the externally added saccharide in step iii) is 50 to 85% by weight.
(5) The production method according to (4), wherein the saccharide contains glucose.
(6) The production method according to any one of (3) to (5), wherein the sugar alcohol contains sorbitol and/or reduced starch syrup.
(7) The production method according to (6), wherein the total amount of sorbitol and reduced starch syrup in the externally added saccharide in step iii) is 20 to 40% by weight.
(8) The production method according to any one of (3) to (7), wherein the step i) does not involve contact between the green vegetable and the pH adjuster.
(9) A dry food obtained by bringing monosaccharides, sorbitol and/or reduced starch syrup into contact with green vegetables and drying them.

ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the dry food of green vegetables which browning does not produce easily. In addition, according to the present invention, it is possible to provide a method for producing a dried green vegetable food that is less prone to browning.

1 is a photograph showing the appearance of dried cabbage of Comparative Example and Examples 1 to 4 after storage treatment.

In this specification, the description of "A to B" using numerical values A and B indicates "A or more and B or less" unless otherwise specified. In addition, the description of "%" representing the concentration indicates "% by weight" unless otherwise specified. In the present specification, the weight, content and concentration of carbohydrates, sugars and sugar alcohols refer to the weight, content and concentration of solids, unless otherwise specified.

1. First Embodiment - Dried Food The first embodiment of the present invention is a dried food made by drying green vegetables, having a total sugar content of 60 to 85% by weight and a sugar alcohol content. is 7 to 70% by weight.

Green vegetables have the effect of improving the appearance of food due to their coloration by being included in instant foods and the like in a dried state. There is a problem that browning tends to occur over time. For example, even if a means effective for maintaining the coloration of vegetables other than green vegetables is applied to green vegetables in the same way, the same effect cannot necessarily be obtained. The dried food of the present embodiment is a dried food of such green vegetables, and has the advantage of being resistant to browning.

The term "browning" as used herein refers to a change in the appearance of food to brown due to cooking, processing, storage, or the like. Browning is broadly classified into enzymatic browning caused by the action of enzymes derived from foodstuffs and non-enzymatic browning (mainly known as the Maillard reaction caused by heating), but both types of browning are included here. be. Although the principle of browning of dried food of green vegetables has not been specified at present (see, for example, Patent Document 2), the dried food of the present embodiment undergoes browning over time regardless of the generation principle. The advantage is that it does not occur.

As used herein, the term “green vegetables” is not particularly limited as long as the edible parts of the vegetables exhibit a green color derived from chlorophyll. Examples include asparagus, green beans, okra, cabbage, Japanese mustard spinach, perilla, garland chrysanthemum, bok choy, rape blossoms, chives, green onions, basil, parsley, green peppers, broccoli, spinach, Japanese honeywort, mulukhiya, lettuce, and avocado. The dried food of the present embodiment can be, for example, a cabbage dried food that is used as an instant food or the like and consumed in a very large amount.

According to the Ministry of Education, Culture, Sports, Science and Technology's "Japanese Food Standard Composition Tables 2020 Edition (8th Edition)", the contents of water and carbohydrates contained in 100 g of raw cabbage are 92.7 g and 3.5 g, respectively. Carbohydrates also include 0.1 g of starch, 1.8 g of glucose, 1.4 g of fructose and 0.1 g of sucrose.

As used herein, the term "dry food" refers to food that has been dried by naturally (eg, drying in the sun) or artificially dehydrating fresh food. The drying means is not particularly limited, but artificial drying means is preferable. As the artificial drying means, any known drying means such as ventilation, hot air, freezing, vacuum freezing, dry heat, microwave, infrared rays, etc. may be applied. It is preferable to apply hot air drying because it is possible to dry at room temperature and it is easy to maintain the texture of vegetables. In particular, it is preferable to use hot air drying in which hot air of 40 to 120°C, 45 to 110°C, or 50 to 90°C is directly blown onto the foodstuff.

As used herein, the term "moisture content" refers to a value measured using a normal pressure heat drying method. Specifically, a weighed 10 g target is heated at 105 ° C. for 4 hours using a forced circulation ventilation dryer, and the weight change of the target after heating is calculated by the following formula. say quantity.
(Weight before heating - Weight after heating) / Weight before heating (%)
In the dried food of the present embodiment, the moisture content is preferably 14% by weight or less, particularly 10% by weight or less, 8% by weight or less, or 7% by weight or less.

As used herein, the term "carbohydrate" refers to carbohydrates excluding dietary fiber, and more specifically refers to sugars and sugar alcohols. As used herein, the term "sugars" includes both monosaccharides and disaccharides among carbohydrates. Monosaccharides include, but are not limited to, glucose, fructose, galactose, and the like. Examples of disaccharides include, but are not limited to, maltose, sucrose, lactose, and trehalose. As used herein, "sugar alcohol" refers to a substance obtained by reducing the carbonyl group of carbohydrate. Examples of sugar alcohols include, but are not limited to, erythritol, glycerin, lactitol, mannitol, sorbitol, xylitol, maltitol, and reduced starch syrup. As a reduced starch syrup, for example, one having a monosaccharide ratio of 15% or less, for example, 10% or less in sugar alcohol composition is known, but it is not particularly limited. Sugar alcohols are known to have characteristics such as being resistant to acids and alkalis and being difficult to digest and absorb as compared to sugars.

In the dried food of the present embodiment, the total sugar content is 60-85% by weight, preferably 65-80% by weight. The total saccharide content here includes both saccharides derived from green vegetables and saccharides externally added during production (externally added saccharides). Further, in the dried food of the present embodiment, the sugar alcohol content is 7 to 70% by weight, preferably 7 to 35% by weight, more preferably 10 to 30% by weight.

The amount of externally added saccharide contained in the dry food of the present embodiment is preferably 2 to 5 times, particularly 3 to 4 times that of the saccharide derived from green vegetables. The composition of the externally added saccharide is not particularly limited as long as it contains a sugar alcohol, but it preferably contains a saccharide. Dried food of green vegetables is usually dried in a cut state, but it is desirable to keep the outer shape and have a certain degree of hardness in order to maintain the appearance and the production efficiency. By externally adding saccharides, the above effect can be obtained.

The saccharides to be externally added are not particularly limited, but glucose can be preferably used because it is readily available and has a high effect of maintaining the outer shape. In the dry food of the present embodiment, glucose is added so that the content is 15 to 65% by weight, preferably 30 to 60% by weight, particularly 40 to 55% by weight, together with glucose derived from green vegetables. is preferred.

The content of carbohydrates, sugars, and sugar alcohols contained in the dried food of this embodiment is, for example, the Consumer Affairs Agency "Food Labeling Act (Law No. 70 of 2013) Article 4, Paragraph 1. Labeling standards (published on June 30, 2015)” and “Attachment: Methods for analyzing nutritional components, etc.” can be used for measurement. Specifically, the carbohydrate content can be calculated by subtracting protein, lipid, dietary fiber, ash and moisture content from the mass of the food. The content of sugars and sugar alcohols can be measured by gas chromatography or high-performance liquid chromatography.

2. Second Embodiment - Process for Producing Dried Food A second embodiment of the present invention comprises the following steps i)-iv):
i) blanching green vegetables;
ii) dehydrating the green vegetables of i);
iii) a step of mixing the green vegetables and the externally added saccharide of ii) in a weight ratio of 80:20 to 90:10; and iv) a step of drying the green vegetables;
A method for producing a dry food, wherein the sugar alcohol accounts for 10% by weight or more of the externally added saccharide.

The method for producing dried food of the second embodiment (hereinafter also referred to as "the method of this embodiment") has the above characteristics, so that it is possible to obtain a dried food of green vegetables that is less likely to brown. . Definitions of terms and the like in the second embodiment are the same as definitions and the like in the first embodiment unless there is a particular contradiction.

2-1 step i)
Step i) of the method of the present embodiment is a step of blanching green vegetables. The method of the invention may comprise, prior to step i), the step of cutting the edible portion of the green vegetable and cutting it to the desired size.

As used herein, "blanching" refers to heating green vegetables for a short period of time and then cooling them. The heating means can be, for example, boiling, steaming, Joule heating, infrared rays, microwave heating, high-frequency heating, or the like. In particular, heating by boiling can be preferably used. When performing boiling heating, the boiling liquid can be, for example, water or an aqueous solution. When an aqueous solution is used as the boiled liquid, the boiled liquid preferably does not contain a pH adjuster, more specifically a pH adjuster used to raise the pH of green vegetables. Examples of such pH adjusters include sodium hydrogen carbonate and potassium carbonate. Many of green vegetables are usually weakly acidic (approximately pH 4 or more and less than pH 7), but in this step, it is not necessary to adjust the pH of the green vegetables to over 7, that is, to be weakly basic. The boiling temperature can be 70-100°C, especially 90-100°C. The heating time varies depending on the heating means, but can be, for example, 30 seconds to 3 minutes, 1 to 2 minutes, or the like.

Blanching also includes cooling after heating. For cooling, any means such as water cooling, ice cooling, and wind cooling may be used, but water cooling is particularly preferable. For water cooling, a cooling liquid at 0° C. or more and room temperature or less can be used. The cooling liquid can specifically be water or an aqueous solution, but when an aqueous solution is used as the cooling liquid, the cooling liquid is a pH adjuster, more specifically used to raise the pH of green vegetables. It preferably does not contain any pH adjuster. That is, in the method of the present embodiment, step i) preferably does not involve contacting the green vegetable with a pH adjuster, especially a pH adjuster for raising the pH. Depending on the foodstuff, raising the pH may cause unnecessary changes in texture and flavor, so it is desirable to avoid using such pH adjusters.

2-2 step ii)
Step ii) of the method of this embodiment is a step of dehydrating the green vegetables. Green vegetables blanched in step i) are drained and then subjected to a dehydration step. The dehydration means is not particularly limited, and any known means such as means using a centrifugal dehydrator and means for contacting with a water-absorbent material can be applied. It is preferable to select means and conditions that are less likely to damage green vegetables depending on the type of green vegetables. Most of the tissue structure of green vegetables after blanching is maintained, and moisture is maintained here. remains.

2-3 step iii)
Step iii) of the method of the present embodiment is a step of mixing green vegetables and externally added saccharides. The mixing ratio of the green vegetable and the externally added saccharide is preferably 80:20 to 90:10, particularly 82:18 to 87:13 by weight. The weight ratio as used herein refers to the ratio of the weight of the dehydrated green vegetable containing water to the weight of the externally added saccharide equivalent to the solid content. The externally added saccharide may be mixed with the green vegetables as it is, or may be mixed with the green vegetables as an aqueous solution. From the viewpoint of work convenience, it is preferably mixed as it is with green vegetables. The means for mixing the green vegetables and the externally added saccharides is not particularly limited as long as the saccharides are evenly added to the surfaces of the green vegetables.

Sugar alcohol accounts for 10% by weight or more, preferably 15 to 50% by weight, and more preferably 20 to 40% by weight of the externally added saccharide. As the sugar alcohol, any known sugar alcohol such as erythritol, glycerin, lactitol, mannitol, sorbitol, xylitol, maltitol, and reduced starch syrup can be used. In particular, it is preferable to use sorbitol and/or reduced starch syrup. In this case, the total amount of sorbitol and reduced starch syrup in the externally added saccharide is preferably 20 to 40% by weight. The total amount here refers to the amount of reduced starch syrup only when sorbitol is not included, refers to the amount of sorbitol alone when reduced starch syrup is not included, and refers to the amount of sorbitol and reduced starch syrup when both sorbitol and reduced starch syrup is included. Refers to the sum of quantities.

The externally added saccharides may be all sugar alcohols, but preferably contain saccharides. The ratio of saccharides in the externally added saccharides is preferably 50 to 85% by weight, particularly 60 to 80% by weight. As sugars, any of glucose, fructose, galactose, maltose, sucrose, lactose and trehalose, and combinations thereof may be used. In particular, it is preferred that part or all of the saccharide is glucose. When the externally added saccharide includes sugar alcohols and sugars, these can be added to green vegetables separately or together. For convenience of work, they may be added together (eg as a mixture or premix).

2-4 Step iv)
Step iv) of the method of this embodiment is a step of drying the green vegetables. As long as the water content of the green vegetables can be sufficiently reduced, for example, to 14% by weight or less, the drying means is not particularly limited, and includes hot air, freezing, vacuum freezing, dry heat, microwaves, infrared rays, and the like. Although any known drying means can be applied, it is preferable to apply hot air drying because it can be dried in a relatively short time and does not easily affect the texture of green vegetables. Specifically, a hot air dryer or the like can be used. Green vegetables to which carbohydrates have been externally added are likely to undergo the Maillard reaction at high temperatures, so the hot air temperature in the hot air drying is preferably 120° C. or lower, more preferably 100° C. or lower. More specifically, it is preferably 40 to 120°C, 45 to 110°C, or 50 to 90°C.

Drying is preferably carried out until the water content of the green vegetables is 14% by weight or less, particularly 10% by weight or less, 8% by weight or less, or 7% by weight or less. The drying time is preferably 1 to 24 hours, more preferably 5 to 12 hours, depending on the drying means and drying temperature.

2-5 Other Steps The dried food obtained through the above steps may be packaged as it is or in combination with a separately prepared dried food, such as other ingredients. At that time, a desiccant, a deoxidizing agent, etc. may be enclosed together in the package.

3. Third Embodiment - Dried Food A third embodiment of the present invention is a dried food obtained by contacting a monosaccharide, sorbitol and/or reduced starch syrup with green vegetables and drying them. In the present specification, "contact" may be by any means such as mixing, spraying, immersion, and impregnation, but mixing is preferably carried out from the viewpoint of work convenience. Monosaccharides, sorbitol, and reduced starch syrup can all be brought into contact with green vegetables as they are (for example, in paste or solid form) or in the form of aqueous solutions, but they are preferably brought into contact as they are from the viewpoint of work simplicity. Monosaccharides and sorbitol and/or reduced starch syrup can be brought into contact with green vegetables separately or together, but from the viewpoint of convenience, they are preferably brought into contact together (eg, as a mixture or premix).

The dried food of this embodiment is obtained by drying the green vegetables after the contacting. The drying means is not particularly limited as long as the moisture content of the green vegetables can be sufficiently reduced, for example, to 14% by weight or less, and any known drying means may be used. In particular, it is preferable to dry by hot air drying. The dried food of the present embodiment has a moisture content of preferably 14% by weight or less, particularly 10% by weight or less, 8% by weight or less, or 7% by weight or less, by drying means.

The dry food of this embodiment may be, for example, the dry food produced by the method of the second embodiment of the present invention. In this case, the conditions for producing the dried food of this embodiment can be the conditions described in the second embodiment unless there is a particular contradiction. In this case, "external sugar" refers to a combination of monosaccharides and sorbitol and/or reduced starch syrup, "sugar alcohol" refers to sorbitol and/or reduced starch syrup, "sugars" refers to monosaccharides such as glucose, and " "Mixing" can be appropriately read as "contact".

Definitions of terms in this embodiment are the same as those in the first embodiment of the present invention unless there is a particular contradiction. In addition, each feature such as composition and physical properties of the dried food of the present embodiment may be the same as those of the dried food of the first embodiment unless there is a particular contradiction.

Examples of the present embodiment will be described below in more detail, but the present embodiment is not limited to these.

(1) Pretreatment of Cabbage Cabbage leaves were cut into 30×30 mm pieces and subjected to blanching treatment including boiling in hot water of 92 to 95° C. for 90 seconds. Cold water was added to the drained cabbage, and the mixture was stirred and cooled to 40°C or less. The drained cabbage was further wrapped in a towel and squeezed to dehydrate. Cabbage was dehydrated to approximately 65% of its pre-boil weight.

(2) Sweetening/drying treatment As comparative examples and Examples 1 to 4, cabbage after dehydration treatment and carbohydrates having the respective compositions shown in Table 1 were added at a weight ratio of dehydrated cabbage to carbohydrates of 84: It was put in a container so as to be 16 and mixed with stirring. In addition, the numerical values in Table 1 all show the weight of the solid content except for the dehydrated cabbage. Comparative Examples and Examples 1 to 4 were specifically carried out under the following conditions.
Comparative Example: All 16 parts by weight of externally added saccharide were replaced with glucose.
Example 1: All 16 parts by weight of externally added saccharides were reduced starch syrup 1 (Ueno Food Techno Co., Ltd., sugarless syrup MU-50, solid content conversion).
Example 2: Of the glucose in Comparative Example, 4.8 parts by weight was replaced with reduced starch syrup 1 (converted to solid content).
Example 3: Of the glucose in the comparative example, 4.8 parts by weight was replaced with reduced starch syrup 2 (Ueno Food Techno Co., Ltd., sugarless syrup MU-75, solid content conversion).
Example 4: Of the glucose in the comparative example, 4.8 parts by weight was replaced with sorbitol.

The mixed cabbage was dried at 70° C. using a multi-stage hot air dryer to prepare dried cabbage. Drying was carried out for 8 hours to 8 hours 30 minutes until the loss on drying in 30 minutes was less than 0.5% of the initial weight before drying. The water content after drying was less than 7% by weight. Based on the standard water content, sugar content, and glucose content of raw cabbage and the blending amounts in Table 1, the theoretical content of sugar, glucose, reduced starch syrup, and sorbitol in dried cabbage with a water content of 7% by weight was calculated. (Table 2). The numbers in parentheses in Table 2 indicate the theoretical content ranges of carbohydrates, glucose, reduced starch syrup and sorbitol in dried cabbage when the water content is 0 to 14% by weight.

Calculation of the theoretical contents of carbohydrates and glucose in Comparative Examples was performed as follows. The standard amounts of moisture, solids, sugars and glucose in 100 g of cabbage before processing are 92.7 g, 7.3 g, 3.5 g and 1.8 g, respectively. The weight after dehydration is 65% of that before processing, ie 65 g. Since most of the weight loss is water, the solid content after dehydration remains the same and only the water content is reduced. 3g, 3.5g and 1.8g. When 65 g of dehydrated cabbage and externally added sugar (in this case, all glucose) are mixed at a weight ratio of 84:16, the amount X of the externally added sugar (glucose) is 12.4 g from the following formula (I). is calculated as
65:X=84:16 (I)
The weight of the cabbage before drying is 77.4 g (65 g + 12.4 g), of which the solid content is 19.7 g (7.3 g (derived from cabbage) + 12.4 g (external additive)) and the sugar is 15.9 g ( 3.5 g (derived from cabbage) + 12.4 g (externally added)), and glucose accounts for 14.2 g (1.8 g (derived from cabbage) + 12.4 g (externally added)). When the water content after drying is 7% by weight, the weight Y after drying is calculated as 21.2 g from the following formula (II) based on the weight of the solid content of 19.7 g.
19.7: Y=93:100 (II)
In this case, the theoretical contents of sugar and glucose in the dried cabbage of the comparative example are 75.0% by weight (15.9/21.2×100), 67.0% by weight (14.2/ 21.2×100).
In fact, the weight loss of cabbage after dehydration includes not only water but also solids. On the other hand, even if the dehydrated cabbage and the externally added saccharide are mixed at a weight ratio of 84:16, some of the externally added saccharide is not added to the cabbage because it adheres to the container wall or the like during mixing. remain in the container for a long time. However, it has been confirmed from the results of measuring the sugar content of dried cabbage that the sugar content in dried cabbage almost matches the theoretical value obtained by the above calculation. It is presumed that this is because the effect of the loss of the solid content and the effect of the loss of the externally added saccharide were canceled out.

(3) Preservation Treatment 25-30 g each of the prepared dried cabbages of Comparative Example and Examples 1-4 were placed in a nylon/PE 95 μm thick seal bag and tightly sealed. The seal bag was stored in a constant temperature bath at 40°C for 6 weeks. The degree of browning of the dried cabbage after storage was visually observed. A photograph of each dried cabbage is shown in FIG. The degree of browning of each dried cabbage was evaluated based on the following criteria. Table 2 shows the evaluation results.
◎: almost no browning observed; 〇: slightly browned partially but not entirely browned; △: slightly browned overall; ×: browned overall .

As shown in Table 2 and FIG. 1, browning was observed on the whole in Comparative Examples, but almost no browning was observed in Examples 1 and 4. Further, in Examples 2 and 3, although light browning was observed partially, green color was maintained as a whole. As described above, it was confirmed that browning of dried cabbage was suppressed by replacing part or all of the externally added saccharides with sugar alcohols in the production of dried cabbage.

The dried food and method for producing the dried food of the present invention can be mainly used in the food industry.

Claims (5)

The following steps i) to iv):
i) blanching green vegetables;
ii) dehydrating the green vegetables of i);
iii) a step of mixing the green vegetables and the externally added saccharide of ii) in a weight ratio of 80:20 to 90:10; and iv) a step of drying the green vegetables;
A method for producing a dry food, wherein the externally added saccharide contains sorbitol and reduced starch syrup in a total amount of 10% by weight or more. 2. The production method according to claim 1 , wherein the externally added saccharide contains sugars, and the amount of the saccharides in the externally added saccharide in step iii) is 50 to 85% by weight. 3. The production method according to claim 2 , wherein the saccharide contains glucose. The production method according to any one of claims 1 to 3 , wherein the total amount of sorbitol and reduced starch syrup in the externally added saccharide is 20 to 40% by weight. The production method according to any one of claims 1 to 4 , wherein step i) does not involve contacting the green vegetable with a pH adjuster.

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