JP7029982B2 - How to dry leafy vegetables - Google Patents

Description

The present invention relates to a method for drying leafy vegetables.

Patent Document 1 discloses a method for producing a dried food. The method for producing this dried food is to dry the leafy vegetables with hot air and then freeze-dry the leafy vegetables. In this hot air drying, the leafy vegetables are dried at 40 degrees Celsius to 120 degrees Celsius for 30 minutes to 5 hours until the water content reaches 85 to 40% by weight. According to the method for producing a dried food disclosed in Patent Document 1, it is possible to obtain a dried food having an original color tone such as vegetables and fruits, which has an excellent texture and does not require the addition of a coloring agent.

Japanese Unexamined Patent Publication No. 6-153782

However, the method for producing a dried food disclosed in Patent Document 1 has a problem that it does not swell so much when the dried leafy vegetables are immersed in water.

The present invention solves such a problem. Its purpose is to provide a method for drying leafy vegetables that swell well when soaked in water.

As a result of diligent studies on the above problems, the present inventors have brought the water distribution of the leafy vegetables closer to uniform prior to freeze-drying, so that the leafy vegetables after freeze-drying swell well when immersed in water. And completed the present invention. That is, the present invention is as follows.

In order to solve the above problems, according to a certain aspect of the present invention, the method for drying leafy vegetables includes a wind drying step S100 and a freeze-drying step S102. The wind drying step S100 is a step of drying the leafy vegetables by blowing wind on the leafy vegetables. Wind is a flow of gas. The freeze-drying step S102 is a step of freeze-drying the dried leafy vegetables in the air-drying step S100. The freeze-drying step S102 includes a dried vegetable freezing step S120, a thawing step S130, a water addition step S132 , a refreezing step S124, and a sublimation step S126. The dried vegetable freezing step S120 is a step of freezing the dried leafy vegetables in the air drying step S100. The water distribution correction step S122 is a step of correcting the water distribution in the frozen leafy vegetables in the dried vegetable freezing step S120 so as to approach uniform. The refreezing step S124 is a step of refreezing the leafy vegetables to which water has been added in the water addition step S132 . The sublimation step S126 is a step of sublimating the water contained in the leafy vegetables frozen in the refreezing step S124.

The thawing step S130 is a step of thawing the leafy vegetables frozen in the dried vegetable freezing step S120. The water addition step S132 is a step of adding water to the leafy vegetables thawed in the thawing step S130.

Alternatively, it is desirable that the above-mentioned water addition step S132 has a step of adding water of 21% by weight or more and 100% by weight or less of the leafy vegetables thawed in the thawing step S130 to the leafy vegetables.

According to the present invention, it is possible to provide a method for drying leafy vegetables that swell well when immersed in water.

It is a flowchart which shows the procedure of the drying method of a leafy vegetable which concerns on an embodiment of this invention. It is a flowchart which shows the procedure of the water distribution correction process which concerns on an embodiment of this invention. It is a schematic diagram which shows the appearance of the container for refreezing which concerns on an embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.

<Explanation of vegetables subject to the present invention>
The present invention targets leafy vegetables. Leafy vegetables are vegetables whose leaves are mainly edible. Examples of leafy vegetables include oilseed rape, cabbage, Japanese mustard spinach, bok choy, nira, garlic leaves, green onions, onion leaves, nozawana, Chinese cabbage, fuki, fudansou, and spinach. , Mizuna and lettuce. However, in the present invention, leafy vegetables may be dried in a state of being mixed with other substances. Examples of other things are root vegetables, grains and meat.

<Explanation of the apparatus used in the present invention>
The devices used in certain embodiments of the present invention are air drying devices, freezing devices, mixing devices, and vacuum freeze drying devices. The wind drying device dries the leafy vegetables by blowing wind on the leafy vegetables. The wind may be hot air or cold air. The freezing device freezes the leafy vegetables dried by the wind drying device. The freezing device is also a device for refreezing leafy vegetables mixed with water by a mixing device. The mixing device mixes the leafy vegetables once frozen and thawed by the freezing device with water. The vacuum freeze-dryer sublimates the water content of the leafy vegetables that have been re-frozen by the freeze-drying device. In carrying out the present invention, the mixing device may not always be used. In the case where the mixing device is not used, the leafy vegetables once frozen and thawed by the freezing device may not be mixed with the water. Further, even if the device is different from the freezing device for freezing the leafy vegetables dried by the wind drying device and the freezing device for freezing the leafy vegetables once thawed and mixed with water. good. All of these devices are well known devices. Therefore, the detailed description is not repeated here. Further, the apparatus and tools for carrying out the steps of blowing the wind on the leafy vegetables, freezing the leafy vegetables, mixing the leafy vegetables with water, and sublimating the water content of the leafy vegetables are not particularly limited.

<Process description>
FIG. 1 is a flowchart showing a procedure of a method for drying leafy vegetables according to the present embodiment. Based on FIG. 1, a step of a method for drying leafy vegetables according to the present embodiment will be described. The method for drying leafy vegetables according to the present invention includes a wind drying step S100 and a freeze-drying step S102.

The wind drying step S100 is a step of blowing wind on leafy vegetables. The wind here means the flow of gas. Leafy vegetables are dried by being blown by the wind. The wind drying device described above can be used to blow wind on leafy vegetables. The specific method for blowing the wind on the leafy vegetables is not particularly limited. The specific method may be a well-known method. The attributes of the wind are not particularly limited. For example, the temperature, humidity, and composition of the gas constituting the wind are not particularly limited. However, it is desirable that the gas is air. This is because it is easily available. In addition to air, nitrogen gas and carbon dioxide gas are examples of such gases. It is desirable that the temperature of the gas is 70 degrees Celsius or more and 90 degrees Celsius or less. This is because the possibility of damaging the leafy vegetables can be suppressed and the effect of drying the leafy vegetables can be achieved at the same time as compared with the case where the temperature is less than 70 degrees Celsius and the case where the gas exceeds 90 degrees Celsius. The humidity of the gas is preferably less than 100% relative humidity. It is more desirable that the humidity is as low as possible. This is because the effect of drying leafy vegetables improves as the humidity decreases.

The freeze-drying step S102 is a step of freeze-drying the dried leafy vegetables in the air-drying step S100. In the present embodiment, the freeze-drying step S102 includes a dried vegetable freezing step S120, a water distribution correction step S122, a refreezing step S124, and a sublimation step S126.

The dried vegetable freezing step S120 is a step of freezing the dried leafy vegetables in the air drying step S100. The freezing device described above can be used to freeze the leafy vegetables. The specific method for freezing leafy vegetables is not particularly limited. The specific method may be a well-known method.

The water distribution correction step S122 is a step of correcting the water distribution in the frozen leafy vegetables in the dried vegetable freezing step S120 so as to approach uniform. The correction in the present invention means, for example, to reduce the difference in water content between the former and the latter when the water content in the center of the leaf of the leafy vegetable is higher than the water content in the surface of the leaf. Instead of the surface and center of the leaf, the difference in water content between the portion near the root of the stem and the portion near the tip of the stem may be reduced.

The refreezing step S124 is a step of refreezing the leafy vegetables corrected in the water distribution correction step S122 so that the water distribution approaches uniform. The freezing device described above can be used to refreeze the leafy vegetables. The specific method for refreezing leafy vegetables is not particularly limited. The specific method may be a well-known method.

The sublimation step S126 sublimates the water contained in the leafy vegetables. This leafy vegetable is a leafy vegetable frozen in the refreezing step S124. The sublimation of the water causes the leafy vegetables to dry. The vacuum freeze-drying device described above can be used to sublimate the water content of the leafy vegetables. The specific method for sublimating the water contained in the leafy vegetables is not particularly limited. The specific method may be a well-known method.

The water distribution correction step S122 includes a thawing step S130 and a water addition step S132. FIG. 2 is a flowchart showing the procedure of the water distribution correction step S122 according to the present embodiment. Based on FIG. 2, the step of the water distribution correction step S122 according to the present embodiment will be described.

The thawing step S130 is a step of thawing the leafy vegetables frozen in the dried vegetable freezing step S120. The specific method for defrosting is not particularly limited. Leaving the room in a room where the temperature exceeds 0 degrees Celsius is an example of such a method.

The water addition step S132 is a step of adding water to the leafy vegetables thawed in the thawing step S130. The mixing device described above can be used to add water to the leafy vegetables. In this case, water is added to the leafy vegetables by putting the leafy vegetables and the aqueous solution into the mixing device and then mixing the leafy vegetables and the aqueous solution by the mixing device. The composition of the aqueous solution is not particularly limited. Examples of substances contained in the aqueous solution include sodium hydrogen carbonate, sodium dextrin chloride, monosodium glutamate, vitamin E, and paste. Examples of pastes include pectin, guar gum, xanthan gum, tamarind gum, carrageenan, propylene glycol and carboxymethyl cellulose. It is desirable that the weight% of the water content is 21% by weight or more and 100% by weight or less of the leafy vegetables thawed in the thawing step S130. This is because the leafy vegetables dried by the method for drying the leafy vegetables according to the present embodiment swell particularly well when immersed in water. Of course, the specific method for adding water in this step is not limited to those described above. The specific method may be a well-known method.

The embodiments disclosed this time are exemplary in all respects. The scope of the present invention is not limited based on the above-described embodiment, and it goes without saying that various design changes may be made without departing from the spirit of the present invention.

For example, as long as the thawing step S130 and the water addition step S132 are included, the specific method for correcting the water distribution in the water distribution correction step S122 is not particularly limited.

<Explanation of how to eat>
The method of using the leafy vegetables dried by the drying method according to the present embodiment is not particularly limited. For example, the leafy vegetables may be used as an ingredient for instant noodles. In that case, the leafy vegetables are changed to a state close to that before drying by being sprinkled with hot water. By changing to a state close to that before drying, the leafy vegetables can be eaten in the same manner as well-known cooked vegetables.

<Explanation of Examples>
Hereinafter, examples of the present invention will be described. However, the present invention is not limited to the following examples.

[Example 1]
<Preparation>
The worker cut the cabbage leaves one by one and washed them with water. After washing, the operator removed leaf veins of 10 mmφ or more from the washed cabbage leaves. After removal, the worker cut the remaining cabbage leaves into 50 x 50 mm squares. After cutting, the worker weighed the cabbage leaves with the general-purpose electronic balance FX-2000i manufactured by A & D Co., Ltd. Once the weight was measured, the operator calculated the weight of the cabbage's moisture by multiplying the weight by 0.927. Multiplying the weight by 0.927 is the cabbage in the 7th edition of the Standard Tables of Food Composition in Japan in the 7th edition of the Food Composition Tables of the First Edition, January 2004, published by the Kagawa Nutrition University Publishing Division. This is because the weight% of the water content in the cabbage before the pretreatment was regarded as 92.7% by weight based on the water content of the above. Also in the following, the weight% of the water content in the cabbage before the pretreatment is considered to be 92.7% by weight. When the weight of the water content of the cabbage was calculated, the worker calculated the weight of the non-moisture component of the cabbage by subtracting the weight of the water content from the measured weight of the cabbage. Once their weight was calculated, the worker boiled the cut cabbage leaves in saline solution. The temperature of the saline solution was 90 degrees Celsius. The concentration of salt in the saline solution was 1% by weight. The cabbage leaves were boiled for 60 seconds. Workers cooled the boiled cabbage leaves with cold water to 20 degrees Celsius. After cooling, the worker drained the cooled cabbage leaves. The worker puts 3.5% by weight of lactose on the drained cabbage leaves, 1.5% by weight of glucose on the weight of the cabbage leaves, and the cabbage. 0.5 wt% salt was added to the weight of the leaves. After they were added, the operator heated them to 65 degrees Celsius with uniform stirring. Meanwhile, water came out of the cabbage leaves. The worker discarded the water. In the present embodiment, adding salt to a leafy vegetable to discharge the water contained in the leafy vegetable is referred to as "osmotic dehydration". The cabbage after osmotic dehydration is the prepared cabbage according to this example.

The worker removed the root 20 mm of bok choy. When the roots were removed, the worker cut off the leaves of bok choy one by one. When the bok choy leaves were cut off, the worker washed them with water. After washing, the worker cut the bok choy to a length of 50 mm. The direction of the cut was perpendicular to the fiber bundle of the bok choy leaf. After that, it was the same as the prepared cabbage. Of course, the weight of the bok choy leaf was measured by the general-purpose electronic balance FX-2000i manufactured by A & D Co., Ltd. The bok choy after osmotic dehydration is the prepared bok choy according to this example. In this example, the water content of bok choy in the 7th edition of the Standard Tables of Food Composition in Japan in the 7th edition of the food composition table issued by the First Edition of January 2004, which was published by the Kagawa Nutrition University Publishing Division. Based on this, the weight% of the water content in the bok choy before the pretreatment was regarded as 96.0% by weight.

The worker removed the root portion 10 mm and the dark green portion of the white onion. Once they were removed, the workers washed the white onions with water. After cleaning, the worker cut the white onions to a length of 10 mm. The direction of the cut was 45 ° oblique to the fiber bundle of white onion. After that, it was the same as the prepared cabbage. Of course, the weight of the white onion was measured by the general-purpose electronic balance FX-2000i manufactured by A & D Co., Ltd. The white onion after osmotic dehydration is the prepared white onion according to this example. In this example, the water content of white onion in the 7th edition of the Standard Tables of Food Composition in Japan in the 7th edition of the food composition table issued by the First Edition of January 2004, which was published by the Kagawa Nutrition University Publishing Division. Based on this, the weight% of the water content in the white onion before the pretreatment was regarded as 89.6% by weight.

Workers thawed pre-boiled and frozen sweet corn. After thawing, the worker boiled the thawed sweet corn again in salt water. The temperature of the saline solution was 90 degrees Celsius. The concentration of salt in the saline solution was 1% by weight. When the sweet corn was boiled again, the boiled time was 60 seconds. Workers cooled the boiled sweet corn again with cold water to 20 degrees Celsius. After cooling, the worker drained the cooled sweet corn. The sweet corn after draining is the prepared sweet corn according to this embodiment. This sweet corn is used as a color for the sample according to this example.

The worker washed the carrots with water. After washing, the worker removed the washed carrot rind. After removal, the worker cut the carrots to a length of 20 mm. The direction of the cut was horizontal (parallel) to the ginseng fiber bundle. After cutting, the worker cut the carrots into 3 x 3 mm julienne. After shredding, the worker boiled the chopped carrots in saline solution. The temperature of the saline solution was 90 degrees Celsius. The concentration of salt in the saline solution was 1% by weight. The time the carrots were boiled was 60 seconds. Workers cooled the boiled carrots with cold water to 20 degrees Celsius. After cooling, the worker drained the cooled carrots. The carrot after draining is the prepared carrot according to this embodiment. This ginseng is used as a color for the sample according to this example.

<Wind drying process>
The worker blew hot air on the prepared cabbage. The temperature of the hot air was controlled to be 70 degrees Celsius or more and 90 degrees Celsius or less. As a result, the prepared cabbage was dried. While hot air was blown onto the prepared cabbage, the operator weighed the cabbage at any time. The weight was measured by A & D Co., Ltd. general-purpose electronic balance FX-2000i. Once the weight was measured, the operator calculated the percentage of water content of the cabbage by the procedure described below. First, the worker subtracted the weight of the components other than water from the measured weight of the cabbage. As the value of the weight of the components other than the water content of the cabbage, the value calculated in the pretreatment was used. As a result, the weight of water in the cabbage blown with hot air was calculated. The worker then divided the weight of the water by the weight of the measured cabbage and multiplied by 100. This value is the weight% of the water content of the cabbage. In the following examples and comparative examples, the weight was measured by the same procedure, and the weight% of the water content was calculated. Hot air blowing was continued until the calculated percentage of water content was 57.06% by weight.

When the weight% of the water content of the cabbage reached 57.06% by weight, the worker calculated the dry weight loss rate based on the following formula.
Dry weight loss rate [%] = {(Weight of cabbage other than water + Weight of water when it is assumed that cabbage contains 92.7% by weight)-(Other than water in cabbage) Weight of the part + calculated weight of the water content of the cabbage)} ÷ (weight of the part of the cabbage other than water content + weight of the water content assuming that the cabbage contains 92.7% by weight of water ) × 100 = (Weight of the cabbage assuming that it contains 92.7% by weight of water-Calculated weight of the cabbage water) ÷ (Weight of the part of the cabbage other than water + Weight of water when cabbage is assumed to contain 92.7% by weight) x 100 = (assuming that cabbage contains 92.7% by weight of water) Weight-0.5706 x Weight of cabbage measured in this step) ÷ (Weight of the part of the cabbage other than water + 92.7% by weight of the cabbage when it is assumed that the water content is contained in the cabbage Weight) x 100 = {(1-0.5706) x cabbage weight measured in this process x 0.927 ÷ (1-0.927) -0.5706 x cabbage weight measured in this process} ÷ {(1-0.5706) × cabbage weight measured in this process + (1-0.5706) × cabbage weight measured in this process × 0.927 ÷ (1-0.927)} × 100 = {(1-0.5706) × 0.927 ÷ (1-0.927) × cabbage weight measured in this process −0.5706 × cabbage weight measured in this process} ÷ { (1-0.5706) × Weight of cabbage measured in this process + (1-0.5706) × 0.927 ÷ (1-0.927) × Weight of cabbage measured in this process} × 100 = {(1-0.5706) x 0.927 ÷ (1-0.927) -0.5706} ÷ {(1-0.5706) + (1-0.5706) x 0.927 ÷ (1) -0.927)} x 100 = (0.4294 x 0.927 ÷ 0.073-0.5706) ÷ (0.4294 + 0.4294 x 0.927 ÷ 0.073) x 100 = 4.88 ÷ 5 .88 × 100 = 0.829 × 100 = 83

When the weight% of the water content of the cabbage reached 57.06% by weight, the worker calculated the water removal rate based on the following formula.
Moisture removal rate [%] = (Weight of the water when it is assumed that the cabbage contains 92.7% by weight-Calculated weight of the water of the cabbage) ÷ 92.7% by weight of the cabbage Weight of the water when it is assumed that it contains water x 100 = (Weight of the water when it is assumed that the cabbage contains 92.7% by weight of water-Cabbage measured in this step Weight x 0.5706) ÷ Weight of the water when it is assumed that the cabbage contains 92.7% by weight x 100 = {(1-0.5706) x cabbage measured in this step Weight x 0.927 ÷ (1-0.927) -Cabbage weight measured in this process x 0.5706} ÷ {(1-0.5706) x Cabbage weight measured in this process x 0 .927 ÷ (1-0.927)} × 100 = {(1-0.5706) × 0.927 ÷ (1-0.927) -0.5706} ÷ {(1-0.5706) × 0 .927 ÷ (1-0.927)} × 100 = (0.4294 × 0.927 ÷ 0.073-0.5706) ÷ {0.4294 × 0.927 ÷ 0.073} × 100 = (5) .453-0.5706) ÷ 5.453 × 100 = 4.882 ÷ 5.453 × 100 = 89.53

The worker blew hot air on the prepared bok choy. The temperature of the hot air was controlled to be 70 degrees Celsius or more and 90 degrees Celsius or less. As a result, the prepared bok choy was dried. While the prepared bok choy was blown with hot air, the worker measured the weight of the bok choy at an arbitrary timing and calculated the weight%. Hot air blowing was continued until the calculated percentage of water content was 69.23% by weight.

When the weight% of the water content of bok choy reached 69.23% by weight, the worker calculated the dry weight loss rate in the same manner as in the case of cabbage. The calculated dry weight loss rate was 87% by weight.

When the weight% of the water content of bok choy was 69.23% by weight, the worker calculated the water removal rate in the same manner as in the case of cabbage. The calculated water removal rate was 90.63% by weight.

The worker blew hot air on the prepared white onions. The temperature of the hot air was controlled to be 70 degrees Celsius or more and 90 degrees Celsius or less. As a result, the prepared white onions were dried. While the hot air was blown on the prepared white onion, the worker measured the weight of the white onion at an arbitrary timing and calculated the weight%. Hot air blowing was continued until the calculated percentage of water content was 51.18% by weight.

When the weight% of the water content of the white onion was 51.18% by weight, the worker calculated the dry weight loss rate in the same manner as in the case of cabbage. The calculated dry weight loss rate was 79% by weight.

When the weight% of the water content of the white onion was 51.18% by weight, the worker calculated the water removal rate in the same manner as in the case of cabbage. The calculated moisture removal rate was 87.83% by weight.

<Dried vegetable freezing process>
Workers placed the dried leafy vegetables in the air-drying process in a polyethylene bag. Leafy vegetables were placed in polyethylene bags to separate them by type. Workers housed polyethylene bags containing leafy vegetables in the freezer. The temperature inside the freezer was -25 degrees Celsius. The bags were housed in the freezer for 24 hours. After the bags were housed in the freezer for 24 hours, the workers confirmed that all the leafy vegetables contained in the bags were frozen.

<Thawing process>
The worker left the leafy vegetables frozen in the dried vegetable freezing step outside the freezer. The temperature outside the freezer was above 0 degrees Celsius. As a result, the leafy vegetables in the polyethylene bag were thawed.

<Moisture addition process>
The worker put 7.4 g of cabbage, 5.5 g of bok choy, and 5.5 g of white onion among the leafy vegetables thawed in the thawing step into a container for mixing. After that, the worker put 11.2 g of the paste liquid described below into the container. This paste contained dextrin, salt, sodium L-glutamate, and vitamin E. This paste was produced by heating an aqueous solution containing them to 85 degrees Celsius. The weight% of dextrin in this paste was 12.8% by weight. The weight% of salt in this paste was 0.9% by weight. The weight% of Na L-glutamic acid in this paste was 0.9% by weight. The weight% with vitamin E in this paste was 0.4% by weight. This paste was added for the purpose of improving the strength of the dried vegetables after the sublimation step S126, seasoning the dried vegetables, and preventing oxidation of the dried vegetables. When the paste was placed in the mixing container, the worker heated the leafy vegetables and the paste to 70 degrees Celsius with stirring. After heating, the worker placed 5.0 g of the prepared sweet corn and 0.4 g of the prepared carrot in a container for mixing. When the sweet corn and carrots were placed in the container, the worker mixed the contents of the container evenly.

<Refreezing process>
The operator housed the contents of the mixing container in the refreezing container 200 described below. FIG. 3 is a schematic view showing the appearance of the refreezing container 200. The refreezing container 200 is made of polypropylene. The width and length of the outer edge of the opening 210 of the refreezing container 200 is greater than the width and length of the bottom 212. The width and length of the outer edge of the opening 210 of the refreezing container 200 are both 45 mm. The width and length of the outer edge of the bottom 212 of the refreezing container 200 are both 43 mm. The depth from the opening 210 of the refreezing container 200 to the inner peripheral surface 220 of the bottom 212 is 18 mm. The volume of the refreezing container 200 is 35 ml. The contents of the mixing container were 200 slices of the refreezing container. When the contents of the mixing container were housed in the refreezing container 200, the worker housed the refreezing container 200 in the freezer. The temperature inside the freezer was -25 degrees Celsius. The refreezing container 200 was housed in the freezer for 16 hours. As a result, the contents contained in the refreezing container 200 were frozen.

<Sublimation process>
The worker housed the refreezing container 200 housed in the freezer in the refreezing step in the vacuum freeze-drying device. The air pressure in the vacuum freeze-dryer was 100 Pa. At that time, the temperature of the refreezing container 200 was 50 degrees Celsius. In the vacuum freeze-dryer, the contents of the refreezing container 200 were dried until the percentage of water content was 5% by weight or less. The content after drying is the sample according to this example.

[Example 2]
Except for the following three points, the method for drying leafy vegetables according to this embodiment is the same as the method for drying leafy vegetables according to Example 1. The first point is that in the air drying step, the blowing of hot air was continued until the weight% of the water content of the cabbage reached 70.8% by weight. As a result, the dry weight loss rate of the cabbage according to this example was 75%. The water removal rate of the cabbage according to this example was 80.91%. The second point is that in the air drying step, the blowing of hot air was continued until the weight% of the water content of the bok choy reached 64.71% by weight. As a result, the dry weight loss rate of bok choy according to this example was 83%. The water removal rate of bok choy according to this example was 88.3%. The third point is that in the air drying step, the blowing of hot air was continued until the weight% of the water content of the white onion reached 66.8% by weight. As a result, the dry weight loss rate of the white onion according to this example was 69%. The water removal rate of the white onion in this comparative example was 76.57%.

In the refreezing step according to this example, the content of the mixing container was the same as that of the refreezing container 200, as in the case of Example 1.

[Example 3]
<Preparation>
The pretreatment of the cabbage is the same as in Example 1. In this example, no pretreatment of bok choy, green onion, sweet corn, and carrot was performed.

<Wind drying process>
The worker blew hot air on the prepared cabbage. The temperature of the hot air was controlled to be 70 degrees Celsius or more and 90 degrees Celsius or less. As a result, the prepared cabbage was dried. While hot air was blown onto the prepared cabbage, the operator measured the weight of the cabbage at an arbitrary timing and calculated the weight%. Hot air blowing was continued until the calculated percentage of water content was 72.61% by weight. As a result, the dry weight loss rate of the cabbage according to this example was 73.35%. The water removal rate of the cabbage according to this example was 89.5%.

<Dried vegetable freezing process>
The worker molded the dried cabbage into a plate having a thickness of 18 mm in the wind drying step. The worker put the cabbage in the freezer. At that time, the coating with the polyethylene sheet and the coating with the corrugated cardboard were not performed. The temperature inside the freezer was minus 35 degrees Celsius. The cabbage was housed in the freezer until frozen. During freezing, the worker measured the temperature of the central part of the cabbage. The worker measured the time when the temperature was -3 degrees Celsius or less and -5 degrees Celsius or more. The time was 23 minutes.

<Thawing process>
The worker left the frozen cabbage outside the freezer for 55 minutes in the dried vegetable freezing step. The temperature outside the freezer was above 0 degrees Celsius. This thawed the cabbage.

<Moisture addition process>
The worker put the cabbage thawed in the thawing step and the paste liquid corresponding to 58.8% by weight of the weight of the cabbage into a container for mixing. This paste contained dextrin, salt, sodium L-glutamate, and vitamin E. This paste was produced by heating an aqueous solution containing them to 85 degrees Celsius. The weight% of dextrin in this paste was 12.8% by weight. The weight% of salt in this paste was 0.9% by weight. The weight% of Na L-glutamic acid in this paste was 0.9% by weight. The weight% of vitamin E in this paste was 0.4% by weight. When the paste was placed in the mixing container, the worker heated the cabbage and the paste to 70 degrees Celsius with stirring.

<Refreezing process>
The operator housed the contents of the mixing container in the same refreezing container 200 as in Example 1 so as to be completely filled. When the contents of the mixing container were contained in the refreezing container 200, the operator covered the refreezing container 200 with a polyethylene sheet having a thickness of 0.02 mm. After coating, the worker housed the refreezing container 200 in a freezer. The temperature inside the freezer was -25 degrees Celsius. As a result, the contents contained in the refreezing container 200 were frozen. During the refreezing, the worker measured the temperature of the central part of the cabbage. The worker measured the time when the temperature was -3 degrees Celsius or less and -5 degrees Celsius or more. The time was 62 minutes.

<Sublimation process>
The worker housed the refreezing container 200 housed in the freezer in the refreezing step in the vacuum freeze-drying device. The air pressure in the vacuum freeze-dryer was 100 Pa. At that time, the temperature of the refreezing container 200 was 50 degrees Celsius. In the vacuum freeze-dryer, the contents of the refreezing container 200 were dried until the percentage of water content was 5% by weight or less. The content after drying is the sample according to this example.

[Example 4]
<Preparation>
The specific content of the pretreatment for cabbage is the same as in Example 3.

<Wind drying process>
The specific content of the air drying step is the same as that of the third embodiment.

<Dried vegetable freezing process>
The specific contents of this step are the same as those in the third embodiment except that the cabbage molded into a plate shape is covered with a polyethylene sheet having a thickness of 0.02 mm and the cabbage is further covered with corrugated cardboard. be. During freezing, the worker measured the temperature of the central part of the cabbage. The worker measured the time when the temperature was -3 degrees Celsius or less and -5 degrees Celsius or more. The time was 194 minutes.

<Thawing process-sublimation process>
The specific contents of the thawing step to the sublimation step are the same as those in the third embodiment. During the refreezing, the worker measured the temperature of the central part of the cabbage. The worker measured the time when the temperature was -3 degrees Celsius or less and -5 degrees Celsius or more. The time was 62 minutes.

[Example 5]
<Preparation-thawing process>
The specific contents of the pretreatment to thawing steps are the same as in Example 1.

<Moisture addition process>
The worker put 7.9 g of cabbage, 5.9 g of bok choy, and 5.9 g of white onion among the leafy vegetables thawed in the thawing step into a container for mixing. After that, the worker put 9.9 g of the paste liquid described below into the container. The amount of this paste is 50% by weight of the total of the weight of cabbage, the weight of bok choy, and the weight of white onion. This paste contained dextrin, salt, sodium L-glutamate, and vitamin E. This paste was produced by heating an aqueous solution containing them to 85 degrees Celsius. The weight% of dextrin in this paste is 12.8% by weight. The weight% of salt in this paste is 0.9% by weight. The weight% of Na L-glutamic acid in this paste is 0.9% by weight. The weight% with vitamin E in this paste is 0.4% by weight. When the paste was placed in the mixing container, the worker heated the leafy vegetables and the paste to 70 degrees Celsius with stirring. After heating, the worker placed 5.0 g of the prepared sweet corn and 0.4 g of the prepared carrot in a container for mixing. When the sweet corn and carrots were placed in the container, the worker mixed the contents of the container evenly.

<Refreezing process-sublimation process>
The specific contents of the refreezing step to the sublimation step are the same as those in the first embodiment.

[Example 6]
<Preparation>
The pretreatment for leafy vegetables is the same as in Example 1 except for the following points. That point is a substance that is added to leafy vegetables after draining. In the case of this example, 5.0% by weight of glucose with respect to the weight of the leafy vegetables and 0.5% by weight of salt with respect to the weight of the leafy vegetables are added to the leafy vegetables. there were.

<Wind drying process-thawing process>
Except for the following points, the specific contents of the air drying step to the thawing step are the same as those in the first embodiment. The point is that in the air drying step, the blowing of hot air was continued until the weight% of the measured water content of the bok choy reached 76.47% by weight. As a result, the dry weight loss rate of the bok choy was 83% by weight. The water removal rate of the bok choy was 86.46% by weight.

<Moisture addition process>
The worker put 7.44 g of cabbage, 5.58 g of bok choy, and 5.58 g of white onion among the leafy vegetables thawed in the thawing step into a container for mixing. After that, the worker put 9.3 g of the paste liquid described below into the container. 9.3 g of the paste solution corresponds to 50% by weight of the total weight of 18.6 g of these leafy vegetables. This paste solution is made by adding 1.4 g of dextrin, 0.09 g of salt, 0.09 g of Na L-glutamic acid, and 0.06 g of vitamin E to 9.3 g of water to make a total of 10.94 g, which is 85 degrees Celsius. It was heated to. Therefore, the water content of the paste liquid corresponds to 43% by weight (9.3 g ÷ 10.94 g × 9.3 g ÷ 18.6 g × 100 = 43% by weight) of the total weight of these leafy vegetables of 18.6 g. .. When the paste was placed in the mixing container, the worker heated the leafy vegetables and the paste to 70 degrees Celsius with stirring. After heating, the worker placed 5.0 g of the prepared sweet corn and 0.4 g of the prepared carrot in a container for mixing. When the sweet corn and carrots were placed in the container, the worker mixed the contents of the container evenly.

<Refreezing process>
The operator puts the contents of the mixing container in the same refreezing container 200 as in Example 1. The amount of the contents contained in the refreezing container 200 is the full amount of the refreezing container 200. It was a minute. When the contents of the mixing container were housed in the refreezing container 200, the worker housed the refreezing container 200 in the freezer. The temperature inside the freezer was -25 degrees Celsius. The refreezing container 200 was housed in the freezer for 16 hours. As a result, the contents contained in the refreezing container 200 were frozen.

<Sublimation process>
The specific content of the sublimation step is the same as that of the first embodiment.

[Example 7]
<Preparation>
The specific content of the pretreatment is the same as in Example 6.

<Wind drying process-thawing process>
The specific contents of the air drying step to the thawing step are the same as those in Example 6.

<Moisture addition process>
The worker put 6.24 g of cabbage, 4.68 g of bok choy, and 4.68 g of white onion among the leafy vegetables thawed in the thawing step into a container for mixing. After that, the worker put 11.7 g of the paste liquid described below into the container. 11.7 g of the paste solution corresponds to 75% by weight of the total weight of 15.6 g of these leafy vegetables. This paste solution is made by adding 1.76 g of dextrin, 0.12 g of salt, 0.12 g of Na L-glutamic acid, and 0.06 g of vitamin E to 11.7 g of water to make a total of 13.76 g, which is 85 degrees Celsius. It was heated to. Therefore, the water content of the paste liquid corresponds to 64% by weight (11.7 g ÷ 13.76 g × 11.7 g ÷ 15.6 g × 100 = 64% by weight) of the total weight of these leafy vegetables of 15.6 g. .. When the paste was placed in the mixing container, the worker heated the leafy vegetables and the paste to 70 degrees Celsius with stirring. After heating, the worker placed 5.0 g of the prepared sweet corn and 0.4 g of the prepared carrot in a container for mixing. When the sweet corn and carrots were placed in the container, the worker mixed the contents of the container evenly.

<Refreezing process and sublimation process>
The specific contents of the refreezing step and the sublimation step are the same as those in Example 6. The amount of the contents of the mixing container housed in the refreezing container 200 was the same as that of the refreezing container 200.

[Example 8]
<Preparation>
The specific content of the pretreatment is the same as in Example 6.

<Wind drying process-thawing process>
The specific contents of the air drying step to the thawing step are the same as those in Example 6.

<Moisture addition process>
The worker put 5.44 g of cabbage, 4.08 g of bok choy, and 4.08 g of white onion among the leafy vegetables thawed in the thawing step into a container for mixing. After that, the worker put 13.6 g of the paste liquid described below into the container. 13.6 g of the paste solution corresponds to 100% by weight of the total weight of 13.6 g of these leafy vegetables. This paste solution is made by adding 2.04 g of dextrin, 0.14 g of salt, 0.14 g of L-glutamic acid Na, and 0.06 g of vitamin E to 13.6 g of water to make a total of 15.98 g, which is 85 degrees Celsius. It was heated to. Therefore, the water content of the paste liquid corresponds to 85% by weight (13.6 g ÷ 15.98 g × 13.6 g ÷ 13.6 g × 100 = 85% by weight) of the total weight of these leafy vegetables 13.6 g. .. When the paste was placed in the mixing container, the worker heated the leafy vegetables and the paste to 70 degrees Celsius with stirring. After heating, the worker placed 5.0 g of the prepared sweet corn and 0.4 g of the prepared carrot in a container for mixing. When the sweet corn and carrots were placed in the container, the worker mixed the contents of the container evenly.

<Refreezing process and sublimation process>
The specific contents of the refreezing step and the sublimation step are the same as those in Example 6. The amount of the contents of the mixing container housed in the refreezing container 200 was the same as that of the refreezing container 200.

[Example 9]
<Preparation>
The specific content of the pretreatment is the same as in Example 6.

<Wind drying process-thawing process>
The specific contents of the air drying step to the thawing step are the same as those in Example 6.

<Moisture addition process>
The worker put 7.44 g of cabbage, 5.58 g of bok choy, and 5.58 g of white onion among the leafy vegetables thawed in the thawing step into a container for mixing. After that, the worker put 4.65 g of the paste liquid described below into the container. 4.65 g of glue solution corresponds to 25% by weight of the total weight of 18.6 g of these leafy vegetables. This paste solution is made by adding 0.7 g of dextrin, 0.05 g of salt, 0.05 g of Na L-glutamic acid, and 0.06 g of vitamin E to 4.65 g of water to make a total of 5.51 g, which is 85 degrees Celsius. It was heated to. Therefore, the water content of the paste liquid corresponds to 21% by weight (4.65 g ÷ 5.51 g × 4.65 g ÷ 18.6 g × 100 = 21% by weight) of the total weight of these leafy vegetables (18.6 g). .. When the paste was placed in the mixing container, the worker heated the leafy vegetables and the paste to 70 degrees Celsius with stirring. After heating, the worker placed 5.0 g of the prepared sweet corn and 0.4 g of the prepared carrot in a container for mixing. When the sweet corn and carrots were placed in the container, the worker mixed the contents of the container evenly.

<Refreezing process and sublimation process>
The specific contents of the refreezing step and the sublimation step are the same as those in Example 6. The amount of the contents of the mixing container housed in the refreezing container 200 remained about 3 mm below the opening 210 of the refreezing container 200.

[Example 10]
<Preparation>
The pretreatment for cabbage is the same as in Example 1 except for the following two points. The first point is that lactose, glucose and salt were not added to the drained cabbage leaves with respect to the weight of the drained cabbage leaves. The second point is that we do not use bok choy, green onions, sweet corn, and carrots.

<Wind drying process>
The worker blew hot air on the prepared cabbage. The temperature of the hot air was controlled to be 70 degrees Celsius or more and 90 degrees Celsius or less. As a result, the prepared cabbage was dried. While hot air was blown onto the prepared cabbage, the operator weighed the cabbage at any time. When the weight was measured, the worker calculated the percentage of water content of the cabbage based on the weight. The blowing of hot air was continued until the measured and calculated weight% of water reached 62.27% by weight. As a result, the dry weight loss rate of the cabbage according to this example was 80.65%. The water removal rate of the cabbage according to this example was 87%.

<Dried vegetable freezing process>
The worker molded the dried cabbage into a plate having a thickness of 18 mm in the wind drying step. The worker covered the cabbage molded into a plate shape with a polyethylene sheet having a thickness of 0.02 mm. The worker put the cabbage in the freezer. The temperature inside the freezer was -25 degrees Celsius. The cabbage was housed in the freezer until frozen.

<Thawing process>
The worker left the frozen cabbage outside the freezer in the dried vegetable freezing process. The temperature outside the freezer was above 0 degrees Celsius. This thawed the cabbage.

<Moisture addition process>
The worker put the cabbage thawed in the thawing step and the following paste solution, which is 75% by weight of the weight of the cabbage, in a container for mixing. In this paste solution, 3% by weight of potato starch was added to water, and the mixture thereof was heated to 85 degrees Celsius to be sufficiently gelatinized. When the paste was placed in the mixing container, the worker heated the cabbage and the paste to 70 degrees Celsius with stirring.

<Refreezing process>
The operator housed the contents of the mixing container in the same refreezing container 200 as in Example 1 so as to be completely filled. The weight of the cabbage that could be filled was 103.5 g. When the contents of the mixing container were housed in the refreezing container 200, the worker housed the refreezing container 200 in the freezer. The temperature inside the freezer was -25 degrees Celsius. As a result, the contents contained in the refreezing container 200 were frozen.

<Sublimation process>
The worker housed the refreezing container 200 housed in the freezer in the refreezing step in the vacuum freeze-drying device. The air pressure in the vacuum freeze-dryer was 133 Pa. At that time, the temperature of the refreezing container 200 was 50 degrees Celsius. In the vacuum freeze-dryer, the contents of the refreezing container 200 were dried until the percentage of water content was 5% by weight or less. The content after drying is the sample according to this example.

[Comparative Example 1]
<Preparation>
The pretreatment of the cabbage is the same as in Example 3.

<Wind drying process>
The specific content of the air drying step is the same as that of the third embodiment.

<Dried vegetables freezing process-thawing process>
In this comparative example, the dried vegetable freezing step to the thawing step were not carried out.

<Moisture addition process-sublimation process>
The specific contents of the water addition step to the sublimation step are the same as those in the third embodiment.

[Comparative Example 2]
<Preparation-air drying process>
The specific contents of the pretreatment to air drying steps are the same as in Example 5.

<Dried vegetables freezing process-thawing process>
In this comparative example, the dried vegetable freezing step to the thawing step were not carried out.

<Moisture addition process>
The specific content of the water addition step is the same as in Example 5.

<Refreezing process-sublimation process>
The specific contents of the refreezing step to the sublimation step are the same as those in the fifth embodiment.

[Comparative Example 3]
<Preparation>
The specific content of the pretreatment is the same as that of the tenth embodiment.

<Wind drying process-thawing process>
In this comparative example, the air drying step to the thawing step were not carried out.

<Moisture addition process>
The worker put the cabbage thawed in the thawing step and the paste liquid described below, which is 30% by weight of the weight of the cabbage, in a container for mixing. In this paste solution, 3% by weight of potato starch was added to water, and the mixture thereof was heated to 85 degrees Celsius to be sufficiently gelatinized. When the paste was placed in the mixing container, the worker heated the cabbage and the paste to 70 degrees Celsius with stirring.

<Refreezing process>
The operator housed the contents of the mixing container in the same refreezing container 200 as in Example 1 so as to be completely filled. The weight of the cabbage that could be filled was 29.9 g. When the contents of the mixing container were housed in the refreezing container 200, the worker housed the refreezing container 200 in the freezer. The temperature inside the freezer was -25 degrees Celsius. As a result, the contents contained in the refreezing container 200 were frozen.

<Sublimation process>
The specific content of the sublimation step is the same as that of the tenth embodiment.

<Explanation of effect>
[About Example 1 and Example 2]
In the sample according to Example 1 and the sample according to Example 2, the time required for reconstitution with hot water and the state after reconstitution with hot water were evaluated. First, the worker randomly selected 5 samples according to Example 1 and 5 samples according to Example 2 as evaluation targets. Workers placed the samples to be evaluated in separate, heat-insulating Styrofoam containers. When the sample was placed in a styrofoam container, the worker poured 300 ml of boiling water at 90 degrees Celsius over the sample and then covered the upper surface of the styrofoam container with aluminum foil. The worker evaluated the sample 3 minutes after pouring the boiling water. The evaluation was highly evaluated for those that restore the color tone, texture, and flavor of each vegetable to a more natural state. No stirring or loosening was performed during the 3-minute rehydration time. As a result, there was no significant difference in the time required for reconstitution between the five samples according to Example 1 and the five samples according to Example 2. All were almost completely unraveled and restored in 3 minutes. These were in a fully edible state. There was no significant difference in the color tone, texture, and flavor of the vegetables between the five samples according to Example 1 and the five samples according to Example 2. In these samples, the characteristics of each raw material used in terms of color tone and flavor were sufficiently restored. There was no discomfort during chewyness or swallowing in these samples. However, there was a difference in the amount of cabbage, bok choy, and green onion between the five samples according to Example 1 and the five samples according to Example 2. The difference was not overlooked, assuming that those samples were used in instant foods that used a lot of vegetables.

[About Example 3, Example 4, and Comparative Example 1]
In the sample according to Example 3, the sample according to Example 4, and the sample according to Comparative Example 1, the time required for reconstitution with hot water and the state after reconstitution with hot water were evaluated. First, the operator randomly selected 5 samples according to Example 3, 5 samples according to Example 4, and 5 samples according to Comparative Example 1 as evaluation targets. Workers placed the samples to be evaluated in separate, heat-insulating Styrofoam containers. When the sample was placed in a styrofoam container, the worker poured 300 ml of boiling water at 90 degrees Celsius over the sample and then covered the upper surface of the styrofoam container with aluminum foil. The worker evaluated the sample 3 minutes after pouring the boiling water. The evaluation was highly evaluated for those that restore the color tone, texture, and flavor of each vegetable to a more natural state. As a result, there was no significant difference in the time required for reconstitution between the 5 samples according to Example 3, the 5 samples according to Example 4, and the 5 samples according to Comparative Example 1. All were almost completely unraveled and restored in 3 minutes. These were in a fully edible state. Regarding the color tone of the vegetables, there was no significant difference between the five samples according to Example 3, the five samples according to Example 4, and the five samples according to Comparative Example 1. In these samples, the characteristics of the raw materials were sufficiently restored in terms of color tone. Of these samples, the cabbage after reconstitution with Comparative Example 1 felt a little hard. The texture of the cabbage after reconstitution with water according to Example 3 and the texture of the cabbage after reconstitution with water according to Example 4 were not uncomfortable as compared with the texture originally possessed by the cabbage. As a result, the usefulness of the dried vegetable freezing step and the thawing step after the wind drying step was confirmed. There was no clear difference in shape, color tone, and texture between the five samples according to Example 3 and the five samples according to Example 4. The difference between Example 3 and Example 4 is the presence or absence of coating during freezing of cabbage in the dried vegetable freezing step. The difference affects the time when the temperature of the central part of the cabbage was -3 degrees Celsius or less and -5 degrees Celsius or more. This is because the presence or absence of coating affects the cooling rate of cabbage. Since there was no clear difference in shape, color tone, and texture between the sample according to Example 3 and the sample according to Example 4, the influence of the freezing rate in the dried vegetable freezing step was small. I came to the conclusion.

[About Example 5 and Comparative Example 2]
In the sample according to Example 5 and the sample according to Comparative Example 2, the time required for reconstitution with hot water and the state after reconstitution with hot water were evaluated. First, the worker randomly selected 5 samples according to Example 5 and 5 samples according to Comparative Example 2 and used them as evaluation targets. Workers placed the samples to be evaluated in separate, heat-insulating Styrofoam containers. When the sample was placed in a styrofoam container, the worker poured 300 ml of boiling water at 90 degrees Celsius over the sample and then covered the upper surface of the styrofoam container with aluminum foil. The worker evaluated the sample 3 minutes after pouring the boiling water. The evaluation was highly evaluated for those that restore the color tone, texture, and flavor of each vegetable to a more natural state. No stirring or loosening was performed during the 3-minute rehydration time. As a result, there was no significant difference in the time required for reconstitution between the 5 samples according to Example 5 and the 5 samples according to Comparative Example 2. All were almost completely unraveled and restored in 3 minutes. These were in a fully edible state. There was no significant difference in the color tone of the vegetables between the 5 samples according to Example 5 and the 5 samples according to Comparative Example 2. In the evaluation of texture, the sample according to Comparative Example 2 was partially harder than the sample according to Example 5. In particular, the difference was remarkable in the stem of bok choy. The degree to which the hardness of the sample according to Comparative Example 2 was felt was not so great as to significantly impair the characteristics of various vegetable raw materials. However, the comparative difference between the sample according to Comparative Example 2 and the sample according to Example 5 was clear. The difference in hardness of cabbage and white onion was similar to that of bok choy. In addition, a difference in hardness was also felt in the individual comparison between the five samples according to Example 5 and the five samples according to Comparative Example 2. As a result, it was confirmed that the water distribution correction step for eliminating the partial water gradient inside the leafy vegetables after the wind drying step was completed was useful.

[About Examples 6 to 9]
Of the samples according to Examples 6 to 9, the samples according to Example 6 to the samples according to Example 8 did not hinder the work of filling the molding container at all. On the other hand, since the amount of water added to the sample according to Example 9 was small, it was somewhat difficult to fill the molded container. As a result, it was determined that the amount of water added in the water addition step of Example 9 (4.65 g ÷ 5.51 g × 4.65 g ÷ 18.6 g × 100 = 21% by weight) was the lower limit of the amount of water added in the water addition step. ..

Further, in the sample according to Example 6 to the sample according to Example 9, the time required for reconstitution with hot water and the state after reconstitution with hot water were evaluated. First, the worker randomly selected five samples from Examples 6 to 9 and used them as evaluation targets. Workers placed the samples to be evaluated in separate, heat-insulating Styrofoam containers. When the sample was placed in a styrofoam container, the worker poured 300 ml of boiling water at 90 degrees Celsius over the sample and then covered the upper surface of the styrofoam container with aluminum foil. The worker evaluated the sample 3 minutes after pouring the boiling water.

When the apparent amount of the five samples according to each example after rehydration was visually confirmed, the sample according to Example 6 was most likely to be felt, followed by the sample according to Example 9. It was felt that the number of the sample according to Example 7 and the sample according to Example 8 decreased in this order.

Although the amount of vegetables used in Example 9 and the amount of vegetables used in Example 6 were the same, the sample in Example 9 seemed to be slightly less than that in the above-mentioned rehydration. It seems to be derived from the bad unraveling. Next, it was felt that the number of samples according to Example 7 was increased next to the sample according to Example 9, and the number of samples according to Example 8 was decreased in the order of the sample according to Example 7 and then the sample according to Example 8. It seemed to be the reason stated. The reason is that the amount of vegetables used in Example 7 is smaller than that in the sample according to Example 6 and the sample according to Example 9, and the amount of vegetables used in Example 8 is further reduced. It is a thing.

The sample according to Example 9 was slightly unraveled by visual evaluation immediately after the lid was removed after 3 minutes, but it became fully edible by stirring with chopsticks. This tendency was observed in all five samples according to Example 9, but none of them felt a hindrance in actually using the samples according to this example as ingredients for instant foods. However, when the sample according to Example 9 was compared with the sample according to Examples 6 to 8, the resilience was slightly inferior. As a result, the amount of water added in the water addition step of Example 9 (4.65 g ÷ 5.51 g × 4.65 g ÷ 18.6 g × 100 = 21% by weight) is the vacuum of various vegetables dried in the air drying step. It was judged to be close to the lower limit of the appropriate amount of water added to ensure the return of hot water after freeze-drying. All the samples according to Examples 6 to 8 were in good condition for reconstitution with hot water. These samples were almost completely loosened and restored after 3 minutes. No dominant difference was observed between the samples of Example 6, Example 7, and Example 8.

Therefore, from the results of Examples 6 to 9, it was concluded that the necessity of water addition in the water addition step and that the amount of water added should be 21% by weight or more and 100% by weight or less.

[About Example 10 and Comparative Example 3]
The sample according to Comparative Example 3 was quickly unraveled when the product after vacuum freeze-drying was reconstituted with boiling water at 90 degrees Celsius or higher. The sample according to Comparative Example 3 required a short time of about 3 minutes for almost complete restoration. In the sample according to Comparative Example 3, a bright green color peculiar to cabbage was observed in the color tone. On the other hand, the sample according to Comparative Example 3 had a weak texture of cabbage at the time of eating. As a result, the sample according to Comparative Example 3 was found to be different from the original texture of cabbage. Compared with this, the sample according to Example 10 took about 2 minutes for complete restoration, but the texture at the time of eating after reconstitution with hot water was better than that of Comparative Example 3. .. That is, the original texture of cabbage was sufficiently felt in this sample. The bright green color peculiar to cabbage of this sample was not inferior to that of Comparative Example 3.

The filling amount of the cabbage in Comparative Example 3 was 29.9 g, whereas that in Example 10 was 103.5 g. That is, there was a marked difference in the filling amount between the examples and the comparative examples.

As a result of comparing Example 10 and Comparative Example 3, sufficient shrinkage was obtained by reducing the water content originally contained in the leafy vegetables in the air drying step. Furthermore, by adding water to the leafy vegetables after undergoing the steps of freezing and thawing, it was possible to sufficiently avoid deterioration of resilience due to shrinkage and entanglement between vegetables.

200 ... Refreezing container 210 ... Opening 212 ... Bottom 220 ... Inner peripheral surface

Claims (2)

The wind drying step of drying the leafy vegetables by blowing the wind, which is a flow of gas, on the leafy vegetables,
A method for drying leafy vegetables, which comprises a freeze-drying step of freeze-drying the leafy vegetables dried in the air-drying step.
The freeze-drying step
A dried vegetable freezing step of freezing the leafy vegetables dried in the wind drying step,
A thawing step of thawing the leafy vegetables frozen in the dried vegetable freezing step, and a thawing step.
A water addition step of adding water to the leafy vegetables thawed in the thawing step, and a water addition step .
A refreezing step of refreezing the leafy vegetables to which the water was added in the water addition step, and a refreezing step of refreezing the leafy vegetables to which the water was added.
A method for drying leafy vegetables, which comprises a sublimation step of sublimating the water contained in the leafy vegetables frozen in the refreezing step . The first aspect of claim 1 , wherein the water addition step includes a step of adding the water content of 21% by weight or more and 100% by weight or less of the leafy vegetables thawed in the thawing step to the leafy vegetables. How to dry leafy vegetables.

Images