JPH08332023A - Pretreatment before preparation of dry vegetable or dry fruit - Google Patents

Abstract

PURPOSE: To obtain dry vegetables and fruits having excellent softness and swelling reconstitution property and keeping the original palatability, taste and flavor of vegetables and fruits. CONSTITUTION: Dry vegetables or dry fruits are prepared by immersing the vegetables or fruits in an aqueous solution of a hydrolyzed product of reduced starch having a sweetness of <=30 and containing <=50% sugars consisting of mono to trisaccharides. Preferably, the immersion treatment is carried out under reduced pressure and/or positive pressure optionally under heating at 30-60 deg.C.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pretreatment method for producing dried vegetables or dried fruits, more specifically, dried vegetables or dried which can be preferably used for ingredients such as instant noodles and instant soups, toppings, seasonings, snack foods and the like. In the production of fruits, the present invention relates to a pretreatment method performed before the drying treatment of vegetables and fruits, and in particular, the obtained dried product has not only excellent flexibility and good swelling restoration property upon returning to hot water, The present invention relates to a method for pretreatment of a dried vegetable or a dried fruit, which is characterized in that the vegetable and the fruit also have a good texture and flavor originally possessed.

[0002]

BACKGROUND ART Conventionally, vegetables and fruits (hereinafter referred to as vegetables) have been distributed as fresh products or processed into dried products or frozen products and distributed. In, there were some problems.
For example, fresh products have problems that their prices are likely to fluctuate depending on the season, or that they are difficult to transport while maintaining their freshness, and frozen products are fresh products. Although the storability is improved more than that of the conventional one, it has a problem that the quality is deteriorated such as discoloration of vegetables during long-term storage. Therefore, the demand for dried products suitable for long-term storage is further increasing.However, even if such dried products are produced, when the vegetables are simply dried as they are, The tissue is very brittle, and it has the problems that it is shattered due to vibrations received during transportation, or that when it is reconstituted with hot water, swelling is insufficient and restoration is poor. . Further, in recent years, demands for the flavor and texture of dried vegetables have been increasing along with the trend toward higher quality of consumers.

Therefore, conventionally, in order to improve the flexibility and the swelling restoration property of the obtained dried product, when producing a desired dried product of vegetables, the raw material is treated with sugar before the drying treatment. Immersion in an aqueous solution is generally performed. For example, mushrooms are DE (Dextrose
A method of performing a drying treatment after immersing in an aqueous dextrin solution having an Equivalent value of 5 to 30 (JP-A-58-58).
No. 40037), and a method of immersing vegetables in an aqueous solution of a hydrophilic substance and further performing microwave treatment before or after the immersion (Japanese Patent Laid-Open No. 54-52745). As an oil temperature dehydration treatment method for vegetables and the like, a method of immersing a starch syrup on the surface of the raw material by dipping it in a starch syrup, and then heating this with oil under reduced pressure (Japanese Patent Laid-Open No. 61-227734) or reduced pressure As a pretreatment method for frying, a method of immersing it in an aqueous solution of a saccharide such as disaccharide, dextrin, polysaccharide, or starch syrup (Japanese Patent Laid-Open Publication No. Sho 6-62).
No. 2-224247) is also known.

However, each of these methods is
Since the purpose is merely to improve the flexibility and the swelling restoration property upon returning to hot water, the dried product obtained by drying the pretreated product has good flexibility and swelling restoration property. Although it has it, it has not yet been able to satisfy the good texture and flavor required by consumers toward the trend of upsizing. More specifically,
When sugars with a high degree of sweetness are used when dipping the vegetables, they penetrate well into the vegetables, and the resulting dried product has excellent flexibility and swelling restoration property. On the contrary, due to its high degree of sweetness, the flavor and texture of the resulting dried product are lost. On the other hand, saccharides having a low degree of sweetness in the dipping treatment as the pretreatment, for example, when a high molecular weight dextrin or starch syrup is used, the permeation into the inside of the vegetables is deteriorated, and like the untreated dry product, Not only does it have poor flexibility and poor swelling / restoring properties when reconstituted with hot water, but also when used as a normal dry product, due to the sugar attached to its surface,
The stickiness remains forever and the texture becomes worse.

As described above, although the pretreatment method conventionally proposed for producing dried vegetables can improve the flexibility and the swelling / restoring property upon returning to hot water, it is still a good food. At present, it is not possible to provide a dried product having a feeling or flavor. Therefore, there is a strong demand for a method capable of providing a dried product which is excellent not only in flexibility and swelling / restoring property upon reconstitution with hot water but also in texture and flavor.

[0006]

The present invention has been made in view of the circumstances as described above, and its object is not only excellent in flexibility and swelling restoration property but also vegetables and fruits. The object of the present invention is to provide a method for pretreatment of dried vegetables or dried fruits, which can advantageously provide the dried vegetables having the original texture and flavor in the above.

[0007]

[Means for Solving the Problems] In order to solve such a problem, the inventors of the present invention pay attention to sugars used in a dipping treatment as a pretreatment, and the obtained dried product has good flexibility and swelling restoration property. However, as a result of systematically searching for those that have the original texture and flavor of vegetables,
The present invention has been reached. More specifically,
In order to satisfy the purpose of improving the flavor, it is generally appropriate to use sugars having a sweetness of 40 or less. As such sugars, various starch syrups obtained by hydrolyzing starches are used. As a result, the dried product obtained by using the unreduced starch syrup was inferior in flexibility, whereas the dried product obtained by using the reduced starch syrup had good flexibility. It was also found that the reconstitution with hot water was also good, and it was obtained using such a reduced starch hydrolyzate in which the content ratio of sugars from monosaccharides to trisaccharides was 50% or less. It was found that dried products strongly retain the original texture and flavor of vegetables,
The present invention has been completed.

That is, according to the present invention, when a dried vegetable or a dried fruit is produced, before the drying treatment, the vegetable or the fruit has a sweetness of 30 or less and a content ratio of sugars from monosaccharide to trisaccharide. The gist of the present invention is a method for pre-treatment of production of dried vegetables or dried fruits, which is characterized by immersing in an aqueous solution of a reduced starch hydrolyzate having a content of 50% or less.

According to a preferred embodiment of the pretreatment method for producing dried vegetables or dried fruits according to the present invention, the dipping treatment of the reduced starch hydrolyzate in an aqueous solution comprises
It is carried out under reduced pressure and / or pressure, and more preferably, the dipping treatment is carried out under reduced pressure and / or pressure under heating conditions of 30 ° C to 60 ° C.

According to another preferred embodiment of the present invention, the weight of the dried product obtained by the immersion treatment is adjusted by adjusting the conditions of the immersion treatment to obtain the dry weight obtained without the immersion treatment. It is designed to be 1.2 to 2.5 times the weight of the product.

[0011]

[Specific Structure] By the way, the saccharides used in the pretreatment method for producing dried vegetables or dried fruits according to the present invention are:
It has a sweetness of 30 or less, from monosaccharides to trisaccharides (hereinafter,
The characteristic feature of the reduced starch hydrolyzate is that it is a reduced starch hydrolyzate having a sugar composition in which the content ratio of saccharides (hereinafter referred to as “three sugars” or less) is 50% or less. It is obtained by hydrogenating (reducing) a saccharified product that has been hydrolyzed with an acid or an enzyme. It has a greater sweetness than non-reduced saccharified product, and its aqueous solution has excellent permeability. It becomes a thing.

However, when the reduced starch hydrolyzate used in the present invention has a sweetness of more than 30, the sweetness becomes too large, resulting in poor flavor, and the product was soaked when eaten. It feels unpleasant and makes it difficult to attain the object of the present invention. If the sweetness is too low, the permeability of the aqueous solution of the reduced starch hydrolyzate will be poor when the vegetables are treated, and the immersion time will be too long. Generally, about 10 is desirable.

Further, the content ratio of sugars less than trisaccharide is 50%.
In the case of more reduced starch hydrolysates, the sweetness increases, and even if the amount of saccharides penetrating is adjusted by adjusting the soaking conditions, the taste becomes poor and the object of the present invention is sufficiently achieved. Difficult to achieve. If this content ratio becomes too small, the content ratio of saccharides of tetrasaccharides or higher will increase, resulting in poor permeability and impracticality. Therefore, the lower limit of the content ratio is generally 20%.
It is preferable that the degree is set.

However, Japanese Patent Laid-Open No. 60-37940 discloses a method of immersing vegetables in an aqueous solution of reducing sugars when producing dried vegetables, and the reduction used in such methods is disclosed. Since sugar is merely used for the purpose of preventing blackening of the obtained dried product and contamination with bacteria, the predetermined reducing sugar used in the pretreatment method for producing dried vegetables or dried fruits according to the present invention. That is, it is essentially different from and should be distinguished from a reduced starch hydrolyzate having a sweetness of 30 or less and a saccharide content of trisaccharide or less of 50% or less.

As the reduced starch hydrolyzate satisfying the conditions defined by the present invention, various commercially available products can be appropriately selected and used. Specific examples thereof include: S-E30 (manufactured by Nikken Chemical Co., Ltd.), S-E100 (manufactured by Nikken Chemical Co., Ltd.), PEO 20 (manufactured by Towa Kasei Kogyo Co., Ltd.), PEO 30 (manufactured by Towa Kasei Kogyo Co., Ltd.), HS20 (Hayashibara Shoji Co., Ltd.) Reduced starch syrup such as HS30 (manufactured by Hayashibara Shoji Co., Ltd.) and the like.

The vegetables targeted in the pretreatment method for production according to the present invention are not particularly limited, and various vegetables and fruits can be targeted. Specific examples are spinach, cabbage, carrot,
Examples include vegetables such as perilla, trefoil, parsley, fruits such as apples, pineapples, persimmons and pears, and peels such as oranges, lemons and citrons.

The vegetables are appropriately sliced before use, depending on the form of the product in which the desired dried product is used. For example, small vegetables are used in the whole form, and thick ones are sliced into about 5 to 10 mm and used. Moreover, these vegetables are optionally subjected to a blanching treatment before the pretreatment method according to the present invention is applied. This blanching treatment is carried out for the purpose of maintaining the color of the dried product by deactivating the enzyme and improving the flexibility by breaking the tissue of vegetables. More specifically, it is generally carried out by immersing in water, saline, sodium bicarbonate water or the like under a temperature condition of 80 ° C. or higher and boiling for a predetermined time.

Further, the method for pretreatment of dried vegetables or dried fruits according to the present invention is carried out before the drying treatment when producing dried vegetables or dried fruits.
The target dried vegetables are actually manufactured as follows. That is, first, sliced or cut vegetables are prepared as needed as described above, and then, if necessary, blanching treatment is performed. Then, such a vegetable is treated with the pretreatment method according to the present invention, and then dried to obtain a desired dried product.

In such a process for producing dried vegetables, the concentration of the reduced starch decomposition products in the dipping sugar solution when the pretreatment method according to the present invention is carried out is slightly different depending on the vegetables to be treated. However, it is generally 10 to 60% by weight, preferably 20 to 55% by weight, based on the weight of the solid matter. The concentration of hydrolyzed starch and hydrolyzed starch is 1
When it is less than 0% by weight, the penetration of sugars into vegetables is not sufficient, and the flexibility of the obtained dried product and the swelling restoration property upon returning to hot water become poor, and more than 60% by weight. When the amount is high, the osmotic pressure of the dipping sugar solution becomes very high, so that the saccharides do not uniformly permeate into the vegetables, and as a result, wrinkles easily occur in the thin portion of the vegetable tissue. This is because the appearance of the product deteriorates and the commercial value of the product decreases. In addition, such an immersion sugar solution,
If necessary, the flexibility and swelling recovery of the dried product obtained,
As long as it does not adversely affect the texture, flavor, and other physical properties, even if other sugars, salts, seasonings, etc. are added,
No problem whatsoever.

The dipping time and dipping temperature for the dipping treatment differ depending on the vegetables to be treated, but usually the dipping time is about 30 minutes to 300 minutes, and the dipping temperature is It is set to about 20 to 60 ° C.
Specifically, the thinner the tissue of the vegetables to be treated, the weaker the treatment, and the thicker the tissue, the stronger the treatment.For example, in the case of leafy vegetables with a thin tissue, , When the temperature of the dipping sugar solution is 20 ° C,
The soaking time is about 90 minutes to 120 minutes, and when the temperature of the soaking sugar solution is 50 ° C, the soaking time is about 60 minutes to 90 minutes, while in the case of root vegetables and fruits with thick tissues. If the temperature of the soaking sugar solution is the same, 1.
The immersion time is required to be about 5 to 2 times.

The vegetables subjected to the pretreatment method according to the present invention as described above may be subjected to various conventional drying treatments such as hot air drying, microwave drying and infrared drying. Alternatively, they are applied in combination, whereby the aforementioned pretreated vegetables are dried to obtain the desired dried vegetables.

By the way, in the above description, the dipping treatment with the aqueous solution of the reduced starch hydrolyzate (dipping sugar solution)
It is carried out under normal pressure, but in particular under reduced pressure and / or increased pressure, in other words under reduced pressure,
Alternatively, it is desirable to be performed under a pressured state or under a state in which a pressure-reduced state and a pressured state alternately act. When the dipping treatment is carried out under reduced pressure and / or under pressure, the dipping sugar solution can be uniformly and finely penetrated into the vegetables, and the dipping time can be shortened and obtained. This is because the flexibility of the dried product, the swelling restoration property upon reconstitution with hot water, the texture and the flavor are excellent. For example, when treating leafy vegetables having a thin tissue, when the temperature of the dipping sugar solution is 20 ° C., a treatment time of 90 minutes to 120 minutes at normal pressure is required, whereas a reduced pressure state and / or a pressurized state. Then, 60 minutes to 9
The treatment can be performed for about 0 minutes, and if the temperature is 50 ° C., a treatment time of about 60 minutes to 90 minutes at normal pressure is required, whereas in the reduced pressure state and / or the pressurized state, 20 minutes to The immersion time is significantly shortened so that the treatment can be performed in about 40 minutes.

The dipping treatment in the depressurized state or the pressurized state may be carried out only in the depressurized state or only in the pressurized state, but the dipping treatment is performed by alternately repeating the depressurized state and the pressurized state. There is no problem even if processing is performed. The reduced pressure state referred to here is 50 to 100.
A state under a pressure of about Torr is represented, and a pressurized state refers to a state of being pressurized up to about 3 kgf / cm ² . Of course, if the pressure is further reduced or increased, that is, if the processing pressure is lower than 50 Torr or higher than 3 kgf / cm ² ,
The effect can be increased, but it is not practical because it requires a large-scale and special mechanical device to realize it.

Further, in the pretreatment method for producing dried vegetables according to the present invention, the dipping treatment is carried out under reduced pressure and / or pressure and is generally under heating at 30 ° C. to 60 ° C., preferably 40 ° C. It is more preferable that the heating is performed at a temperature of 50 ° C to 50 ° C. The reason is that, by performing the dipping treatment in such a state, in addition to the effect obtained by performing the dipping treatment in the reduced pressure state and / or the pressurized state, the condition of the blanching treatment can be relaxed. This is because the blanching treatment can be completely omitted for some vegetables.

More specifically, when the pretreatment (immersion treatment) according to the present invention is performed in the above-mentioned state, that is, in the reduced pressure state and / or the pressurized state, and in the heated state of 30 ° C. to 60 ° C., For thick tissues such as cabbage, the branching treatment can be performed under mild conditions, and for relatively thin tissues such as parsley and trefoil, the branching treatment can be omitted. In this way, the dried product obtained by performing the blanching treatment under mild conditions or by omitting the blanching treatment is a food product from which the tissue destruction due to the blanching treatment is not caused. The feeling and flavor can be significantly improved.

The reason why the texture and flavor are improved is that the blanching treatment retains the color of the dried product or destroys the texture of vegetables by deactivating the enzyme as described above. However, depending on the processing conditions, the tissue of vegetables is destroyed too much, and the texture of the resulting dried product is impaired. It is conceivable that the liquid may penetrate too much and spoil the flavor, and therefore it is desirable to carry out the conditions under the mildest conditions.

Incidentally, here, regarding the relationship between the treatment conditions of such a blanching treatment and the treatment condition of the immersion treatment, taking spinach as an example, based on the test results,
A more specific description will be given. In the test, first, spinach was immersed in sodium bicarbonate water having the concentrations shown in Table 1 below, and subjected to blanching treatment at 80 ° C. for 3 minutes. Then, after this blanching treatment, it was immersed in an aqueous solution of starch syrup having a sweetness of 65 at a temperature of 50 ° C. under the normal pressure or reduced pressure conditions shown in the table. In addition, the processing conditions of this dipping treatment are such that the weight of the obtained dried product is 1.5 times the weight of the dried product obtained without performing the dipping treatment.
The conditions were chosen so that it would be 2.5 times. Then, the vegetables after the dipping treatment were dried with hot air to obtain a desired dried product.

The dried product thus obtained was examined for its properties such as flexibility, appearance and texture after restoration, and the results are also shown in Table 1. In addition, in Table 1, the softness is represented by the reasonably soft one as good and too soft as poor. In addition, the appearance was expressed as good if it had a solid shape without uneven color. Further, the texture after restoration is evaluated 1: slightly soft but has sufficient texture, evaluation 2: less than Evaluation 1, but has texture, evaluation 3: almost no texture, evaluation 4: Evaluated on the basis of 4 grades as having no chewy texture at all.

[0029]

[Table 1]

As is clear from the results shown in Table 1, when the dipping treatment is carried out at normal pressure, the use of baking soda in the blanching treatment enhances the effect of the blanching treatment depending on the concentration thereof. However, if appropriate conditions are not selected, that is, if the concentration of baking soda is too low or too high, problems occur. More specifically, if the concentration of baking soda is too low, the destruction of the tissue will be insufficient, and as a result, the permeation of the starch syrup will be uneven in the subsequent dipping treatment. Color unevenness occurs on the
On the contrary, if the concentration of baking soda is too high, not only the enzyme will be inactivated but also the tissue of spinach will be destroyed, so that the dried product obtained is too soft and not crunchy, and the appearance is also shabby. It becomes the state of.

As described above, the blanching treatment is not preferable if the treatment conditions are too strong or too weak. For example, when the dipping treatment is carried out at 80 ° C. for 3 minutes under normal pressure. Then, a baking soda concentration of about 0.3% is appropriate. However, in Table 1, the texture after restoration of blanching-treated under such conditions is evaluated as 3, or in other words, it is evaluated that the texture is not so crunchy when the sweetness of the dipping sugar solution is 65. This is because the aqueous solution of starch syrup is used, and in the examples described later, the use of the predetermined reduced starch hydrolyzate according to the present invention provides good texture and flavor.

On the other hand, in the case where the dipping treatment in the dipping sugar solution is carried out under a reduced pressure, it can be obtained even if the blanching treatment is carried out under a weak condition that the concentration of sodium bicarbonate water is 0% by weight, that is, only water. The flexibility, appearance and texture of the dried product are all satisfactory results. This is because the immersion treatment of vegetables under the condition of soaking, depressurization and / or pressurization makes the immersion sugar solution permeate into vegetables uniformly, and the degree of destruction of the tissues of vegetables is This is because the immersion sugar solution has sufficiently penetrated even if it is low. In this way, the dipping treatment of vegetables in the dipping sugar solution is performed under reduced pressure and / or pressure, so that the blanching treatment conditions are moderated, and thus in terms of flexibility, appearance and texture. It is possible to obtain an excellent dried product.

Further, in the pretreatment method according to the present invention, the ratio of the weight of the dried product obtained by the immersion treatment in the dipping sugar solution to the weight of the dried product obtained without the immersion treatment (hereinafter The increase in the weight ratio) is preferably 1.2 to 2.5 times, and the immersion condition is adjusted so that the object of the present invention can be better achieved. Becomes That is, 0.2 times the weight of the dried product obtained without performing the dipping treatment in the dipping sugar solution.
A saccharide equivalent to 1.5 times is contained in the dried product obtained by performing the immersion treatment, in other words, by allowing a predetermined amount of saccharide to be contained in the dried product, only flexibility and appearance can be obtained. In addition, a dried product which is excellent in texture and flavor can be advantageously obtained.

If the above-mentioned weight increase ratio is less than 1.2 times, the amount of permeated saccharides is insufficient, and thus the flexibility and swelling recovery of the obtained dried product tend to deteriorate. If the increase weight ratio is more than 2.5 times, the amount of permeated saccharide tends to be excessive,
The flavor and texture tend to be inferior to those with an increase weight ratio of 2.5 times or less.

[0035]

EXAMPLES In order to clarify the present invention in more detail, some examples of the present invention will be shown below.
It goes without saying that the present invention is not limited by the description of such embodiments. In addition to the following embodiments, the present invention further includes various changes and modifications based on the knowledge of those skilled in the art, in addition to the above specific description, without departing from the spirit of the present invention. It should be understood that improvements and the like can be added.

Example 1 First, spinach was prepared, the small ones remained in the whole shape, and the large ones were cut in half, and then 80
Immerse in 0.3 wt% sodium bicarbonate water kept at ℃ for 3 minutes,
A branching process was performed. Then, each of various sugars having a sweetness and a content ratio of sugars equal to or less than trisaccharide as shown in Table 2 below were dissolved in water to prepare various immersion sugar solutions. After that, with respect to each of the obtained immersion sugar solutions,
The spinach after the blanching treatment was dipped under normal pressure. In this dipping treatment, the concentration of the dipping sugar solution, the dipping time and the dipping temperature are increased by an increasing weight ratio (the weight of the dried product obtained by performing the dipping treatment relative to the weight of the dried product obtained without the dipping treatment). Ratio) is 2.0 times to 2.
It was set to be 5 times (however, in Examples 3 and 4 of the present invention, the increasing weight ratio is 3.5 times). Then, after the completion of the dipping treatment, the surface of the spinach was lightly washed with water, and then dried with hot air at 50 ° C. until the loss on drying became 5% to obtain a desired dried product. In addition, when the weight of the obtained dried product is 1,
It means that the weight reduced by further drying is 5%, and the same meaning will be used hereinafter.

The flexibility of the various dried products thus obtained, the reconstitution after soaking in hot water for 1 minute, and the texture and flavor after reconstitution were examined, and the results are also shown in Table 2 below.

The reduced starch hydrolysates S 30, S 57 and S 1 used as sugars were used.
00 is manufactured by Nikken Chemical Co., Ltd.,
In addition, the starch decomposition products San Marto and Tetrap are manufactured by Hayashibara Shoji Co., Ltd., and oligotoses are manufactured by Sanwa Starch Industry Co.
TK-16 and Paindex # 100 were manufactured by Matsutani Chemical Co., Ltd., and Isomalt 900 was manufactured by Showa Sangyo Co., Ltd.

[0039]

[Table 2]

As is clear from the results shown in Table 2, the dried products of Examples 1 to 4 of the present invention which employ the pretreatment method according to the present invention are all excellent in flexibility and restorability. Not only that, even after reconstitution, it had a flavor close to that of raw spinach and had an excellent texture, although the texture was slightly inferior to that of raw spinach. Moreover, the increase weight ratio is 1.2 times
The dried products of Inventive Examples 1 and 2 in which the immersion treatment was performed 2.5 times were the dried products of Inventive Examples 3 and 4 in which the immersion treatment was performed 3.5 times. It was found that the texture and flavor after restoration are superior, and as a result, by controlling the increasing weight ratio, it is possible to advantageously obtain a dried product having excellent properties.

On the other hand, as in the case of Examples 1 to 4 of the present invention, the dried product of Comparative Example 1 using the reduced starch hydrolyzate as the saccharide was
The reduced starch decomposed product has a sweetness of more than 30, and the content ratio of sugars less than trisaccharide exceeds 50%, so that the texture and flavor after restoration are inferior. Also, when a starch decomposition product is used as the saccharide, the sweetness is 3
50% content of sugars greater than 0 or less than trisaccharide
The dried products of Comparative Examples 2, 3 and 7 using the starch decomposition products exceeding the above range are inferior in texture and flavor after reconstitution, have a sweetness of 30 or less, and contain sugars of trisaccharide or less. Ratio is 5
Although it is 0% or less, the dried products of Comparative Examples 4 to 6 using a saccharide which is not a reduced starch hydrolyzate as in the present invention but a simple starch degradation product can be obtained because the saccharide penetration is weak. The flexibility of dried products is poor.

As described above, the saccharide used for the dipping treatment (pretreatment) is a reduced starch hydrolyzate having a sweetness of 30 or less and a saccharide content of trisaccharide or less of 50% or less, The flexibility and swelling restoration of the obtained dried product, and the texture and flavor after restoration are satisfactory.

Example 2 First, a citrus peel was prepared, sliced into 2 to 3 mm, and immersed in a 0.2% phytic acid aqueous solution for 30 minutes. Next, various sugars having the sweetness and the content ratio of sugars not more than trisaccharide shown in Table 3 below are dissolved in water,
An immersion sugar solution was prepared, and each of the obtained immersion sugar solutions was immersed in the above-mentioned yuzu peel under normal pressure. In this immersion treatment, the concentration of the immersion sugar solution, the immersion time and the immersion temperature are
The weight increase ratio was set to be 2.0 times to 2.5 times (however, for the invention examples 7 and 8, the weight increase ratio was 3.5 times). Then, after the completion of the dipping treatment, the surface of the citrus peel was lightly washed with water, and then dried with hot air at 50 ° C. until the loss on drying was 5% to obtain a desired dried product.
Then, the obtained dried product of each citrus peel was immersed in boiling water for 1 minute to examine the restorability and the flavor after restoration, and the results were
The results are also shown in Table 3 below.

[0044]

[Table 3]

In the case of citrus fruit peel, the flavor is particularly important in view of its properties as a food material, but as is clear from the results of Table 3, the dried products of Examples 5 to 8 of the present invention are:
It has both excellent restorability and flavor after restoration. On the other hand, the sweetness of the saccharides used for the dipping treatment is greater than 30, the content ratio of saccharides of trisaccharides or less exceeds 50%,
Alternatively, the dried products of Comparative Examples which were not reducing sugars were all inferior in restorability and flavor.

Example 3 In this example, it is shown that the conditions of the blanching treatment can be made mild by performing the dipping treatment in a reduced pressure state or a pressurized state.

First, spinach was prepared, the small ones were left as they were, and the large ones were cut in half. Then, this was subjected to blanching treatment with water at 80 ° C. for 3 minutes or 7 minutes. Also, prepare cabbage, about 1
After being cut into a width of cm, this was blanched with 80 ° C. water for 7 minutes or 90 ° C. water for 5 minutes. Next, as sugar, S-30 (sweetness: 30, content ratio of sugars less than trisaccharide: 35.0%) was used, and this was dissolved in water to prepare a dipping sugar solution. The spinach or cabbage that had been subjected to the aging treatment was dipped under the pressure conditions shown in Table 4 or Table 5 below. The dipping treatment was performed under treatment conditions such that the weight increase ratio was 1.5 to 2.0. Then, after the soaking treatment, the spinach and the cabbage were dried with hot air until the loss on drying became 5%, to obtain a desired dried product.

The appearance of each of the leaf portion and the core portion of the thus obtained dried product was examined and found to be good. Further, these were dipped in boiling water at 90 ° C. for 1 minute, and the texture of the leaf portion after restoration was examined, and the restitution (restorability) of the core portion was examined. The results are shown in Table 4 below for spinach and Table 5 below for cabbage.
Are shown below. The evaluation of the texture of the leaves is the same as in Table 1 above, and the return of the core is ◯: good return, Δ: insufficient return,
X: The evaluation was made in three stages, assuming that it did not return.

[0049]

[Table 4]

[0050]

[Table 5]

As is clear from the results shown in Tables 4 and 5, it is understood that the pretreatment method according to the present invention is preferably carried out under reduced pressure or under pressure rather than atmospheric pressure. To be done. More specifically, when spinach was subjected to blanching treatment at 80 ° C. for 3 minutes and then immersed in a dipping sugar solution under normal pressure, the obtained dried product was , The texture of the leaves is good, but the return of the core is poor, whereas
After blanching under the same conditions, dipping treatment in a dipping sugar solution was performed under reduced pressure or pressure, and the resulting dried product had both the texture of the leaves and the return of the core. It will be excellent. Further, in the case of performing the dipping treatment in the dipping sugar solution under the normal pressure state, it is conceivable that the condition of the blanching treatment is strengthened in order to improve the return of the core portion. When the treatment is carried out under a strong condition, the wicking of the core is improved, but the texture of the leaves is deteriorated. In this way, the dipping treatment in the dipping sugar solution is performed in a reduced pressure state or a pressurized state, so that even if the blanching treatment is performed under mild conditions, the return of the core portion does not deteriorate,
It is also understood that such mild blanching conditions can be advantageously prevented from impairing the texture of the leaves. The results for cabbage are similar to those for spinach.

Example 4 In Example 3, the dipping treatment of spinach and cabbage in the dipping sugar solution was carried out under reduced pressure and / or pressure to make the conditions of the blanching treatment gentle. Although obtained, the blanching treatment cannot be omitted by performing the dipping treatment in the dipping sugar solution in a reduced pressure state and / or a pressurized state when manufacturing a dried product having a thin tissue. In order to predict that, and to confirm that, we used trilobes as thin tissue and conducted experiments on them.

First, prepare all three leaves,
100 Torr was added to the dipping sugar solution containing 30% of S100 as a reduced starch hydrolyzate kept at 55 ° C.
It was immersed in a reduced pressure state of r. The dipping treatment was performed by adjusting the dipping time and the dipping temperature so that the increased weight ratio was 1.3 to 1.6 times. Then, after the dipping treatment, the three leaves are dried with hot air until the loss on drying is 5%,
A desired three-leaf dried product was obtained. Then, the obtained dried product was divided into a leaf portion and a stem portion, and the appearance was examined. As a result, neither the leaf portion nor the stem portion was discolored, and the texture after reconstitution with hot water was also compared to that of the blanching-treated one. , Was much better.

As is clear from the results of Example 4,
By performing the dipping treatment in the reduced pressure state and / or the pressurized state, the blanching treatment can be omitted. In addition, when three leaves without blanching treatment are immersed in a dipping sugar solution under normal pressure, the resulting dried product will turn brown in a few days and become of no commercial value. Therefore, the blanching process cannot be omitted when the process is performed under normal pressure.

Further, in the present embodiment, three leaves were targeted as a thin tissue, but the present invention is not limited to this, and other vegetables such as thin tissue, for example parsley, are treated. Also in this case, the present invention can be advantageously applied in a depressurized state and / or a pressurized state by omitting the blanching process. By omitting the blanching treatment, it is possible to produce a dried product having an excellent flavor and texture that cannot be obtained by conventional products.

[0056]

As is clear from the above description, as a pretreatment method carried out when producing dried vegetables or dried fruits, the production pretreatment method according to the present invention, that is, an aqueous solution of a predetermined reduced starch hydrolyzate ( By adopting the method of immersing in a dipping sugar solution), not only the obtained dried product is excellent in flexibility and swelling restoration property, but also it has excellent flavor and texture. Specifically, the dried product produced after the pretreatment according to the present invention has a flavor close to that of a fresh product, either as it is or when it is reconstituted with hot water, and the product reconstituted with hot water is: It has a texture similar to that of fresh products.

When the pretreatment method is carried out under reduced pressure and / or pressure, the dipping sugar solution uniformly permeates into vegetables and fruits, and the above-mentioned effects are obtained. Furthermore, the dipping treatment (pretreatment) is performed in a reduced pressure state and / or a pressurized state and a heating state of 30 ° C. to 60 ° C., so that the blanching is performed. The treatment conditions can be mild, and in the case of some vegetables having a thin tissue, the blanching treatment can be completely omitted.

Furthermore, the increased weight ratio, that is, the ratio of the weight of the dry product obtained by the immersion treatment to the immersion sugar solution to the weight of the dry product obtained without the immersion treatment,
By performing the dipping treatment so as to be 1.2 times to 2.5 times, it is possible to produce a dried product which is further excellent in texture and flavor after restoration.

Claims (4)

[Claims] 1. When producing dried vegetables or fruits, before the drying treatment, the vegetables or fruits have a sweetness of 30 or less and a saccharide content ratio of monosaccharide to trisaccharide of 50% or less. A method for pre-treatment of production of dried vegetables or dried fruits, which comprises immersing the reduced starch hydrolyzate in an aqueous solution. 2. The pretreatment method for producing dried vegetables or fruits according to claim 1, wherein the dipping treatment of the reduced starch hydrolyzate in an aqueous solution is carried out under reduced pressure and / or pressure. 3. The pretreatment method for producing dried vegetables or fruits according to claim 2, wherein the immersion treatment of the reduced starch hydrolyzate in an aqueous solution is performed under a heating condition of 30 ° C. to 60 ° C. 4. The weight of the dried product obtained by the immersion treatment of the reduced starch hydrolyzate in an aqueous solution is 1.2 times to 2. times the weight of the dried product obtained without the immersion treatment. 5
The production pretreatment method for dried vegetables or dried fruits according to any one of claims 1 to 3, which is twice as long.