JP2716656B2 - Method for producing cold water soluble gelled gelatin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing cold water-soluble gelled gelatin and a cold water soluble gelled gelatin.
More specifically, the present invention relates to a method for producing gelatin which can be dissolved well in cold water and form a gel having sufficient performance thereafter, and a gelatin produced by the method.

[0002]

2. Description of the Related Art Conventionally, general gelatin is usually at 60 ° C.
Gels are formed by dissolving in the above-mentioned hot water or hot water and then cooling to about room temperature.
Even when conventional gelatin was poured into cold water at room temperature or lower, it was not sufficiently dissolved, and a gel having uniform and required functions could not be formed.

However, when a gelatin gel is used for various purposes, it is often used at a relatively low temperature.
For example, dessert jelly is stored and provided for eating and drinking while being cooled to about the refrigeration temperature. Gelatin capsules
When filling a drug or the like, unless the temperature is relatively low, there arises a problem that the drug is deteriorated or an unexpected reaction occurs. Gelatin carriers that support enzymes and microorganisms adversely affect enzymes and the like at high temperatures.

Accordingly, as described above, after gelatin that has been dissolved at a high temperature is cooled and gelled, the gelatin gel is further cooled to a low temperature below room temperature,
It is troublesome to use for each purpose.
In addition, when using a gelatin gel containing a drug component or a food component, since various components are dissolved or dispersed in a high-temperature gelatin solution, there is a restriction that heat-sensitive components cannot be used. is there.

If the purpose is only to dissolve at a low temperature, there is a so-called degraded gelatin or a water-soluble gelatin obtained by decomposing ordinary gelatin molecules. However, this degraded gelatin is characterized in that it has no gelling ability, and cannot be used in the above-mentioned application fields of gelatin gel. Therefore, there is a demand for a method for producing gelatin that has good solubility in water even at a relatively low temperature and can form a good gel.
Conventionally, many methods for improving the solubility of gelatin have been proposed.

For example, an aqueous gelatin solution is spray-dried,
There is a method for producing powdered gelatin. The gelatin powder obtained by spray drying has a small particle size and an internal structure having a porous structure, so that the water absorption is extremely improved and the gelatin powder is easily dissolved in water. Further, Japanese Patent Application Laid-Open No.
No. 1 discloses that a gelatin aqueous solution is sprayed on a cooling surface to freeze gelatin droplets adhered to the cooling surface.
A method is disclosed in which the frozen gelatin droplets are dried in a frozen state, that is, a freeze-drying process is performed, and the obtained dried gelatin is further pulverized to obtain a gelatin powder. According to this method, since gelatin is powdered in a sol-state structure, the solubility in cold water is very good, and the gelling ability after dissolution is also excellent.

[0007]

However, even gelatin obtained by conventional methods for producing gelatin having good solubility does not sufficiently dissolve in water at a low temperature of room temperature or lower, and forms a good gel. I couldn't. For example, the gelatin powder obtained by the above-mentioned spray drying method, when put into low-temperature water, becomes lumpy and hardens,
It does not dissolve enough. This is because the gelatin powder
Due to the porous structure with a lot of voids, water absorption when poured into water is too fast, and it is considered that the cause is that the water-absorbed powders solidify before the powder is dispersed in water. . To spray the aqueous gelatin solution,
It is necessary to keep the concentration of the aqueous gelatin solution relatively low. If a relatively thin aqueous gelatin solution is sprayed and dried in the form of fine water droplets, the water in the water droplets is quickly removed to form a gelatin powder. But,
At this time, traces of water removal remain as a porous structure. Spray drying is easier as the concentration of the gelatin aqueous solution is lower,
Since the ratio of the voids in the porous structure increases, lumps easily occur when dissolved in water.

In the above-mentioned method of spraying an aqueous gelatin solution onto a cooling surface and freeze-drying, when the concentration of the aqueous gelatin solution is low, as in the case of the spray-drying method, the obtained gelatin powder becomes porous and porous. The structure results in poor low-temperature solubility. When the concentration of the aqueous gelatin solution is increased,
Spraying or spraying cannot be performed. Spraying can be performed practically only when the concentration of the gelatin aqueous solution is up to about several percent. When the concentration exceeds 10 and several percent, industrial implementation is extremely difficult.

Furthermore, in this method, the gelatin aqueous solution is cooled to a certain extent before the gelatin aqueous solution is cooled before being attached to the cooling surface and frozen, by spraying the aqueous gelatin solution, thereby effecting expansion cooling or air cooling. Problem. Even if gelatinized gelatin is dried and powdered, the above-mentioned good low-temperature solubility and gelling ability cannot be exhibited. Even when the sprayed aqueous gelatin solution adheres to the cooling surface, the gelatin droplets are cooled only from the cooling surface side. Will freeze. Therefore, in the obtained gelatin powder, a portion having good low-temperature solubility and gelling ability freeze-dried in a sol state and a portion having poor low-temperature solubility and gelling ability via a gel state are mixed. As a result, the overall performance is not enough. In particular,
When the use temperature of the gelatin powder is as low as about 15 ° C. or less, neither the low-temperature solubility nor the gelling ability can be sufficiently exhibited.

[0010] In particular, when the concentration of the aqueous gelatin solution is increased, the gelatin droplets formed on the cooling surface by spraying become large due to the effect of surface tension or the like. The portion that is delayed increases, and the proportion of the portion that is frozen after passing through the gel state increases. Therefore, even if a high-concentration gelatin aqueous solution can be sprayed, the low-temperature solubility of gelatin cannot be sufficiently improved.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to form a uniform and high-quality gel which dissolves well in water even at a low temperature lower than ordinary temperature. It is an object of the present invention to provide a method for producing cold water-soluble gelled gelatin. Another object of the present invention is to provide an excellent cold water-soluble gelled gelatin as described above.

[0012]

Means for Solving the Problems To solve the above-mentioned problems, a method for producing a cold water-soluble gelled gelatin according to the present invention comprises:
An aqueous gelatin solution having a concentration of 20 to 60% by weight is frozen by sandwiching it between opposed cooling bodies cooled to -20 ° C. or lower, and after being freeze-dried, pulverized. As a material for gelatin, bones and skins of various animal species are used as raw materials,
Gelatin obtained by various extraction treatment methods, for example, alkali-treated gelatin, acid-treated gelatin and the like can be used.
In the present invention, gelatin having relatively low viscosity and high gel strength is preferable as gelatin. Specifically, JI
Preferably, the viscosity value specified in S is 10 to 100 mps, and the gel strength is about 50 to 500 g.

Such gelatin is dissolved in water to form an aqueous solution having a concentration of 20 to 60% by weight. If the concentration is less than 20% by weight, many voids are formed in the finally obtained gelatin powder, and the above-mentioned problems such as generation of lumps occur. As the concentration is higher, a gelatin product excellent in low-temperature solubility and gelling ability is obtained, and the productivity or the economic efficiency is also excellent. However, when the concentration exceeds 60% by weight, the viscosity of the gelatin aqueous solution increases, During the freezing treatment, it is difficult to handle the aqueous gelatin solution, and it is not possible to form a layer of the aqueous gelatin solution as thin as the whole can be rapidly frozen. On the other hand, if the concentration is too high, during the freeze-drying process, the rate of water evaporation from the gelatin aqueous solution is poor, and the freeze-drying time is long, and the moisture does not completely escape, and a rubber-like dried product is formed. There is also a problem.

In order to prepare an aqueous gelatin solution by dissolving a gelatin material, it is necessary to dissolve gelatin in a heated state and keep the aqueous gelatin solution at or above its gelling temperature until the next freezing step is performed. There is. Specifically, although it depends on the gelation temperature of the gelatin used, the temperature of ordinary gelatin should be kept at about 30 to 60 ° C.

[0015] The cooling body basically employs the same structure as the cooling body in various cooling devices conventionally used for freezing various solutions. For example, as a material of the cooling body, a metal plate such as iron, copper, aluminum, and stainless steel, a ceramic, and other materials are used. A normal cooling mechanism is provided inside or behind the cooling body so that the surface of the cooling body can be cooled to a predetermined freezing temperature. The cooling temperature of the cooling body is set to −20 ° C. or less. -2
At a temperature exceeding 0 ° C., the gelatin aqueous solution cannot be rapidly frozen to such an extent that the effects of the present invention can be sufficiently exerted. The lower the cooling temperature, the quicker the freezing is performed, and the better the performance of the manufactured gelatin, such as low-temperature solubility, can be improved. However, the cooling temperature may be set in consideration of the capacity and economy of the cooling device. Under general conditions, -70 ° C
About -20 ° C is a preferable range. Further, when the gelatin aqueous solution is brought into contact with the cooling body, the cooling capacity or cooling capacity of the cooling body is set so that the temperature of the cooling body does not rise and the surface temperature of the cooling body does not exceed the cooling temperature. It is preferable to keep it.

The cooling bodies having such a structure are arranged so as to face each other, and the aqueous gelatin solution is interposed therebetween. The cooling body may be arranged so that smooth flat cooling plates are opposed to each other in a parallel state, or the gap between the cooling plates is arranged so as to narrow from one side to the other side. You can also put it. Grooves or depressions may be formed on the opposite surface of the cooling body so that the gelatin aqueous solution can easily flow.

The aqueous gelatin solution is kept in a sol state until immediately before being sandwiched in the gap between the cooling bodies. At the same time, the gelatin aqueous solution is rapidly frozen without passing through the gel state. Need to be supplied. For this purpose, it is preferable that a means for supplying an aqueous solution of gelatin such as a nozzle is provided immediately before the gap of the cooling body. It is preferable to adjust the supply amount of the gelatin aqueous solution, but the specific supply amount is determined by conditions such as the size of the gap of the cooling body and the temperature. The spacing between the opposing cooling bodies varies depending on conditions such as the concentration and supply amount of the gelatin aqueous solution and the temperature of the cooling body, but is 0.5 to 10 mm.
It is preferable to set to about. If the gap exceeds 10 mm, the gelatin aqueous solution in the central part of the thickness tends to be in a gel state. If it is less than 0.5 mm, it is difficult to stably form a thin film of the aqueous gelatin solution in the gap between the cooling bodies. The aqueous gelatin solution may be sandwiched between the cooling bodies in a state of being spread in a planar manner, or may be sandwiched in a narrow band or rod shape. The smaller the width of the gelatin aqueous solution at the time of freezing, the better the cooling efficiency. A number of grooves and ridges may be formed side by side on the cooling body, and the gelatin aqueous solution may be frozen by simultaneously sandwiching a plurality of strips or rods.

The aqueous gelatin solution sandwiched between the opposing cooling bodies is rapidly cooled without passing through the gel state, and freezes while adhering to the surface of the cooling body. After the gelatin solution is held on the surface of the cooling body until the gelatin aqueous solution is sufficiently frozen, the frozen gelatin adhered to the surface of the cooling body may be collected from the surface of the cooling body with a knife-like scraping member or the like.

If rotating cylinders whose surfaces are cooling surfaces are arranged opposite to each other as a cooling body, an aqueous gelatin solution is sandwiched between the rotating cylinders and the space between the rotating cylinders closest to each other is frozen to freeze the gelatin. By scraping off the product with a knife placed in contact with the rotating cylinder, a frozen gelatin product can be obtained continuously. In addition, a plate-like cooling body can be freely reciprocated or horizontally swirled so that the operation of supplying the aqueous gelatin solution and the operation of scraping after freezing can be continuously repeated.

The frozen gelatin is subjected to a so-called freeze-drying process in which the frozen gelatin is dried in a frozen state by evacuation or a combination of evacuation and heating. Until the freeze-drying is completed, temperature control or cooling can be performed so that the frozen gelatin does not exceed the freezing temperature. The specific apparatus and processing conditions for the freeze-drying process are the same as those for the freeze-drying process for various foods and the like. It is preferable that the water content of the frozen gelatin be removed by lyophilization until the water content becomes 5 to 15%. The dried gelatin obtained by freeze-drying is in the form of a transparent crystal, which is clearly different from the appearance of a white porous material in the spray-dried product.

The resulting dried gelatin product is pulverized by a pulverizer. In the pulverization stage, the temperature of the dried gelatin may be raised to a freezing temperature or higher. As the pulverizing apparatus, the same pulverizing apparatus used for ordinary gelatin production and the like is used. The particle size of the gelatin powder obtained by the pulverization can be freely set according to the pulverization conditions such as the pulverization time and the adjustment of the pulverization apparatus in accordance with the use and required performance of the gelatin powder. Therefore, those having a particle size of about 20 to 200 μm are preferable.

The gelatin powder ground to a predetermined particle size is
It can be used for distribution as it is, or used for various purposes. Also, after subjecting the gelatin powder to various treatments used in conventional gelatin products, etc.,
Can also be used. Specifically, it is possible to mix another powder material with the gelatin powder or to obtain granulated gelatin by granulation.

As for the cold water solubilized gelatin obtained by the above-mentioned method, the temperature range of the dissolvable cold water can be adjusted by selecting the gelatin material and processing conditions, but various excellent functions which are difficult with conventional gelatin can be used. In order to exhibit the above, those which can be dissolved in water at 15 ° C. or lower are preferable. Further, the density of gelatin is smaller, worsened dispersibility when dissolved in water, Ru inconvenient der to distribution storage increasing bulk.
The density of gelatin can be set by adjusting the concentration of the aqueous gelatin solution.

[0024]

When a high-concentration aqueous gelatin solution is rapidly frozen without undergoing a gel state, the obtained frozen gelatin product maintains the tissue structure in the sol state.
If water is removed from the frozen gelatin by so-called freeze-drying, the resulting gelatin dried product will also maintain the above-mentioned tissue structure in the sol state. As a result, the gelatin powder obtained by pulverizing the dried gelatin can be very well dissolved in low-temperature water and can exhibit good gelling ability.

The reason is not clear in detail, but when gelatin has a matrix structure in a gel state like ordinary gelatin powder, when gelatin is dissolved in water and gelled, Once the matrix structure of the gel has been decomposed, the matrix structure between adjacent geralan powders must be reconstituted to form a gel, whereas the sol state, that is, the constituent molecules of gelatin are in a state of being separated, In the gelatin powder obtained by the present invention, when it comes into contact with water, the individual constituent molecules can be easily dispersed and bound in water to reconstitute the matrix structure. It is considered to be.

Since the gelatin powder obtained by the present invention is a freeze-dried state of a high-concentration aqueous gelatin solution, there is no excessive internal space unlike a spray-dried product. This is easily understood from the fact that the dried gelatin obtained by freeze-drying in the present invention has a dense crystal appearance. Therefore, the density is higher than that of the spray-dried product, and when poured into water, there is no problem that the product floats on the water surface, so that the product can be well dispersed and dissolved in water.

In the freezing treatment, a thin film of the gelatin aqueous solution can be strongly cooled from both sides by sandwiching and freezing the gelatin aqueous solution between opposed cooling bodies cooled to -20 ° C. or lower. . That is, the cooling efficiency of the aqueous gelatin solution is much higher than in the method of spraying the aqueous gelatin solution on the cooling surface.
As a result, the aqueous gelatin solution freezes very quickly without substantially undergoing a gel state. Further, as compared with the case where the gelatin aqueous solution is adhered to the cooling surface by spraying, even if the gelatin aqueous solution has a high concentration, it can be easily operated by simply sandwiching it between the cooling bodies.
As a result, it is possible to further enhance the solubility and the gelling ability by using a high-concentration aqueous gelatin solution.

The gelatin produced by such a method is as follows:
If the particles are dissolved in water at 15 ° C. or lower and gelled, the dissolving operation can be facilitated when used in various applications in which gelatin has been conventionally used, and cold water which could not be used in the past was used. , It is possible to dissolve gelatin satisfactorily. As a result, wasteful work of cooling and using gelatin dissolved at high temperature can be omitted, and various materials that are difficult to use at high temperature can be used together with gelatin.

[0029]

【Example】

Example 1 Gelatin (viscosity: 31.5 mps, gel strength: 326 g) was swelled in water and heated to 80 ° C. in a water bath to dissolve it to obtain an aqueous gelatin solution. As the gelatin aqueous solution, those having the following concentrations were prepared.

When the obtained aqueous gelatin solution was cooled down to 40 ° C., it was cooled to −40 ° C., and poured into a pair of cooling bodies having an interval of 5 mm to freeze. FIG. 1 shows a schematic structure of the cooling device. Lower cooling body 10
Has a cooling surface 12 formed of a flat surface of metal or ceramic having a high thermal conductivity on the upper surface, and has a normal cooling mechanism inside. Above the lower cooling body 10, a gelatin tank 20 and an upper cooling body 30 are provided so as to be integrally movable in the horizontal direction. The gelatin tank 20 contains the above-mentioned aqueous gelatin solution G and is provided with a heater (not shown) for heating the aqueous gelatin solution G. The upper cooling body 30 includes a cooling bag body 32 in the form of a tire tube having a wide width and rotating rollers 34, 3.
4 and held. The cooling bag 32 is formed in a flexible bag shape by braiding a metal wire or the like having a high thermal conductivity, and the inside of the cooling bag 32 is filled and supplied with a cooling medium. When the flexible cooling bag 32 is rotated by the rotating rollers 34, 34 in accordance with the horizontal movement of the upper cooling body 30 and the gelatin tank 20, the lower surface of the cooling bag 32
The lower cooling body 10 is arranged to face the upper cooling body 10 at a certain interval.

From the gelatin tank 20, an aqueous gelatin solution G
Is gradually moved to the surface of the lower cooling body 10 while the gelatin tank 20 and the upper cooling body 30 are horizontally moved.
Is immediately sent to the lower surface of the cooling bag body 32 of the upper cooling body 30. Since the lower surface of the cooling bag body 32 is sequentially sent backward, the layer of the aqueous gelatin solution G sandwiched between the cooling bag body 32 and the lower cooling body 10 receives strong cooling action from above and below at the same position. It will freeze without going through a gel state. The cooling condition of the aqueous gelatin solution G can be changed by adjusting the moving speed of the gelatin tank 20 and the upper cooling body 30 or the distance between the lower surface of the cooling bag body 32 and the lower cooling body 10.

The aqueous gelatin solution was kept frozen for 2 hours to stabilize the frozen state. The frozen product of the gelatin aqueous solution was freeze-dried in a vacuum dryer set at a shelf temperature of 30 ° C. and a degree of vacuum of 1 Torr so that the water content was 15% or less. The obtained dried gelatin product was pulverized with a pulverizer so as to have a size of 60 mesh or less to obtain a sample of gelatin powder. The shape, solubility in cold water, and gel strength of the obtained gelatin powder were measured, and the results are shown in Table 1. In the table, 15 ° C. water was used as cold water. The gel strength was measured according to the method specified in JIS. Concentrations are expressed in weight%.

[0033]

[Table 1] 濃度 Concentration [%] Shape Cold water solubility (15 ℃ ) Gel strength [g] １０ 10 White, hollow inside Not dissolved and not gelled 20 crystalline dispersion, dissolved 293 40 crystalline dispersed, dissolved 289 60 crystalline dispersed, dissolved 288 70 rubbery, not pulverizable--────────────── ──────────────────── As a result, the concentration of the aqueous gelatin solution is 20 to 60% by weight.
It turns out that it is necessary to keep it.

Example 2 A gelatin powder was obtained from a 50% by weight aqueous gelatin solution in the same manner as in Example 1. 3 g of this gelatin powder was put into water at various temperatures, stirred with a stirrer, and the time until complete dissolution and gel strength were measured.
As a comparative example, a gelatin powder produced by the same method using a 2% by weight gelatin aqueous solution was used. Table 2 shows the results.

[0035]

[Table 2] 溶解 Dissolution time [min] Gel strength [g] Water temperature [° C] Example Comparative Example ───────────────────────────155 × 20.4 No gelation 203 × 18.6 No gelation 253 × 20.0 No gelation 352 × 19.8 No gelation ─────────────────────────── ×: 30 Even after stirring for more than a minute, it remained in a lump state. As a result of the above test, in Examples of the present invention, good solubility was exhibited and gel strength was sufficient irrespective of the temperature of water to be dissolved.

[0036]

As described above, the method for producing a cold water soluble gelled gelatin and the cold water soluble gelated gelatin according to the present invention are obtained by freezing a gelatin aqueous solution without passing through a gel state, drying it as it is, and pulverizing it. By doing so, gelatin showing good solubility and gelling ability even at low temperatures can be produced with high productivity.

As a result, it is possible to efficiently and economically use gelatin gel at a low temperature, such as in the production of frozen desserts, without performing unnecessary heat treatment. In addition, it is possible to use materials that could not be used conventionally together with gelatin, such as gelling drugs and food materials that are sensitive to heat, and this can greatly contribute to the expansion of the use field and demand of gelatin.

[Brief description of the drawings]

FIG. 1 is a schematic structural diagram of a cooling device used in an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lower cooling body 20 Gelatin tank 30 Upper cooling body G Gelatin aqueous solution

Claims (1)

(57) [Claims] 1. An aqueous gelatin solution having a concentration of 20 to 60% by weight is sandwiched between opposed cooling bodies cooled to -20 ° C. or less, frozen, freeze-dried, and then pulverized. For producing cold water soluble gelled gelatin .