JPH0573379B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for producing square agar, and more specifically to a method for producing square agar, and more specifically, a method for freezing and drying raw square agar, which is made of gel-like raw agar and has a rectangular cross section. Concerning a method for producing agar.

(Prior Art) There are three types of agar based on its shape: square agar, fine agar, and powder agar. Among these types of agar, square agar, which has a substantially rectangular cross-sectional shape, is produced using natural cold air.

In such a conventional method for producing square agar, first, seaweed (such as tengusa) is boiled to extract the nori content, poured into a morobuta, and cooled to produce gel-like (tokoroten-like) raw agar.

Furthermore, this raw agar is cut and formed into square rod-shaped fresh agar with a rectangular cross-sectional shape. Multiple pieces of molded raw square agar are lined up on a single frame board outdoors.
Freeze using natural cold air. This freezing is
It will take about three nights to complete.

Note that a plurality of pores formed by nailing are formed on the upper surface of the fresh horn agar.

FIG. 5 shows the state in which fresh horn agar is frozen in such a conventional method for producing horn agar.

Figure 5a shows the state in which raw horn agar was exposed to the cold air on the first night outdoors. Freezing (freezing) progresses vertically downward from the top surface of the raw horn agar, especially the nailed part.
Frozen part 2 where about 1/3 to 1/2 of the top is frozen
It is 0. The lower part of this frozen portion 20 is an unfrozen raw agar portion 22.

In the state shown in FIG. 5a, when the frozen portion 20 starts to thaw as the temperature rises during the day, the fresh agar portion 22 is present at the bottom of the raw horn agar.
The thawing water near the sides of the raw horn agar is separated from the sides, but the thawing water near the center of the raw horn agar is removed by evaporation or the like from the upper surface of the raw horn agar. frozen part 2
This is considered to be because the freezing direction of No. 0 is vertical, so the passage through which the thawing water passes is also formed in the vertical direction.

Figure 5b shows the state in which fresh horn agar, in which the frozen portion 20 has been partially thawed, is exposed to the cold air on the second night.
Shown below. In FIG. 5b, the frozen portion 20 advances further downward and the volume of the fresh agar portion 22 decreases.

When the frozen part 20 of the raw horn agar in the state shown in FIG. At the same time, drying starts from the top surface.

Furthermore, when the raw agar that has started drying from the top is exposed to the cold air on the third night, the raw agar portion 22 disappears and the freezing of the raw horn agar is completed, as shown in FIG. 5c. At this time, honeycomb-shaped freezing is observed vertically from the top surface of the frozen agar.

Next, the frozen raw horn agar shown in Figure 5c was
Gradually dry naturally under natural weather to form square agar. This natural drying usually requires about 14 days.

In such conventional methods for producing square agar, controlling the frozen state of fresh agar is extremely important in order to obtain square agar with a substantially rectangular cross-sectional shape (square agar with good squareness) after drying.

For example, if the nighttime temperature decreases so little that freezing is not completed within three nights, mold may grow in the fresh agar portion 22.

On the other hand, if the nighttime temperature decreases significantly and freezing progresses from the sides of fresh square agar, the cross-sectional shape of the square agar obtained after drying will be bent at the waist, as shown in Figure 6, and the square agar will not stand well. Unable to obtain square agar.

As described above, in the conventional method of manufacturing square agar using natural cold air, the regions where square agar can be manufactured are limited, and the quality of the square agar obtained is influenced by weather conditions.

In addition, as in recent years, the cold weather in winter has become milder due to global warming, which has become a major obstacle to the production of agar cubes.

These problems in the conventional method for producing horn agar can be solved by artificially freezing and drying raw horn agar to enable artificial production of horn agar.

(Problems to be Solved by the Invention) If it is possible to obtain square agar with good square standing through artificial production of square agar, it will be possible to eliminate the regional limitations in which square agar can be manufactured and to avoid being bothered by climate fluctuations. square agar can be produced without

Moreover, the time required for manufacturing the square agar can also be shortened.

However, when raw horn agar is artificially frozen, freezing tends to proceed from the entire surface of the raw horn agar, and the square agar obtained after drying has a cross-sectional shape of 6
As shown in the figure, the shape is bent at the waist, resulting in a defective product.

Therefore, an object of the present invention is to provide a method for producing square agar that can obtain square agar with good square standing by artificially freezing and drying raw horn agar.

(Means for Solving the Problems) As a result of studies to achieve the above object, the present inventors discovered that when thawing frozen angle agar obtained by proceeding freezing from the entire surface of raw horn agar, By thawing a portion of the agar and then refreezing the thawed portion, repeating partial thawing and refreezing from near the surface of the frozen angle agar to the depths, square agar with good squareness can be obtained. The present invention was achieved based on the discovery that

That is, in the present invention, when producing horn agar by freezing and drying raw horn agar that is made of gel-like raw agar and having a rectangular cross-sectional shape, freezing proceeds from the entire surface of the raw horn agar. Partial thawing/re-freezing involves partially thawing a certain depth from the circumference of the frozen angle agar and then refreezing the thawed part so that a rod-shaped frozen residue remains in the frozen angle agar in the direction of the central axis of the frozen angle agar. Freezing is applied repeatedly toward the deep part of the frozen angle agar, and the rod-shaped frozen residue is reduced while releasing the water in the thawed part, and the frozen angle agar obtained when the frozen residue disappears, The method for producing square agar is characterized by drying at low temperature and low humidity so that the thawed square agar does not shrink and deform.

(Function) In the present invention, when thawing the frozen angle agar that has been evenly frozen as a whole, after partially thawing the frozen angle agar so that rod-shaped frozen residue remains within the frozen angle agar,
Partial thawing and refreezing, in which the thawed portion is frozen, is gradually repeated in the direction of the deep part of the frozen angle agar.

Therefore, during thawing, since rod-shaped frozen residues are present in the partially thawed angle agar, the latent heat of melting of the ice can suppress the temperature rise of the thawed portion, and low-temperature thawing can be performed.

Moreover, by refreezing the thawed part,
In the thawed portion that was previously thawed, the water content further decreases due to sublimation, and together with the denaturation of the agar components, solidification progresses.

Therefore, even if the volume of the previously thawed portion decreases due to a decrease in water content during re-thawing, the thawed portion will not be substantially deformed.

By repeating such partial thawing and refreezing, thawing is performed while gradually solidifying the thawed portion, so that the thawed angle agar substantially retains the form of frozen angle agar. I can do it.

Since the thawed square agar thawed in this way is soft, in the present invention, in order to avoid rapid drying,
By drying the thawing angle agar under low temperature and low humidity conditions so that the thawing angle agar does not shrink and deform, it is possible to prevent the thawing angle agar from deforming and obtain square agar with good squareness.

(Example) The present invention will be explained in more detail by way of examples.

In this example, first, a plurality of pieces of raw square agar with a rectangular cross section made of gel-like raw agar were
Arrange the pieces about 8 to 9 mm apart on a breathable mesh board and freeze in the freezer.

The raw horn agar used in this example is usually
42mm, height 46mm, length 300mm, and weight 580g
It is cut into square rod shapes, and its ingredients are water-free.
98.7%, and the agar component is about 1.3%.

Multiple sticks (usually 42 sticks) of Kakatsu Fresh Horn Agar are lined up on a mesh board, and freezing progresses from the entire surface of the Fresh Horn Agar at a temperature of -5 to -10°C, so that the whole piece is evenly distributed. Frozen angle agar is used. FIG. 1 shows a state in which frozen angle agar 1 is arranged on a mesh plate 2.

The frozen angle agar 1 frozen on the mesh board 2 shown in FIG. 2
will be inserted.

In this example, the freezing angle agar 1 inserted into the partial thawing/refreezing chamber 9 is moved from the circumferential surface of the freezing angle agar 1 so that a rod-shaped frozen residue remains in the central axis direction of the freezing angle agar 1. After partially thawing a portion at a certain depth, partial thawing and refreezing of the thawed portion is repeated as shown in FIG. 2, gradually going deeper into the freezing angle agar 1.

That is, the frozen square agar 1 placed in the freezing/refreezing chamber 9 is first partially thawed and refrozen for the first time.

In this first partial thawing, the room temperature of the partial thawing/refreezing chamber 9 is maintained at around 10°C by introducing well water or heat medium of 15 to 17°C into the warmers 6 and 6. 5
Frozen square agar 1, which has been cooled to -10°C, is thawed from the peripheral surface. This thawing is stopped when about 4 to 5 mm from the circumferential surface is partially thawed and a rod-shaped frozen residue 1a remains in the direction of the central axis of the partially thawed angle agar, as shown in FIG. 2a. The thawing time required for such partial thawing is about 6 hours.

Next, the room temperature of the partial thawing/refreezing chamber 9 is brought to around -5°C by introducing refrigerant from a refrigerator (not shown) into the refrigerant evaporator 7, and the thawed portion thawed in the first partial thawing is heated. Perform the first refreeze.

By this first refreezing, the sublimation effect due to refreezing is added to the surface layer, which is the thawed part that was thawed in the first partial thawing, and the remaining moisture content is approximately 30% of the initial moisture content. decreases to a certain degree. This reduction in water content in the surface layer portion and the denaturation effect of the agar components combine to promote solidification of the surface layer portion, which effectively maintains the shape of the frozen horn agar 1.

The temperature control of the partial thawing/refreezing chamber 9 is semi-automatically controlled by the controller 8, and the water droplets separated from the freezing angle agar 1 are collected in the drain 5 and drained outside the partial thawing/refreezing chamber 9. be discharged.

After this first refreezing is completed, a second partial thawing/refreezing is performed at the same temperature as the first partial thawing/refreezing.

In this second partial thawing, the rod-shaped frozen residue 2a remains in the partially thawed angle agar, so even if thawing is performed at an ambient temperature of around 10°C,
It is possible to prevent the thawed portion from being heated above 0° C. due to the latent heat of melting of the ice, and it is possible to perform partial thawing at a low temperature.

This second partial thawing is stopped when thawing has progressed to about 6 to 7 mm from the surface of the freezing angle agar, and a second refreezing is performed in the same manner as the first refreezing.

Here, when the second partial decompression is completed,
As shown in Figure 2b, the frozen residue 2a remains in the partially thawed angle agar, but its volume is is getting smaller.

Also, when the second refreezing is completed, the second
The surface layer portion, which is the thawed portion that has been thawed by the second partial thawing, has a moisture content of about 20% of the initial moisture content, becoming semi-dry, and the solidification of the surface layer portion further progresses.

In this example, by repeating such partial thawing and refreezing, as shown in FIG. 2c,
The remaining frozen portion 3a becomes smaller and finally, as shown in FIG. 2d, the frozen portion disappears and thawing is completed.

In the thawing process of this example, as shown in FIG. 2, thawing progresses as the volume of the partially thawed angle agar decreases, but thawing progresses while solidifying the thawed portion by refreezing. In addition, during partial thawing, rod-shaped frozen residues exist in the partially thawed angle agar, so a sudden volume reduction does not occur, and the shape of the frozen angle agar 1 is substantially maintained. You can unzip it while doing so.

The thawed square agar that has been thawed through this thawing process has a weight of 70~70g compared to the raw horn agar's 580g.
It is in a semi-dry state, reduced to about 75g.

In the thawing process of this example, the thawing time and refreezing time are preferably varied depending on the state of the frozen angle agar, etc., and the time required to complete thawing is 30 to 35 hours. be.

Further, during thawing, it is preferable to adjust the relative humidity in the thawing/refreezing chamber using a dehumidifier, so that the thawed portion can be dried.

Since the thawed square agar thus obtained is still soft, it is subjected to final drying in the drying chamber shown in FIG. 4.

In the drying chamber 14 shown in FIG. 4, the thawed square agar 51, which has been thawed in FIG. Ru.

The thawed angle agar 51 inserted into the drying chamber 14 is temperature and humidity controlled by the air conditioner 10, and is dried by dry air that passes through the duct 11 and is blown out from the air outlet 12 into the drying chamber 14.

It is important that such drying is carried out at low temperature and low humidity so that the thawing angle agar 51 does not shrink and deform.

Therefore, in this embodiment, the dry air blown into the drying chamber 14 has a temperature of about 10°C and a relative humidity of 25°C.
Adjusted to below %. When the thawing angle agar 51 comes into contact with the dry air, moisture begins to evaporate from the surface, and the absorbed air is sucked into the air conditioner 10, dehumidified and temperature-adjusted, and then blown into the drying chamber 14 again.

This is because the thawed angle agar 51 that has been completely thawed is soft, so if the temperature of the drying air is increased at the beginning of drying, the thawed angle agar 51 is likely to undergo shrinkage deformation.

By continuing drying in dry air at a temperature of 10°C and a relative humidity of 25% or less for about 10 to 12 hours, the surface layer of the thawed angle agar 51 loses almost all moisture and becomes dry. The tissue becomes in a state that can withstand the rise in air temperature.

Therefore, the temperature of the dry air is gradually increased, the relative humidity is lowered, and the evaporation of the internal moisture of the thawing angle agar 51 is promoted.

In the final stage of drying, this drying air has a temperature of 20
It is preferable that the temperature is about 0.degree. C. and the relative humidity is about 20%.

Adjustment of the temperature, humidity, etc. of the dry air is automatically or semi-automatically controlled by the controller 13.

In this example, the time required for the final drying process varies depending on the capacity of the air conditioner 10, etc., but the time required for the final drying process is approximately 35
It took about 40 hours.

The square agar obtained in this manner did not exhibit the bending phenomenon shown in FIG. 6, and had a good square shape. In addition, in the cross section of the obtained square agar, the agar components are not oriented in a striped manner in one direction, unlike the square agar obtained using natural cold air, but the orientation direction of the agar components is random. .

Moreover, the total time required from thawing the frozen cube agar to final drying was about 65 to 75 hours, which was about 1/5 of the time required for natural production.

(Effects of the Invention) According to the present invention, by artificially producing square agar, the square agar is comparable to naturally produced square agar.
It is possible to stably obtain square agar of good quality.

Therefore, it is possible to industrially produce agar cubes without being limited by season or region.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the state of frozen angle agar, Figure 2
The figure is an explanatory diagram to explain the state when partial thawing and refreezing of frozen angle agar is repeatedly performed. Figure 3 shows an outline of the thawing/rethawing chamber for partially thawing and rethawing frozen angle agar. A schematic diagram, FIG. 4 is a schematic diagram showing the outline of a drying chamber for final drying of thawed square agar, and FIG. 5 is an explanatory diagram illustrating the progress of freezing in natural production of square agar, and FIG. 6 is a cross-sectional view showing the cross-sectional shape of the obtained square agar when freezing also progresses from the sides of the raw square agar in natural production of square agar. 1...Frozen angle agar, 2...Mesh plate, 1a, 2a,
3a... stick-shaped thawed residue, 9... partial thawing/refreezing room, 14... drying room.

Claims (1)

[Scope of Claims] 1. When producing square agar by freezing and drying raw horn agar made of gel-like raw agar and having a rectangular cross-sectional shape, freezing proceeds from the entire surface of the raw horn agar. Partial thawing/thawing involves partially thawing a certain depth from the circumference of the frozen angle agar and then refreezing the thawed part so that a rod-shaped frozen residue remains in the frozen angle agar in the direction of the central axis of the frozen angle agar. Refreezing is repeated to gradually move deeper into the frozen angle agar, and while releasing the water in the thawed part, the rod-shaped frozen residue is reduced, and the frozen angle agar obtained when the frozen residue disappears. , A method for producing square agar, which is characterized by drying at low temperature and low humidity to prevent the thawed square agar from shrinking and deforming.