JPS61199771A - Method of drying laver - Google Patents

Abstract

PURPOSE:To keep a flavor of dried laver well, to eliminate influence by change in environmetal conditions, and to make process control easy, by regulating water content and temperature of air to be fed during drying in specific ranges, respectively. CONSTITUTION:Air sucked in the air inlet 19 of the dehumidifier 18 is dehumidi fied by the dehumidifier 18 into <=0.0065kg/kg(air) water content, and sent through the air feed ipe 17 to the dryer 11. The air introduced in the dryer sucked into the heater 15 by the fan 14, heated to <=50 deg.C, passed through laver to lower the temperature of the air, partially discharged from the exhaust vent 16 from the machine and partially raised again in the arrow direction and circulated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for improving the drying process, which is one of the steps in producing seaweed products.

[Technical background of the invention and its problems] In order to produce seaweed products from collected seaweed fronds, the seaweed fronds are first washed and cut, then made into a sheet shape, and then the moisture is removed by 8 to 80%. Dry to about 12%. This is generally called fresh plate nori and is sold to distributors and processors through cooperative sales by fishing associations.

In order to maintain long-term quality, the distribution processor that purchased the fresh sheet nori further dries and stores this moisture to 3-5%, and stores it throughout the year.
Roast, season, etc. as necessary. The latter drying process is particularly called pasteurization.

The above is a general manufacturing method for seaweed products, but in the above manufacturing process, the drying process called pasteurization was carried out as in conventional machines. That is, FIG. 6 is a sectional view of a conventional fire dryer, and as shown in the figure, the drying l1i
Boxes 2 containing seaweed are installed in several tiers in a box 11, and natural environmental air is taken into this drying Ifil from an air intake port 3. The air that has entered the dryer 1 is sucked by the fan 4 to the heater 5 installed at the top of the dryer.
After being heated to approximately 60 to 80°C by this heater 5,
The hot air flows down through the seaweed stored in the box 2, rises again in the direction of the arrow, and is partially discharged outside the machine through the exhaust port 6. As the hot air passes through the seaweed, heat is supplied to the seaweed, promoting the evaporation of moisture, and as the temperature rises, the relative humidity of the air decreases, making it easier for the moisture in the seaweed to move into the air, causing the seaweed to evaporate. Water is gradually removed.

By the way, seaweed is collected in winter, so most of the burning work is done in winter.

Therefore, if all the moisture-containing air is exhausted from the inside of the dryer and replaced with fresh air, it will take time to raise the temperature inside the dryer to a predetermined temperature. Therefore, even after the air that enters through the intake port 3 has gone through one cycle, not all of it is exhausted, but a portion of it is circulated again. Therefore, if the humidity of the intake air is high from the beginning, the air inside the dryer 1 will approach the saturated water vapor amount in a short time, and the drying speed will rapidly decrease. For example, considering the case of rainy weather, if natural environmental air with a temperature of 15°C and relative humidity of 90% is put into the dryer, and the temperature inside the dryer is set to 50°C, the relative humidity of the air sent to the nori is theoretically 1. It will be about 14%. On the other hand, in the case of clear skies,
Assuming natural environmental air with a temperature of 15℃ and a relative humidity of 60%,
At the same set temperature of 50°C, the relative humidity of the air sent to the seaweed is approximately 9.3%, and the drying speed is much faster than in the case of rain. Therefore, in order to keep the relative humidity inside the dryer on rainy days at 9.3%, the same as on sunny days, the temperature inside the dryer should be set at 6.
The temperature must be raised to 5°C.

If the set temperature inside the dryer is changed in this way depending on the environmental conditions, the quality of the seaweed will change accordingly, and there is a drawback that a uniform product cannot be obtained, and the process management will also become complicated. Furthermore, if the drying temperature is set to a high temperature, the flavor components of the seaweed will volatilize or change, resulting in a problem that the quality of the seaweed will deteriorate.

[Object of the Invention] The present invention has been made in view of the above circumstances, and is capable of retaining the original flavor of seaweed well, maintaining uniform quality even under changes in environmental conditions, and moreover, It is an object of the present invention to provide a method for drying seaweed that can be dried in a short time and that allows easy process control.

[Structure of the Invention] As shown in Experimental Example 1 to be described later, the present inventor found that seaweed retains its original flavor well when dried at a temperature of 50°C or lower, and furthermore As a result of studying the method of drying seaweed in the drying process, we found that, as shown in Experimental Example 2 below, the air introduced during drying was not natural as in the past, but the moisture content was adjusted to the air IK (+ medium 0. It was discovered that if the drying process is adjusted to 0.065 kg or less, the flavor of the dried seaweed is good, the drying process can be carried out in a short time, and the process control is also easy. It's arrived.

That is, the present invention introduces air that has been dehumidified to a moisture content of 0.0 Oes Kg/Kg (air) or less using a dehumidifier into a dryer containing seaweed, adjusts the air to a temperature of 50°C or less, and then cools the inside of the dryer. This invention relates to a method for drying seaweed, which is characterized by circulating and then exhausting the seaweed.

An experimental example regarding the drying temperature of kasu nori is shown below.

Experimental Example 1 The following experiment was conducted to investigate the relationship between the temperature of the air drawn into the dryer and the flavor of seaweed.

40℃, 45℃, 50℃ using a conventional seaweed dryer
.

The plate nori was dried at temperatures of 60°C, 70°C, and 80°C. The environmental conditions at this time were a temperature of 11℃ and a relative humidity of 5.
It was 3%. After drying the sheet nori at the above-mentioned temperatures under these conditions to a moisture content of 4.5%, the taste and aroma of this dried nori (dried nori) and roasted nori (roasted nori) were tested. did. The test was conducted using a panel test and was evaluated in five stages. The larger the value, the better the result. The results are shown in the table below.

(Margin below) As is clear from the table above, both dried and roasted seaweed when pasteurized and dried at 40°C and 45°C were clearly superior in both taste and aroma to seaweed that was pasteurized and dried at other temperatures.

Experimental Example 2 The following experiment was conducted to investigate the relationship between the humidity of the air fed into the dryer and the drying state of seaweed.

The temperature inside the dryer was set at 50°C, and air adjusted to various humidity levels was introduced into the dryer to dry the seaweed.
The moisture content of the seaweed was measured 150 minutes after the start of drying. The results are shown in FIG. In Figure 5, the vertical axis is the moisture content of seaweed (m (%)), and the horizontal axis is the absolute humidity of the air (Kg/Kg
). As is clear from FIG. 5, it was found that the absolute humidity of the air, that is, the moisture content of the air, greatly influenced the drying of the seaweed. At a drying temperature of 50°C, in order for the moisture content of seaweed to become 5% or less 150 minutes after the start of drying, the absolute humidity of the air must be o, oo6s K (1/Kg
I found that I needed to do the following.

[Embodiments of the invention] The present invention will be explained by examples.

Example 1 FIG. 1 shows an example of an apparatus for carrying out the method of the present invention. In Figure 1, seaweed drying I! Several boxes 12 containing seaweed are placed inside the box 111, and a fan 14 and a heater 15 are installed on top of the boxes 12.

The air intake port 13 is connected to the dehumidifier 611 &
It is connected to the. Dehumidify now! The air sucked through the air intake port 19 of 118 is dehumidified by the dehumidifier 18 to a moisture content of 0.0065 K11l/K11l (air) or less, and reaches the dryer 11 through the air introduction pipe 17 as shown by the arrow. . The air that entered the dryer is passed through fan 14.
The air is sucked into the heater 15 installed at the top of the dryer, and after being heated by the heater 15, it becomes hot air and descends through the seaweed, and a part of it is discharged outside the machine from the exhaust port 16. The area rises again as indicated by the arrow.

The seaweed was dried using the seaweed drying apparatus described above. 36,000 sheets of seaweed with an initial moisture content of 8.5% are placed in the box 12 in the device.
The sheets were loaded, the inside of the machine was set to have an air temperature of 45°C, and air with a moisture content adjusted to 0.004KllI/KC+ (air) was fed in using a dehumidifier to dry the paper.

For comparison, 36,000 sheets of the same seaweed were placed in a conventional seaweed dryer shown in FIG. 6 and dried at the same temperature.

During drying, the moisture content of each piece of seaweed was measured over time.
The time required for the moisture content of seaweed to reach 4.5% or less was determined. The environmental conditions at this time were a room temperature of 14.5° C. and a relative humidity of 52%.

The results of the above experiment are shown in FIG. The vertical axis of the graph is the water content (%) of the seaweed, and the horizontal axis is the elapsed time (minutes), the solid line is for the method of the present invention, and the broken line is for the conventional method. Second
As is clear from the figure, the drying method according to the present invention reached the predetermined moisture content in a shorter time.

Example 2 As in Example 1, seaweed 3 with an initial moisture content of 9.7% was prepared using the seaweed drying device shown in FIG. 1 and the conventional seaweed dryer shown in FIG.
6,000 sheets were dried at an air temperature of 45° C., and the change in moisture content over time was measured in the same manner as in Example 1.

Furthermore, for the conventional dryer, the test was also carried out at an air temperature of 60°C. For the environmental conditions, we chose rainy weather as a bad condition.
The temperature was 18.5°C and the relative humidity was 15.6%.

The results of the above experiment are shown in FIG. The vertical and horizontal axes of the graph are the water content (%) P) and elapsed time (minutes) of the seaweed, respectively, as in FIG. 2. The solid line is for the method of the present invention, and the broken line is for the conventional method.

As is clear from FIG. 3, in the method of the present invention, the predetermined moisture content was reached in a shorter time than in the conventional method when the air temperature was 60°C.

Example 3 Seaweed having an initial moisture content of 9.5% was dried using the seaweed drying apparatus shown in FIG. The temperature inside the dryer was set at 40° C., and air whose water content was adjusted to 0.0022 Kg/KO was introduced into the dryer to measure changes in the water content of the seaweed over time. The environmental conditions at this time were an air absolute humidity of 0.0074 to 0.0079 K(]/KQ.

The measurement results are shown in FIG.

In FIG. 4, the vertical axis shows the water content (%) of seaweed, and the horizontal axis shows the elapsed time (minutes). As is clear from FIG. 4, the seaweed was sufficiently dried even at 40°C, and good quality was obtained.

[Effects of the Invention] As explained above, according to the drying method of the present invention, seaweed with good flavor and constant quality can be obtained without being affected by environmental conditions such as weather. Additionally, since it is not affected by environmental conditions, the process can be easily managed, and it can be dried in a short time, improving productivity.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of the apparatus used in the method of the present invention, and Figs. 2 and 3 show the moisture content of seaweed over time in the drying method of the present invention and the conventional drying method at a drying temperature of 45°C, respectively. Graph showing the changes. Figure 4 is a graph showing the change over time in the moisture content of seaweed when the temperature is set at 40'C in the drying method of the present invention. Figure 5 is the absolute humidity and moisture content of the air introduced. FIG. 6 is a cross-sectional view of a device used in a conventional seaweed drying method. 11... Dryer, 12... Seaweed storage box 13... Air intake port, 15... Heater 16... Exhaust 0.17
... Air introduction pipe 18 ... Dehumidifier (8733) Representative Patent attorney Yoshiaki Inomata (and 1 others)
Name) Tokikai (I 2 3 Zuchi Tomo (minute) 6 Figure Proceedings Amendment (Voluntary)

Claims (3)

[Claims] (1) A dehumidifier is placed in the dryer containing the seaweed to reduce the moisture content to 0.
．． A method for drying seaweed, which comprises feeding air that has been dehumidified to 0.065 Kg/Kg (air) or below, adjusting the temperature of the air to a temperature of 50° C. or below, circulating the air within the dryer, and then exhausting the air. (2) Moisture content of air is 0.004Kg/Kg (air)
The method for drying seaweed according to claim 1, wherein the temperature is 45°C. (3) The method for drying seaweed according to claim 1, wherein the moisture content of the air is 0.0022 Kg/Kg (air) and the temperature is 40°C.