JPS6360982B2 - - Google Patents

Description

[Detailed description of the invention]

a. Industrial Application Field The present invention relates to a method for processing raw seaweed. b. Conventional technology Traditionally, raw seaweed has been processed by shredding, papermaking, and drying to produce plate-shaped products, and vacuum freezing, loosening, and drying to produce vacuum freeze-dried products. For preservation, they are dehydrated, loosened, and frozen. During these treatments, the loosening process is carried out either manually or by passing the nori clumps through a rotating blade. c Problems to be Solved by the Invention In all conventional loosening treatments, the water adhering to the surface is not sufficiently removed, so it is natural that the adhesion of leaf bodies to each other cannot be avoided even after the loosening treatment. Therefore, in order to obtain a dried product in bulk, it is necessary to further loosen the product after drying, which is a rather difficult task. If there is a treatment method that prevents the adhesion of leaves to each other before drying, it would be easy to obtain dried pieces. In addition, when storing raw seaweed in a frozen state, it is expected that it will freeze and thaw more quickly if it is not only made into non-clumps as in the conventional loosening process, but also the sheets of seaweed are kept from sticking to each other. can. d Means for Solving the Problems The present invention involves washing and dehydrating fresh seaweed, mainly consisting of leaf pieces with a thickness of 30 μm or more, with fresh water or a salt solution, and reducing the seaweed to a moisture content that does not cause mutual adhesion of the leaf bodies. In a dry atmosphere, the adhered seaweed leaves are treated with stirring blades, gas injection, etc.
This method is characterized by performing a discrete process of separating the seaweed leaves from each other by applying an instantaneous blow. By carrying out this treatment, it is possible to obtain seaweed in which the leaves do not stick to each other when a subsequent drying treatment or freezing treatment is performed. In the present invention, it is preferable to use raw seaweed containing 90% or more of this for the leaves with a thickness of 30 μm or more,
If less than 90% of the leaflets have a thickness of 30 μm or more, it becomes difficult to eliminate surface adhesion of the leaflets to each other. FIG. 1 shows an example of an apparatus for carrying out the present invention, which was used in Experiments 1 to 3. 1 in the diagram
2 is a drum-shaped drying basket with a diameter of 400 mm and a length of 500 mm and 16 meshes, and 2 is a rotating shaft on which 16 stirring blades (rotating diameter of 390 mm) 3 are arranged in alternating positions. 4
is a dry air outlet. Experiment 1 In this experiment, the effects of various discrete conditions on the moisture content of seaweed at the end of the discrete period and its discrete state were investigated. First, it contains 95% leaf pieces with a thickness of 30 μm or more, and has a leaf length of 2.
~5 cm of seaweed produced in Aichi Prefecture was washed with fresh water, dehydrated by centrifugation, and placed in drying basket 1. By turning the rotating shaft 2 and giving an instantaneous blow to the seaweed with the stirring blade 3, the seaweed is dispersed, and the dry air is ventilated from the air outlet 4 in an almost even distribution from the bottom to the top of the drying basket 1. did. After a certain period of time, stirring was stopped, air drying was continued, and after drying, the discrete state of the seaweed was observed. As shown in Table 1, the results show that, regardless of the temperature and humidity of the drying air, the air volume, the drying speed set by the amount of seaweed input, and the speed of the tip of the stirring blade, the moisture content generally remains the same.
It was found that if the discrete processing was performed up to the 400% point, a good discrete state of the seaweed could be obtained. However, when the stirring blade tip speed was less than 1 m/sec, the dispersion was insufficient even though the water content was below 400%. Note that the determination of discrete state is based on the fact that the leaves are not attached to each other.
Less than 10% was considered good, and 10% or more was bad. Experiment 2 In this experiment, we investigated the effect of the discrete frequency of seaweed on the discrete state. Discrete raw seaweed 0.6Kg, air volume 40
m ³ /min, temperature 50°C, humidity 15% RH, stirring blade tip speed 1.0 and 2.0 m/s, and the discrete frequency was adjusted by adjusting the rotation speed and intermittent operation of the rotating shaft on which the stirring blade was arranged. . After performing the discrete treatment for 5 minutes, the sample was transferred to ventilation drying, and the results shown in Table 2 were obtained. Unless the frequency of dispersing the seaweed was 40 times/min or more, clumps were formed during stirring, and a good dispersion state could not be obtained. Experiment 3 In this experiment, when a saline solution was used as a cleaning solution, the influence of its type and concentration on discrete processing was investigated. Raw seaweed was washed with various salt solutions of 0 to 4% concentration and dehydrated by centrifugation at 1000 revolutions/minute for 5 minutes.
FIG. 2 shows the water content of washing and dehydration at this time, and Table 3 shows details of the values displayed in FIG. 2. As shown in the table, the slope differs depending on the type of salt in the cleaning solution, but it decreases as the concentration increases. Furthermore, the amount of input is 0.6Kg, 1.2Kg, and the air volume is 40m ³ /
Discrete treatment was carried out under the following conditions: temperature: 50° C., humidity: 15% RH, stirring blade tip speed: 2 m/sec, dispersion frequency: 170 times/min. FIG. 3 shows the case where the cleaning solution is saline, but as the concentration increases, a good discrete state cannot be obtained unless the discrete treatment is performed in the low water content range. The time required for the discrete treatment at this time tends to be shorter as the salt concentration of the cleaning liquid is higher, and it seems to be influenced by the initial water content during the discrete treatment, that is, the water content of cleaning and dehydration. When the salt concentration is around 4%, the seaweed tends to stick to the stirring blades and become tangled, resulting in poor yields.
% or less is preferable. From FIG. 3, the upper limit of the water content at the end of the discrete process to obtain a good discrete state is expressed as (400-33X)% when the salt concentration is X%. For other salt solutions, the only difference is that the slope is different from that of saline solution.
The salt concentration is multiplied by the conversion factor, and the salt equivalent concentration
If expressed as %, the upper limit of water content at the end of discrete treatment is expressed as (400-33X)%, as in the case of saline water.
Table 4 shows examples of conversion factors. Examples are shown below. Experiment 3 for both examples
A discrete treatment similar to that described above was carried out, but fresh water was used as the cleaning liquid in Example 1, and a 2% magnesium chloride solution was used in Example 2. At this time, the upper limit of the moisture content at the end of the discrete processing to obtain a good discrete state is 400% (400-33 x 2 x 0.88 = 342%). Example 1 1.2 kg of raw seaweed was washed with fresh water, centrifugally dehydrated, and then subjected to discrete treatment for 7 minutes to reach a water content of 372%. When this was freeze-dried in a vacuum, 200 g of good dried seaweed pieces could be obtained. Example 2 When 0.6 kg of raw seaweed was washed with a 2% magnesium chloride solution, dehydrated, and dispersed for 3 minutes, a good dispersed state was obtained as shown in the table below.

[Table] e Effects of the invention Since the treatment of the present invention increases the surface area of seaweed due to its loosening effect, it is expected to improve the efficiency of subsequent treatments such as vacuum freeze drying, drying treatment during hot air drying, freezing treatment, thawing treatment, etc. It is possible to shorten these processing times and save energy. Furthermore, if it is performed as a pre-drying treatment, a new form of dried seaweed can be created, which can be used to meet the diversification of consumption.

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【table】 [Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing an example of an apparatus for implementing the present invention. Figure 2 is a diagram showing the relationship between the salt concentration of the cleaning solution and the moisture content during dehydration of seaweed, and Figure 3 is a diagram showing the influence of the saline cleaning solution on the relationship between the moisture content at the end of the discrete process and the discrete state. . 1... Drum-shaped drying basket, 2... Rotating shaft, 3...
Stirring blade, 4...Dry air outlet.

Claims (1)

[Scope of Claims] 1. Raw seaweed mainly consisting of leaf pieces with a thickness of 30 μm or more is washed and dehydrated with a cleaning solution, and the seaweed leaves are dried in a dry atmosphere to a moisture content that does not cause mutual adhesion. A method for processing raw seaweed, characterized by performing a discrete process of separating the seaweed fronds from each other by applying an instantaneous blow to the seaweed fronds. 2. The method for processing raw seaweed according to claim 1, wherein the raw seaweed contains 90% or more of leaf pieces with a thickness of 30 μm or more. 3. The method for treating raw seaweed according to claim 1, wherein the cleaning liquid is fresh water, and the discrete treatment is performed until the water content reaches about 400%. 4. The method for treating raw seaweed according to claim 3, wherein the water content after washing and dehydration is 450 to 800%. 5. The method for treating raw seaweed according to claim 1, wherein the cleaning liquid is salt water containing 3% or less. 6. The method for treating raw seaweed according to claim 5, characterized in that when the concentration of the salt water is X%, the discrete treatment is performed until the water content reaches (400-33X)%. 7. The treatment of raw seaweed as set forth in claim 1, characterized in that the above-mentioned discrete treatment is carried out in an air-permeable container having a rotating horizontal axis equipped with stirring blades in a dry atmosphere while ventilation is provided inside the container. Method. 8. The method for treating raw seaweed according to claim 7, wherein the frequency of the discrete treatment is 40 times/min or more, and the stirring blade tip speed is 1 m/sec or more. 9. The method for processing raw seaweed according to claim 1, characterized in that the raw seaweed obtained by the above-mentioned discrete treatment is subjected to bulk drying treatment or freezing treatment.