JPH0249565A - Dry hizikia and production thereof - Google Patents

Abstract

PURPOSE:To obtain hizikia short in water-reconstituting time without impairing flavor and texture by introducing a pressurized carbon dioxide gas into a pressure vessel in which hizikia has been put to impregnate the hizikia with said gas followed by quick heating treatment. CONSTITUTION:A carbon dioxide gas is introduced into a pressure vessel in which hizikia has been put, and the in-vessel pressure is kept at >=15 (pref. >=25)kg/cm<2> to impregnate the hizikia with said gas followed by releasing the pressure and making a quick heating treatment (pref. at 200 deg.C for >=5-6sec), thus obtaining the objective dry hizikia.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to dried hijiki seaweed and a method for producing the same.

[Prior Art and Problems] Hijiki seaweed is known as a food containing a large amount of iodine. Iodine is one of the essential trace minerals for humans, and insufficient iodine intake reduces thyroid hormone synthesis and induces goiter.

By the way, many seaweeds such as Hijiki are distributed in a dried state and are also used as ingredients for instant foods. Foods used as ingredients for instant foods are usually prepared by freeze-vacuum drying or hot air drying. According to freeze-vacuum drying, the flavor is not lost,
Moreover, although excellent dried foods can be obtained in terms of ease of subsequent cooking, processing costs are very high, and the texture of the food is damaged, resulting in a loss of the original texture of the food.

On the other hand, the hot air drying method has a much lower processing cost than the freeze-vacuum drying method and causes less tissue damage, but the food obtained by this method does not require hot water rehydration or is difficult to rehydrate.
It is not suitable for use in instant foods that require reconstitution in hot water in a short period of time, such as cup noodles. In addition, if you do not reconstitute it with hot water or reconstitute it for a long time, the iodine contained in hijiki will be eluted into the water and will not be effectively ingested.

Therefore, an object of the present invention is to provide dried hijiki seaweed that does not impair its flavor and structure, and that does not lose its iodine content due to the short rehydration time, and a method for producing the same.

[Means for Solving the Problems] In order to solve the above problems, this invention puts Hijiki in a pressure vessel, introduces carbon dioxide gas into the pressure vessel, and maintains the carbon dioxide gas pressure at 15 kg/Cm" or higher. Impregnate Hijiki with carbon dioxide gas, release the pressure in the pressure vessel,
The present invention provides a method for producing dried Hijiki Hijiki characterized by subjecting the obtained Hijiki Hijiki impregnated with carbon dioxide gas to rapid heating treatment, and the dried Hijiki Hijiki obtained by this method.

This invention will be explained in more detail below.

In the method for producing dried Hijiki Hijiki of this invention, first, raw Hijiki Hijiki is put into a pressure vessel. As the raw material hijiki, commercially available dried hijiki can be used. It is desirable to adjust the moisture content of the raw Hijiki seaweed to 10 to 60% (on a dry basis, hereinafter the same applies to moisture), preferably 30 to 50%, before putting it into a pressure vessel. This moisture content adjustment is done by immersing raw hijiki in air with a humidity of 60% or more.
This can be conveniently carried out by storing for 0 hours or more, preferably overnight. If necessary, after spraying a predetermined amount of water onto the raw Hijiki seaweed for water content, the mixture may be stored for 10 minutes or more, preferably 30 minutes or more.

After the raw Hijiki seaweed whose moisture content has been adjusted in this way is placed in a pressure vessel, the pressure vessel is purged with carbon dioxide gas or evacuated, and then carbon dioxide gas is introduced into the pressure vessel and the carbon dioxide gas is introduced into the Hijiki tissue. Impregnate. In this invention, the carbon dioxide gas pressure during impregnation is set at 15 kg/Cm.
” carbon dioxide gas pressure is 25 kg
/ cm is particularly preferred. The holding time in this pressurized state is 5 minutes or more, preferably 10 minutes or more, although it depends on the carbon dioxide gas pressure. Needless to say, the temperature during carbon dioxide gas impregnation is a temperature at which carbon dioxide in the pressure vessel maintains a gas state. The pressure vessel used for carbon dioxide gas impregnation is equipped with a carbon dioxide gas inlet pipe, a discharge pipe, a hijiki inlet and an outlet, and can be sealed and withstand high pressure, as well as maintain the introduced carbon dioxide in a gaseous state. Temperature control means (
For example, any material can be used as long as it has a jacket).

After carbon dioxide gas impregnation is completed, the pressure in the pressure vessel is released, the carbon dioxide gas-impregnated hijiki is taken out, and it is subjected to rapid heating treatment. The rapid heat treatment can be carried out at a temperature of 100°C or higher, preferably about 200°C. For example, carbon dioxide gas-impregnated hijiki is treated for 5 to 6 seconds or less using a flash drying device in which a heat medium at the above temperature selected from air, water vapor, or a mixture thereof is circulated, and a tangential separator or the like is removed. Separate the hijiki from the air stream and take it out. Alternatively, rapid heating treatment can also be performed by heating with high frequency dielectric heating. The heating time depends on the output, but it is 600W.
In this case, it is 30 seconds or more.

In addition, after the Hijiki seaweed is taken out from the pressure vessel, it is desirable to subject it to rapid heating treatment within 5 minutes at room temperature, within as short a time as possible. However, the time can be extended at low temperatures; for example, when cooled to -20°C or lower, it can be extended to about 60 minutes.

In this way, dried hijiki is obtained.

By the way, the present inventors have found that from a sanitary point of view, it is desirable that the moisture content of the final Hijiki product is 10% or less. If the moisture content exceeds 10%, the hijiki will become discolored, rot, and shrivel due to the proliferation of microorganisms. By the way, if the water content of the Hijiki seaweed is directly reduced to 10% or less by the above-mentioned rapid heating treatment, the Hijiki may be carbonized (scorched) or the original flavor may be lost due to roasting. Therefore, the Hijiki seaweed subjected to the above rapid heating treatment was
The water content is reduced to 10 by subjecting it to hot air drying at 0℃ to 80℃.
% or less, preferably to a moisture content corresponding to a monomolecular adsorption layer. Incidentally, hijiki seaweed that has undergone the above-mentioned rapid heating treatment often has a water content of 15 to 35%.

[Example] Hereinafter, this invention will be explained in more detail with reference to Examples.

Example 1 Moisture content 7.1%, apparent density 1, 50 g/c
Spread 500 g of commercially available hijiki dried to m3 on a wire mesh,
It was stored in humidified air at a temperature of 20.0° C. and a relative humidity of 80% for 48 hours, and the moisture content was adjusted to 34.2%. Next, this hijiki was placed in a cylindrical basket made of all-wire mesh, and placed in a pressure vessel with an internal volume of 4 liters maintained at approximately 17°C by circulating a heat exchange medium inside the outer jacket, and carbon dioxide gas was introduced into the vessel for 50 minutes. It was pressurized to ``kg/cm''.

This condition was maintained for 20 minutes to impregnate carbon dioxide gas.

Thereafter, the pressure inside the container was released, and the carbon dioxide gas-impregnated hijiki was taken out. This was immediately supplied to a flash dryer in which a flow of superheated steam at 230° C. flows at a rate of 25 m/sec to heat and dry it, and after about 2 seconds, it was separated from the flow of superheated steam and the hijiki was taken out. This was further dried in hot air at 50°C until the moisture content was about 8%.

When the apparent density of the Hijiki thus obtained was measured by mercury porosimetry, a value of 0.38 g/cm3 was obtained, indicating that the Hijiki had swollen approximately four times as much as before treatment.

Approximately 100g of Hijiki after this treatment was boiled for a few seconds in boiling water at 90°C, drained, and then boiled in vegetable oil, cooked with dashi, sugar, and soybean oil, tasted by a panel of 10 people, and rehydrated in hot water. , the state of flavor was observed. In addition, for the raw Hijiki (Hijiki Hijiki) that was not subjected to the treatment of this invention (untreated Hijiki), we also compared the conditions of those that were rehydrated and cooked in the same way, and those that were rehydrated and cooked in water for 30 minutes as usual. Observed. As a result, the treated hijiki of this invention had good flavor and texture, and was also excellent in hot water reconstitution. On the other hand, untreated hijiki that had been rehydrated for 30 minutes had the same texture as the hijiki treated with the present invention, but the flavor was inferior, and hijiki that had been rehydrated in the same way as the hijiki treated with the present invention had a soft core. remained, and the texture was poor, both of which were inferior to the Hijiki Hijiki treated according to the present invention.

In addition, each of the above-mentioned treated Hijiki of the present invention and untreated Hijiki was weighed by tg, placed in a stainless steel wire mesh basket with a lid having an opening equivalent to 1 mm, and immersed in boiling water at 97°C.
The adhering water was centrifugally dehydrated at 600 rpm and 60 G for 1 minute, its weight was measured, and the time required to soak it in boiling water for the weight to increase four times its original weight was determined. and 1.50 for untreated hijiki
Furthermore, the above-mentioned Hijiki Hijiki treated according to the present invention and untreated Hijiki Hijiki were placed in stainless steel wire mesh baskets with lids, immersed in boiling water at 97°C for 1 minute and 3 minutes, and then tasted by 15 expert panelists. The result is A, which has no core and has a good texture.
, B for those with a slight core remaining, C for those with a core remaining and poor chewability, and D for those with a core remaining and difficult to chew.

As a result, when the present invention-treated Hijiki seaweed was rehydrated in hot water for 1 minute, B.
It was A when it was rehydrated for 3 minutes. On the other hand, untreated Hijiki was graded D when rehydrated in hot water for 1 minute, and B when rehydrated in hot water for 3 minutes.

Experimental example: After three healthy male adults ate low iodine food for two days,
At breakfast (9 a.m.) on the third day, I ate 50 g of cooked hijiki. After that, while eating low iodine foods for 2 days, after eating cooked hijiki,
Urine was collected for five periods from 24 to 36 hours and from 36 to 48 hours, and the amount of iodine in the urine was determined to determine the amount of iodine absorbed by the human body. The results are shown in Figure 1.
The cooking method was as follows: Hijiki treated according to the present invention (Example 1) was massaged and washed in lukewarm water for a few seconds and then cooked (Iodine content: 5301Lg/g after rubbing;
662 pg). For untreated Hijiki, it was soaked in water for 30 minutes and then cooked (Iodine content: 440IL after soaking in water)
g/g, 2g/g/g after cooking (42g/g/50g). (The iodine content of untreated Hijiki itself is 540 Ii, g/g).

From the above, it has become clear that compared to untreated Hijiki Hijiki, Hijiki Hijiki treated with the present invention has less iodine leached out when rehydrated in hot water, has a high iodine content in cooked products, and is highly absorbed into the human body.

Example 2 Under the conditions shown in Table 1 below, raw Hijiki seaweed having the water content shown in the same table was impregnated with carbon dioxide gas, rapidly heated, and dried with hot air, and the moisture content, swelling rate, and Condition of reconstitution (according to evaluation in Example 1)
was measured. The results are shown in the same table. The swelling ratio is the quotient obtained by dividing the density of the treated Hijiki seaweed by the mercury intrusion method by the density of the raw Hijiki seaweed obtained by the mercury intrusion method.

[Effects of the Invention] As described above, the present invention provides dried hijiki that does not impair the flavor and structure, and that can be rehydrated in hot water or rehydrated in a short period of time, resulting in less loss of iodine, and a method for producing the same. Ru.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the amount of urinary excretion of iodine when ingesting dried hijiki of the present invention compared to that of untreated hijiki. System suitable time (Figure (time)

Claims (2)

[Claims] (1) Place the Hijiki in a pressure vessel, introduce carbon dioxide gas into the pressure vessel, and increase the carbon dioxide gas pressure to 15 kg/cm^2.
A method for producing dried Hijiki Hijiki, which comprises impregnating Hijiki Hijiki with carbon dioxide gas while maintaining the above conditions, releasing the pressure in a pressure vessel, and subjecting the obtained Hijiki Hijiki impregnated with carbon dioxide gas to rapid heating treatment. (2) Dried hijiki obtained by the method according to claim 1.