JPS647603B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for efficiently producing carrageenan containing countercation species from red algae. More specifically, before extracting red algae using a conventional method, the acid treatment is repeated and then neutralized and extracted with an alkali containing the desired countercation species to easily produce carrageenan prepared with the desired countercation species. The goal is to provide a way to do so. Carrageenan is a sulfated galactan contained in red algae, and is used in a wide range of fields including the food industry due to its unique gelling ability and viscous protein reactivity.
The red algae include, for example, Chondrus crispus, Gikarteina, Euchyuma kotonii, Euchyuma spinosum, and the like. Carrageenan is produced by extracting, filtering, dehydrating, drying and pulverizing these red algae with neutral to slightly alkaline hot water. Carrageenan has a molecular weight ranging from tens of thousands to hundreds of thousands, but is generally classified into three types based on its chemical structure: κ, λ, and ι, each with unique characteristics such as gelation ability, viscosity, water solubility, and protein reactivity. have a property. In other words, κ carrageenan has the highest gelling ability but does not dissolve in cold water, whereas λ carrageenan has no gelling ability and dissolves in cold water. ι Carrageenan has properties intermediate between the two, with weak gelling ability and swelling in cold water. These differences in properties are due to differences in the 3,6-anhydrogalactose content and the number of sulfate groups in the chemical structure of carrageenan.
However, the above properties vary depending on the cation species bonded to the sulfate group. In other words, for example, the potassium salt of κ-carrageenan, in which potassium ions are bound to the sulfate groups, is soluble in hot water, showing the greatest gelling ability, but is insoluble in cold water, whereas the sodium salt shows no gelling ability. Ammonium salts, calcium salts, and magnesium salts are soluble in cold water, and exhibit intermediate properties between the potassium salts and sodium salts. The calcium salt of κ-carrageenan is extremely important from the point of view of protein reactivity. In other words, in order to complete the reaction between carrageenan and protein in a PH (hydrogen ion concentration) range above the isoelectric point of the protein, the coexistence of polyvalent cations such as calcium ions is required. In the case of ι-carrageenan, calcium salts show the greatest gelling ability and are soluble in hot water but swell in cold water, whereas sodium salts do not show gelling ability and dissolve in cold water, while ammonium salts, potassium salts , magnesium salt exhibits intermediate properties between the above calcium salt and sodium salt. The calcium salt of ι carrageenan is extremely important from the point of view of protein reactivity, as in the case of κ carrageenan. In this way, carrageenan has extremely different properties depending on the counter cation species, and furthermore, by supplying various cation species from the outside, its physical properties change more widely, and the range of uses of carrageenan is greatly expanded. , control of the countercation species is very important. On the other hand, in other words, controlling the counter cation species is important in controlling the physical properties of carrageenan extracted from red algae within a certain range.
In other words, it is necessary to suppress the breakdown of countercation species within a certain range. Based on the above two requirements, the present invention provides an extremely effective method that makes it possible to efficiently produce carrageenan that has a sulfate group bonded to a desired cationic species.
In other words, it has the advantage that it is extremely easy compared to conventional methods, and does not have an adverse effect on filtration, etc., unlike ion exchange using carbonates. The key point is to process red algae, which has been washed with water as necessary, with an acid having an appropriate concentration under appropriate conditions to produce acid-type carrageenan, and then to prepare an alkaline carrageenan containing the desired cationic species. The method consists in neutralizing the algae with a substance and then extracting it with hot water using a conventional method. Generally, carrageenan has no resistance to acidity.
At pH 5 or lower, the viscosity rapidly decreases to the point where gelation does not occur, and this tendency is said to be particularly pronounced in κ-carrageenan. However, as a result of various studies, it has been found that by appropriately selecting conditions, the above-mentioned deterioration phenomenon can be reduced to a practically negligible level even under extremely high concentration of strong acid. At this time, it is an extremely important feature of the present invention to obtain carrageenan in the algae in the acid form. In other words, for 1 part by weight of red algae used for extraction,
The carrageenan contained in red algae is obtained by repeating the acid treatment 1 to 10 times, which consists of adding 5 to 20 parts by weight of an acid aqueous solution having a specified concentration of 0.005 to 0.1 and contacting it for 5 to 30 minutes at a temperature below 30°C. is converted to the acid form. Acids used in the acid treatment include hydrochloric acid, nitric acid,
Inorganic acids such as phosphoric acid and sulfuric acid, and organic acids such as acetic acid can be used in combination. Hydrochloric acid, nitric acid, and acetic acid are preferred. The concentration and amount of the acid aqueous solution should be selected from a range that is necessary to elute and remove the counter cation originally bound to carrageenan in red algae and that does not cause a decrease in the molecular weight of carrageenan, and the concentration is 0.005 as described above. The appropriate amount is 5 to 20 parts by weight per 1 part by weight of the red algae to be extracted. The most important point among the processing conditions is temperature. In other words, since carrageenan undergoes rapid hydrolysis in an acidic atmosphere at high temperatures, it is necessary to treat it at as low a temperature as possible, preferably at a temperature of at least 30°C. The treatment time depends on the method of contact between the acid aqueous solution and the algae, but in terms of the efficiency of converting carrageenan into acid form, after a short treatment time, the treatment solution is removed, a new acid aqueous solution is supplied, and the same treatment is repeated. This is desirable.
Therefore, as mentioned above, the treatment for 5 to 30 minutes is performed for 1 to 10 minutes.
selected from the processing condition range to be performed twice. As a result of the acid treatment, the carrageenan contained in the red algae has a very highly acidic structure, and the reduction in molecular weight can be virtually ignored. Therefore, by neutralizing the treated red algae with an alkaline substance containing the desired cation, it is possible to easily adjust the counter cation of the carrageenan contained in the red algae to a high degree of the desired cation type. . That is, for example, when the potassium salt of carrageenan is the objective, the alkaline substance used for neutralization can be selected from potassium hydroxide, potassium carbonate, potassium acetate, and other potassium salts of weakly acidic acids. Since extraction is generally carried out at high temperatures of 60°C or higher, neutralization prior to extraction is necessary to at least reduce the pH.
It is necessary to make it 6.0. It is clear that it is undesirable for the pH of the finally produced carrageenan product to be too high, and it is desirable that the pH after neutralization be at least 12 or less. After such neutralization, it is subjected to extraction by a conventional method, passes through a filtration step, is appropriately dehydrated as required, and is subjected to a drying and pulverizing step to obtain powdered carrageenan. When subjected to the treatment according to the present invention, the cations of carrageenan are extremely highly ordered, so that the physical properties of the produced carrageenan product have very little variation. The present invention will be specifically described below based on Examples. Example 1 1 part by weight of Euchyuma cotoni was washed with water, 60 parts of water was added, the pH was adjusted to 8.0 with potassium hydroxide, the mixture was stirred, extracted and filtered at 70°C, precipitated with isopropanol, and dried and ground to obtain carrageenan powder. (Sample A) On the other hand, after washing with water in the same manner as above, Euchyuma kotoni is immersed in 40 parts of 0.07N hydrochloric acid aqueous solution at 15°C for 15 minutes, the liquid is removed, and a new hydrochloric acid aqueous solution under the same conditions is added and immersed in the same manner. 20 after repeating 4 times
of water, neutralized with potassium hydroxide, pH 8.0, extracted, filtered, precipitated, dried, and crushed in the same manner as Sample A to obtain carrageenan powder. (Sample B) The results of chemical analysis and physical measurements of Samples A and B are shown in Table-1.

[Table] Example 2 After washing 1 part by weight of Yukiyuma spinosam with water,
After stirring and extracting at 70°C, the mixture was precipitated with isopropanol and dried and ground to obtain carrageenan powder. (Sample C) On the other hand, euchyuma spinosum after washing with water as above is immersed in 30 parts of 0.03N hydrochloric acid aqueous solution at 15°C for 10 minutes, then the liquid is removed, a new 0.03N hydrochloric acid aqueous solution is added and immersed in the same manner. After repeating the treatment three times, add 15 parts of water and neutralize with sodium hydroxide to pH 8.2.
This was extracted, filtered, precipitated, dried, and crushed in the same manner as Sample A to obtain carrageenan powder. (Sample D) The results of chemical analysis and physical measurements of Samples C and D are shown in Table 2.

[Table] Sample D dissolved in cold water and did not gel, exhibiting the properties of a sodium salt of iota-carrageenan.

Claims (1)

[Claims] 1 5 to 20 parts by weight per 1 part by weight of red algae
The process of adding 0.005 to 0.1 normal acid aqueous solution and soaking for 5 to 30 minutes at a temperature below 30°C is repeated 2 to 10 times, and the red algae are neutralized with an alkaline substance containing the necessary cationic species to reach a pH of 6. 1. A method for producing carrageenan with a counter cation species, which comprises extracting the alkaline substance with hot water of 0 to 12.0.