JP3145172B2 - Novel high melting point agarose type agar and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel high melting point agarose type agar having a high melting point and a method for producing the same.

[0002]

2. Description of the Related Art Agar has long been known as a food and is a substance mainly composed of polysaccharides extracted from seaweeds of red algae. The chemical structure of agar is mainly composed of agarose consisting of repeating α-1,3 bonds of agarobiose residues consisting of D-galactose, which is β-1,4 binding to 3,6-anhydro-L-galactose, and agarobiose residues. It consists of agaropectin to which sulfuric acid and pyruvate are bound. Among them, D-galactose which is partially methylated to form 6-methyl-D-galactose is also known, and a red alga Amixa (scientific name: Ceramium boydeni) is known.
In the agarose extracted from i), D-galactose vs. 6
There is an example in which the ratio of -methyl-D-galactose is 3 to 2. On the other hand, 30% of 3,6-anhydro-L-galactose is methylated to give 2-methyl-
3,6-Anhydro-L-galactose is found in agarose extracted from the red alga Fujimatsumo (scientific name: Rhodomela larix). However, those in which the degree of methylation of the constituent sugars exceeds 50% are not yet known. Agar is extracted and produced from various red algae seaweeds,
The extraction temperature is usually 70-100 ° C, and rarely 100-1 ° C.
The extraction may be performed in a temperature range of 20 ° C.

[0003]

When a food made by gelling agar such as bean or tocorotene is to be stored for a long period of time, at present, a temperature at which the gel does not re-dissolve at a temperature of about 80 ° C. Sterilization is taking place. However, sterilization at a low temperature requires long heating to ensure the sterilization effect. Agarose purified from agar is also widely used as a support for electrophoresis as a means for studying proteins and nucleic acids. However, it is desirable that agarose contain a small amount of acidic sulfate groups in its structure. It is rare. For this reason, in the production of current agarose for electrophoresis, a treatment for removing the sulfate group is required. Therefore, the present invention provides a novel high melting point agarose-type agar which can be sterilized by heating at a high temperature for a short period of time and has a very low content of sulfate groups and which can be used for high-quality electrophoresis, and easily produces the agar. It is an object to provide a manufacturing method which can be performed.

[0004]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and in the process, the red alga seaweed Ryukyu ogonori in the first stage was 95%.
Hot water extraction at a temperature of １００100 ° C .;
It has been found that the two-stage hot water-extracted agar having a hot water extraction at a temperature of 40 ° C. has a high melting point. The novel high melting point agarose-type agar according to the present invention comprises 6-methyl-D-galactose bound at the 1,3-position and 2-methyl-3,6-anhydro-L-galactose bound at the 1,4-position. Methylated agarose alternately repeated, or mainly composed of this methylated agarose and agaropectin other than the methylated agarose, wherein the ratio of the methylated agarose is in the range of 90 to 100% by weight based on the total weight. Features.

The agar protozoa used for producing the novel high-melting-point agarose-type agar according to the present invention is a red algae marine algae, and among them, particularly preferred is a species of Ryukyu ogonori (Science: Gracilaria eucheumoides). It is. In order to produce the above-mentioned novel high-melting-point agarose-type agar according to the present invention using the agar protoalga, first, the agar protozoa as a raw material is washed with water at normal temperature (10 to 30 ° C.) for 5 to 24 hours. Thereby, water-soluble salts are removed. Then 9
Agar I is obtained by extracting with hot water at 5 to 100 ° C, preferably 100 ° C, and dehydrating and drying the filtrate. Agar II obtained by extracting the extraction residue of agar I with hot water at 110 to 140 ° C. and dehydrating and drying the filtrate is the novel high melting point agarose type agar according to the present invention. The novel high melting point agarose type agar II according to the present invention has an extremely low sulfate group content of 0.5 to 1.2%.

The physicochemical properties of the novel high melting point agarose type agar II according to the present invention obtained by the above method are as follows. (1) Elemental analysis value Measurement value: C: 46.5%, H: 7.4%, O: 45.7% Theoretical value: C: 50.3%, H: 6.6%, O: 43.1% (2) Average molecular weight 650,000 (TSK-Gel Gel filtration by PW-5000-XL and pullulan are used as standard.) (3) Infrared absorption spectrum The infrared absorption spectrum is shown in FIG. Using JASCO IRA-2, KBr tablet method (1mg
/ 200mgKBr). (4) Ultraviolet absorption spectrum Shown in FIG. Using Hitachi 220S, concentration 0.6%, cell length 1
Measured at 0 mm and at a temperature of 60 ° C (after melting at 121 ° C). (5) Color reaction The color reaction of ordinary neutral sugars (phenol sulfate method [M. Duboi
s et al., Analyt. Chem., 28, 350 (1956)], anthrone sulfate method [R. Dreywood, Ind. Eng. Chem., 18, 499 (194
6)]) and color reaction to 3,6-anhydrogalactoses (resorcinol sulfate method [W. Yaphe, Analyt.
Chem., 32, 1327-308 (1960)]). (6) Color of substance Colorless (7) ¹³ C-NMR spectrum Shown in FIG. Measured using a Varian XL-200 under the conditions of a sample: 2% solution (D ₂ O), temperature: 80 ° C. (8) Structural formula FIG. 6-O-methyl-D- bonded at the 1,4-position
2-O- bonded to the galactopyranose residue at the 1,3-position
A structure in which methyl-3,6-anhydro-L-galactopyranose residues are alternately repeated. (9) Types and composition ratios of constituent components are shown in Table 1. The qualitative analysis of sugar was carried out by derivatizing the hydrolyzate of this product into alditol acetate and performing gas chromatography and mass spectrometry. The quantification was performed by adding glucose as an internal standard. The sulfate group content was determined by the rhodizonic acid method [T. TTerho and K. Hartiala, Anal.
m., 41, 471 (1971)].

[0007]

[Table 1]

[0008]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. Example 1 1 kg of red algae seaweed Ryukyu ogonori was placed in a container large enough to soak the alga body, and washed overnight while continuously flowing tap water. After draining, 5 l of hot water was added and heated. After boiling, heating was continued for 30 minutes. Filtration with gauze gave filtrate IA. 5 l of hot water was added to the filtration residue, and the mixture was heated again. After boiling, heating was continued for 30 minutes. Filtration with gauze gave filtrate IB. 5 l to the obtained filtration residue
Was added to a high-pressure steam kettle and heated at 120 ° C. for 30 minutes under pressure. After the temperature dropped to 100 ° C., it was taken out of the kettle and filtered with gauze to obtain a filtrate IIA. 5 l of hot water is added to the filtration residue, and the mixture is put into a high-pressure steam kettle.
After heating under pressure at 20 ° C. for 30 minutes, it was taken out of the kettle and filtered with gauze to obtain a filtrate IIB. Then filtrate IA
The filtrate IB was combined with the filtrate IB to obtain a filtrate I, which was frozen, thawed, and dehydrated with a filter cloth. This is freeze-dried and
g of agar I was obtained. The filtrate IIA and the filtrate IIB were combined to give a filtrate II, which was frozen, thawed, dehydrated with a filter cloth, and freeze-dried to obtain 20 g of agar II.

[0009] 1 g of agar II obtained through the above process is added to 100 g
After suspending in 120 ml of water and dissolving it by pressurizing and heating at 120 ° C. for 20 minutes, the mixture was poured into a cylindrical mold, cooled and gelled, and cut into a cylindrical shape having a height of 17 mm. This was put into a beaker containing boiling water maintained at 99 to 100 ° C. by hot water bath, and the change in the form was observed. As a comparative control, a commercially available high melting point agar which is considered to have the highest gel melting point was melt-molded in the same manner, boiled in the same conditions, and observed for changes in form. Table 2 shows the results.

[0010]

[Table 2]

Example 2 The shape of the gel of agar II listed in Example 1 was extruded with a tocorotene extruder to form a tocorotene, and the change was observed under the same boiling conditions. As a result, the tocorotene-like gel of Agar II maintained its original shape until 60 minutes later.

Example 4 50 g of the agar II tocorotene-like gel described in Example 2 was placed in a bowl, and 250 ml of boiling broth was poured into the bowl to make a tocorotene-containing soup. At this time, the tocorotene did not melt or lose its shape, and a soup with a texture unique to agar was formed.

[0013]

As described in detail above, the novel high melting point agarose-type agar according to the present invention has a higher gel dissolution temperature than conventional agar, so that agar such as tocorotene and honey bean can be obtained. In the case of heat sterilization for the purpose of preserving food made by gelling for a long time, it is possible to heat at higher temperature, not only to improve efficiency by shortening the sterilization time, but also to preserve by increasing the sterilization effect This has the effect of extending the period. In addition, foods made by gelling agar have conventionally been usually cooled and eaten. However, if the novel high melting point agarose-type agar according to the present invention is used, the above-mentioned tocorotene can be used as a soup, a cooking pot, etc. It can be used for hot dishes. Furthermore, by using the feature that the components of the novel high melting point agarose-type agar according to the present invention have an extremely small number of sulfate groups, they can be used as a support for electrophoresis as a means for studying proteins and nucleic acids. Thus, the electrophoresis operation at a higher temperature than before can be performed. The industrial value of the present invention having such various advantages is very large.

[Brief description of the drawings]

FIG. 1 is a view showing an infrared absorption spectrum of agar II produced in Example 1.

FIG. 2 is a view showing an ultraviolet absorption spectrum of agar II produced in Example 1.

FIG. 3 is a view showing a ¹³ C-NMR spectrum of agar II produced in Example 1.

FIG. 4 shows a 6-O-methyl-D-galactopyranose residue bonded at the 1,4-position of agar II prepared in Example 1 and 1,
2-O-methyl-3,6-anhydro- bonded at the 3-position
1 is a structural formula of a structure in which L-galactopyranose residues are alternately repeated.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) A23L 1/337 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A 6-methyl-D-galactose bonded at the 1,3-position and a 2-methyl-3,6-bonded at the 1,4-position.
Anhydro-L-galactose alternately repeats methylated agarose, or is mainly composed of the methylated agarose and the agaropectin other than the methylated agarose, and the ratio of the methylated agarose is 90 to 100.
A novel high melting point agarose-type agar characterized in the range of weight percent. 2. A method for producing a novel high-melting-point agarose-type agar, which comprises extracting hot water from agar algae at a temperature of 95 to 100 ° C. and then extracting the residue with hot water at 110 to 140 ° C. . 3. The method for producing a novel high-melting-point agarose-type agar according to claim 2, wherein the agar-producing algae is a red alga, Ryukyu ogonori (scientific name: Gracilaria eucheumoides).