WO2011155352A1

WO2011155352A1 - Highly viscoelastic and highly strong agar, and method for producing same

Info

Publication number: WO2011155352A1
Application number: PCT/JP2011/062319
Authority: WO
Inventors: 敬祐前川; 中村　彰宏
Original assignee: 不二製油株式会社
Priority date: 2010-06-07
Filing date: 2011-05-30
Publication date: 2011-12-15
Also published as: ES2422531R1; CN102917607B; KR20130086529A; JP5196075B2; ES2422531A2; JPWO2011155352A1; CN102917607A; ES2422531B1

Abstract

Disclosed is a method for producing an agar that is also provided with a high rupture strength even while having a high viscoelasticity that has not been obtained in conventional agars. By performing an extraction operation from an agar source seaweed under certain alkalinity conditions and temperature conditions, an agar was obtained that was also provided with a high rupture strength even while having a high viscoelasticity that has not been obtained in conventional agars.

Description

High viscoelastic and high strength agar and method for producing the same

The present invention relates to agar having high viscoelasticity but also having high breaking strength, and a method for producing the same.

Agar has long been known as a food, and its main chemical structure is a structure in which D-galactose and 3,6-anhydro-L-galactose are repeated. In addition, it is said that there is a slight change in a part of the structure, and there are cases where esterified sulfuric acid is contained in a small amount (Non-patent Document 1). The raw material for agar is algae such as Gelidium, Pterocladia, Gracilaria, Ahnfeltia plicata, etc., which are used alone or in a blend of two or more. .
As an example of agar production, first agar algae are washed with water, extracted with hot water at 70-120 ° C for 1-2 hours in the presence of acids such as acetic acid, sulfuric acid and hydrochloric acid, and then coagulated. Extract the sol component with the property. And it filters so that an extraction component and an insoluble matter may be isolate | separated with a high temperature state. Next, the filtrate is cooled and gelled, and the gelled extracted component is freeze-thawed and dehydrated by filter pressing. Further, the water is removed from the extracted components using a centrifuge or the like, and the mixture is dried.

In general, it is rarely carried out in the genus Genus, Opera and Catania, but in the genus Oronori, a few percent to 20% by weight, usually 4 to 10% sodium hydroxide is used as a pretreatment for hot water extraction. Gelling ability is enhanced by alkali treatment with an alkali agent at 10 to 120 ° C. for 0.5 to 16 hours (Patent Document 1). However, the agar algae after alkali treatment are washed with water, then acid-treated, and then boiled and extracted near neutrality. Use components extracted during alkali treatment, or extract in an alkaline state. There is no suggestion.
For example, Patent Document 2 discloses an application that describes the extraction of agar with alkalinity. Here, it is described that “wet algal bodies are obtained by adjusting the pH to 7 to 9, and agar is extracted from the wet algal bodies”. However, there is no description regarding extraction at a higher pH.

JP 7-184608 A Japanese Patent No. 2844065

An object of the present invention is to provide an agar that has high viscoelasticity and breaking strength that is not found in conventional agar and can be used for a wider range of applications, and a method for producing the same.

In order to solve the problems, the inventor has intensively studied the production conditions of agar. As a result, the present inventors have found that the components extracted from agar algae under specific alkaline conditions contain components that can impart high viscoelasticity and breaking strength to agar.
That is, the present invention
(1) Agar having a breaking strength at 20 ° C. of 1000 g / cm ² or more and a breaking distance of 3.3 mm or more in a cylindrical 1.5 wt% gel having a diameter of 22 mm and a height of 18 mm.
(2) The method for producing agar according to (1), wherein the agar is extracted from agar algae at a pH of 10 to 13.5 by heating at 70 to 135 ° C. and then dried.
(3) A food or drink containing the agar according to (1).
(4) A gelling agent containing the agar according to (1).
(5) A dispersion stabilizer containing the agar according to (1).
It is about.

ADVANTAGE OF THE INVENTION According to this invention, the agar characterized by having high fracture strength while having the outstanding viscoelasticity can be obtained easily.

1. Preparation of agar algae Various agar algae can be used in the present invention. The agar algae referred to in the present invention is a seaweed that is a raw material for agar, and examples thereof include red algae. Among the red algae, the genus Tengusa, Obakusa, Yuikiri, Ogonori, Saimi, Igis, and Egonori are preferable, and the Tengusa is particularly preferable. This is due to the large breaking strength in the extracted agar in the genus Amaranthus. The agar algae may be in either a wet or dry state, but agar with higher breaking strength tends to be obtained by drying and crushing. In addition, before using as a raw material, operation, such as washing | cleaning and removing a contaminant etc., can be suitably performed as needed.

(Opinion for alkali treatment)
In the conventional technique, “alkaline treatment” may be performed as a pretreatment on agar algae before extraction. For example, according to Eiichi Nishide's “Seaweed Industry” (http://wwwsoc.nii.ac.jp/jsp/pdf-files/38SeaweedIndustry.pdf (P124) as of March 29, 2010) As a result of research by Yoshio Funaki and Yoshio Kojima at the university, treatment of ogonori in 1.5-2% sodium hydroxide solution at 90 ° C for 3-4 hours leads to 3,6-anhydro-L-galactose of galactan sulfate. It has been found that a conversion reaction occurs, and the gel strength has been dramatically improved. "
However, in the present invention, “alkali treatment” in the pre-extraction stage is not necessary. Moreover, although the raw material which performed "alkali treatment" can also be used, the influence of the "alkali treatment" in a final product was not able to be confirmed. That is, even if the “alkali treatment” is performed as a pretreatment, there is almost no influence on the “gel strength” (breaking strength) and the breaking distance in the final product.
In both Patent Document 1 and the above-mentioned “Seaweed Industry”, the alkali solution is discarded after the alkali treatment as a pretreatment of the raw material. That is, “alkaline treatment” as referred to in Patent Document 1 and “seaweed industry” is a process from immersing agar algae into an alkaline solution to removing the alkaline solution. In the present invention, the term “alkali treatment” refers to a method of finally removing the alkali solution.
Such “alkali treatment” is different from the extraction under alkaline conditions performed in the present invention, and the resulting agar has completely different properties. That is, in the extraction under alkaline conditions of the present invention, it is assumed that a phenomenon different from the conventional “alkali treatment” occurs.

2. Extraction of Agar Extraction of agar in the present invention is as follows. The alkaline aqueous solution is 10 to 300 times, more preferably 20 to 200 times that of the agar algae. If the amount of the aqueous alkaline solution for the agar algae is too small, the amount of agar remaining in the agar algae residue may increase in one extraction, while if the amount of the alkaline aqueous solution for the agar algae is too large, Extra energy may be required for subsequent drying.
Examples of the alkali agent used in the present invention include sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium hydrogen carbonate, and ammonia. Among these, sodium hydroxide, potassium hydroxide, water Calcium oxide is preferred, and sodium hydroxide is more preferred. By using such a “preferable alkali agent”, the target pH can be easily realized.

The pH at the time of extraction is in the range of 10 to 13.5, more preferably 10.5 to 12.5, and even more preferably 11 to 12.5. When the pH at the time of extraction is too low, a product having sufficiently high viscoelasticity and breaking strength may not be obtained. Moreover, when pH is too high, a yield may fall.
The concentration of the alkaline agent to be used is preferably 5 to 300 mM, more preferably 10 to 250 mM. If the alkali concentration is too high, the pH of the product may be high, or if neutralized, the salt concentration of the product may be high. If the alkali concentration is too low, the pH may be outside the target range during extraction.

The temperature at the time of extraction is 70 to 135 ° C, more preferably 100 to 135 ° C, and further preferably 105 to 130 ° C. If the temperature is too low, the extraction efficiency may decrease. Even if the temperature is too high, the improvement effect such as extraction efficiency is often limited.
The extraction time is desirably 1 to 50 hours, more desirably 1 to 20 hours, and further desirably 5 to 20 hours. If the extraction time is short, the active ingredient may not be sufficiently extracted. If the extraction time is too long, production efficiency may be affected.

3. Post-extraction treatment After extraction, it is desirable to separate agar components by diatomaceous earth, screen filter, filter press, centrifugation, etc. under high temperature conditions that do not form a gel. At this time, the separation property can be improved by adding a filter aid such as cellulose powder before or after the extraction as necessary. The clear agar liquid obtained here can be dried and powdered by various methods. Specifically, natural freeze-drying, freeze-thaw dehydration by mechanical freezing can be given, and after gelation, press dehydration by a filter press, or drying after insolubilization with a hydrophilic organic solvent (preferably ethanol etc.), or directly Powdering can also be performed after freeze-drying and drum-drying the gel.
In order to improve the color tone of the agar obtained, bleaching with various bleaching agents generally used for raw algae, extract filtrate, or agar, preferably sodium hypochlorite, hydrogen peroxide, bleaching powder is performed. It is also possible.

The gel properties of the agar produced by this method are agar showing a new texture in which the relationship between the breaking strength and the breaking distance is clearly different from the region exhibited by conventional natural agar and industrial agar. Desirable physical properties include a breaking strength of 1000 g / cm ² or more and a breaking distance of 3.3 mm or more in a cylindrical 1.5 wt% gel (20 ° C.) having a diameter of 22 mm and a height of 18 mm, more preferably The breaking strength is 1100 g / cm ² or more, the breaking distance is 3.5 mm or more, and further desirable physical properties are a breaking strength of 1200 g / cm ² or more and a breaking distance of 4 mm or more. The breaking strength and the breaking distance shown here are measured by the method described in the examples.

In order for other agar to obtain the same breaking strength as the product of the present invention, it is necessary to prepare a gel at a very high concentration. However, even if the breaking strength can be increased thereby, the breaking distance as in the present invention cannot be obtained at the same time. That is, the product of the present invention has obtained elasticity that cannot be obtained by ordinary agar even with the same breaking strength. Thus, it can be used as a dispersion stabilizer for cocoa beverages and the like in which carrageenan and cellulose have been used. Moreover, it can be used as a jelly drink or a liquid food as a thickening polysaccharide substitute. In addition, it can be used widely from those requiring elasticity such as jelly to livestock and marine products such as desserts, sausages and wieners with a crisp and preferable texture unique to agar.

Furthermore, use in the form of konjac and noodles, which was difficult with conventional agar, is also possible. For use as these dispersion stabilizers and gelling agents, not only agar of the present invention alone, but also starch, dextrin, cellulose, carrageenan, ferreran, guar gum, locust bin gum, tamarind seed polysaccharide, tara gum, gum arabic, gum tragacanth, It can also be used in a mixed system, that is, in a formulation, in which polysaccharides such as karaya gum, pectin, xanthan gum, pullulan and gellan gum, or proteins such as milk protein and soy protein, and a fraction thereof are combined.
Hereinafter, the present invention will be described more specifically by way of examples and comparative examples.

Study 1 Examination Examples 1 to 8 of extraction temperature
A total of 700g was added to 31.6mM sodium hydroxide aqueous solution to 7.0g of dried proboscis algae collected along the coast of Kyushu. The pH at this time was 12.3. Thereafter, pressure extraction with an autoclave (HICLAVE HV-50, HIRAYAMA) was performed for 4 hours at each temperature shown in Table 1 (no pressure was applied when extracting at 100 ° C. or lower). After the extraction treatment, the insoluble matter was removed by filtration through filter paper while maintaining the temperature at 60 ° C. or higher to obtain a clear agar liquid. After this agar solution was frozen and thawed, the precipitate obtained by centrifugation was collected and dehydrated. Then, after drying by air drying, it was pulverized to obtain agar. The obtained agar was evaluated by the following “measurement of gel breaking strength and breaking distance”.
Table 1

"Measurement of gel breaking strength and breaking distance"
Each powdered agar was suspended in distilled water to a concentration of 1.5% by weight and then dissolved in an autoclave (120 ° C., 10 minutes).
After being allowed to solidify at 20 ° C. for 15 hours, the test was carried out with an Instron at a rate of 30 mm / min with a cylindrical (φ10 mm) plunger (cylindrical shape with a test piece diameter of 22 mm and a height of 18 mm). The stress required for breaking was defined as breaking strength (gf). The length distorted until the break was taken as the break distance (mm). In addition, the measured value took the average of three points.

The measurement results of the breaking strength and breaking distance of the gel are also shown in Table 1.
As shown in Table 1, agar showing sufficient breaking strength and breaking distance was obtained in the extraction temperature range of 70 to 135 ° C.

Study 2 Examination Examples 9 to 11 and pH 1 to 3
After adding 700 ml of distilled water to 7.0 g of the same algae genus algae as in Study 1, it was adjusted to each pH shown in Table 2 with 0.3 N hydrochloric acid or 0.25 N sodium hydroxide, and autoclaved at 120 ° C. for 4 hours. Pressurized extraction with (HICLAVE HV-50, HIRAYAMA) was performed. After the extraction treatment, the insoluble matter was removed by filtration through filter paper while maintaining the temperature at 60 ° C. or higher to obtain a clear agar liquid. After this agar solution was frozen and thawed, the precipitate obtained by centrifugation was collected and dehydrated. Then, after drying by air drying, it was pulverized to obtain agar.
The obtained agar was evaluated according to “Measurement of breaking strength and breaking distance of gel” shown in Study 1.
The evaluation results are shown in Table 2.
Table 2

As shown in Table 2, agar showing sufficient breaking strength and breaking distance was obtained when the pH during extraction was in the range of 10 to 13.5.

Study 3 Comparison with Existing Products The product “Yamato” marketed by Ina Foods Co., Ltd. as a super high viscoelastic agar, the reagent “Agar” manufactured by Wako Pure Chemical Industries, and the sample of Example 8 of the present invention are examined 1 The measurement was performed in the “Measurement of Breaking Strength and Breaking Distance of Gel” described, and the compression displacement at each compression load was graphed. The results are shown in Figure 1. In each graph, the fracture occurred at the peak point, and the compressive load at this point was called the breaking strength, and the compression displacement at this point was called the breaking distance.
As shown in FIG. 1, the agar of the present invention showed higher breaking strength than that of the conventional product, but its compressive displacement was as large as that of agar commercially available as “ultra-high viscoelastic agar”.
Discussion In normal agar, the breaking strength may be increased by increasing the gel concentration, but the viscoelasticity (breaking distance) decreases accordingly. That is, it becomes harder as the concentration is increased, but it becomes brittle along with it. This is generally recognized as a physical property unique to agar gel.
Under such circumstances, there is a product that demands high viscoelasticity (compression displacement) although the breaking strength is low (Ina Foods Co., Ltd. “Yamato”). However, the product of the present invention exhibits viscoelasticity (compression displacement) at the same level as the conventional “ultra-high viscoelastic agar” while having a breaking strength more than double that of conventional commercial products. It is agar with special properties and high viscoelasticity.

Study 4 Basic analysis value of the present invention agar In order to obtain basic data of the present invention agar, the weight average molecular weight (Mw) was first measured. Moreover, the melting point of the agar gel was measured by differential scanning calorimetry (DSC measurement) as a thermodynamic property value. Specific methods are shown below. For comparison, the measured values of “Agar” manufactured by Wako Pure Chemical Industries and Comparative Example 2 are also shown.

Weight average molecular weight (Mw): Measured according to GPC method by HPLC. 0.3 g of each sample was dissolved in 200 ml of ultrapure water (110 ° C., 5 minutes) and measured using a column (TOSOH TSK-GEL for HPLC, TSK-GEL GMPWXL).
Table 3 shows the measurement results of the weight average molecular weight (Mw).
Table 3

DSC measurement: 3.0 g of each sample was dissolved in 100 ml of ultrapure water (120 ° C., 10 minutes), sealed in a sealed sample container made of silver, and gelled. After keeping the temperature at 10 ° C., the melting point was measured by raising the temperature to 140 ° C. Distilled water was used as a reference sample.
The DSC measurement results are shown in FIG.

As shown in Table 3, the Mw of the product of the present invention was about 390,000. The Mw of Comparative Example 2 and commercially available agar of the same material was around 150,000, indicating that it was agar with a large molecular weight.
As shown in FIG. 2, the DSC measurement results showed that the agar of the present invention was greatly different from other agars. The melting point of the product of the present invention is higher than that of other agar by 10 ° C. or more, suggesting that it is greatly different in terms of the heat resistance of the agar gel.

It is the figure which compared the compression load and compression displacement of the agar of this invention, and the conventional agar. It is the figure which compared melting | fusing point of the agar of this invention and the comparison object agar.

Claims

Agar having a breaking strength at 20 ° C. of 1000 g / cm 2 or more and a breaking distance of 3.3 mm or more in a cylindrical 1.5 wt% gel having a diameter of 22 mm and a height of 18 mm.
The method for producing agar according to claim 1, wherein the agar is extracted from agar algae at a pH of 10 to 13.5 by heating at 70 to 135 ° C and then dried.
A food and drink comprising the agar according to claim 1.
A gelling agent comprising the agar according to claim 1.
A dispersion stabilizer comprising the agar according to claim 1.