JPS58162249A - Stable gel - Google Patents

Abstract

PURPOSE:A stable gel useful for preparing imitation foods, etc., having high strength and transparency, obtained by adding a specific polyol to an aqueous solution of a water-soluble polysaccharide. CONSTITUTION:A water-soluble polysaccharide (e.g., agar, carrageenan, gelatin, etc.) having gelatinizing ability is dissolved in water to give 0.1-5wt% aqueous solution. (A) 1pt.wt. aqueous solution of the polysaccharide is then blended with (B) 0.05-2pts.wt. 2-5C polyol (e.g., ethylene glycol, 1,5-pentanediol) having two or more hydroxyl groups in the molecule, to form a gel.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water gel that has high gel strength and transparency, and has excellent stability over time in a form that suppresses the formation of an undesirable film on the surface, and a method for producing the same.

Gels formed by dissolving polysaccharides in water or hot water and then cooling or adding a third component are widely used in various fields, especially as imitation foods.

Polysaccharides that can be used for this purpose include agar, farcellane, carrageenan, gelatin, pectin, etc. To produce a gel using these polysaccharides, generally 0.5 to 5 parts of the polysaccharide is mixed with 100 parts of the polysaccharide. A method is adopted in which the dispersion in water is heated to 40 to 80°C to dissolve and then cooled again. Gels made by these methods are called water gels because they use water as a medium, and are extremely easy to manufacture. However, when left under normal conditions, the surface of the gel evaporates as water evaporates from the gel surface. The volume shrinks over time and local concentration of the surface occurs, forming a film-like coating, which significantly reduces its commercial value.

In view of this situation, the present inventors conducted intensive research with the aim of obtaining a water gel with less volumetric shrinkage and suppressed film formation on the surface. The present invention was completed based on the discovery that the intended purpose can be fully achieved by adding polyols having two or more hydroxyl groups in one molecule. In addition to the above-mentioned features, the water gel of the present invention has a higher breaking strength and improved transparency compared to conventionally developed gels, and is stable and does not freeze even at the freezing temperature of water. be.

The present invention will be explained in detail using an example in which carrageenan is used as a gelling agent. - However, this description is not intended to limit the invention.

Carrageenan is a sulfated galactan contained in red algae, and is produced by extracting red algae with hot water, filtering it, optionally dehydrating it, and then drying and pulverizing it. Examples of the red algae used for this production include Contras crispus, Cigarteina, Eukyuma kotoni, and Eukyuma kistinosum.

Carrageenan is generally classified into kappa carrageenan, lambda carrageenan, and iota carrageenan, depending on the content of sulfuric acid residues and the content of 3.6 anhydrogalactose. However, it is said that kappa carrageenan iota carrageenan has the ability to gel, but the composition of carrageenan produced by conventional methods depends on the type of red algae used for extraction. Furthermore, carrageenans that have gelling ability, such as kappa carrageenan and iota carrageenan, differ in their gelling ability depending on the type of counter cation of the sulfuric acid residue, and when they contain sodium as a counter cation, they do not have gelling ability. Potassium salt.

It is characterized by gelatinization upon addition of calcium salts, etc. Carrageenan also has gelling ability.

That is, the gel strength is increased by adding potassium salt, calcium salt, etc. to a product containing kappa carrageenan or iota carrageenan having an ionic species other than sodium as a counter cation.

In addition to its strength, an important element of water gel is its water repellency. In other words, a good gel is one that can retain water as a medium for a long period of time. In this respect, iota-carrageenan has the advantage of low hydrorepellency and is stable during gel freeze-thaw cycles. Iota carrageenan is often used in combination with kappa carrageenan because it has the above advantages despite its low gel strength.

Further, when kappa carrageenan is used in combination with locust bean gum, the strength of the gel increases and the water repellency decreases.

As described in Section 2, carrageenan gels can be produced by various methods, but in all cases, it is inevitable that a film will be formed due to evaporation of water as a medium from the gel surface, and volume shrinkage and morphological changes will occur over time. be.

The present invention provides a gel in which the above-mentioned changes are suppressed, but also provides a gel that has improved transparency, improved gel breaking strength, and has the advantage that the gel does not freeze even at freezing temperatures. Its purpose is also to

The gel of the present invention can be obtained by dissolving a polysaccharide having a gel-forming ability in hot water, or in the case of carrageenan containing sodium as a countercation mentioned above, dissolving it in water at room temperature, and then dissolving the polysaccharide having 2 to 5 carbon atoms and 2 or more hydroxyl groups. It can be produced by adding 0.1 to 2 parts of polyol to 1 part of the solution, stirring and mixing uniformly, and then cooling, or by adding a water-soluble potassium salt, calcium salt, etc. to form a gel.

The polysaccharides with gelling ability used in the present invention include agar, farcerelan, carrageenan, gelatin, pectin, etc., which are dissolved in warm water and then cooled, or dissolved in water at room temperature and then added with certain water-soluble metal salts, etc. It refers to polysaccharides that can form gels when xanthan gum and locust bean gum are mixed together and dissolved, but polysaccharide mixtures that do not form gels alone but show the ability to form gels only in a mixed solution. Naturally, polysaccharides such as guar gum and locust bean gum that do not inherently exhibit gelling ability but can form gels by adding a boron compound are also included.

In preparing the gel of the present invention, first, a polysaccharide having gelling ability is dissolved in water at a ratio of 0.1 to 5%. At this time, heat appropriately if necessary.

Polyols having 2 to 5 carbon atoms and two or more hydroxyl groups in one molecule include ethylene glycol propylene glycol, 1
．． Examples include 4-butanediol, 1.3-butanediol/l/, and 1.5-bentanediol.

A polyol selected from these is added in an amount of 0.05 to 2 parts per 1 part of an aqueous polysaccharide solution, but if the amount is too large, the gel strength will decrease, so it is not preferable, and preferably 0.01 to 1.0 parts.
Good range of parts. Two or more types of polyols may be mixed.

The gel of the present invention is produced by cooling the mixed solution by a method such as allowing it to cool, or by gelling it by adding salts containing ions that promote gelation.

The gel produced by the above method was measured using a Neo Card meter (manufactured by Iio Electric Co., Ltd.) in an environment of 20°C and relative humidity of 65%, or the weight change of the gel when left in this environment for several tens of days. The superiority of the present invention is demonstrated by measuring the shape change and evaluating the stability. Also, add 50% of the gel.
The superiority of the present invention is also demonstrated by observing changes in the appearance of the morphology when the sample is cooled to 20°C or heated again to 20°C.

Hereinafter, the present invention will be specifically explained according to Examples.

Example 1 Sample A 1.5 parts by weight of kappa carrageenan containing potassium as the main ion species of the counter ion was dispersed in 98.5 parts of water, heated to 80°C to dissolve, and sealed for 2 hours.
A gel is formed by standing overnight in an environment of 0° C. and 65% relative humidity.

Sample group B Kappa carrageenan solution 10 at 80°C produced in sample A
Add 10 to 100 parts of propylene glycol to 0 parts, mix well, and form a gel in the same manner as Sample A.

Each sample prepared as described above was heated at 20°C and relative humidity 65%.
Table 1 shows the results of measuring the gel breaking strength using a Neocard meter under the following conditions.

Table 1 As is clear from the results, the breaking strength of the gel increased despite the substantial decrease in the concentration of kappa carrageenan.

Example 2 /161 and 42. in Table 1 of Example 1. ,%3 gel in the shape of 5 cm in diameter and 5 cm in height, and 20% in the exposed state.
Table 2 shows the results of leaving the sample in an environment of 65% relative humidity and measuring its weight and observing changes in shape.

For sample /i61 in Table 2, the center of the gel caved in on the third day, the ridge line part solidified locally, and the edges changed to a film-like shape, and on the fourth day, the gel The entire surface solidified and a film was formed, greatly distorting its original shape.

On the other hand, in sample No. 42, A3, no film formation was observed on the gel surface even after 10 days, and no depression occurred in the center of the gel.

Example 3 When Sample/I61 in Table 2 was cooled overnight at -5°C, it froze, and then when heated to 20°C, more than 90% of the water was liberated from the gel.

On the other hand, the gel of sample Ai 2 /163 in Table 2 was
It did not freeze even if it was cooled overnight at 20°C, and no change occurred even when it was heated to 20°C.

Patent applicant Mitsubishi Acetate Co., Ltd. Agent Patent attorney 1) Takeshi Mura (11)

Claims (3)

[Claims] (1) Polyol 005 containing 0.1 to 5% 1 part of water-soluble polysaccharide, carbon number 2 to 5, and two or more hydroxyl groups in one molecule
Gel strength consisting of a mixture with ~2 parts. Stable gel with high transparency (2) The stable gel according to claim 1, characterized in that the water-soluble polysaccharide is a polysaccharide selected from the group consisting of agar, farcelan, carrageenan, pectin, and gelatin. (3) Agar and Farcellan as water-soluble substances. The stable gel according to claim 1, characterized in that a combination of carrageenan, pectin, gelatin and locust bean gum is used.