JP2866746B2 - Gelatin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film containing gelatin cross-linked by transglutaminase. The film of the present invention can be widely applied to edible films, food packaging materials, etc., which have improved heat resistance, strength, swelling resistance, moisture resistance and anti-adhesion on the film surface.

[0002]

2. Description of the Related Art Conventionally, sausage casings, oblates and the like have been used in large quantities as edible films, sheets, tubes and the like. In addition, the edible outer film is dissolved by putting it in hot water, and an outer film containing spices, seasonings, coloring agents, etc. that can be used together with the outer film without opening the seal is considered for instant noodles and the like. I have. These edible films and the like include collagen (JP-A-60-203149), casein (JP-A-51-121535), and gelatin (JP-A-5353) as bases.
-39939) and the like; starch, dextrin,
Starch substances such as amylose and amylopectin; cellulosic substances such as carboxymethylcellulose; gum arabic, pullulan (JP-A-63-256), dextran, pectin, carrageenan (JP-A-63-25854)
Polysaccharides such as 2, JP-A-60-55039); or various combinations of these materials (gelatin, carrageenan, roasted bean gum, etc., JP-A-62-2587). In some cases, a polyhydric alcohol such as glycerol or sorbitol is added to soften a film made of these materials, or glucose or sucrose is added depending on the purpose. As non-edible food packaging materials, plastic films such as polyethylene and polystyrene are widely used, but they are hardly decomposed by bacteria and cause pollution problems at the time of disposal. Gelatin-based coatings are characterized by their good manufacturing suitability and excellent heat-sealing properties because they utilize the sol-gel conversion of gelatin at temperatures, and are widely used. However, since the melting point of gelatin is relatively low at about 25 to 30 ° C., it has a drawback that it is difficult to use it for applications requiring heat resistance. In addition, since the film surface has poor moisture resistance, there is a problem in adhesion between films or between a film and another material. When used as a food packaging material, gelatin has a problem in film strength. Transglutaminase is a glutamine residue in the protein γ-
It is an enzyme that forms a ε- (γ-glutamyl) lysine bond between a carboxamide group and an ε-amino group of a lysine residue to crosslink and polymerize a protein. Examples of the use of transglutaminase include gels obtained by adding transglutaminase to high-concentration solutions of various proteins (JP-A-58-149645, JP-A-1-27471), and adding transglutaminase to a protein solution. Produced protein membrane by casting method (Japanese Patent Application Laid-Open No. 61-15224)
7) A method in which transglutaminase is added to a gelatin solution to inactivate the enzyme before gelation to produce high-viscosity gelatin (JP-A-2-86743).

[0003]

Gelatin is used in various applications by utilizing the so-called sol-gel conversion ability, which becomes a solution when heated and becomes a gel when cooled. The gelatin film is characterized by good workability during production and excellent heat sealing properties. On the other hand, in general, many films prepared using other components do not have heat-sealing properties, and the purpose of use is limited. However, since the melting point of gelatin is relatively low at about 25 to 30 ° C., when high heat resistance is required for the purpose of use, treatment such as adding a thickener or crosslinking gelatin with various crosslinking agents is performed. Must. However, when a thickener is used, there is a limit in imparting heat resistance, and it has been difficult to control the degree of heat resistance. In addition, most of the various crosslinking agents are not suitable for food and medicine, and it is difficult to control the degree of crosslinking. On the other hand, when the film is treated with transglutaminase gelatin, when the amount of transglutaminase to be used is small, the change in quality is small and there is no particular problem. However, in order to apply to the process conditions at the time of food production, it is desired that a large amount of enzyme can be treated in a short time, so that a large amount of enzyme is practically used. It was an important point about stability.

[0004]

Means for Solving the Problems The present inventors molded a film containing gelatin as a main component, and then dipped, coated,
By applying transglutaminase by means such as spraying, the gelatin was cross-linked to increase the melting point of the film while maintaining the heat sealability of the film, thereby improving the heat resistance and the strength. The present inventors have also found that these transglutaminase treatments are effective in suppressing water swelling in water and moisture absorption in air, and are also effective in preventing adhesion between membranes. In addition, when an enzyme is added, it has been found that by inactivating the enzyme during the reaction, the dissolution temperature of the film can be freely controlled, and a film having heat sealability can be obtained. Thus, the present invention has been completed.

When transglutaminase is allowed to act on gelatin in the present invention, a film containing gelatin is formed and then the film is immersed in a solution containing transglutaminase, or a solution containing transglutaminase is applied to the film. A method of applying an enzyme by means such as coating or spraying, and adding a small amount of transglutaminase to a solution containing gelatin, forming a film, forming a film, and immersing the film further in a solution containing transglutaminase, Alternatively, there is a method in which a solution containing transglutaminase is applied to the film by a method such as application or spraying (these methods may be referred to as “immersion method” in this specification). The kneading method of forming a film by adding transglutaminase to a solution containing gelatin and forming the film is a commonly used film method, but not only does the adhesion resistance of the film surface not be much improved, but it is formed into various shapes. In this case, in the kneading method, the viscosity of the solution after the addition of the enzyme is rapidly increased, and molding may be difficult. Also in the film strength, the immersion method has a remarkably greater improvement effect than the kneading method. By drying the obtained film, the preservability is improved and it can be used for various processed foods and the like. It is also possible to control the degree of crosslinking by inactivating the enzyme and to control the dissolution temperature of the film.

[0006] The dipping method of the present invention is specifically described below.
The pH of the film-forming solution containing gelatin is adjusted so as to be suitable for the enzymatic reaction, and the film is formed. This pH is
H6.0-7.0 is preferred, but the reaction proceeds even at pH 4-11. Thereafter, the film is left as it is or after drying, so that the gelatin concentration in the film is adjusted to 1% by weight or more, preferably 5% by weight or more. The amount of transglutaminase is 0.01 units or more per 1 ml of the solution, preferably 2 to 50 units per 1 ml of the solution.
This film is immersed in a solution whose pH has been adjusted to -11, preferably pH 6.0-7.0. The immersion temperature is 1 to 35 ° C, preferably 20 to 27 ° C, and the immersion time is 2 minutes or more, preferably 10 minutes to 5 hours. The temperature at the start of immersion is preferably the above temperature at which the film does not dissolve or excessively soften,
While maintaining this temperature, the coating is immersed for 2 minutes or more, preferably 10 minutes or more. In addition, during the reaction by immersion, the heat resistance increases, and the temperature of the enzyme solution is gradually raised to 40-60 ° C, preferably about 50 ° C, which is near the optimum temperature of the enzyme, so that the reaction is accelerated. You can also proceed.

After the completion of the reaction by immersion, the film is subjected to a heat treatment at 80 ° C. for 15 minutes before or after drying to deactivate the enzyme. If the film softens at 80 ° C., the shape of the film is maintained by the support, and if it does not soften at 80 ° C., the film is heat-treated in a water bath or air bath.
Alternatively, instead of inactivation, the enzyme can be removed by leaching in running water. The film gel is dried and the water content is adjusted to 5-30%, preferably 10-25%, to produce a film. In this manufacturing method, the same effect can be obtained by applying the enzyme solution to the film by means of application or spraying instead of immersion, and it is also possible to treat only one surface of the film as well as both surfaces.

In this production method, there are two methods, a method in which an enzyme is reacted for a long time and acts on the entire film by diffusion, and a method in which the enzyme is applied only to the surface of the film in a short time. In this case, heat resistance, film strength, swelling resistance, moisture resistance and anti-adhesion are mainly improved. When acting only on the film surface, mainly heat resistance, moisture resistance, swelling resistance,
The anti-adhesion property of the film surface is improved. In addition, it retains the heat-sealing property of gelatin, and its heat resistance, strength, water resistance, moisture resistance, and adhesiveness at room temperature or slightly higher than room temperature are comparable to those of the same formulation without enzyme. Have been improved. Further, even when the skin comes into contact with the finger or the like at the time of handling, there is no stickiness due to the body temperature, and the handling is easy. Regarding the method of enzyme inactivation, the method by the heat treatment used in this example, the method of leaching out the enzyme,
To transfer acid to the acid side or alkali side, EDTA
Chelating agents such as, if it loses transglutaminase activity including methods by the action of enzyme inhibitors,
Any method can be used. Regarding the shape of the film, it can be formed into a flat film, cylindrical shape, string shape, bag shape, spherical shape, capsule shape, etc., and immersed in an enzyme solution in those shapes, or by applying and spraying the enzyme solution to react. A film of the desired shape is obtained. According to this method, 1 μm-30 m
m, preferably 30 μm-1 mm. However, when transglutaminase is allowed to act only on the surface of the film, the shape and thickness of the film are not particularly limited.

Transglutaminase crosslinks a protein by forming an ε- (γ-glutamine) lysine bond between the γ-carboxamide group of a glutamine residue and the ε-amino group of a lysine residue in the protein. It is known as an enzyme. If the transglutaminase shows transglutaminase activity other than that derived from the actinomycete streptovertsilium used in the present invention,
It is possible to use one of any origin. Gelatin used in the present invention, regardless of the type of raw material,
It may be produced by any production method such as an acidic method and an alkaline method, but an acidic gelatin having more glutamine residues is preferred. In the present invention, one or two types of materials such as starch, amylose, etc., starch-based materials such as amylose, cellulose-based materials such as CMC, polysaccharides such as pullulan, dextran, pectin, carrageenan, and gums are used in the present invention. These can be used in combination. In this case, the component ratio between these substances and gelatin is preferably 20% or more, and more preferably 50% or more. Further, substances conventionally used for improving the properties of films such as films, sheets, tubes and the like such as polyhydric alcohols such as glycerol and sorbitol can be mixed and used. It is also possible to mix spices, sweeteners, seasonings, coloring agents and the like according to the intended use of the film. Hereinafter, the present invention will be described according to examples,
The present invention is not limited by this.

[0010]

In all of the examples and comparative examples, the jelly strength was J
In the IS method, 196 bloom acidic gelatin was used. Example 1 83 parts of distilled water and 1.5 parts of glycerin were added to 15 parts of gelatin obtained by an acidic method skin having a jelly strength of 196 bloom according to JIS method, and the gelatin was swollen for 1 hour and then heated to 50 ° C.
And adjusted to pH 6.5 with NaOH to obtain a stock solution.
After defoaming this liquid under reduced pressure, the thickness is 0.5 mm by a casting method.
Was prepared. This membrane was placed in an enzyme solution adjusted to pH 6.6 containing 1.5% of glycerin and 5 units of transglutaminase (manufactured by Amano Pharmaceutical Co., Ltd.) per 1 ml of pure water at 22 ° C. for 1.5 hours. Dipped. Thereafter, the enzyme solution was heated at 80 ° C. for 15 minutes to inactivate the enzyme. The membrane thus prepared was allowed to stand at room temperature for 1 hour at 45 ° C.
Air-dried at 40 ° C. for 40 minutes to obtain a target film. As shown in Table 2, this film exhibited 2.2 times the strength at break performed in this test as compared with the comparative sample in which transglutaminase was not used at the same component ratio as in Example 1, and was excellent in strength. It turns out that it is a film. This difference in strength tends to increase as the temperature and humidity increase. This film did not soften at all even in a hot water bath at 93 ° C. and was excellent in heat resistance. Further, as shown in Table 2, this film had improved swelling resistance and moisture absorption resistance, had excellent adhesion resistance on the film surface, and maintained heat sealability. The N content in the film was determined by the Kjeldahl method and the product was 6.0 times as the protein content. Noted. The same applies to the second embodiment.

Example 2 A solution A was prepared by adding 30 parts of distilled water to 15 parts of gelatin and dissolving it. Separately, distilled water (48 parts) was added to carrageenan (1 part) and locust bean gum (1 part), and the mixture was sufficiently swollen while stirring for 1 hour. Solution A and solution B were mixed at 1: 1 to 95 parts, 2 parts of glycerin was added to the mixture, and the mixture was adjusted to pH 6.1 with NaOH, and then a 1.0 mm thick film was formed. This membrane was placed at 26 ° C. in an enzyme solution adjusted to pH 6.0 containing 2.5 units of transglutaminase in 1 ml of pure water containing 2% glycerin.
The gelatin was crosslinked by immersion for 0 minute, 29 ° C for 15 minutes, and 33 ° C for 5 minutes, and then heated to 80 ° C to inactivate the enzyme for 15 minutes. At room temperature, the membrane thus prepared
It was air-dried for 20 minutes to obtain the target film. At 86 ° C., the surface of this film did not soften but dissolved inside. Table 2
As can be seen, the strength, swelling resistance, moisture absorption resistance, and adhesion resistance were improved, and the heat sealability was maintained.

Example 3 20 parts of distilled water was added to 10 parts of gelatin to adjust pH to 6.4.
The solution was adjusted to H and used as solution A. After adding 30 parts of distilled water to 2.4 parts of carrageenan and stirring for 1 hour to absorb water,
It melt | dissolved with stirring at 20 degreeC for 20 minutes, and was set as the liquid B. Solution A and solution B are mixed at a ratio of 1: 1 and then adjusted to pH 6.5,
A stock solution was obtained. This solution was adjusted to pH 6.5 at 25 ° C. from an annular nozzle having a diameter of 20 mm and a gap of 2 mm, and was discharged into a NaCl / KCl saturated solution coagulation bath containing 1 unit of transglutaminase per 1 ml for 20 minutes. Coagulated and reacted. This cylindrical coating was prepared at pH 6 at 15 ° C.
The solution was adjusted to 5 and immersed in a solution containing 5 units of transglutaminase per 1 ml for 60 minutes to further carry out an enzyme reaction. This was continuously washed in a running water bath and passed through a 2% glycerin solution.
It dried with the hot air which changed temperature stepwise to 0 degreeC. 8 more
The enzyme was inactivated by heat at 0 ° C. for 15 minutes, and the film was dried to obtain a target tubular film. The dissolution temperature of this film was around 90 ° C., and as shown in Table 2, the film maintained the heat sealing property.

Example 4 A solution A was prepared by adding 20 parts of distilled water to 10 parts of gelatin and dissolving it. To 2.5 parts of dextrin, add 10 parts of distilled water, and add 1 part.
After stirring for 5 minutes, the mixture was dissolved by holding at 80 ° C. for 20 minutes to obtain a solution B. Solution A and solution B were mixed at a ratio of 1: 1 to 42.5 parts, 1 part of glycerin was added thereto, and the solution was adjusted to pH 6.
4 to obtain a stock solution. To the stock solution, 2 units of transglutaminase were added to 1 g of gelatin, and
After reacting at 0 ° C. for 10 minutes, molding was performed.
A product obtained by performing an enzyme reaction for 0 minutes was obtained. This film is then 1m
The resultant was immersed in an enzyme solution adjusted to pH 6.6 containing 5 units of transglutaminase per 1 liter at 22 ° C. for 1.5 hours. After that, the enzyme solution is placed in an air bath for 8 hours.
The enzyme was inactivated by heating at 0 ° C. for 15 minutes. Finally, the film was air-dried at room temperature for 80 minutes to obtain a film. This coating was excellent in heat sealability as shown in Table 2.

Comparative Example (I) 10 parts of gelatin was dissolved by adding 20 parts of distilled water.
Solution A was used. Distilled water (10 parts) was added to dextrin (2.5 parts), and the mixture was stirred for 15 minutes and dissolved at 80 ° C. for 20 minutes to obtain a solution B. 42. Liquid A and liquid B are mixed 1: 1.
5 parts, and 1 part of glycerin was added thereto.
The solution was adjusted to H6.4 to obtain a stock solution. Transglutaminase was added to this solution at a ratio of 5 units to 1 g of gelatin, and allowed to react at 50 ° C. for 10 minutes.
The enzyme was reacted at 0 ° C. for 20 minutes, the membrane was held in a mold, the enzyme was deactivated at 80 ° C. for 15 minutes in an air bath, and then cooled again to gel. This film was air-dried at room temperature for 80 minutes to obtain a film. This film softened at 40 ° C. but did not dissolve, and slowly dissolved completely at 45 ° C. (II) Distilled water (83 parts) and glycerin (1.5 parts) were added to gelatin (15 parts), gelatin was swelled for 1 hour, dissolved at 50 ° C., and adjusted to pH 6.0 with NaOH. After forming a film having a thickness of 0.5 mm with this solution, the solution was heated at room temperature for 45 minutes at 45 ° C.
For 25 minutes and at 60 ° C. for 15 minutes to obtain a film. This coating was used for comparison with the product of the present invention.

[Table 1] Note) It is the ratio of all components after moisture adjustment used in the following tests of Examples and Comparative Examples.

[Table 2] Note) (1) The breaking strength and elongation are the breaking strength per unit area measured by a rheometer (manufactured by Fudo Industry Co., Ltd., model NRM-3002D) at 33 ° C. and the ratio of the elongation to the film length at that time. (2) The degree of swelling is the degree of swelling expressed as% of the film volume after immersion relative to the film volume before immersion when the film was immersed in distilled water at 21 ° C. for one hour.

The moisture absorption is 2 at 30 ° C. and 79.5% humidity.
This is the moisture absorption of the film expressed as% by weight after moisture absorption with respect to the film weight before moisture absorption when moisture absorption of the film was performed for 0 hour. The adhesiveness of the films after the moisture absorption test was 50 g / cm ^2.
It is the result of having tested by the sensory test the force at the time of making it adhere | attach and peeling it off. Those that did not adhere at all were evaluated as (-), and were evaluated sequentially in four steps from those with weak adhesion (+1) to those with strong adhesion (+3). The heat sealability is a result of a heat sealability test using a heat sealer (manufactured by Fuji Impulse, model M-300). Those having excellent heat sealability were evaluated as (+3), and those showing no heat sealability were evaluated as (-).

[0016]

The film produced by the present invention has excellent effects mainly on heat resistance, strength, swelling resistance, moisture absorption resistance and adhesion prevention of the film surface while maintaining the heat sealing property. (Table 2). By increasing the melting temperature and improving the moisture absorption resistance and water resistance, a film excellent in handling and storage, such as no stickiness during handling, can be obtained. Furthermore, a high drying temperature can be carried by the improvement of heat resistance, and production efficiency can be improved. The film produced according to the present invention is used as a food packaging material such as an edible bag for packaging spices, sweeteners, seasonings, or food ingredients used for dishes such as Chinese dishes and boiled dishes, instant dishes, chilled foods and the like. Of course, it can be applied as a new type of food packaging material or a food packaging material for microwave ovens containing these in the membrane main body.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takahiko Soeda 1-1, Suzuki-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Ajinomoto Co., Inc. Central Research Laboratory (56) References JP-A-61-152247 (JP, A) 58-149645 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A23J 1/00-7/00

Claims (3)

(57) [Claims] 1. A film obtained by crosslinking a molded film containing gelatin with transglutaminase. 2. A solution containing gelatin is added to a solution containing transglutaminase to form a molded film, and the formed film is further reacted with transglutaminase to cause an enzymatic reaction, followed by deactivation of the enzyme. Film obtained by 3. A film obtained by adding a transglutaminase to a solution containing gelatin to form a molded film, further reacting the formed film with a transglutaminase to cause an enzyme reaction, and then deactivating the enzyme. .