JP2003227099A - Material for food packaging and for sanitary good - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new material for food packaging and for sanitary goods, having excellent antibacterial activity against food-poisoning bacteria and pathogenic bacteria and being highly safe for human being. <P>SOLUTION: This material for food packaging and for sanitary goods is characteristically obtained by contacting, in water, a water-soluble protein with a silver salt to obtain a water-insoluble silver-containing conjugated protein and treating a substrate with the conjugated protein, wherein the active thiol content ratio in the protein is 0.1-200 μmol/g. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel material for food packaging or hygiene products, which exhibits excellent antibacterial activity against food poisoning bacteria and pathogenic bacteria which adversely affect the human body.

[0002]

2. Description of the Related Art Various bacteria and molds are present in our living space. These microorganisms often make us uncomfortable by spoiling food or causing malodor. In addition, it causes various diseases such as food poisoning to the human body, and sometimes even loses the lives of infants and the elderly who have weak resistance.
In order to lead a hygienic and comfortable life, the suppression of microbial growth is an important issue, and the addition of antibacterial functions is desired in applications such as food packaging and sanitary goods materials and food packaging materials or sanitary goods using them. It is rare.

Particularly recently, enterohemorrhagic Escherichia coli O-15
7. Food poisoning caused by Salmonella is frequently occurring.
Therefore, the Ministry of Health, Labor and Welfare has been conducting a food poisoning bacteria contamination actual condition survey since 1998 as a food poisoning prevention measure such as elimination of contaminated foods, and tests for enterohemorrhagic Escherichia coli O-157, Salmonella etc. as target bacteria, It calls attention to instructions such as disinfection and prevention of secondary pollution. On the other hand, nosocomial infections due to methicillin-resistant Staphylococcus aureus (MRSA), which is highly resistant to many antibiotics, has become a major social problem. It goes without saying that the use of antibacterial materials in order to prevent such accidents brings added value to food packaging materials and sanitary products themselves.

As a method for imparting antibacterial properties to paper, it is obtained by exchanging metal ions having antibacterial properties such as silver ions and copper ions with inorganic solid particles having an ion exchange capacity such as zeolite compounds and zirconium compounds. An attempt to obtain an antibacterial paper by filling or adhering an inorganic antibacterial agent on the paper has been disclosed in JP-A-62-238900 and JP-A-8
No. 243265, etc. However, in the above invention, bactericidal and bacteriostatic effects against enterohemorrhagic Escherichia coli O-157 which is a food poisoning causative organism, Salmonella, and methicillin-resistant Staphylococcus aureus (MRSA) which is a nosocomial causative organism have not been confirmed, which is suggested. Not even done. In addition, there is concern about the safety of infants with weak skin and the allergic constitution. In addition, practically, non-woven fabrics such as paper, fibers and films,
It is difficult to stably fix inorganic solid particles on a substrate such as a sheet by using the particles alone. Therefore, a suitable resin binder is indispensable, but in the case of inorganic solid particles, there is a problem that the active ingredient is not effectively exposed on the surface because it is buried in the resin binder layer coated on the substrate.

The inventors of the present invention have confirmed that a novel novel silver-containing complex protein, which is a protein used as a raw material in the fields of food and cosmetics, can be applied to bacteria such as Staphylococcus aureus, Escherichia coli, and fungi. It was found that it has remarkable antibacterial and antifungal activity, and a patent application has been made (Japanese Patent Laid-Open No. 2000-34479)
No. 8).

[0006]

The present invention provides a novel food packaging or food product which has excellent antibacterial properties against food poisoning bacteria and pathogenic bacteria which adversely affect the human body and which is highly safe for humans. The task is to provide materials for hygiene products.

[0007]

Means for Solving the Problems The inventor of the present invention has proposed that enterobacterial hemorrhagic Escherichia coli O-157, which is a causative bacterium of food poisoning, such as cotton cloth and non-woven cloth antibacterially processed using the novel silver-containing complex protein proposed above. Not only against Salmonella and Salmonella, but also against methicillin-resistant Staphylococcus aureus (MRSA), which is the causative agent of nosocomial infections, we found the fact that a similar and sustainable bactericidal and bacteriostatic effect is exerted. Regarding safety, it was confirmed that the safety standards established by the Antibacterial Product Technology Council have been cleared, and that there is no problem with human primary skin when impregnated with a cloth such as a bandage. Was completed.

Thus, according to the present invention, the content ratio of the active thiol group in the protein is 0.1 to 200 μmol / g.
A water-insoluble silver-containing complex protein obtained by contacting a water-soluble protein with a silver salt in water is attached to or impregnated on a substrate to provide a material for food packaging or hygiene products. To be done.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As the water-insoluble silver-containing complex protein used in the present invention, the silver-containing complex protein described in JP-A-2000-344798 can be preferably used. This silver-containing complex protein can be obtained by contacting a water-soluble protein having a content ratio of active thiol groups in the protein of 0.1 to 200 μmol / g with a silver salt in water. The "active thiol group" in the water-soluble protein as a raw material is a mercapto group (-S that easily reacts with an aqueous solution of a heavy metal compound to form a metal mercaptide derivative.
H), and the content of active thiol groups in the protein used is 0.1 to 200 μmol / weight of protein.
g, preferably 5 to 100 μmol / g.

When the content ratio of the active thiol group is less than 0.1 μmol / g, the amount of silver bonded to the active thiol group is small and a complex protein having a high silver content may not be obtained, which is not preferable. Further, when the content ratio of the active thiol group exceeds 200 μmol / g, it may be precipitated as a water-insoluble complex in which the bond of silver to the active thiol group is localized, which is not preferable. That is, such a phenomenon causes a reduction in the amount of silver bonds.

The content ratio of the active thiol group was determined in advance by preparing an aqueous solution of protein, and the DTNB method (Ellman method)
L-Cysteine equivalent amount can be measured by the method (Biochemical Experimental Method 10, "Quantitative determination of SH group", published by Japan Society for Publishing, pages 86-93).

"A water-soluble protein having an active thiol group content of 0.1 to 200 μmol / g" in the present invention
Is not particularly limited as long as it is a protein whose active thiol group content is within the above range. Specific examples thereof include whey protein, whey protein hydrolyzate, whey protein water-solubilized product, egg shell membrane protein hydrolyzate and egg shell membrane protein water-solubilized product, and these are preferably used. it can.

"Whey protein" is a protein that originally contains a relatively large amount of cystine, and includes water-soluble proteins such as α-lactalbumin and β-lactoglobulin,
It is abundant in whey, which is a by-product of cheese production, and is industrially available in large quantities. An example of a commercially available whey protein is Sanlacto N-5 (trade name) manufactured by Taiyo Kagaku Co., Ltd. In this case, the content ratio of the active thiol group is about 50 μmol / g.

In addition to whey protein, whey contains reducing sugars such as lactose and inorganic substances. In particular, lactose may inhibit the binding between protein and silver, so it is preferable to remove lactose in advance before contacting with silver. For example, when whey proteins containing whey or lactose remaining therein are used, lactose can be removed by dissolving them in deionized water and dialyzing this solution against deionized water.

The whey protein can be used as it is as a water-soluble protein, but like the eggshell membrane protein described below, a hydrolyzate or water-solubilized product obtained by subjecting it to alkaline decomposition, enzymatic decomposition or treatment with a reducing agent. It can also be used as a product.

The "egg shell membrane protein" is a water-insoluble protein that constitutes the inner membrane of the egg shell of avian eggs. From the viewpoint of easy availability as an industrial material, it can be used in the present invention. It is preferable to use chicken eggs, quail eggs, etc., which are consumed in large quantities in the food industry, as raw materials.

Alkaline decomposition of water-insoluble eggshell membrane protein,
By subjecting it to enzymatic decomposition or treatment with a reducing agent, a water-soluble hydrolyzate or water-solubilized product containing a specific amount of active thiol group can be obtained. That is, the content ratio of the active thiol group in the protein can be adjusted by cleaving the disulfide bond in the egg shell membrane protein and selecting the treatment condition for making the active thiol group.

Alkaline decomposition is carried out by treating the whey protein or egg shell membrane with an aqueous solution of an alkali metal hydroxide (for example, sodium hydroxide or potassium hydroxide) at a concentration of about 1 to 30% (for example, water or ethanol at a concentration of 40%). Aqueous solution). The concentration of the alkali metal hydroxide may be appropriately selected depending on conditions such as the amount of raw material and the treatment temperature. For example, when the amount of eggshell membrane is about 50 g, an aqueous solution of an alkali metal hydroxide prepared to 1N 1000
Treated with ml.

In this case, alkali decomposition can be promoted by mixing and stirring the solution. Processing temperature is 4
It is sufficient that the treatment time is about 0 to 80 ° C. and the treatment time is about 3 to 24 hours. The treated aqueous solution is filtered, and the obtained filtrate is dialyzed against deionized water to obtain a hydrolyzate of the target protein. In the enzymatic degradation, a hydrolyzate is obtained by treating whey protein or egg shell membrane with a protease. Examples of proteolytic enzymes include plant-derived proteolytic enzymes such as papain and bromelain, and animal-derived proteolytic enzymes such as pancreatin, rennin, trypsin, chymotrypsin and pepsin.

This treatment is carried out in a liquid in which the raw materials are dispersed in water, and the temperature and pH during the treatment may be in accordance with the optimum temperature and pH of the enzyme to be used and are not particularly limited. For example, when using pancreatin, the temperature is 35 to 50 ° C., and the pH is
About 6 to 8 is suitable. The treated solution is filtered, and the obtained filtrate is dialyzed against deionized water to obtain a hydrolyzate of the target protein.

In the reducing agent treatment, whey protein or egg shell membrane is treated with a reducing agent. In this method, the disulfide bond in the starting protein is reduced with sodium sulfide, thioglycolic acid and β-thiopropionic acid or its alkali salt, or a reducing agent such as 2-mercaptoethanol. The amount of reducing agent depends on its type, but for example,
When β-thiopropionic acid is used, eggshell membrane 100
It is about 2000 ml of a β-thiopropionic acid aqueous solution adjusted to 5 N with respect to g.

This treatment is carried out in a liquid in which the starting protein is dispersed in water. For example, when β-thiopropionic acid is used as the reducing agent, a temperature of 60 to 80 ° C. and a treatment time of about 5 hours are suitable. is there. The treated solution is filtered, and the obtained filtrate is dialyzed against deionized water to obtain a water-solubilized product of the target protein.

The silver salt is not particularly limited as long as it dissociates silver ions in water and does not inhibit the binding between protein and silver. Specifically, inorganic acid salts such as silver nitrate, silver nitrite, silver sulfate, silver perchlorate, silver oxide and silver chloride,
Examples thereof include organic acid salts such as silver acetate, silver lactate, and silver oxalate, complex salts such as diamine silver nitrate and diamine silver sulfate, and among them, inorganic acid salts are preferable, and silver nitrate and silver acetate are particularly preferable in terms of solubility in water. preferable.

As a method for bringing the protein and the silver salt into contact with each other in water, known methods such as mixing, stirring and shaking can be used. Of these, mixing / stirring is industrially preferable. As a specific method using stirring, a method in which a protein and a silver salt are mixed at once in water and stirred, while stirring the protein in water, gradually adding a silver salt dissolved in water into the mixture, Method to gradually increase the silver ion concentration in water While stirring the protein in water, gradually add finely pulverized silver salt to dissolve it, and gradually increase the silver ion concentration in water. Examples include a method in which an aqueous protein solution is gradually added to this while stirring, and finally the silver ion concentration in water is kept constant. Among these methods, the silver-containing complex protein has good reproducibility and can be obtained in high yield, and thus is particularly preferable.

The ratio of protein to silver salt depends on the contact conditions, but usually 0.2 to 3 silver salt per 1 g of protein.
About g is preferable. More specifically, the concentration is 1 to 20 mg
Concentration of 5 to 1000 ml of protein solution / ml
It is preferable to use it in a ratio of about 1000 ml of a 250 mM silver salt aqueous solution. However, as long as the complex protein having a high silver content can be efficiently obtained, the liquid volume ratio of the protein aqueous solution and the silver salt aqueous solution is not particularly limited. Further, the conditions for contacting the protein and the silver salt may be any conditions as long as the protein and the silver salt are uniformly mixed and a complex protein having a high silver content can be efficiently obtained. For example, in the case of contact by stirring, it is suitable that the temperature is about 0 to 70 ° C. and the treatment time is within 24 hours. The treated mixed solution is filtered, and the filtered residue is washed with deionized water, ethanol and the like, and dried to obtain a silver-containing complex protein. The silver content in the obtained composite protein can be determined, for example, by quantifying the eluted silver using 3% nitric acid.

The substrate used in the present invention is not particularly limited as long as it can be used for food or hygiene products, and specifically, white paperboard, cardboard paper, cotton, cotton cloth, polyester. Various fibers such as fibers, nylon fibers, non-woven fabrics, PET films, polypropylene films and polymer materials can be mentioned. It may be a sheet-shaped material, a paper-shaped material, a felt-shaped material, a knitted material or a woven material obtained by laminating these base materials alone or using an appropriate adhesive.

In the present invention, the method of treating the substrate with the silver-containing complex protein is not particularly limited as long as the silver-containing complex protein dispersed in an appropriate amount of water or an aqueous medium can be uniformly attached to the substrate. , A method of impregnating the base material by coating or dipping or spraying on the surface of the base material. When the base material is used for papermaking, a method of making a paper by adding a silver-containing composite protein to the papermaking step may be used.

When further laminating is carried out, a resin may be selected according to the substrate used and the silver-containing complex protein may be mixed therein. Specific examples of the resin include
Acrylic type, urethane type, vinyl acetate / EVA type, vinyl chloride / vinylidene type, urea / melamine type, epoxy type, PVA type,
Examples include synthetic rubber-based and natural rubber-based rubber.

In the material for food packaging or hygiene products of the present invention, the silver-containing complex protein is added to the above base material in an amount of 1 to 1000 mg / m ² , preferably 20 per surface area of the base material.
It may be adhered to the base material so as to be about 120 mg / m ² . Within this range, O-157, Salmonella,
A bactericidal and bacteriostatic effect can be continuously obtained against food poisoning bacteria and pathogenic bacteria that adversely affect the human body such as MRSA,
Moreover, it does not significantly impair the characteristics of the substrate.

The food packaging material or hygiene product using the food packaging or hygiene product material of the present invention includes food packaging materials such as food packaging paper, food packaging film, food packaging sheet, food packaging container and paper pattern. , Sanitary masks, sanitary wipes, gauze, ear bands, eye patches, menstrual bands, absorbent cotton, bandages, bandages, diapers, surgical clothes, duvets, towels, towel aprons, wallpaper, curtains, and other sanitary items.

EXAMPLES The present invention will be described below with reference to preparation examples and test examples, but the present invention is not limited to these preparation examples and test examples.

Various safety tests and antibacterial tests were carried out on the food packaging or hygiene article material of the present invention. For the test, the Life Science Research Institute and the Japan Food Research Laboratories in Nishi-ku, Osaka City were commissioned as follows.

Preparation Example 1 (Preparation of silver-containing complex protein A using whey protein) In a beaker having a volume of 300 ml, whey protein (New Zealand Milk Products, trade name: Alacene 89)
5, protein content 86.5%, active thiol group content 34.5 μmol / g) 2 g was dissolved in deionized water 200 ml. 20 mM of 50 mM silver nitrate aqueous solution was added to this mixed solution.
0 ml was added and stirred for 1 hour. The obtained mixed solution was allowed to stand overnight and filtered (filter paper No. 2 was used). The filtered residue was washed twice with 100 ml of deionized water and dried to obtain 1646 mg of silver-containing complex protein A (115% yield based on the protein used).

The silver content in the silver-containing complex protein A was 3%.
It was 4.5 as determined by quantification of the eluted silver using nitric acid.
% By weight. Further, the silver ion concentration in the filtrate was quantified and back calculated from this value to obtain the silver content in the silver-containing complex protein A, which was 4.86% by weight.

Test Example 1 (Various safety tests for food packaging materials) 1. Single Oral Toxicity Test in Mice At the Institute of Life Sciences, "Regarding the test facility specified in Article 4 of the order which specifies the items of the test for new chemical substances and the investigation of the toxicity of designated chemical substances (chemical substances GL
P) ”(revised November 18, 1988). Water-insoluble silver-containing complex protein A of Preparation Example 1
As a result of a single oral administration of 2000 mg / kg to male and female mice (in each of the following tests), no abnormalities were observed in the general condition and no deaths were observed during the observation period of 14 days. The average body weight of both males and females also increased steadily during the observation period. In addition, at necropsy after the observation period was over, external findings and major organs were observed macroscopically, but no abnormalities were observed. Based on the above, the LD50 value was 2000 mg / kg for both males and females.
It was estimated to be above.

2. Primary Skin Irritation Test in Rabbit The test was conducted in the same organization as above. The water-insoluble silver-containing complex protein was contacted with intact and wounded skin of 6 rabbits for 24 hours, and its primary irritation was observed for 5 days. As a result, no abnormality was observed in the general condition or body weight in the observation facility, and no irritating symptom was observed on the contacted intact skin. On the injured skin, a slight erythema was observed in the previous example 24 hours after contact, but this was also observed only in the adhesive bandage as a control. These erythema decreased with time and disappeared in all cases over 48 hours to 5 days. This was considered to be an irritation associated with injury, as it was also observed only in the control bandage.

3. Skin sensitization test in guinea pig The test was conducted in the same organization as described above. A skin sensitization test was conducted on the water-insoluble silver-containing complex protein by the Adjuvant and Patch Test method.
After 48 hours, no change was observed in the skin reaction in both the sensitized group and the non-sensitized group. Therefore, it was considered that the water-insoluble silver-containing complex protein has no skin sensitizing property to guinea pigs by the test method.

4. Mutagenicity test using microorganisms Japan Food Analytical Center "Enactment of screening toxicity test method Appendix III Reverse mutation test using bacteria in mutagenicity test" (December 5, 1986 environmental preservation business) No. 700, Yakuhin No. 1039, 61 Base Station No. 1014, partially revised on October 31, 1997) and "Standards for Hazard Investigation" (Ministry of Labor Notification No. 77, September 1, 1988) , Partly revised on June 2, 1997). "Chemical substance GLP" (Showa 59)
March 31, 2016 Environmental protection work No. 39, Yakuhin No. 229, 59 base station No. 85,
(Revised November 18, 1988) and "Standards that test facilities, etc. that conduct a hazard investigation must have" (Ministry of Labor Notification on September 1, 1988)
No. 76) was implemented so as to satisfy the GLP standard. Water-insoluble silver-containing complex protein Escherichia coli WP2 u
vrA strain and four Salmonella Typhimurium TA strains (TA1
00, TA98, TA1535, TA1537) was used for the mutagenicity test. 25-800 μg / plate when not using metabolic activation method, 313-5,000 μ when using metabolic activation method
When the dose was g / plate, no increase in the number of revertant colonies was observed in any of the cases, and it was confirmed that mutagenicity was negative.

5. Human skin primary irritation test by closed patch Tested at Institute of Life Sciences, standard of Japan Patch Test Study Group (reference: Taro Kawamura et al., Basic research on standardization of patch test, Journal of Niskin, 80, 301) -314 (1970)). As for the water-insoluble silver-containing complex protein, 20 healthy humans (18 males and 2 females) were subjected to a primary irritation test on human skin by a closed patch for 48 hours. I was not able to admit.

With respect to the function and safety of the antibacterial agent and the antibacterial product, the results obtained satisfying the criteria set by the Antibacterial Product Technology Association (SIAA), and the skin for human being in the state of being impregnated with a cloth such as a bandage. It was confirmed that there was no problem with the primary property.

Test Example 2 (Antibacterial property test of materials for food packaging or hygiene products) Silver-containing complex protein A at Japan Food Analysis Center
The antibacterial test was carried out on enterohemorrhagic Escherichia coli O-157, Salmonella, and methicillin-resistant Staphylococcus aureus MRSA for cotton and non-woven fabrics antibacterial-treated with. The antibacterial test is based on the antibacterial test of textile products (JIS L 190
2, commonly known as SEK antibacterial test). A non-antibacterial cotton cloth was used as a raw sample. Silver-containing complex protein A
2%, and a commercially available acrylic copolymer resin (Clariant Polymer Co., Ltd., trade name: Movinyl 963A) was separately prepared in water to a final concentration of 20%. In coating the base material, the above-mentioned stock solution was diluted 8 times with water to obtain a coating solution. A commercially available cotton cloth and pulp nonwoven fabric are used as the base material.
It was cut into 4 sizes and used, and each substrate was coated using a coating device (manufactured by Yasuda Seiki Co., Ltd., trade name: Patter Stability Tester). The coating amount was adjusted by immersing each base material in the coating liquid and changing the degree of squeezing when squeezing with a biaxial roll. The amount of coating was calculated from the increase in wet weight of the substrate after squeezing to calculate the amount of silver-containing complex protein per unit m ² . The squeezed substrate was air-dried and then used for each test. The coating amount of the silver-containing complex protein A on the cotton cloth base material and the non-woven cloth base material was 120 mg / m ² .
The bacteriostatic activity value, bactericidal activity value, and increase / decrease difference of the antibacterial cotton cloth and the non-woven cloth against each food poisoning bacteria and pathogenic bacteria were shown. The test results are shown in Tables 1-3.

[0041]

[Table 1] Effect on pathogenic E. coli O-157

[0042]

[Table 2] Effect on Salmonella

[0043]

[Table 3] Effect on methicillin-resistant Staphylococcus aureus

From the above results, it was confirmed that the cotton cloth and the non-woven cloth, which had been subjected to the antibacterial treatment using the water-insoluble silver-containing complex protein A, had a remarkable bactericidal / bacteriostatic effect against food poisoning bacteria and pathogenic bacteria.

[0045]

INDUSTRIAL APPLICABILITY The material for food packaging or hygiene products of the present invention is enterohemorrhagic Escherichia coli O-1 which is a causative bacterium of food poisoning.
57, Salmonella, and methicillin-resistant Staphylococcus aureus (MRSA), which is the causative agent of nosocomial infections, have the same long-lasting outstanding bactericidal and bacteriostatic effects, and are safe. In addition to meeting the safety standards established by the council, there is no problem with skin primaryness for humans when impregnated with a cloth such as a bandage. Therefore, the present invention can be applied to infants and the elderly with peace of mind and can prevent infection of food poisoning bacteria, pathogenic bacteria and the like at home medical sites and medical facilities.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B65D 65/02 D06M 15/15 4L033 81/28 D21H 19/10 B 4L055 D06B 1/08 A61L 15/01 D06M 15/15 A61F 13/18 381 D21H 19/10 F Term (reference) 3B154 AA02 AA07 AA08 AB18 AB22 BA14 BB32 BB34 BB39 BB71 BD12 BE05 BF12 DA28 3E067 AB01 AB83 BA11A BA17A BB01A BB14A BB25A15 BA03 BA01E BB13 CA01 DA08 4C003 BA06 HA02 4C081 CA151 CD021 CD31 CE01 4L033 AA07 AA08 AB04 AB07 AC10 CA08 4L055 AG04 AG54 AG98 AH21 BE08 EA29 FA20 FA30 GA26 GA27 GA30

Claims (4)

[Claims] 1. A water-insoluble silver-containing complex protein obtained by contacting a water-soluble protein having a content ratio of active thiol groups in the protein of 0.1 to 200 μmol / g with a silver salt in water. A material for food packaging or sanitary goods, characterized by treating a base material using the material. 2. The material for food packaging or sanitary goods according to claim 1, wherein the water-soluble protein is whey protein, egg shell membrane protein, or a hydrolyzate or water-solubilized product of whey protein. 3. The base material is paper such as white paperboard, corrugated cardboard, cotton, cotton cloth, fibers such as polyester fiber and nylon fiber, non-woven fabric and synthetic film such as PET film and polypropylene film, or a sheet thereof. The material for food packaging or sanitary goods according to claim 1 or 2, which is a paper-like material, a felt-like material, a knitted material or a woven material. 4. A food packaging material or hygiene article using the food packaging or hygiene article material according to any one of claims 1 to 3.