JPH10158999A - Antifungal and antimicrobial paper for tea bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject paper, having excellent antimicrobial and antifungal properties and capable of retaining a flavor for a long period by including chitosan in a paper for a tea bag consisting essentially of hempen pulp. SOLUTION: This antifungal and antimicrobial paper for a tea bag is obtained by including 0.2-0.8wt.% chitosan in the paper for the tea bag consisting essentially of hempen pulp and regulating the pH of a hot water extract solution within the range of 5-7. The chitosan is converted into an aqueous solution of an organic or an inorganic acid and internally added to a pulp slurry or added by posttreatment by impregnation or coating, etc. The pH of the solution containing the chitosan dissolved therein is regulated so as not to excessively reduce the pH of the hot water extract solution from the tea bag.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tea bag paper for extracting tea components. More specifically, the present invention relates to a tea bag paper which has excellent antifungal properties and antibacterial properties, prevents deterioration of tea leaves due to mold and the like, and enables the flavor to be maintained for a long period of time.

[0002]

2. Description of the Related Art A tea bag is a small bag made of thin paper for packing tea leaves such as black tea, green tea, and oolong tea. A small bag filled with tea leaves is a cup,
The tea component can be extracted by immersing it in boiling water such as boiling water or high-temperature water in a teacup or a kettle. After use, the product can be disposed of with its contents, so consumers can recognize the simplicity of handling.
Demand is increasing in homes, workplaces and hotels.

At present, as a tea bag for the purpose of extracting tea components such as black tea, green tea, and oolong tea, a crimp type made mainly of natural pulp and formed into a bag shape by mechanical crimping, and a heat-fused fiber are blended. There is also a heat seal type in which a bag is formed by heat sealing.

In the operation of packing tea leaves in a crimp-type tea bag, the tea leaves are first dropped onto tea bag paper at two places in two-gram increments, and then the paper is passed through two rotating crimping gears. As a result, the paper is bound by a gear seal and folded in two, and at the same time, the bottom is formed in a W-shaped gusset fold,
After that, fold the upper part of the filter bag, attach the thread and the tag, and wrap it in an envelope to form a tea bag.

[0005] On the other hand, heat-sealing type tea bags contain heat-fusible fibers in tea bag paper.
It is made into a bag shape by heat sealing, and is mainly used for barley tea and oolong tea. Heat-sealable tea bags are available not only for cooking but also for watering, so that fragrant tea can be extracted simply by putting it in water.

The following items can be cited as the quality required for the tea bag paper. (1) It is resistant to boiling water. (2) It does not contain components that impair the aroma of tea and has no unpleasant odor. (3) It has processability. (4) The extraction speed (filtration speed) of tea components is high. (5) Hot water (or water) is good

[0007] In accordance with the required quality, tea bag paper has conventionally been required to have high filterability and high strength when dry and wet. In order to satisfy such a quality, it is necessary to select a pulp having a contradictory performance in which the sheet is porous and high strength can be exhibited.

In view of the above, for teabag paper, Manila hemp, one of the non-wood pulp, has a longer fiber length and is more rigid than wood pulp, so that a high strength and porous sheet can be formed. It has been adopted as having the necessary characteristics. However, Manila hemp pulp alone has insufficient strength when dried and wet when used as tea bag paper, so that at present various paper strength additives are added to the pulp slurry to make paper,
Alternatively, paper obtained after paper making is treated with a chemical to compensate for the lack of strength.

[0009] The processed tea bag is usually 20 to 3
It is available to consumers in a state packed in about 0 bags.
Consumers open the packs and use them one by one, but it can take a long time to use one pack.

Problems after the tea bag pack is opened include flavor and fragrance deterioration due to oxidation of the tea leaves, generation of mold on the sheets and tea leaves due to humidity, and the like. For this reason, measures have been taken to significantly improve the sealing performance and to prevent the alteration (oxidation) of tea leaves by changing the envelope (outer envelope) from a conventional paper type to an aluminum vapor-deposited film. However, since aluminum-deposited films are more expensive than ordinary paper envelopes, they cannot be used for inexpensive tea bags.

As a countermeasure against tea bag paper, Japanese Patent Publication No. Sho 55-112370 discloses that oxidation can be prevented by impregnating colloidal fine particles of barley stone into a sheet. In addition, as a method for improving the tea flavor, a method of containing sepiolite in addition to the barite is disclosed. Also, Japanese Patent Application Laid-Open No.
No. 1190 discloses a method of impregnating tea bag paper with acid to improve the color of the tea extract, but this method has no antibacterial and antifungal effects and is not suitable for long-term storage. Was. Japanese Patent Publication No. 60-14829 discloses a method of adsorbing and removing strong mutagenicity contained in a coffee extract by mixing chitin.

[0012] In general, various organic and inorganic antibacterial agents having high antifungal and antibacterial effects are not suitable for tea bags because they are not suitable for sustainability or food use. It was not used, and it was difficult to provide a cheaper and more effective antifungal and antibacterial property, and it was difficult to maintain the quality and flavor of the tea bag for a long time.

[0013]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a tea bag paper having excellent antibacterial and antifungal properties and capable of maintaining the flavor for a long period of time.

[0014]

In view of such circumstances, the present inventors have conducted intensive studies on a method for preventing tea leaves from deteriorating due to excellent mold resistance under long-term storage of tea bag paper and mold. As a result, by including a predetermined amount of chitosan in a tea bag paper mainly composed of hemp pulp, not only can the paper have high wet strength, but also it has excellent antibacterial and antifungal properties and can maintain its flavor over a long period of time. The present invention has been completed.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tea bag paper mainly composed of hemp pulp, wherein the paper contains 0.2% of chitosan.
% To 0.8% by weight and hot water extraction pH
Is 5-7.

In the present invention, the tea bag paper mainly composed of hemp pulp is a tea bag paper containing hemp pulp in an absolutely dry basis in an amount of 50% by weight or more based on all pulp fibers.

The chitosan used in the present invention refers to a complex of chitin, calcium, protein and the like usually contained in shells of crustaceans such as crabs and shrimps, which is treated with an acid and an alkali to take out chitin as a single substance. It is obtained by treating chitin with a strong alkali and then deacetylating it, and is generally used as a food additive or the like.

[0018] Chitosan can be dissolved in inorganic or organic acids. Examples of the inorganic acids include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and boric acid, and examples of the organic acids include formic acid, acetic acid, glucose acid, oxalic acid, succinic acid, adipic acid, malic acid, maleic acid, and fumaric acid. Acids, tartaric acid, phthalic acid, lactic acid and the like. However, when used for tea bags, those commonly used in food additives such as lactic acid, malic acid, fumaric acid, succinic acid, and acetic acid are preferably used.

Since chitosan is hardly soluble in water, it is preferably used as an aqueous solution of the organic acid or the inorganic acid. In this case, the amount of the organic acid or the inorganic acid used is 0.1 to 1.5 times the weight of chitosan, preferably 0.5 to 1.
It is appropriately selected and used within the range of 0 times. The dissolution of chitosan with acid is preferably carried out at a temperature of 40 ° C. or lower, preferably at a normal temperature of 15 to 25 ° C., for 30 to 180 minutes with stirring to suppress self-reaction.

In the present invention, a tea bag paper containing chitosan is prepared by impregnating a solution obtained by adding an organic acid to chitosan and dissolving it into a sheet mainly composed of hemp pulp, or by spraying or spraying on both sides or on one side, and then drying. Is obtained. Also, at the stage of making a sheet mainly composed of hemp pulp, a paper may be made by adding a chitosan solution to the pulp slurry.

At this time, the content of chitosan in the tea bag paper is preferably in the range of 0.2 to 0.8% by weight. When the content is less than 0.2% by weight, the antibacterial and antifungal properties are insufficient, and when the content exceeds 0.8% by weight, the antibacterial and antifungal properties reach saturation, and the chitosan odor remains in the tea extract, which is preferable. Absent.

With respect to the antibacterial function of chitosan, it is presumed that the cation moiety of the positively charged amino group of chitosan binds to the negatively charged cell wall of bacteria and inhibits the growth of bacteria.

The tea bag paper obtained by the chitosan treatment contains an organic acid in which chitosan is dissolved, and when tea is extracted using this tea bag paper, the extract has a pH of less than 5. , The color of the tea will be light. Therefore, by adjusting the hot water extraction pH of the tea bag paper after the chitosan treatment to a range of 5 to 7, the color of the tea extract becomes good.

In order to adjust the hot water extraction pH of the tea bag paper after the chitosan treatment to 5 or more, when the chitosan-dissolved solution is internally added to the pulp slurry, the acid concentration is usually diluted. Can be used as it is, but when post-treatment is performed by impregnation with a chitosan solution, coating, etc., a dilute alkali solution is added to the chitosan solution in advance to adjust the pH of the chitosan solution to 5 to 7. Adjustment is preferred. If the pH of the chitosan-dissolved solution exceeds 7, chitosan is deposited, and it is difficult to adhere to a uniform sheet, which is not preferable.

Alternatively, after impregnating or applying the chitosan-dissolved solution, the tea bag paper obtained by drying may be neutralized again by impregnating or applying the diluted alkaline solution.

The pulp used for the present invention has not been bleached with a chlorine bleach and has high whiteness, preferably hemp pulp digested with neutral sodium sulfite, other bast fibers and Wood pulp is used, and as described above, hemp pulp is mainly used and other pulp is mixed and used.

In the case of a heat-sealable tea bag, heat-sealing fibers such as polyolefin fibers such as polypropylene and polyethylene and polyester fibers can be appropriately selected and blended.

As raw materials for obtaining the above-mentioned hemp pulp,
Manila hemp, hemp, flax, jute, sisal and the like can be mentioned, but in view of the availability of raw hemp, uniformity of quality, price, etc., Manila hemp from the Philippines, Ecuador, etc. can be preferably used.

The tea bag paper of the present invention can be produced by any of a well-known circular net paper machine, single net paper machine, and inclined paper machine. There is no particular limitation on the drying conditions,
Usually, a hot air dryer at 90 to 150 ° C. is suitably used.

When making paper with a paper machine, in order to improve the wet strength of the tea bag paper, it is preferable to perform beating to such an extent that tea extractability is not deteriorated. Normally, freeness 500
７００700 mlcsf (Canada standard freeness according to JIS P-8121). Depending on the application, all or part of the pulp whose freeness has been reduced to 500 mlcsf or less may be used. Further, in order to impart higher strength, it is preferable to add a chemical such as a water-proofing agent or a wet paper strength enhancer to the stock in advance to make paper. In particular, it is preferable to add a polyamide epichlorohydrin resin and a carboxymethylcellulose ammonium salt.

The basis weight of the tea bag paper varies depending on the desired use, but is preferably in the range of 12 to 25 g / m ² .

[0032]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto. In addition,% in Examples and Comparative Examples indicates% by weight of the active ingredient unless otherwise specified.

Example 1 Manila hemp from Ecuador obtained by sulfite digestion (No.
4 grade) The pulp was beaten using a beater, and the freeness was adjusted to 600 mlcsf. A polyamide epichlorohydrin resin (trade name: WS570, Japan P.L.) is used as a wet paper strength enhancer in the slurry of 100% Manila hemp pulp.
MC) and carboxymethylcellulose ammonium salt (trademark: Kitrate NA)
-L, manufactured by Nichirin Kagaku Co., Ltd.) and 1.0% with respect to pulp was used as a papermaking raw material. Using the obtained papermaking raw material, a tea bag paper having a basis weight of 12 g / m ² was formed using a laboratory square hand-making machine, and then dried with a rotary drum dryer to obtain a tea bag paper. .

On the other hand, lactic acid 1.0%, chitosan (SK-1
And 1.0% of Koyo Chemical Co., Ltd.) and 98% of water, and stirred at 25 ° C. for 120 minutes to dissolve chitosan. The pH of the obtained chitosan-dissolved solution was 3.5 (hereinafter, this chitosan solution is referred to as a non-pH-adjusted chitosan solution). A 2% aqueous solution of caustic soda was gradually added to the chitosan solution while stirring, and the pH of the solution was adjusted.
Was adjusted to 5.0. After pH adjustment, water was further added to obtain a chitosan-dissolved solution having a final chitosan solid content concentration of 0.3%.

The tea bag paper was impregnated with the pH-adjusted chitosan dissolving solution in an experimental impregnating machine to remove excess liquid by squeezing, and then dried with a rotary drum dryer at 105 ° C. to obtain a chitosan treatment. The finished tea bag paper was produced. The chitosan content of the obtained chitosan-treated tea bag paper was 0.3%.

Example 2 A chitosan treatment was carried out under the same conditions as in Example 1 except that the chitosan-dissolved solution adjusted to pH 5.0 was impregnated so that the chitosan content became 0.7%. Tea bag paper was obtained.

Example 3 Example 1 was repeated except that the chitosan-dissolved solution without pH adjustment was internally added so that the chitosan component was 0.5% based on absolute dry pulp. Under the same conditions, a chitosan-treated tea bag paper was obtained. The chitosan content of the tea bag paper after papermaking was 0.3%.

COMPARATIVE EXAMPLE 1 The same procedure as in Example 1 was carried out under the same conditions as in Example 1 except that the chitosan-dissolved solution whose pH was adjusted to 5.0 was impregnated so that the chitosan content was 0.1%. A treated tea bag paper was obtained.

Comparative Example 2 A chitosan-treated tea bag paper was prepared under the same conditions as in Example 1 except that the chitosan solution not adjusted in pH was impregnated so that the chitosan content was 0.1%. I got

COMPARATIVE EXAMPLE 3 The same procedure as in Example 1 was carried out under the same conditions as in Example 1 except that the chitosan-dissolved solution whose pH was adjusted to 8.5 was impregnated so that the chitosan content was 0.1%. A treated tea bag paper was obtained.

Comparative Example 4 A chitosan solution was prepared in the same manner as in Example 1 except that the chitosan dissolving solution whose pH was adjusted to 5.0 was impregnated so that the chitosan content was 1.0%. A treated tea bag paper was obtained.

Comparative Example 5 A chitosan-treated tea bag paper was prepared under the same conditions as in Example 1 except that the chitosan solution not adjusted in pH was impregnated so that the chitosan content was 1.0%. I got

Comparative Example 6 A chitosan solution was prepared in the same manner as in Example 1 except that the solution of chitosan dissolved at pH 8.5 was impregnated so that the chitosan content was 1.0%. A treated tea bag paper was obtained.

Comparative Example 7 A chitosan-treated tea bag paper was prepared under the same conditions as in Example 1 except that the chitosan solution whose pH was not adjusted was impregnated so that the chitosan content was 0.3%. I got

Comparative Example 8 The procedure of Example 1 was repeated, except that the solution of chitosan dissolved at pH 8.5 was impregnated so as to have a chitosan content of 0.3%. A treated tea bag paper was obtained.

Evaluation The hot water extraction pH of the chitosan-treated tea bag paper obtained in the above Examples and Comparative Examples was measured, and a tea bag containing black tea was prepared by hand, and the color and taste of the extract were measured. Was evaluated organoleptically. The antibacterial properties were also evaluated.

The evaluation method was in accordance with the following test method. Hot water extraction pH According to JIS P-8133. Antibacterial property Evaluated according to JIS L-1902. A case where no mold colony was observed was judged as pass (（), and a case where colonies were observed was judged as failed (×). Tea flavor tasting test A tea bag containing black tea was prepared by hand using tea bag paper, and hot water at 80 ° C was poured to extract black tea. The color of the obtained tea was observed and tasted. Judgment criteria: Good color and flavor were evaluated as ○, and poor quality was evaluated as ×.

[0048]

[Table 1]

As is clear from Table 1, the tea bag papers obtained in Examples 1 and 2 have a mildew-proof property as compared with Comparative Example 1. Further, a comparison between Examples 1 and 3 reveals that the same antibacterial effect is exhibited regardless of whether the method of containing chitosan is impregnation or internal addition. Example 1
The tea in the third tea bag has good color and flavor. Further, the tea bags of Comparative Examples 4, 5, and 6 had a high chitosan content and high antibacterial properties, but some of them had a lighter tea color and inferior flavor. Even if the chitosan content is within a predetermined range, the tea color and flavor are poor when the hot water extraction pH is outside the predetermined range.

[0050]

The tea bag paper mainly comprising hemp pulp according to the present invention imparts fungicidal properties by containing 0.2 to 0.8% by weight of chitosan to the paper, and By controlling the hot water extraction pH to 5-7,
This has the effect of imparting antifungal properties without deteriorating the flavor and color of the tea extract.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B65D 81/28 B65D 81/28 C C08B 37/08 C08B 37/08 A D21H 11/00 D21H 5/14 Z

Claims (1)

[Claims] 1. In a tea bag paper mainly composed of hemp pulp, 0.2 to 0.1% by weight based on the paper.
Tea bag paper containing 8% by weight of chitosan and having a hot water extraction pH of 5 to 7 for the paper.