CA1114248A - Tea bags - Google Patents
Tea bagsInfo
- Publication number
- CA1114248A CA1114248A CA301,213A CA301213A CA1114248A CA 1114248 A CA1114248 A CA 1114248A CA 301213 A CA301213 A CA 301213A CA 1114248 A CA1114248 A CA 1114248A
- Authority
- CA
- Canada
- Prior art keywords
- tea
- water
- impregnated
- acid
- tea bag
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 241001122767 Theaceae Species 0.000 claims abstract description 78
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims abstract description 63
- 239000000463 material Substances 0.000 claims abstract description 58
- 230000002378 acidificating effect Effects 0.000 claims abstract description 41
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000000203 mixture Substances 0.000 claims description 9
- 150000003839 salts Chemical class 0.000 claims description 5
- BJEPYKJPYRNKOW-REOHCLBHSA-N (S)-malic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O BJEPYKJPYRNKOW-REOHCLBHSA-N 0.000 claims description 4
- KDYFGRWQOYBRFD-UHFFFAOYSA-N Succinic acid Natural products OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 claims description 4
- BJEPYKJPYRNKOW-UHFFFAOYSA-N alpha-hydroxysuccinic acid Natural products OC(=O)C(O)CC(O)=O BJEPYKJPYRNKOW-UHFFFAOYSA-N 0.000 claims description 4
- 239000001630 malic acid Substances 0.000 claims description 4
- 235000011090 malic acid Nutrition 0.000 claims description 4
- RTBFRGCFXZNCOE-UHFFFAOYSA-N 1-methylsulfonylpiperidin-4-one Chemical compound CS(=O)(=O)N1CCC(=O)CC1 RTBFRGCFXZNCOE-UHFFFAOYSA-N 0.000 claims description 3
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 claims description 3
- JFCQEDHGNNZCLN-UHFFFAOYSA-N anhydrous glutaric acid Natural products OC(=O)CCCC(O)=O JFCQEDHGNNZCLN-UHFFFAOYSA-N 0.000 claims description 3
- 230000003139 buffering effect Effects 0.000 claims description 3
- 238000007654 immersion Methods 0.000 claims description 3
- 239000011975 tartaric acid Substances 0.000 claims description 3
- 235000002906 tartaric acid Nutrition 0.000 claims description 3
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 claims description 2
- KEAYESYHFKHZAL-UHFFFAOYSA-N Sodium Chemical compound [Na] KEAYESYHFKHZAL-UHFFFAOYSA-N 0.000 claims description 2
- KDYFGRWQOYBRFD-NUQCWPJISA-N butanedioic acid Chemical compound O[14C](=O)CC[14C](O)=O KDYFGRWQOYBRFD-NUQCWPJISA-N 0.000 claims description 2
- 229910021653 sulphate ion Inorganic materials 0.000 claims 1
- 239000002253 acid Substances 0.000 abstract description 19
- 238000001802 infusion Methods 0.000 abstract description 11
- 235000013616 tea Nutrition 0.000 description 64
- 238000000034 method Methods 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 239000006172 buffering agent Substances 0.000 description 5
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 4
- 238000001035 drying Methods 0.000 description 3
- -1 hydrogen ions Chemical class 0.000 description 3
- 241000905957 Channa melasoma Species 0.000 description 2
- 239000011668 ascorbic acid Substances 0.000 description 2
- 229960005070 ascorbic acid Drugs 0.000 description 2
- 235000010323 ascorbic acid Nutrition 0.000 description 2
- 235000013361 beverage Nutrition 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 235000021152 breakfast Nutrition 0.000 description 2
- 239000000872 buffer Substances 0.000 description 2
- 239000003086 colorant Substances 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000796 flavoring agent Substances 0.000 description 2
- 235000019634 flavors Nutrition 0.000 description 2
- 230000001976 improved effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- SNICXCGAKADSCV-UHFFFAOYSA-N nicotine Chemical compound CN1CCCC1C1=CC=CN=C1 SNICXCGAKADSCV-UHFFFAOYSA-N 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 101100087530 Caenorhabditis elegans rom-1 gene Proteins 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 101100305983 Mus musculus Rom1 gene Proteins 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- ZPWVASYFFYYZEW-UHFFFAOYSA-L dipotassium hydrogen phosphate Chemical compound [K+].[K+].OP([O-])([O-])=O ZPWVASYFFYYZEW-UHFFFAOYSA-L 0.000 description 1
- WPUMTJGUQUYPIV-JIZZDEOASA-L disodium (S)-malate Chemical compound [Na+].[Na+].[O-]C(=O)[C@@H](O)CC([O-])=O WPUMTJGUQUYPIV-JIZZDEOASA-L 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 235000019265 sodium DL-malate Nutrition 0.000 description 1
- 239000001509 sodium citrate Substances 0.000 description 1
- 239000001394 sodium malate Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000001384 succinic acid Substances 0.000 description 1
- HRXKRNGNAMMEHJ-UHFFFAOYSA-K trisodium citrate Chemical compound [Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O HRXKRNGNAMMEHJ-UHFFFAOYSA-K 0.000 description 1
- 229940038773 trisodium citrate Drugs 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D85/00—Containers, packaging elements or packages, specially adapted for particular articles or materials
- B65D85/70—Containers, packaging elements or packages, specially adapted for particular articles or materials for materials not otherwise provided for
- B65D85/804—Disposable containers or packages with contents which are mixed, infused or dissolved in situ, i.e. without having been previously removed from the package
- B65D85/808—Disposable containers or packages with contents which are mixed, infused or dissolved in situ, i.e. without having been previously removed from the package for immersion in the liquid to release part or all of their contents, e.g. tea bags
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/03—Non-macromolecular organic compounds
- D21H17/05—Non-macromolecular organic compounds containing elements other than carbon and hydrogen only
- D21H17/14—Carboxylic acids; Derivatives thereof
- D21H17/15—Polycarboxylic acids, e.g. maleic acid
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tea And Coffee (AREA)
- Packages (AREA)
- Wrappers (AREA)
- Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
- Paper (AREA)
- Laminated Bodies (AREA)
Abstract
Abstract of the Disclosure:
Tea bags are prepared from water-pervious sheet material, such as paper, which is impregnated with edible acidic material such as citric acid and which thereby has an acid reaction on contact with water. The colour of aqueous infusions obtained from the impregnated tea bags is superior.
Tea bags are prepared from water-pervious sheet material, such as paper, which is impregnated with edible acidic material such as citric acid and which thereby has an acid reaction on contact with water. The colour of aqueous infusions obtained from the impregnated tea bags is superior.
Description
Q~7 ~ he present invention relates to tea bags and -to ma-terial from which tea bags are prepared.
A substantial amount of tea is sold in tea bags. ~ea bags usually contain leaf tea in amounts of about 2 - 3 grams per bag, black leaf tea being the most commonly used. Some-times the leaf tea is blended wi-th minor amounts o~ instant soluble tea.
The beverage qualities of both leaf -tea and instant soluble tea are par-tly determined by the water with which -tbey are infused during preparation of the be~erage. Teas brewed in water with a high temporary hardness often have an undesirable grey_brown colour. In addition, teas from differing geographical sources and growing conditions have differing properties, and as a result some commercial tea blends inherently produce infusions of lower quality colour.
It is known tha-t citric acid improves the colour of the tea liquor obtained on infusion. It has also been suggested to include a buffering agent, such as citric acid and ascorbic acid and their salts, mixed with leaf tea in tea bags to improve the colour of the resulting infusions. Because the amount of such buffering agents necessary is normally quite small, the dosing of such small quantities of ingredients in a tea bag poses considerable practical problemsO Whereas in principle it is possible to dose the buffering agent, usually-a powder, into the bag during the filling operation, this method is not an attractive proposition for use in practice because it needs highly accurate dosing systems and modification of the standard tea bag filling machines.
_ 2 -~ a~
An alternative is to blend the acid or buffering agent into the leaf-stock before filling, but it is very diffi-cult to achieve a homogeneous distribution of the powdered buffering agent in the leaf tea bulk, due to differences in density, shape and particle size. As a result, the tea bags will show a considerable variation in additive content, ranging from nil to much too high a percenl:age.
The present invention provides a method of producing tea bags from which infusions having improved colour can be derived, without incurring the above drawbacks.
B~ the invention it has now been found that an impro-ved colour of the tea liquor on infusion is obtained if the tea bag is made from water-pervious sheet material having acidic material incorporated therein, and the water-pervious sheet material thereby has an acid reaction on contact with water, i.e. results in the liberation of hydrogen ions into solution.
Preferably, the acidic material is edible, and the water used for infusing the leaf tea liberates the acidic material from the water-pervious sheet material into the liquor, leading to the desired colour improvement. The acidic material is incor-porated in the water-pervious sheet material prior to the making of the tea bag, and so the above-described dosing prob-lems are mitigated and a much better control of the content of acidic material per bag can be achieved.
The invention provides a tea bag formed o~ water-pervious sheet material having impregnated therein, at a level of 0.03 to 0.5 mg/sq cm an edible acidic material releasable from the water-pervious sheet material on immersion in water, the tea bag incorporating from 2 to 25 mg of impregnated edible ,B
.. ... , `, .. .`, .......... . .... , ,.. ;.. ... . ..... ..... ;.
,: ' ` ' `' "''' , '' ` ':':' :~':.:`''':~': '' .~'' :'' : '' " '`'' : .: ' ' `
acidic material per gram of leaf tea and the edible acidic material being selected from the following: citric acid, malic acid, glutaric acid, tartaric acid, succinic acid, monosodium hydrosulphate, and buffering mixtures of any of these acidic materials with water-soluble salts of the same acidic materials.
Preferably the amount of acidic material impregnated in the water-pervious sheet material is at least 0.05 mg/sq cm.
Preferably the amount of acidic material impregnated in the water-previous sheet material is not greater than 0.3 mg/sq cm.
Preferably the tea bag contains at least 5 mg of im-pregnated acidic material per gram of tea. Preferably the tea bag contains not more than 20 mg of impregnated acidic material per gram of tea.
Preferably the edible acidic material is water-soluble and has a solid crystalline structure in the dry state. The acidic material can be a free acid. Instead of one acid, mix-tures of two or more can be used. Without detracting from the inventive concept, a buffering mixture comprising an acid and its salt can be used as well, and the expression "acidic material" should be read as including such a combination. Pre-ferably the acidic material impregnated in the tea bag paper always includes citric acid. The advantages of the invention can be achieved in a very straightforward manner simply by the use of citric acid as the sole acidic material. Examples of suitable buffers are combinations of an edible acid with a water-soluble salt of the same acid. Alkali-metal salts are preferred. Specific examples of suitable buffers are citric acid/trisodium citrate, .~
. . , ; ........................ . .. ,, ~ . . .
;, . . ,: -malic aci-l/sodium malate and potassium dihydrogen phospha-te/
dipo-tassium hydrogen phosphate.
~`~s the colour of the tea infus-ion depends upon the -temporary hardness of the water used to prepare the infusion, the more alkaline the water the greater is -the quantity o~
acidic material needed to brighten up -the colour to a su~ficient degree, and less acidic material is necessary in so-fter water areas. The ranges stated above, however, are quite ade~uate to cover a wide range o~ water alkali~ ty, without de~rimentally affecting the other beverage qualities of the tea.
The water-pervious sheet material can be any of the materials in current use, or proposed for use, in tbe manufacture of tea bags. The commonest material is paper, but woven fabrics and synthetic gauzes made ~rom, for e~ample, polypropylene, can be employed. The physical properties, such as porosity and strength when dry and wet, required in a sheet material from which tea bags are to be manu~actured are well known in the art, and form no part o~ the present invention.
For convenience, the invention will be further described in relation to tea bags made from paper, impregnated with water-soluble edible acidic materials.
Various techniques for incorporating an agent in paper are known in the art, and any suitable technique can be employed.
The edible acidic material can be impregna-ted in tbe paper by addition thereto during a we-t stage of the o-therwise conventional process by which commercial tea bag paper is made, ie by incorporation in the pulp prior to or during -the making of -the paper. A convenient apparatus, ~nown for use in the manufacture of impregnated papers in general, is the size press. Alternatively, commercial tea bag paper can be dipped in or sprayed with an aqueous solution of edible acidic material and subsequently dried. Where the edible acidic material is impregnated into commercial tea bag paper1 it is possible that shrinkage of the paper will resul-t. Thus i-t is preferable -that the edible acidic material be impregna-ted in the paper before the paper is cut to a dimension suitable for the manu~acture o~ tea bags. Preferably the aqueous solution of the edible acidic material in-to which commercial tea bag paper is dipped contains ~rom 1 to 10% by weight o~ the acidic material.
When the impregnated paper is made by spraying an aqueous solution onto commercial tea bag paper, the aqueous solution preferably contains from 5 to 6~/o by weight of the acidic material.
The invention is illus-trated by the following Examples.
Examples 1 - 7 The effect of certain edible acids on the colour of tea liquors obtained from tea bags was assessed as follows.
Commercial tea bag paper was impregnated with edible acid -by dipping in an aqueous solution of the acid, and drying, the ;~
resulting acid load in the paper being approximately 0.28 mg/sq cm. The impregnated paper was used to prepare tea bags of the standard heat-sealed type, each bag belng constructed from a total of 106 sq cm of paper and containing 2 grams of "MCTB"
catering grade blend blac~ leaf tea. Each bag therefore contained ~pproximately 30 mg of the acid. Control bags made from non-impregnated paper were prepared also.
200 ml of water having a temporary hardness of 180 ppm was used to infuse one -tea bag, and the properties of the resulting liquor assessed against the control. Colour scoring was in arbitrary units, i.e. highest score = best colour. ~he results " ~. . .
. -~ . . " :
are shown below.
Example Acid Colour Score Flavour ~ e Control None ~ Good l. Citric acid ~1+~ "
A substantial amount of tea is sold in tea bags. ~ea bags usually contain leaf tea in amounts of about 2 - 3 grams per bag, black leaf tea being the most commonly used. Some-times the leaf tea is blended wi-th minor amounts o~ instant soluble tea.
The beverage qualities of both leaf -tea and instant soluble tea are par-tly determined by the water with which -tbey are infused during preparation of the be~erage. Teas brewed in water with a high temporary hardness often have an undesirable grey_brown colour. In addition, teas from differing geographical sources and growing conditions have differing properties, and as a result some commercial tea blends inherently produce infusions of lower quality colour.
It is known tha-t citric acid improves the colour of the tea liquor obtained on infusion. It has also been suggested to include a buffering agent, such as citric acid and ascorbic acid and their salts, mixed with leaf tea in tea bags to improve the colour of the resulting infusions. Because the amount of such buffering agents necessary is normally quite small, the dosing of such small quantities of ingredients in a tea bag poses considerable practical problemsO Whereas in principle it is possible to dose the buffering agent, usually-a powder, into the bag during the filling operation, this method is not an attractive proposition for use in practice because it needs highly accurate dosing systems and modification of the standard tea bag filling machines.
_ 2 -~ a~
An alternative is to blend the acid or buffering agent into the leaf-stock before filling, but it is very diffi-cult to achieve a homogeneous distribution of the powdered buffering agent in the leaf tea bulk, due to differences in density, shape and particle size. As a result, the tea bags will show a considerable variation in additive content, ranging from nil to much too high a percenl:age.
The present invention provides a method of producing tea bags from which infusions having improved colour can be derived, without incurring the above drawbacks.
B~ the invention it has now been found that an impro-ved colour of the tea liquor on infusion is obtained if the tea bag is made from water-pervious sheet material having acidic material incorporated therein, and the water-pervious sheet material thereby has an acid reaction on contact with water, i.e. results in the liberation of hydrogen ions into solution.
Preferably, the acidic material is edible, and the water used for infusing the leaf tea liberates the acidic material from the water-pervious sheet material into the liquor, leading to the desired colour improvement. The acidic material is incor-porated in the water-pervious sheet material prior to the making of the tea bag, and so the above-described dosing prob-lems are mitigated and a much better control of the content of acidic material per bag can be achieved.
The invention provides a tea bag formed o~ water-pervious sheet material having impregnated therein, at a level of 0.03 to 0.5 mg/sq cm an edible acidic material releasable from the water-pervious sheet material on immersion in water, the tea bag incorporating from 2 to 25 mg of impregnated edible ,B
.. ... , `, .. .`, .......... . .... , ,.. ;.. ... . ..... ..... ;.
,: ' ` ' `' "''' , '' ` ':':' :~':.:`''':~': '' .~'' :'' : '' " '`'' : .: ' ' `
acidic material per gram of leaf tea and the edible acidic material being selected from the following: citric acid, malic acid, glutaric acid, tartaric acid, succinic acid, monosodium hydrosulphate, and buffering mixtures of any of these acidic materials with water-soluble salts of the same acidic materials.
Preferably the amount of acidic material impregnated in the water-pervious sheet material is at least 0.05 mg/sq cm.
Preferably the amount of acidic material impregnated in the water-previous sheet material is not greater than 0.3 mg/sq cm.
Preferably the tea bag contains at least 5 mg of im-pregnated acidic material per gram of tea. Preferably the tea bag contains not more than 20 mg of impregnated acidic material per gram of tea.
Preferably the edible acidic material is water-soluble and has a solid crystalline structure in the dry state. The acidic material can be a free acid. Instead of one acid, mix-tures of two or more can be used. Without detracting from the inventive concept, a buffering mixture comprising an acid and its salt can be used as well, and the expression "acidic material" should be read as including such a combination. Pre-ferably the acidic material impregnated in the tea bag paper always includes citric acid. The advantages of the invention can be achieved in a very straightforward manner simply by the use of citric acid as the sole acidic material. Examples of suitable buffers are combinations of an edible acid with a water-soluble salt of the same acid. Alkali-metal salts are preferred. Specific examples of suitable buffers are citric acid/trisodium citrate, .~
. . , ; ........................ . .. ,, ~ . . .
;, . . ,: -malic aci-l/sodium malate and potassium dihydrogen phospha-te/
dipo-tassium hydrogen phosphate.
~`~s the colour of the tea infus-ion depends upon the -temporary hardness of the water used to prepare the infusion, the more alkaline the water the greater is -the quantity o~
acidic material needed to brighten up -the colour to a su~ficient degree, and less acidic material is necessary in so-fter water areas. The ranges stated above, however, are quite ade~uate to cover a wide range o~ water alkali~ ty, without de~rimentally affecting the other beverage qualities of the tea.
The water-pervious sheet material can be any of the materials in current use, or proposed for use, in tbe manufacture of tea bags. The commonest material is paper, but woven fabrics and synthetic gauzes made ~rom, for e~ample, polypropylene, can be employed. The physical properties, such as porosity and strength when dry and wet, required in a sheet material from which tea bags are to be manu~actured are well known in the art, and form no part o~ the present invention.
For convenience, the invention will be further described in relation to tea bags made from paper, impregnated with water-soluble edible acidic materials.
Various techniques for incorporating an agent in paper are known in the art, and any suitable technique can be employed.
The edible acidic material can be impregna-ted in tbe paper by addition thereto during a we-t stage of the o-therwise conventional process by which commercial tea bag paper is made, ie by incorporation in the pulp prior to or during -the making of -the paper. A convenient apparatus, ~nown for use in the manufacture of impregnated papers in general, is the size press. Alternatively, commercial tea bag paper can be dipped in or sprayed with an aqueous solution of edible acidic material and subsequently dried. Where the edible acidic material is impregnated into commercial tea bag paper1 it is possible that shrinkage of the paper will resul-t. Thus i-t is preferable -that the edible acidic material be impregna-ted in the paper before the paper is cut to a dimension suitable for the manu~acture o~ tea bags. Preferably the aqueous solution of the edible acidic material in-to which commercial tea bag paper is dipped contains ~rom 1 to 10% by weight o~ the acidic material.
When the impregnated paper is made by spraying an aqueous solution onto commercial tea bag paper, the aqueous solution preferably contains from 5 to 6~/o by weight of the acidic material.
The invention is illus-trated by the following Examples.
Examples 1 - 7 The effect of certain edible acids on the colour of tea liquors obtained from tea bags was assessed as follows.
Commercial tea bag paper was impregnated with edible acid -by dipping in an aqueous solution of the acid, and drying, the ;~
resulting acid load in the paper being approximately 0.28 mg/sq cm. The impregnated paper was used to prepare tea bags of the standard heat-sealed type, each bag belng constructed from a total of 106 sq cm of paper and containing 2 grams of "MCTB"
catering grade blend blac~ leaf tea. Each bag therefore contained ~pproximately 30 mg of the acid. Control bags made from non-impregnated paper were prepared also.
200 ml of water having a temporary hardness of 180 ppm was used to infuse one -tea bag, and the properties of the resulting liquor assessed against the control. Colour scoring was in arbitrary units, i.e. highest score = best colour. ~he results " ~. . .
. -~ . . " :
are shown below.
Example Acid Colour Score Flavour ~ e Control None ~ Good l. Citric acid ~1+~ "
2 Malic acid
3. Glutaric acid .~ "
4. Tartaric acid
5. Succinic acid ~+ Slight off--taste
6. NaES04 +~ Good 10. 7. Ascorbic acid ++-~
Example 8 The effect o~ citric acid on the pE values of in~usions obtained ~rom various commercial tea blends was examined. Tea bags o~ the "Constanta" type were made from paper which had been 15. impregnated, by dipping and drying, with citric acid at a level o~ approximately 0.23 mg/sq cm, each bag being constructed from 130 sq cm of paper and there~ore con-taining a total o~ 30 mg acid. The bags each contained 2 grams of lea~ tea of one of the following blends. Control bags were prepared using non-20. impregnated paper. Each bag was in~used in 180 ml o~ boilingwater, and the pH o~ the resulting liquor measured using a standard pE meter. ~he pE values measured were as ~ollows:
pE values Control tea 25. Tea Blend without acid Citrated_tea "Yellow label" 6.14 5.54 China 6.03 5.55 Ceylon 6.85 6.37 Darjeeling 6.78 6.37 30. "English Breakfast" 6.70 6.00 : . , . :: ~, : ,, , ~ ,::
The above results show -tha-t an acid: tea ratio of 15 mg/gram produces a pH value safely above 4.6, -the pE value at which milk curdlesO
Example 9 This Example shows tristimulus colour values of -the liquors produced from various commercial -tea blends with and without citric acid (30 mg/bag: standard heat-sealed type made as per Examples 1 to 7 above). The tea colours were measured under standard conditions with the Pretema ~eflectance Spectrophotometer.
Colours were expressed in terms of luminance (Y), dominant wavelength (LD) and purity of colour (P). Each tea bag, containing 2 grams of leaf tea, was infused with 200 ml boiling water.
The results were as follows:
Tea Blend Sample Y LD P
"Yellow label" Control 11.28 581.B 0.466 Citrated 13.86 583.4 0.448 Ceylon Control 11.30 ~80.3 0.440 Citrated 11.54 581.5 0.437 Darjeeling Control 11.69 5~9.6 0.421 Citrated 12.16 580.1 0.393 "English Control 11.64 580.2 0.425 Breakfast"
Citrated 12.22 582.2 0.439 The above results show that in all cases citric acid increases the luminance value (Y) of the tea and shifts the dominant wavelength (LD) by 1 _ 2 nanometres towards ths red end of the spectrum. Although in most instances the purity of colour (P) was inferior in the citrated infusions, as measured by the colorimeter, this parameter is swamped by the improvements 30 in Y and LD and -the human eye sees an overall improvemsnt.
.
: . :
- ~ , ,, , : : : -In each instance the measured changes were accompanied by a marked increase in brighteness and orangeness as perceived by the eye.
Exam~le 10 This Exam~le illustrates the large-scale preparation o~
tea bags from paper impregnated with citric acid.
2,600m of Crompton 15 gsm oo~mercial tea bag paper, width 282 mm, was unrolled and passed tbrough a bath contai~ing 20 1 of 2.12% by weight aqueous citric acid, and dried by passage through a drying chamber con-taining heating zones at temperatures ranging from 38C to 56C. After rewinding, two 94 mm wid-th reels were cut, and this paper used to produce "Constanta" tea bags. Each tea bag contained 2 gm commercial black leaf tea, and approximately 9.7 mg acid. On infusion in 180 ml of boiling water, sample bags yielded liquors of good appearance and flavour.
Examples 11 and 12 ~he procedure of Example 10 was repeated, but using instead stronger solutions of citric acid at the impregnation stage, namely 4.24/g (Example 11) and 6.360/o (Example 12). These gave rise to "Constanta" tea bags each containing approximately 18.8 mg and 29.9 mg of citric acid respectively. Aqueous infusions obtained from these bags were e~en be-tter than those obtained from the tea bags o~ Example 10, this being consistent with the higher acid levels used.
_ g _ .
.
:~ . : , . :.: : .. . . .
: . , .::
. . .: : ~ ~ . . : : : . , , ~, ::' ;: :: '.: : . . : : ~ ' , :
Example 8 The effect o~ citric acid on the pE values of in~usions obtained ~rom various commercial tea blends was examined. Tea bags o~ the "Constanta" type were made from paper which had been 15. impregnated, by dipping and drying, with citric acid at a level o~ approximately 0.23 mg/sq cm, each bag being constructed from 130 sq cm of paper and there~ore con-taining a total o~ 30 mg acid. The bags each contained 2 grams of lea~ tea of one of the following blends. Control bags were prepared using non-20. impregnated paper. Each bag was in~used in 180 ml o~ boilingwater, and the pH o~ the resulting liquor measured using a standard pE meter. ~he pE values measured were as ~ollows:
pE values Control tea 25. Tea Blend without acid Citrated_tea "Yellow label" 6.14 5.54 China 6.03 5.55 Ceylon 6.85 6.37 Darjeeling 6.78 6.37 30. "English Breakfast" 6.70 6.00 : . , . :: ~, : ,, , ~ ,::
The above results show -tha-t an acid: tea ratio of 15 mg/gram produces a pH value safely above 4.6, -the pE value at which milk curdlesO
Example 9 This Example shows tristimulus colour values of -the liquors produced from various commercial -tea blends with and without citric acid (30 mg/bag: standard heat-sealed type made as per Examples 1 to 7 above). The tea colours were measured under standard conditions with the Pretema ~eflectance Spectrophotometer.
Colours were expressed in terms of luminance (Y), dominant wavelength (LD) and purity of colour (P). Each tea bag, containing 2 grams of leaf tea, was infused with 200 ml boiling water.
The results were as follows:
Tea Blend Sample Y LD P
"Yellow label" Control 11.28 581.B 0.466 Citrated 13.86 583.4 0.448 Ceylon Control 11.30 ~80.3 0.440 Citrated 11.54 581.5 0.437 Darjeeling Control 11.69 5~9.6 0.421 Citrated 12.16 580.1 0.393 "English Control 11.64 580.2 0.425 Breakfast"
Citrated 12.22 582.2 0.439 The above results show that in all cases citric acid increases the luminance value (Y) of the tea and shifts the dominant wavelength (LD) by 1 _ 2 nanometres towards ths red end of the spectrum. Although in most instances the purity of colour (P) was inferior in the citrated infusions, as measured by the colorimeter, this parameter is swamped by the improvements 30 in Y and LD and -the human eye sees an overall improvemsnt.
.
: . :
- ~ , ,, , : : : -In each instance the measured changes were accompanied by a marked increase in brighteness and orangeness as perceived by the eye.
Exam~le 10 This Exam~le illustrates the large-scale preparation o~
tea bags from paper impregnated with citric acid.
2,600m of Crompton 15 gsm oo~mercial tea bag paper, width 282 mm, was unrolled and passed tbrough a bath contai~ing 20 1 of 2.12% by weight aqueous citric acid, and dried by passage through a drying chamber con-taining heating zones at temperatures ranging from 38C to 56C. After rewinding, two 94 mm wid-th reels were cut, and this paper used to produce "Constanta" tea bags. Each tea bag contained 2 gm commercial black leaf tea, and approximately 9.7 mg acid. On infusion in 180 ml of boiling water, sample bags yielded liquors of good appearance and flavour.
Examples 11 and 12 ~he procedure of Example 10 was repeated, but using instead stronger solutions of citric acid at the impregnation stage, namely 4.24/g (Example 11) and 6.360/o (Example 12). These gave rise to "Constanta" tea bags each containing approximately 18.8 mg and 29.9 mg of citric acid respectively. Aqueous infusions obtained from these bags were e~en be-tter than those obtained from the tea bags o~ Example 10, this being consistent with the higher acid levels used.
_ g _ .
.
:~ . : , . :.: : .. . . .
: . , .::
. . .: : ~ ~ . . : : : . , , ~, ::' ;: :: '.: : . . : : ~ ' , :
Claims (9)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A tea bag, formed from water-pervious sheet material having impregnated therein at a level of 0.03 to 0.5 mg/sq cm an edible acidic material releasable from the water-pervious sheet material on immersion in water, the tea bag incorporating from 2 to 25 mg of impregnated edible acidic material per gram of leaf tea and the edible acidic material being selected from the following: citric acid, malic acid, glutaric acid, tartaric acid, succinic acid, monosodium hydro-sulphate, and buffering mixtures of any of these acidic materials with water-soluble salts of the same acidic materials.
2. A tea bag as claimed in Claim 1, wherein the edible acidic material is impregnated in the water-pervious sheet material at a level of at least 0.05 mg/sq cm.
3. A tea bag as claimed in Claim 1, wherein the edible acidic material is impregnated in the water-pervious sheet ma-terial at a level of not greater than 0.3 mg/sq cm.
4. A tea bag as claimed in Claim 1, incorporating at least 5 mg of impregnated edible acidic material per gram of leaf tea.
5. A tea bag as claimed in Claim 1, incorporating not more than 20 mg of impregnated acidic material per gram of leaf tea.
6. A tea bag as claimed in Claim 1, wherein the water-pervious sheet material is paper.
7. A tea bag as claimed in any one of Claims 1, 4 or 6, wherein the edible acidic material is citric acid.
8. A tea bag as claimed in any one of Claims 1, 4 or 6, wherein the edible acidic material is malic acid.
9. A tea bag r containing from 2 to 3 gm of leaf tea and formed from water-pervious paper impregnated with citric acid at a level of 0.05 to 0.3 mg/sq cm, the tea bag containing from 5 to 20 mg of impregnated citric acid per gram of leaf tea, and the impregnated citric acid being releasable from the paper on immersion in water.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB16824/77A GB1603414A (en) | 1977-04-22 | 1977-04-22 | Tea bags |
| GB16824/77 | 1977-04-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1114248A true CA1114248A (en) | 1981-12-15 |
Family
ID=10084356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA301,213A Expired CA1114248A (en) | 1977-04-22 | 1978-04-17 | Tea bags |
Country Status (18)
| Country | Link |
|---|---|
| JP (1) | JPS541190A (en) |
| AT (1) | AT366120B (en) |
| AU (1) | AU515207B2 (en) |
| BE (1) | BE866274A (en) |
| BR (1) | BR7802476A (en) |
| CA (1) | CA1114248A (en) |
| CH (1) | CH627708A5 (en) |
| DE (1) | DE2816829A1 (en) |
| FI (1) | FI781176A7 (en) |
| FR (1) | FR2387860A1 (en) |
| GB (1) | GB1603414A (en) |
| IE (1) | IE46798B1 (en) |
| IN (1) | IN148240B (en) |
| IT (1) | IT1111463B (en) |
| NL (1) | NL7804257A (en) |
| NO (1) | NO148549C (en) |
| SE (1) | SE7804611L (en) |
| ZA (1) | ZA782290B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO177624C (en) * | 1989-10-31 | 1995-10-25 | Philip Morris Prod | Paper cover for a smoking article and its use |
| PL1883309T3 (en) * | 2005-02-01 | 2010-01-29 | Koerber Helmut | Method for preparing tea from black or green tea leaves |
| JP5836692B2 (en) * | 2011-08-09 | 2015-12-24 | 守康 村田 | Tea bag |
| JP6297595B2 (en) * | 2013-01-31 | 2018-03-20 | グラットフェルター ゲルンスバッハ ゲーエムベーハー | Crosslinking / functionalizing system for paper or non-woven fabric |
| DE102013227044B4 (en) | 2013-12-20 | 2018-03-22 | Martin Bauer Gmbh & Co. Kg | Brewing capsule for producing a tea beverage in capsule brewing machines and filling for such a brewing capsule |
| CN109561708A (en) | 2016-08-15 | 2019-04-02 | 荷兰联合利华有限公司 | Method for producing leaf tea product |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3006764A (en) * | 1959-02-17 | 1961-10-31 | Duncan Coffee Company | Tea bag |
| DE2332227A1 (en) * | 1972-06-29 | 1974-01-10 | Unilever Nv | TEABAG |
| US3914439A (en) * | 1974-08-16 | 1975-10-21 | Shepard Chemical Ind Inc | Dry particulate flavor composition, method of making same and use thereof |
-
1977
- 1977-04-22 GB GB16824/77A patent/GB1603414A/en not_active Expired
-
1978
- 1978-04-17 CA CA301,213A patent/CA1114248A/en not_active Expired
- 1978-04-18 IN IN420/CAL/78A patent/IN148240B/en unknown
- 1978-04-18 AU AU35183/78A patent/AU515207B2/en not_active Expired
- 1978-04-18 FI FI781176A patent/FI781176A7/en not_active Application Discontinuation
- 1978-04-18 DE DE19782816829 patent/DE2816829A1/en not_active Withdrawn
- 1978-04-20 NO NO781394A patent/NO148549C/en unknown
- 1978-04-20 BR BR7802476A patent/BR7802476A/en unknown
- 1978-04-20 NL NL7804257A patent/NL7804257A/en not_active Application Discontinuation
- 1978-04-20 FR FR7811693A patent/FR2387860A1/en active Granted
- 1978-04-21 BE BE187032A patent/BE866274A/en not_active IP Right Cessation
- 1978-04-21 JP JP4763978A patent/JPS541190A/en active Pending
- 1978-04-21 IT IT67917/78A patent/IT1111463B/en active
- 1978-04-21 IE IE784/78A patent/IE46798B1/en unknown
- 1978-04-21 SE SE7804611A patent/SE7804611L/en unknown
- 1978-04-21 CH CH433978A patent/CH627708A5/en not_active IP Right Cessation
- 1978-04-21 ZA ZA00782290A patent/ZA782290B/en unknown
- 1978-04-24 AT AT0291878A patent/AT366120B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| BR7802476A (en) | 1978-12-12 |
| ZA782290B (en) | 1979-11-28 |
| IE780784L (en) | 1978-10-22 |
| IN148240B (en) | 1980-12-13 |
| NO148549B (en) | 1983-07-25 |
| NO781394L (en) | 1978-10-24 |
| CH627708A5 (en) | 1982-01-29 |
| AU3518378A (en) | 1979-10-25 |
| JPS541190A (en) | 1979-01-06 |
| FR2387860B1 (en) | 1983-05-27 |
| IE46798B1 (en) | 1983-09-21 |
| ATA291878A (en) | 1981-07-15 |
| IT7867917A0 (en) | 1978-04-21 |
| IT1111463B (en) | 1986-01-13 |
| FI781176A7 (en) | 1978-10-23 |
| NO148549C (en) | 1983-11-02 |
| NL7804257A (en) | 1978-10-24 |
| FR2387860A1 (en) | 1978-11-17 |
| AT366120B (en) | 1982-03-10 |
| BE866274A (en) | 1978-10-23 |
| SE7804611L (en) | 1978-10-23 |
| GB1603414A (en) | 1981-11-25 |
| AU515207B2 (en) | 1981-03-19 |
| DE2816829A1 (en) | 1978-10-26 |
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