CA1316753C - Tea concentrate having freeze/thaw stability and enhanced cold water solubility - Google Patents
Tea concentrate having freeze/thaw stability and enhanced cold water solubilityInfo
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- CA1316753C CA1316753C CA000536499A CA536499A CA1316753C CA 1316753 C CA1316753 C CA 1316753C CA 000536499 A CA000536499 A CA 000536499A CA 536499 A CA536499 A CA 536499A CA 1316753 C CA1316753 C CA 1316753C
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Abstract
TEA CONCENTRATE HAVING
FREEZE/THAW STABILITY AND
ENHANCED COLD WATER SOLUBILITY
Abstract of the Disclosure A tea concentrate which is stable against flake formation during cyclic freezing and thawing and which has enhanced solubility in cold water is disclosed. The tea concentrate comprises from about 0.4 to about 8% by weight tea solids, an edible gum selected from xanthan gum, cellulose gums, locust bean gum, guar gum and mixtures thereof in specified amounts, and optionally a solubilizer selected from the sugars, the polyols and mixtures thereof in specified amounts. The tea concentrate has a pH of about 4.6 or less at 20°C and is therefore stable against the growth of most microbial pathogens without the use of preservatives. Tea beverages prepared from this tea concentrate also have low astringency, fresh brewed tea flavor, and an enhanced mouthfeel.
FREEZE/THAW STABILITY AND
ENHANCED COLD WATER SOLUBILITY
Abstract of the Disclosure A tea concentrate which is stable against flake formation during cyclic freezing and thawing and which has enhanced solubility in cold water is disclosed. The tea concentrate comprises from about 0.4 to about 8% by weight tea solids, an edible gum selected from xanthan gum, cellulose gums, locust bean gum, guar gum and mixtures thereof in specified amounts, and optionally a solubilizer selected from the sugars, the polyols and mixtures thereof in specified amounts. The tea concentrate has a pH of about 4.6 or less at 20°C and is therefore stable against the growth of most microbial pathogens without the use of preservatives. Tea beverages prepared from this tea concentrate also have low astringency, fresh brewed tea flavor, and an enhanced mouthfeel.
Description
1 31 67J ) TEA CONCENTRATE HAVING
FREEZE/THAW STABILITY AND
ENHANCED COLD WATER SOLUBILITY
Technical Field The present invention relates to tea concentrates having ~tability against flake formation during cyclic freezing and thawing and enhanced qolubility when reconstituted with cold 5 tap water.
Tea creaming occurs during the production of tea extracts in the commercial manufacture of various types of tea products. The cream is a precipitate resulting primarily from the formation of polyphenol-caffeine complexes. Some 10 components of this cream have limited solubility in cold water which causes clouding of tea beverage~.
A decreaming step is employed in the manufacture of many tea products to precipitate and remove these complexes.
Several decreaming methods are known in the art. These 15 methods include adjustments in operating variables, especially temperature, to cause precipitation of the tea cream complexes, followed by centrifugation, flltration or other equivalent techniques to remove the precipitated complexe3.
During manufacture and sale, frozen tea concentrates 20 can also endure cycles of partial thawing and refreezing due to temperature variations in the distribution system, as well as in store and consumer freezers. Even though the majority of tea cream components which cause clouding in cold water are removed during production of the concentrate, addi~onal 2 5 precipitation can occur due to freeze concentration of the remaining tea solids because of this freeze/thaw cycling.
During the "freeze" portion of the cycle, ice crystals form in the tea concentrate. The tea solids are rejected by ths ice crystals and are concentrated in the boundary layer between ~k ~.
the liquid tea phase and the ice crystals. AB the concentration of tea solid~ in this boundary layer increases, the polyphenols present (e. g. thearubigins and theaflavin~) begin to interact with themselves and other materials such a~
S caffeine and protein to form larger, heavier complexes which precipitate out as visible flakes when the concentrate is thawed . A tea concentrate containing these insolub le flakes, even when added to hot water, yields a cloudy tea beverage which has visible particles.
Even when distributed frozen, tea concentrates may be subjected to warm or nonrefrigerated temperatures for significant length~ of time before u~e . Accordingly > the tea concentrate needs to be stable against the growth of most microbial pathogens. Most tea extracts have a pH of about 5.0 or higher. At such pHQ, a preservative would have to be added to inhibit microbial growth in case the tea concentrate thawed. Preservatives can impart undesired flavor effects. In the absence of preserva~ves, the tea concentrate needs to have a pH of about 4 . 6 or less to be 2 0 ~table against the growth of microbial pathogens when nonfrozen.
Besides freeze/thaw and microbial stability, a frozen tea concentrate should provide a tea beverage which has a relatively low to moderate astringency. Tea tannins (polyphenolic compounds of molecular weight 500 to 3000) are known to interact with sulivary protein~ in the mouth to form tannin-protein complexes. These complexes can precipitate out and give a puckering mouthfeel referred to as astringency. Some astringency is desirable from a tea beverage. However, exceAsive astringency and bitterness from a tea beverage can provîde an unplea~ant mouthfeel.
Tea beverage~ obtained from a frozen tea concentrate should also have a fre~h brewed flavor. The principle polyphenols of fresh brewed tea are the theaflavins and the theaxubigin~. TheaflaYins are believed to contribute to black tea flavor and color. Thearubigins are high molecular weight 131675 ~
~..~
compounds which also contribute flaYor and color. Although theaflavins make sign~ficant contributions to the flavor and appearance of a tea beverage, they are almost always present in lower amounts than the thearubifins. However, too high a 5 ratio of thearubigins/theailavins i8 indicative of a tea beverage having a flat taste and a dull appearance.
Preferred tea concentrates have a thearubigin:theaflavin ratio similar to that of fresh brewed tea.
An enhanced mouthfeel in a tea beverage obtained from a 10 frozen tea concentrate would also be desirable. Typical tea beverages have a viscosity of about 1 cenffpoise or le~ at 45F (7C). A higher viscosity tea beverage would provide a much more preferred thicker mouthfeel.
BACKGROUND ART
U.S. Patent 4,051,267 to Jonge]ing, issued Sept. 27, 1977, discloses that carrageenans are particularly suitable for suspending and stabilizing tannins (polyphenols) in a tea extract which is transported in a frozen or chilled condition for use in vending machines. The pH of the tea extracts 2 0 used appears to be at least 4.9 ba8ed on the Examples .
Jongeling also teaches that good suspension and stabilization can be obtained with xanthan gum. However, Jongeling found that even small amounts (less than 1 g. of xanthan gum per 100 ml. of tea extract) increased the viscosity of the tea 25 extract 80 thst the accuracy of dosing in the dispensing machine was impaired.
U.S. Patent 2,9B3,368 to Greenbaum, issued December 6, , 1960, disclo~es the use of small proportion of a su~pending agent, such as cellulose gum, a solubilizer, such as glycerol, 3 0 or both, in a tea concentrate to prevent precipitaffon of remaining caffeine and tannin constituents. The tea concentrate is prepared from a tea extract having a total solids content of 11 to 12% and a pH OI 4.8 to 5Ø The tea concentrate is preferably raised to a p~ of 5 . 5 by adding 35 sodium bicarbonate and is protected from microbial growth by the inclusion of sodium benzoate.
1 3 1 675 7~
DISCLOSURE OF THE INVENTION
An aspect of this invention is as follows:
A frozen tea concentrate having a pH of about 4.6 or less at 20~C and which comprises:
a. from about 0.4 to about 8% by weight decreamed tea solids;
b. an edible gum selected from the group consisting of xanthan gum in an amount of from about 5 to about 12% by weight of said tea solids; natural and modified gums selected from the group consisting of cellulose gums, locust bean gum, guar gum and mixtures thereof in an amount of from about 15 to about 50% by weight of said tea solids; and mixtures of from about 2 to about 5% by weight of said tea solids of said xanthan gum and from about 5 to about 25~ by weight of said tea solids of said natural and modified gums;
c. the balance water.
~0 A preferred optional component of the tea concentrate is a solubilizer selected from the sugars, polyols and mixtures thereof in a weight ratio to the tea solids of from about 0.5 to about 5.
Inclusion of the edible gum in the tea concentrates of the present invention makes them stable against flake formation during cyclic freezing and thawing. Inclusion of the gum also gives the resulting tea beverage an increased viscosity and therefore an enhanced mouthfeel.
Inclusion of the optional solubilizers make the tea concentrate much more cold water soluble. The tea ~oncentrates of the present invention are also stable against the growth of most microbial pathogens without the use of preservatives due to the relatively low pH.
These tea concentrates also provide tea beverages having a fresh brewed tea flavor which are relatively low in astringency and are non-bitter.
4a Another aspect of this invention is as follows:
A frozen tea concentrate having a pH of about 4.6 or less at 200c and which comprises:
a. from about 1 to about 4% by weight decreamed tea solids;
b. from about 6 to about 10% by weight of said tea solids of xanthan gum;
c. a solubilizer selected from the group consisting of high fructose corn syrup, maltodextrins, glycerol and mixtures thereof in a weight ratio to said tea solids of from about 0.~ to about 5;
d. the balance water.
Brief Description of the Drawings Figure 1 represents an HPLC chromatograph of the polyphenols present in an ice tea beverage prepared from the tea concentrate made according to the present invention.
.:
Figure 2 represents an HPLC chromatograph of the polyphenols present in an ice tea beverage prepared from a commercial bag tea product.
A. Deflnitions A8 used herein, the term "tea concentrate" refers to a product derived from concentrated tea extract which is diluted with water to form a drinkable tea bevera~e. Tea concentrates of the present invention comprise from about 0 . 4 to about 8% tea solids. Preferred tea concentrates of the pre~ent invention eomprise from about 1 to about 4% by wei~ht tea solids. The tea concentrates of the present invention can be in liquid product form but are preferably in frozen product form.
A~ used herein, the term "tea beverage" refers to a lS drinkable beverage prepared from the tea concentrates of the present invention by dilution with water. The tea concentrates of the present invent~on are generally diluted with from about 1 to about 40 parts water to provide the tea beverage. Preferred tea concentrates are typically diluted with from about 4 to about 20 parts water to provide the tea beverage .
As used herein, the term "tea solids" refers to those solids normally present in 8 tea extract. Polyphenolic compounds are normally the primary component of tea solids.
However, tea solids can also include caffeine, theobromine, proteins, amino acid~, minerals and carbohydrate~.
As used herein, the term "flake8" refers to insoluble tea so~d partieles formed at the boundary layer between the liquid tea phase and ice crystals due to freeze concentration of the tea concentrate. These insoluble llakes are extremely difficult to redis~olve in cold or hot water without the u~e of ultrasonic or high shear mixing.
As used herein, the term "comprising" means valiou~
components can be conjointly employed in the tea concentrates of the present invention. Accordingly, the term "comprising"
1 31 675~
encompasses the more restrictive terms "consisting essentially of" and "consisting of"
B. Tea Concentrate In addi~on to the tea solids, another key component of the tea concentrates of the present invention are certain edible gums. These edible gums perform at least four functions. The primary function is to prevent the tea polyphenols from forming a concentrated hydrophobic boundary phase between the liquid tea phase and ice crystals during the "freeze" por~on of cyclic freezing and thawing of the tea concentrate. This prevents the formation of in~oluble flakes that are visible in tea beverages when the tea concentrate i8 reconstituted with either hot or cold water.
The gums also perform a second, related function of ~olubilizing the tea solid~ of the concentrate when diluted with water to form the tea beverage.
The other two functions performed by the edible gums are related to mouthfeel effects in the tea beverage. The first i9 enhancing the mouthfeel of the beverage due to an 2 0 increased actual viscosity . As previously mentioned, tea beverages typically have a viscosity OI about 1 centipoise or less at 45F (7C). By contrast, tea beverages prepared from tea concentrates of the present invention typically have a viscosity of from about 2 to about 10 centipoise at 45F
(7C). This higher viscosity provides a desirable thicker mouthfeel impression.
The other mouthfeel function i8 reducing the astringency and perceived bitterness of the tea beverage. The gums are believed to aid in complexing the polyphenolic tannins. These tannins, when uncomplexed, are astringent because they bind salivary proteins. However, once the tannins form soluble complexes with the gum, they are much les~ likely to bind salivary protein. This reduces the astringency of the tea beverage .
The pre~erred edible gum for use in the tea concentrates of the present invention is xanthan gum. Xanthan gum i8 preferred because the resul'dng tea beverage, at dlqnking 1 3 1 675~
~.
strength, has a relatively high pH (about 5 . 6) which i~
considered de3irable. When used alone, the amount of xsnthan gum present in the tea concentrate i8 from about 5 to about 12% by weight of the tea solids. At levels much below about 5%, xanthan gum alone i8 not very effec'dve in preventing flake formation during freeze/thaw cycling of the tea concentrate. At levels much above about 12%, the re~ulting tea beverage ha~ too high a viscosity. Preferably, the amount of xanthan gum included is from about 6 to about 10% by weight of the tea solids.
Other modified and natural gums which are useful in the tea concentrates of the present invention are the cellulose gums, locust bean gum, guar gum and mixtures thereof.
Suitable cellulose gums include methylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, hydroxypropylcellulo~e, hydroxyethylcellulose, ethylhydroxyethylcellulose, and mixtures thereof. The preferred cellulose gum is carboxymethylcellulose. These other gums provide tea concentrates which yield tea beverages having a lower pH at drinking strength than those where xanthan gum is used. For example, carboxymethylce~ulose provides tea beveragas having a pH of about 5.
When used alone, these other gums (or mixtures thereof) 2 5 are included in the tea concentrate in an amount of from about 15 to about 50% by weight of the tea solids. At levels much below about 1596, these other gums alone sre not very ef~ective in preventing flake formation during ~reezelthaw cycling of the tea concentrate. At levels much above about 3 0 50%, the resulting tea beverage has too high a visco~ity .
Preferably, these other gums are included in an amount of from about 20 to about 40% by weight of the tea solids.
Effective mixtures of xanthan gum with these other natural and modified gums can also be used in tea 3 5 concentrates of the present invention . As used herein, the term "effective mixture" includes mixtures where xanthan ~ 3 1 675:3 ~ .~
gum is present in an effective amount ( from about 5 to about 1296 by weight of the tea solid~); mlxtures where the other modified and natural gums are present in an effec~ve amount ( from about 15 to about 50% by weight of the tea olids);
mixtures where both the xanthan gum and other gums are present in an effective amount; as well as mixtures of xanthan gum and other gums where neither alone is present in an effective smount but which together provide an effective amount of the edible gum for the purpose of inhibiting formation of insoluble ilakes during freeze/thaw cycling of the tea concentrate. For example, a mixture of about 4% xanthan gum and about 14% carboxymethylcellulose by weight of the tea solids i8 an effective mixture within the meaning of the present invenffon. Typically, these mixtures comprise xanthan gum in an amount of from about 2 to about 59~ by weight tea solids, and the other gums in an amount of from about 5 to about 25% by weight tea solids.
A preferred optionfll component included in the tea concentrates of the present invention i8 a solubilizer. The 2 0 solubilizer helps to keep the tea solids dissolved in the liquid tea phase to prevent the formation of cream and other precip-itates. Inclusion of solubilizers is particularly important if the tea concentrate is to have cold water solubility. As used herein, the term "cold water solubility" refers to a tea 2 5 concentrate which iB substantially soluble in water having a temperature of about 20C or less. Tea concentrates which contain a solubi~zer provide tea beverages having a turbidity of less than about 50 nephelometrics turbidity units (herein NTU). By comparison, tea concentrates of the present 3 0 invention which do not contain a solubilizer typically provide tea beverages having turbidity values of from about 50 to about 100 NTU . ( Turbidity values for the tea beverages resulting from these tea concentrates are measured by the analy'dcal method described hereafter.) Solubilizers useful in the tea concentrates of the pre~ent invention are ~elected from sugars, pol~ols and mixtures 1 31 675 ) ~ .
g thereof. Suitable sugars inclucle ructose, glucose, maltose, corn syrups (high fructose corn syrups and high maltose corn 3yrups), invert sugar, maltodextrins, polydextrose, cyclodextrinR and mixtures thereof. Preferred sugars for use in the present in~ention are the high fructose corn syrups and the maltodextrins. Suitable polyols for use in tea concentrates of the present include glycerol, propylene glycol, the sugar alcohols such as sorbitol, mannitol, maltol and xylitol, and ~he polyglycerols such as triglycerol, hexaglycerol, and decaglycerol. The preferred polyol for use in the tea concentrates of the present invention is glycerol.
The solublizers are included in the tea concentrates of the present invention in a weight ratio to the tea solids of from about 0 . 5 to about 5 . The particular amount included will depend upon the solubilizer choqen and the effects desired. For example, high fructose corn syrups are preferably included in a weight ratio to tea solids of from about 0 . 5 to about 2 . Another preferred sugar solubilizer, maltodextrin, is preferably included in a weight ratio to tea 2 0 solids of from about 0 . 5 to about 4 . The preferred polyol solubilizer, glycerol, is preferably included in the tea concentrates of the present invention in a weight ra'do to tea solids of from about 0 . 5 to about 2 . Care should also be taken to make sure that the solublizer is not included at a h}gh enough level to cause an off-flavor.
Certain combinations of edible gums with the solubilizers are especially preferred for use in the tea concentrates of the present invention. These preferred combinations include xanthan gum with high fructose corn syrup; xanthan gum 3 0 with maltodextrin; xanthan gum with a mixture of high fructose corn syrup and maltodextrin; carboxymethylcellulose with maltodextrin; carboxymethylcellulose with high fructoae corn syrup; carboxymethylcellulose with a mixturs of maltodextrin and high fructose corn syrup; and a mixture of 3 5 xanthan gum and carboxymethylcellulose with a mixture of high fructose corn ~yrup and maltodextrin. These preferred combinations can al o conta~n glycerol.
The tea concentrateq of the present invention have a pH
of about 4.6 or le~s at 20C, i.e. room temperature. As such, they are essentially stable against the growth oP most pathogenic bacteria without the use of pre~ervatives.
Typically, the pH of the tea concentrates of the present invention is from about 2 . 5 to about 4 . 6 at 20C . Generally, tea extracts used in the preparation of the tea concentrates of the present invention have a pH above ~.6, and typically about 5 . 0 . To acidify ~he tea extract for use in the tea concentrates of the present invention a suitable edible acid can be added in an amount appropriate to lower the pH to about 4.6 or les~. Suitable edible acids include fumaric acid, citric acid, adipic acid, tartaric acid, succinic acid, malic acid, hydrochloric acid, carbonic acid, ascorbic acid, phosphoric acid, as well as mixtures of these acid~ (e . g .
ascorbic acid and phosphoric acid). Malic acid, and especially phosphoric acid, are preferred for use in the tea concentrates of the present invention since they provide a tea beverage having a much higher pH when diluted to drinlcing strength. The tea concentrate can also be acidified by contact with an appropriate ion exchange resin. Examples of suitable ion exchange resins include Dowex HCR-S~, available from Dow Chemical Co. of Midland, MI, and Rohm ~ Haas IRC-5~ acid cationic exchange re~in available from Rohm h Haas of Philadelphia, PA. Acidification with ion exchange resins is a particularly us2ful method since the tea concentrate will provide a tea beverage having a much higher pH at drinking strength.
A particularly important property of the tea concentrates of the present invention i8 the fact that they provide tea beverages having a polyphenolic profile similar to that of fresh brewed tea. As previously mentioned, the principle polyphenols in tea are the theailavins and the thearubigins.
One adverse effect of ~he formation of ~soluble ~lakes during 1 3 1 675 ~
freeze/thaw cycles iB that the ratio of thearubigills to theaflavins increases with each cycle because the theaflavins are preferentially involved in flake formation. Thus, by preventing flake formation, the tea concentrates of the 5 present invention maintain a theaflavin content similar to that of fresh brewed tea. The tea concentrates of the present invention have a thearubigin to theaflavin ratio of from about 4 to about 8. By comparison, standard fresh brewed teas have a ratio from about 3 to about 10. This ratio is based on 10 the polyphenolic profile of the tea concentrate (or re~ulting tea beverage) obtained by high pressure liquid chrom-atography ~HPLC) according to a method described hereafter.
The similarity in flavor profile between the tea concentrates of the present invention and freshly brewed tea 15 is illustrated by a comparison of the HPLC chromatographs of ~igures 1 and 2 and especially the thearubigin to theaflavin ratios defined by these chromatographs. Figure 1 represents the HPLC chromatograph of a drinking strength iced tea beverage prepared from a tea concentrate made similar to 2 0 Embodiment 1 of the present invention . The retention time (minutes) and area under the curve for each peak of this chromatograph are as follows:
13167~3 Retention Time Area 1.07 6507 1.24 16~7 1.36 2633 1.65 829 2.04 1650 3.51 164 4.27 1190 6.08 333 6.49 131 10.87 382 12.87 624 13.28 184 13.49 1237 13.97 54 14.52 255 15.24 44 16.00 1569 16.4~ 4029 17.10 2300 17.90 4110 18.88 1299 19.09 1723 19.48 10485 20.10 6165 ~0.62 11152 21.18 2623 21.67 368 21.98 258 22.31 549 22.77 124 23.09 4607 24.08 4902 24.76 414 25.06 569 25.30 330 26.14 315 28.30 346 28.92 697 29.29 1~0 29.71 249 30.27 274 30.74 115 31.14 120 32.05 573 32.21 618 33.34 5542 34.32 218 34.71 606 35.41 86 36.12 1894 36.57 16a5 36.98 1760 38.08 143 38.63 46 40.19 93 42.36 42 The peaks at retention times 16.00 through 24.08 minutes are believed to represent the thearubigins and provide a total area of 57,385. The peaks at retention times 33.34 through 38.98 minutes are believed to represent the theaflavins and provide a total area of 11,731. The ratio of these total areas lO is 4.89.
Figure 2 represent~ an E~PLC chromatograph of an ice tea beverage freshly prepared from a commercial bag tea product. The retention time~ and area under the curve for each peak are as follows:
Retention Time Area 1.37 656 1.66 684 2.03 3267 2.45 2912 3.62 199 4.52 2919 6.12 82 6.37 339 l 0 6.67 843 7.18 63 8.63 76 9.93 45 10.31 128 11.00 382 11.89 133 13.09 1783 13.35 370 13.58 1345 14.08 81 14.62 214 15.08 272 16.14 16g4 16.61 4513 16.93 453 17.19 1631 17.98 2569 18.93 1682 19.18 1967 19.56 11491 20.20 6932 20.70 13261 21.25 1531 21.44 984 21.77 726 22.37 645 22.82 1399 23.12 5143 24.09 5622 4 0 24.79 787 25.01 616 25.30 400 26.15 638 27.00 133 28.26 603 28.90 932 29.63 381 30.19 189 30.65 76 32.07 1148 32.83 165 33.24 6821 34.15 274 13~6757) 34.5~ 773 35.27 441 35. g6 3133 3~.41 2805 36.79 3623 37.90 208 38.50 49 39.20 46 40.02 50 10 The peaks at reten'don times 16.14 through 24.09 minutes are believed to represent the thearubigins and provide a total area of 62,243. The peaks at retention times 33.24 through 36.79 minutes are believed to represent the theaflavins and provide a total area of 17,870. The ratio of these total areas 15 is 3.48.
Suitable optional ingredients for use in the tea concentrates of the pre~ent invention are chelating agents such as ethylenediaminetetraacetic acid (EDTA) or poly-phosphates such as sodium metaphosphate, sodium 2 0 pyrophosphate, tetra~odium pyrophosphate, sodium tripolypho~phate, potassium tripolyphosphate, tetrapotassium polyphosphate, tetrasodiummonopotassium tripolyphosphate, and hexaphos (sodium hexametaphosphate). Inclusion of these agents aids in maintaining tea beverage clarity in hard 25 water. Very low levels of preservatives such as the benzoates and sorbatas can also be included to inhibit mold growth. However, tea concentrates of the present invention are typically 3ubstantially free of such preservatives.
Generally, the tea concentratefi of the present invention 3 can be ~weetened or unAweetened . The use of the edible gums according to the present invention i8 particularly useful in preparing diet tea concentrates which contain a sweetening amount of a noncaloric swaetener such as saccharin, cyclamates, aoetosulfam, Lraspartyl-L,phenylalanine lower aIkyl ester sweetener~ (e.g. ASPAR~AME),IM L,aspartyl-D-alanine amides disclosed in U.S. Patent 4,411,925 to Brennan et al., issued October 23, 1983, L,aspartyl-D-serine amides disclosed in U.S.
Paten~ 4,399,163 . -:. ,~; ,.
13167~) to Brennan et al., issued August 16, 1983, L,aspartyl-Irl-hydroxy-methylaIkaneamide sweeteners disclosed in U.S. Patent 4,338,346 to Brand, issued December 21, 1982, ~,aspartyl-1-hydroxyethyl-alkaneamide sweeteners disclosed in U.S. Patent 4,423,029 to Rizzi, issued December 27, 1983, L,aspartyl-D-phenylglycine ester and amide sweeteners disclosed in European Patent Application 168,112 to J.M. Janusz, published January 15, 1986 and the like. A particularly preferred noncaloric sweetener for use in such diet tea concentrates is aspartame.
The tea concentrate of the present invention can also be flsvored with various natural or synthetic flavors. Natural and synthetic coloring agenta can also be included.
Particularly preferred are lemon flavoring (e.g. lemon oil~
and caramel coloring. These flavoring and coloring agents are included in the tea concentrates in amounts well known to those ~ki~led in the tea art.
Method for Preparing Tea Concentrates The tea extracts used in preparing the tea concentrates of the preserlt invention can be obtained from fermented and unfermented teas, e.g., black tea, oolong tea, green tea, or mixtures thereof. Typically, the tea extract i8 obtained from about 85 to 1009~i black tea leave~ and from 0 to about 15%
green tea leaves. When black tea is used in preparing the tea extract, it can be enzymatically pretreated according to the method described in European Patent Applica~on 135, 222 to C.H. Tsai, published May 27, 1985. In the Tsai method, black tea leaves are wetted with water containLng tannase and one or more cell-wall-digest mg enzymes, such as cellulase, pectinase, or hemicellulase prior to extraction. The enzyme-moistened ~ea leaves are incubated in a closed system at room temperature for a few hours, neutralized with a suitable ., 1 3 1 67 ~J ) foodgrade base and then heated to inactivate the enzymes.
The resulting enzyme-treated tea leaves provide a higher yield of tea extract which has better solubi3ity in cold water.
Ihe tea leaves, with or without pretreatment with enzymes, can then be extracted in a conventional manner to provide the tea ext~act. See P~ntauro, Tea and Soluble Tea Products ME~nufac~ure (1977), pp. 39-81, for various methods of obtaining tea extract from tea leaves. The tea leaves are typically slurried with 10 water followed by separation of the leave~ from the resulting tea extract. This extraction can be performed in a ~ingle batch fashion, as a continuous process, as a countercurrent multiple vessel process, or any combinaffon thereof.
Continuous countercurrent tea extraction i8 the mo~t 15 preferred method. If desired, tea aroma and flavor components can be volatilized from the extract, collected, condensed and added back at a later point in the process.
Also, the tea desorbate process disclosed in U . S . Patent 4,220,673 to Strobel, issued Sept. 2, 1980, can be used to 20 provide the tea extract. A tea extraction process ~ich avoids harsh tea flavors and preserves real tea flavor is desirable.
The tea extract resulting from slurry or countercurrent extraction of tea leaves produces a turbid beverage when 25 diluted with cold water. Typically, the tea extract is cooled to separate solids which form in a decreaming step. Solids which are precipitated by cooling consist chieily of tea creams resulting &om the formation vf complexes of polyphenolic compounds and caffeine. Removal of tea creams is typically 30 achieved by centrifugation, filtration or other suitable means.
Depending upon the desired concentration of tea solids in the product, the clarified extract can be further concentrated by ~uitable methods such as evaporation or rever~e osmosi~. See Pintauro, supra, pp. 82-141 (herein incorporated by 35 reference), for various representatlve methods for decreaming~, filtering and concentra'dng tea extract~.
.. ., 7, 1 31 6~53 The edible gums, solubilizers and other optional ingredients can be added at variou~ point~ in thi~ process.
For example, some or all of these product additives can be added to the tea extraction water prior to contact with the tea leaves. In particular, the addition of solubilizers to the water u3ed in tea extraction aids in the extraction of theaflavins and other tea components. Also, the previously described chelating agents such as EDTA and the polyphosphates can be added to the extraction water to sequeater undesired minerals such as calcium and magnesium typically present in hard water and tea leaves. The product additives, especially the edible gums and solubilizers, can also be added later in this process, such as before or after decreaming and clarification of the tea extract.
The tea extract, after appropriate processing to provide the desired level of tea solids and after the edible gums, solublizers and optional ingredients have been added, forms the tea concentrate of the present invention. This tea concentrate is preferably pasteurized or sterilized prior to packing in containers. The tea concentrate product can be distributed as a liquid tea concentrate or else can be chilled to provide a frozen tea concentrate product.
D. Analyffcal Methods The following analytical methods are used in the present 2 5 application to evaluate the polyphenolic profile and turbidity propertles of tea concentrates or tea beverages.
1. Polyphenols The polyphenols present in the tea concentrates or tea beverages are analyzed using a modification of the high 3 0 presaure liquid chrome.tography procedure described by Hoefler and Coggon, Journal of Chromatography, Yol. 129, (1976), pp. 460-63.
A DuPont model 8800 liquid chromatographic system (manufactured by DuPont Company, Analytical Instrument Division, Wilmington, DE 19898) with a variable wavelength ultraviolet spectrophotometlqc detector se~ at 380 nm is used.
Samples are injected onto a chromatographic column using a Dynatech Precision Sampling model LC-241 autosampler (available from Dynotech Preci~ion SampL~ng, Baton Rouge, LA
70895)~ A high pressure liquid chromatographic column, Supelco LC-18 3 um ODS, 15 cm x 4.6 mm (available from Supelco Inc., Bellefonte, PA 16823) is used. Chromato-graphic peaks are recorded using a Spectra-Physic~ model 4290 recording integrator (available from Spectra-Physics, 3333 N. Eirst St., San Jose, CA 95134). Peak integration i8 1 O accomplished u~ing a Hewlett-Packard model 1000 computer (available from Hewlett-Packard, 1820 Embarcadero Rd., Palo Alto, CA 94303).
A binary mob1le phase system i8 used. Mobile phase A
consists of O .24% glacial acetic acid in Milli-Q water (water purified in a Milli-Q Purification Unit, available from Millipore Corp. of Bedford, IIlIA 01730). Mobile phase B consi~ts of 50%
of O .24% glacial acetic acid in Milli-Q water and 50% acetone (HPLC grade3, available from Burdick ~ Jackson, 1953 S.
Harvey St., Muslcegon , ~II 49g42.
Sample~ are eluted in four timed solvent segments:
1) an isocratic segment of 80% mobile phase A and 20% mobile phase B for 2 minutes; 2) a linear gradient from 75% mobile phase A:25% mobile phase B to 25% mobile phase A:75% mobile phase B in 30 minutes; 3) an isocratic segment of 10% mobile phase A and 90% mobile phase B for 8 minutes; and 4) an isocratic segment of 80% mobile phase A and ~0% mobile phase B for 1 minute.
Tea solutions containing no carbohydrate additives are first made to drink~ng strength. An approximate volume of 2 3 0 ml is filtered through a O .45 um cellulose-scetate disposable filter, Millex HA, 25 mm diameter, available from IYlillipore Corp., Bedford, MA 01730. A 50 ul injectdon of the filtered solution is made.
Tea solutions containing carbohydrate additlves are 3 5 sequentially diluted with acetone and water to precipitate the carbohydrates insoluble in mobile phase B. For example, the ..
tea concentrate of the present inven'don is diluted as follows:
1 ) 1 ml tea concentrate is diluted with 2 ml acetone ( ~ource as above); 2~ precipitated carbohydrate material i8 removed with a pasteur pipet; 3 ) 1 ml of the resultant solution i8 S further diluted with 1. 67 ml l~lli-Q water; 4 ) 1 ml of the resulting ~olution is further diluted with 1 ml Milli-Q water to make a drinking strength solution. Approximately 2 ml of this solution is filtered through a 0 . 45 um ilter, described above, and 50 ul is injected onto the chromatographic column.
2. Turbidity The nephelometric method and nephelometric turbidity unit, as described in " Standard Methods for the Examination of Water and Waste Water", 14th ed., published by American Public Health Association, Wsshington, D. C ., is used to determine the cloudiness or turbidity of the tea beverages.
A Hach Ratio Turbidimeter, Model 18900-00, available from Hach Chemical Company , Loveland , Col ., is employed . It is calibrated prior to each measurement using Latex Standard solutions provided by Hach Chemical Company. For 2 0 refrlgerated beverages, the turbidity is measured at the refrigerated temperature, i.e. 45F (7C).
E. Specific Embodiments of Tea Concentrates of Present Invention The fo~owing specii~c embodiments are used to illustrate the tea concentrates of the present invention:
Embodiment 1 A blend of 909~ black tea leaves (Tender Lea~ blend) and 109~l Taiwanese green tea fannings was fed to a Niro~) countercurrent extractor (Model A27) at a rate of 0. 33 lbs./min. (.15 kg/min.). Distilled water wa~ treated with 0.02% sod~um hexametaphosphate and fed into the extractor at a flow rate and temperature of 3.5 lbs./min. (1.6 kg/min.) and 180F (82.2C), respe¢tively. The extract was cooled to a temperature of 124F (51.1C) at the discharge port of the 3 5 extractor . The extract was passed through a No . 200 (A.S.T.M. Standard) filter screen. This extract had a tea solids concentration of 4.~5%.
t316753 The extract was cooled to 85F (29.4C) and fed to a continuouq centrifuge (West Falia Separator Type SA-14-47-076) after a 30 minute hold time at 85F (29.4C) . The centrifuge was operated at 75~0 rpm. After clarifieation, the tea ~olid~ concentration wa~ 4.15% . The extract was diluted with distilled water to a concentration of 3.7% tea solids.
To 100 lbs. (45.4 kg~ of this tea extract were added and mixed 0.27 lbs. (276 grams) Keltrol-l~) foodgrade xanthan gum and 2.5 lbs. (1.1 kg) of maltodextrin using a contînuouq blender (Ladish Co. Triblender, Model No. F2116 ~ID-S).
Then, 4.0 lb~. (1.8 kg) of high fructose corn syrup-55, 0.49 lb. (222 grams) caramel color, and 0.0043 lbs. (1.95 grams) of FD~C Red Dye #40 were added and mixed in. The pH of the mixture was adjusted to 4.6 u~ing 0.08 lbs. (36.3 grams) of foodgrade 75% phosphoric acid. The tea concentrate was then packed into 4 oz. can~ after pasteurizing in a Crepaco UHT unit. The cans were then frozen at -10F (-23.3C).
The frozen concentrate obtained had 3% tea solids, 7%
(tea solids basis) of xanthan gum, 107% (tea solids basis) of high fructose corn syrup and 66% (tea solids bssis) of maltodextrin. One part of the tea concentrate diluted with 15 parts water provided a tea beverage having a turbidity value of 15 NTU and a viscosity of 2.7 centipoise at 45F (7C).
Embodiments 2 to 7 Six hundred and fifty (650) pounds (295.5 kg.) of distilled deaerated water at 70F (20C) is placed in a stainless steel tank. Thirty-two and one-half (32.5) pounds (14.8 kg.) of black tea leaves (Tender Lea~) blend) are mixed into the water. After constant agitaffon for 20 minutes, the glurry is allowed to settle for 20 minutes. The mixture i8 maintained at about 70F (21C) during this time.
Five hundred (500) pound~ (227.3 kg.) of the 70F
(21C) extract are then removed from the leaves by pumping the extract through a No. 200 lA.S.T.M. Standard filter screen . Five hundred (500) pounds (227.3 kg. ) of water are added to the residua~ leaves. This mixture is heated to 180F
1 3 1 67~3 (82C) while under constant agitation. Five hundred (500) pound~ (227.3 kg.) of tea extract i8 recovered fro~the heaffng tank by deleafing using a West Falia Separator (Type CA 220-010). The deleafed tea extract i8 mixed with the 70F
FREEZE/THAW STABILITY AND
ENHANCED COLD WATER SOLUBILITY
Technical Field The present invention relates to tea concentrates having ~tability against flake formation during cyclic freezing and thawing and enhanced qolubility when reconstituted with cold 5 tap water.
Tea creaming occurs during the production of tea extracts in the commercial manufacture of various types of tea products. The cream is a precipitate resulting primarily from the formation of polyphenol-caffeine complexes. Some 10 components of this cream have limited solubility in cold water which causes clouding of tea beverage~.
A decreaming step is employed in the manufacture of many tea products to precipitate and remove these complexes.
Several decreaming methods are known in the art. These 15 methods include adjustments in operating variables, especially temperature, to cause precipitation of the tea cream complexes, followed by centrifugation, flltration or other equivalent techniques to remove the precipitated complexe3.
During manufacture and sale, frozen tea concentrates 20 can also endure cycles of partial thawing and refreezing due to temperature variations in the distribution system, as well as in store and consumer freezers. Even though the majority of tea cream components which cause clouding in cold water are removed during production of the concentrate, addi~onal 2 5 precipitation can occur due to freeze concentration of the remaining tea solids because of this freeze/thaw cycling.
During the "freeze" portion of the cycle, ice crystals form in the tea concentrate. The tea solids are rejected by ths ice crystals and are concentrated in the boundary layer between ~k ~.
the liquid tea phase and the ice crystals. AB the concentration of tea solid~ in this boundary layer increases, the polyphenols present (e. g. thearubigins and theaflavin~) begin to interact with themselves and other materials such a~
S caffeine and protein to form larger, heavier complexes which precipitate out as visible flakes when the concentrate is thawed . A tea concentrate containing these insolub le flakes, even when added to hot water, yields a cloudy tea beverage which has visible particles.
Even when distributed frozen, tea concentrates may be subjected to warm or nonrefrigerated temperatures for significant length~ of time before u~e . Accordingly > the tea concentrate needs to be stable against the growth of most microbial pathogens. Most tea extracts have a pH of about 5.0 or higher. At such pHQ, a preservative would have to be added to inhibit microbial growth in case the tea concentrate thawed. Preservatives can impart undesired flavor effects. In the absence of preserva~ves, the tea concentrate needs to have a pH of about 4 . 6 or less to be 2 0 ~table against the growth of microbial pathogens when nonfrozen.
Besides freeze/thaw and microbial stability, a frozen tea concentrate should provide a tea beverage which has a relatively low to moderate astringency. Tea tannins (polyphenolic compounds of molecular weight 500 to 3000) are known to interact with sulivary protein~ in the mouth to form tannin-protein complexes. These complexes can precipitate out and give a puckering mouthfeel referred to as astringency. Some astringency is desirable from a tea beverage. However, exceAsive astringency and bitterness from a tea beverage can provîde an unplea~ant mouthfeel.
Tea beverage~ obtained from a frozen tea concentrate should also have a fre~h brewed flavor. The principle polyphenols of fresh brewed tea are the theaflavins and the theaxubigin~. TheaflaYins are believed to contribute to black tea flavor and color. Thearubigins are high molecular weight 131675 ~
~..~
compounds which also contribute flaYor and color. Although theaflavins make sign~ficant contributions to the flavor and appearance of a tea beverage, they are almost always present in lower amounts than the thearubifins. However, too high a 5 ratio of thearubigins/theailavins i8 indicative of a tea beverage having a flat taste and a dull appearance.
Preferred tea concentrates have a thearubigin:theaflavin ratio similar to that of fresh brewed tea.
An enhanced mouthfeel in a tea beverage obtained from a 10 frozen tea concentrate would also be desirable. Typical tea beverages have a viscosity of about 1 cenffpoise or le~ at 45F (7C). A higher viscosity tea beverage would provide a much more preferred thicker mouthfeel.
BACKGROUND ART
U.S. Patent 4,051,267 to Jonge]ing, issued Sept. 27, 1977, discloses that carrageenans are particularly suitable for suspending and stabilizing tannins (polyphenols) in a tea extract which is transported in a frozen or chilled condition for use in vending machines. The pH of the tea extracts 2 0 used appears to be at least 4.9 ba8ed on the Examples .
Jongeling also teaches that good suspension and stabilization can be obtained with xanthan gum. However, Jongeling found that even small amounts (less than 1 g. of xanthan gum per 100 ml. of tea extract) increased the viscosity of the tea 25 extract 80 thst the accuracy of dosing in the dispensing machine was impaired.
U.S. Patent 2,9B3,368 to Greenbaum, issued December 6, , 1960, disclo~es the use of small proportion of a su~pending agent, such as cellulose gum, a solubilizer, such as glycerol, 3 0 or both, in a tea concentrate to prevent precipitaffon of remaining caffeine and tannin constituents. The tea concentrate is prepared from a tea extract having a total solids content of 11 to 12% and a pH OI 4.8 to 5Ø The tea concentrate is preferably raised to a p~ of 5 . 5 by adding 35 sodium bicarbonate and is protected from microbial growth by the inclusion of sodium benzoate.
1 3 1 675 7~
DISCLOSURE OF THE INVENTION
An aspect of this invention is as follows:
A frozen tea concentrate having a pH of about 4.6 or less at 20~C and which comprises:
a. from about 0.4 to about 8% by weight decreamed tea solids;
b. an edible gum selected from the group consisting of xanthan gum in an amount of from about 5 to about 12% by weight of said tea solids; natural and modified gums selected from the group consisting of cellulose gums, locust bean gum, guar gum and mixtures thereof in an amount of from about 15 to about 50% by weight of said tea solids; and mixtures of from about 2 to about 5% by weight of said tea solids of said xanthan gum and from about 5 to about 25~ by weight of said tea solids of said natural and modified gums;
c. the balance water.
~0 A preferred optional component of the tea concentrate is a solubilizer selected from the sugars, polyols and mixtures thereof in a weight ratio to the tea solids of from about 0.5 to about 5.
Inclusion of the edible gum in the tea concentrates of the present invention makes them stable against flake formation during cyclic freezing and thawing. Inclusion of the gum also gives the resulting tea beverage an increased viscosity and therefore an enhanced mouthfeel.
Inclusion of the optional solubilizers make the tea concentrate much more cold water soluble. The tea ~oncentrates of the present invention are also stable against the growth of most microbial pathogens without the use of preservatives due to the relatively low pH.
These tea concentrates also provide tea beverages having a fresh brewed tea flavor which are relatively low in astringency and are non-bitter.
4a Another aspect of this invention is as follows:
A frozen tea concentrate having a pH of about 4.6 or less at 200c and which comprises:
a. from about 1 to about 4% by weight decreamed tea solids;
b. from about 6 to about 10% by weight of said tea solids of xanthan gum;
c. a solubilizer selected from the group consisting of high fructose corn syrup, maltodextrins, glycerol and mixtures thereof in a weight ratio to said tea solids of from about 0.~ to about 5;
d. the balance water.
Brief Description of the Drawings Figure 1 represents an HPLC chromatograph of the polyphenols present in an ice tea beverage prepared from the tea concentrate made according to the present invention.
.:
Figure 2 represents an HPLC chromatograph of the polyphenols present in an ice tea beverage prepared from a commercial bag tea product.
A. Deflnitions A8 used herein, the term "tea concentrate" refers to a product derived from concentrated tea extract which is diluted with water to form a drinkable tea bevera~e. Tea concentrates of the present invention comprise from about 0 . 4 to about 8% tea solids. Preferred tea concentrates of the pre~ent invention eomprise from about 1 to about 4% by wei~ht tea solids. The tea concentrates of the present invention can be in liquid product form but are preferably in frozen product form.
A~ used herein, the term "tea beverage" refers to a lS drinkable beverage prepared from the tea concentrates of the present invention by dilution with water. The tea concentrates of the present invent~on are generally diluted with from about 1 to about 40 parts water to provide the tea beverage. Preferred tea concentrates are typically diluted with from about 4 to about 20 parts water to provide the tea beverage .
As used herein, the term "tea solids" refers to those solids normally present in 8 tea extract. Polyphenolic compounds are normally the primary component of tea solids.
However, tea solids can also include caffeine, theobromine, proteins, amino acid~, minerals and carbohydrate~.
As used herein, the term "flake8" refers to insoluble tea so~d partieles formed at the boundary layer between the liquid tea phase and ice crystals due to freeze concentration of the tea concentrate. These insoluble llakes are extremely difficult to redis~olve in cold or hot water without the u~e of ultrasonic or high shear mixing.
As used herein, the term "comprising" means valiou~
components can be conjointly employed in the tea concentrates of the present invention. Accordingly, the term "comprising"
1 31 675~
encompasses the more restrictive terms "consisting essentially of" and "consisting of"
B. Tea Concentrate In addi~on to the tea solids, another key component of the tea concentrates of the present invention are certain edible gums. These edible gums perform at least four functions. The primary function is to prevent the tea polyphenols from forming a concentrated hydrophobic boundary phase between the liquid tea phase and ice crystals during the "freeze" por~on of cyclic freezing and thawing of the tea concentrate. This prevents the formation of in~oluble flakes that are visible in tea beverages when the tea concentrate i8 reconstituted with either hot or cold water.
The gums also perform a second, related function of ~olubilizing the tea solid~ of the concentrate when diluted with water to form the tea beverage.
The other two functions performed by the edible gums are related to mouthfeel effects in the tea beverage. The first i9 enhancing the mouthfeel of the beverage due to an 2 0 increased actual viscosity . As previously mentioned, tea beverages typically have a viscosity OI about 1 centipoise or less at 45F (7C). By contrast, tea beverages prepared from tea concentrates of the present invention typically have a viscosity of from about 2 to about 10 centipoise at 45F
(7C). This higher viscosity provides a desirable thicker mouthfeel impression.
The other mouthfeel function i8 reducing the astringency and perceived bitterness of the tea beverage. The gums are believed to aid in complexing the polyphenolic tannins. These tannins, when uncomplexed, are astringent because they bind salivary proteins. However, once the tannins form soluble complexes with the gum, they are much les~ likely to bind salivary protein. This reduces the astringency of the tea beverage .
The pre~erred edible gum for use in the tea concentrates of the present invention is xanthan gum. Xanthan gum i8 preferred because the resul'dng tea beverage, at dlqnking 1 3 1 675~
~.
strength, has a relatively high pH (about 5 . 6) which i~
considered de3irable. When used alone, the amount of xsnthan gum present in the tea concentrate i8 from about 5 to about 12% by weight of the tea solids. At levels much below about 5%, xanthan gum alone i8 not very effec'dve in preventing flake formation during freeze/thaw cycling of the tea concentrate. At levels much above about 12%, the re~ulting tea beverage ha~ too high a viscosity. Preferably, the amount of xanthan gum included is from about 6 to about 10% by weight of the tea solids.
Other modified and natural gums which are useful in the tea concentrates of the present invention are the cellulose gums, locust bean gum, guar gum and mixtures thereof.
Suitable cellulose gums include methylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, hydroxypropylcellulo~e, hydroxyethylcellulose, ethylhydroxyethylcellulose, and mixtures thereof. The preferred cellulose gum is carboxymethylcellulose. These other gums provide tea concentrates which yield tea beverages having a lower pH at drinking strength than those where xanthan gum is used. For example, carboxymethylce~ulose provides tea beveragas having a pH of about 5.
When used alone, these other gums (or mixtures thereof) 2 5 are included in the tea concentrate in an amount of from about 15 to about 50% by weight of the tea solids. At levels much below about 1596, these other gums alone sre not very ef~ective in preventing flake formation during ~reezelthaw cycling of the tea concentrate. At levels much above about 3 0 50%, the resulting tea beverage has too high a visco~ity .
Preferably, these other gums are included in an amount of from about 20 to about 40% by weight of the tea solids.
Effective mixtures of xanthan gum with these other natural and modified gums can also be used in tea 3 5 concentrates of the present invention . As used herein, the term "effective mixture" includes mixtures where xanthan ~ 3 1 675:3 ~ .~
gum is present in an effective amount ( from about 5 to about 1296 by weight of the tea solid~); mlxtures where the other modified and natural gums are present in an effec~ve amount ( from about 15 to about 50% by weight of the tea olids);
mixtures where both the xanthan gum and other gums are present in an effective amount; as well as mixtures of xanthan gum and other gums where neither alone is present in an effective smount but which together provide an effective amount of the edible gum for the purpose of inhibiting formation of insoluble ilakes during freeze/thaw cycling of the tea concentrate. For example, a mixture of about 4% xanthan gum and about 14% carboxymethylcellulose by weight of the tea solids i8 an effective mixture within the meaning of the present invenffon. Typically, these mixtures comprise xanthan gum in an amount of from about 2 to about 59~ by weight tea solids, and the other gums in an amount of from about 5 to about 25% by weight tea solids.
A preferred optionfll component included in the tea concentrates of the present invention i8 a solubilizer. The 2 0 solubilizer helps to keep the tea solids dissolved in the liquid tea phase to prevent the formation of cream and other precip-itates. Inclusion of solubilizers is particularly important if the tea concentrate is to have cold water solubility. As used herein, the term "cold water solubility" refers to a tea 2 5 concentrate which iB substantially soluble in water having a temperature of about 20C or less. Tea concentrates which contain a solubi~zer provide tea beverages having a turbidity of less than about 50 nephelometrics turbidity units (herein NTU). By comparison, tea concentrates of the present 3 0 invention which do not contain a solubilizer typically provide tea beverages having turbidity values of from about 50 to about 100 NTU . ( Turbidity values for the tea beverages resulting from these tea concentrates are measured by the analy'dcal method described hereafter.) Solubilizers useful in the tea concentrates of the pre~ent invention are ~elected from sugars, pol~ols and mixtures 1 31 675 ) ~ .
g thereof. Suitable sugars inclucle ructose, glucose, maltose, corn syrups (high fructose corn syrups and high maltose corn 3yrups), invert sugar, maltodextrins, polydextrose, cyclodextrinR and mixtures thereof. Preferred sugars for use in the present in~ention are the high fructose corn syrups and the maltodextrins. Suitable polyols for use in tea concentrates of the present include glycerol, propylene glycol, the sugar alcohols such as sorbitol, mannitol, maltol and xylitol, and ~he polyglycerols such as triglycerol, hexaglycerol, and decaglycerol. The preferred polyol for use in the tea concentrates of the present invention is glycerol.
The solublizers are included in the tea concentrates of the present invention in a weight ratio to the tea solids of from about 0 . 5 to about 5 . The particular amount included will depend upon the solubilizer choqen and the effects desired. For example, high fructose corn syrups are preferably included in a weight ratio to tea solids of from about 0 . 5 to about 2 . Another preferred sugar solubilizer, maltodextrin, is preferably included in a weight ratio to tea 2 0 solids of from about 0 . 5 to about 4 . The preferred polyol solubilizer, glycerol, is preferably included in the tea concentrates of the present invention in a weight ra'do to tea solids of from about 0 . 5 to about 2 . Care should also be taken to make sure that the solublizer is not included at a h}gh enough level to cause an off-flavor.
Certain combinations of edible gums with the solubilizers are especially preferred for use in the tea concentrates of the present invention. These preferred combinations include xanthan gum with high fructose corn syrup; xanthan gum 3 0 with maltodextrin; xanthan gum with a mixture of high fructose corn syrup and maltodextrin; carboxymethylcellulose with maltodextrin; carboxymethylcellulose with high fructoae corn syrup; carboxymethylcellulose with a mixturs of maltodextrin and high fructose corn syrup; and a mixture of 3 5 xanthan gum and carboxymethylcellulose with a mixture of high fructose corn ~yrup and maltodextrin. These preferred combinations can al o conta~n glycerol.
The tea concentrateq of the present invention have a pH
of about 4.6 or le~s at 20C, i.e. room temperature. As such, they are essentially stable against the growth oP most pathogenic bacteria without the use of pre~ervatives.
Typically, the pH of the tea concentrates of the present invention is from about 2 . 5 to about 4 . 6 at 20C . Generally, tea extracts used in the preparation of the tea concentrates of the present invention have a pH above ~.6, and typically about 5 . 0 . To acidify ~he tea extract for use in the tea concentrates of the present invention a suitable edible acid can be added in an amount appropriate to lower the pH to about 4.6 or les~. Suitable edible acids include fumaric acid, citric acid, adipic acid, tartaric acid, succinic acid, malic acid, hydrochloric acid, carbonic acid, ascorbic acid, phosphoric acid, as well as mixtures of these acid~ (e . g .
ascorbic acid and phosphoric acid). Malic acid, and especially phosphoric acid, are preferred for use in the tea concentrates of the present invention since they provide a tea beverage having a much higher pH when diluted to drinlcing strength. The tea concentrate can also be acidified by contact with an appropriate ion exchange resin. Examples of suitable ion exchange resins include Dowex HCR-S~, available from Dow Chemical Co. of Midland, MI, and Rohm ~ Haas IRC-5~ acid cationic exchange re~in available from Rohm h Haas of Philadelphia, PA. Acidification with ion exchange resins is a particularly us2ful method since the tea concentrate will provide a tea beverage having a much higher pH at drinking strength.
A particularly important property of the tea concentrates of the present invention i8 the fact that they provide tea beverages having a polyphenolic profile similar to that of fresh brewed tea. As previously mentioned, the principle polyphenols in tea are the theailavins and the thearubigins.
One adverse effect of ~he formation of ~soluble ~lakes during 1 3 1 675 ~
freeze/thaw cycles iB that the ratio of thearubigills to theaflavins increases with each cycle because the theaflavins are preferentially involved in flake formation. Thus, by preventing flake formation, the tea concentrates of the 5 present invention maintain a theaflavin content similar to that of fresh brewed tea. The tea concentrates of the present invention have a thearubigin to theaflavin ratio of from about 4 to about 8. By comparison, standard fresh brewed teas have a ratio from about 3 to about 10. This ratio is based on 10 the polyphenolic profile of the tea concentrate (or re~ulting tea beverage) obtained by high pressure liquid chrom-atography ~HPLC) according to a method described hereafter.
The similarity in flavor profile between the tea concentrates of the present invention and freshly brewed tea 15 is illustrated by a comparison of the HPLC chromatographs of ~igures 1 and 2 and especially the thearubigin to theaflavin ratios defined by these chromatographs. Figure 1 represents the HPLC chromatograph of a drinking strength iced tea beverage prepared from a tea concentrate made similar to 2 0 Embodiment 1 of the present invention . The retention time (minutes) and area under the curve for each peak of this chromatograph are as follows:
13167~3 Retention Time Area 1.07 6507 1.24 16~7 1.36 2633 1.65 829 2.04 1650 3.51 164 4.27 1190 6.08 333 6.49 131 10.87 382 12.87 624 13.28 184 13.49 1237 13.97 54 14.52 255 15.24 44 16.00 1569 16.4~ 4029 17.10 2300 17.90 4110 18.88 1299 19.09 1723 19.48 10485 20.10 6165 ~0.62 11152 21.18 2623 21.67 368 21.98 258 22.31 549 22.77 124 23.09 4607 24.08 4902 24.76 414 25.06 569 25.30 330 26.14 315 28.30 346 28.92 697 29.29 1~0 29.71 249 30.27 274 30.74 115 31.14 120 32.05 573 32.21 618 33.34 5542 34.32 218 34.71 606 35.41 86 36.12 1894 36.57 16a5 36.98 1760 38.08 143 38.63 46 40.19 93 42.36 42 The peaks at retention times 16.00 through 24.08 minutes are believed to represent the thearubigins and provide a total area of 57,385. The peaks at retention times 33.34 through 38.98 minutes are believed to represent the theaflavins and provide a total area of 11,731. The ratio of these total areas lO is 4.89.
Figure 2 represent~ an E~PLC chromatograph of an ice tea beverage freshly prepared from a commercial bag tea product. The retention time~ and area under the curve for each peak are as follows:
Retention Time Area 1.37 656 1.66 684 2.03 3267 2.45 2912 3.62 199 4.52 2919 6.12 82 6.37 339 l 0 6.67 843 7.18 63 8.63 76 9.93 45 10.31 128 11.00 382 11.89 133 13.09 1783 13.35 370 13.58 1345 14.08 81 14.62 214 15.08 272 16.14 16g4 16.61 4513 16.93 453 17.19 1631 17.98 2569 18.93 1682 19.18 1967 19.56 11491 20.20 6932 20.70 13261 21.25 1531 21.44 984 21.77 726 22.37 645 22.82 1399 23.12 5143 24.09 5622 4 0 24.79 787 25.01 616 25.30 400 26.15 638 27.00 133 28.26 603 28.90 932 29.63 381 30.19 189 30.65 76 32.07 1148 32.83 165 33.24 6821 34.15 274 13~6757) 34.5~ 773 35.27 441 35. g6 3133 3~.41 2805 36.79 3623 37.90 208 38.50 49 39.20 46 40.02 50 10 The peaks at reten'don times 16.14 through 24.09 minutes are believed to represent the thearubigins and provide a total area of 62,243. The peaks at retention times 33.24 through 36.79 minutes are believed to represent the theaflavins and provide a total area of 17,870. The ratio of these total areas 15 is 3.48.
Suitable optional ingredients for use in the tea concentrates of the pre~ent invention are chelating agents such as ethylenediaminetetraacetic acid (EDTA) or poly-phosphates such as sodium metaphosphate, sodium 2 0 pyrophosphate, tetra~odium pyrophosphate, sodium tripolypho~phate, potassium tripolyphosphate, tetrapotassium polyphosphate, tetrasodiummonopotassium tripolyphosphate, and hexaphos (sodium hexametaphosphate). Inclusion of these agents aids in maintaining tea beverage clarity in hard 25 water. Very low levels of preservatives such as the benzoates and sorbatas can also be included to inhibit mold growth. However, tea concentrates of the present invention are typically 3ubstantially free of such preservatives.
Generally, the tea concentratefi of the present invention 3 can be ~weetened or unAweetened . The use of the edible gums according to the present invention i8 particularly useful in preparing diet tea concentrates which contain a sweetening amount of a noncaloric swaetener such as saccharin, cyclamates, aoetosulfam, Lraspartyl-L,phenylalanine lower aIkyl ester sweetener~ (e.g. ASPAR~AME),IM L,aspartyl-D-alanine amides disclosed in U.S. Patent 4,411,925 to Brennan et al., issued October 23, 1983, L,aspartyl-D-serine amides disclosed in U.S.
Paten~ 4,399,163 . -:. ,~; ,.
13167~) to Brennan et al., issued August 16, 1983, L,aspartyl-Irl-hydroxy-methylaIkaneamide sweeteners disclosed in U.S. Patent 4,338,346 to Brand, issued December 21, 1982, ~,aspartyl-1-hydroxyethyl-alkaneamide sweeteners disclosed in U.S. Patent 4,423,029 to Rizzi, issued December 27, 1983, L,aspartyl-D-phenylglycine ester and amide sweeteners disclosed in European Patent Application 168,112 to J.M. Janusz, published January 15, 1986 and the like. A particularly preferred noncaloric sweetener for use in such diet tea concentrates is aspartame.
The tea concentrate of the present invention can also be flsvored with various natural or synthetic flavors. Natural and synthetic coloring agenta can also be included.
Particularly preferred are lemon flavoring (e.g. lemon oil~
and caramel coloring. These flavoring and coloring agents are included in the tea concentrates in amounts well known to those ~ki~led in the tea art.
Method for Preparing Tea Concentrates The tea extracts used in preparing the tea concentrates of the preserlt invention can be obtained from fermented and unfermented teas, e.g., black tea, oolong tea, green tea, or mixtures thereof. Typically, the tea extract i8 obtained from about 85 to 1009~i black tea leave~ and from 0 to about 15%
green tea leaves. When black tea is used in preparing the tea extract, it can be enzymatically pretreated according to the method described in European Patent Applica~on 135, 222 to C.H. Tsai, published May 27, 1985. In the Tsai method, black tea leaves are wetted with water containLng tannase and one or more cell-wall-digest mg enzymes, such as cellulase, pectinase, or hemicellulase prior to extraction. The enzyme-moistened ~ea leaves are incubated in a closed system at room temperature for a few hours, neutralized with a suitable ., 1 3 1 67 ~J ) foodgrade base and then heated to inactivate the enzymes.
The resulting enzyme-treated tea leaves provide a higher yield of tea extract which has better solubi3ity in cold water.
Ihe tea leaves, with or without pretreatment with enzymes, can then be extracted in a conventional manner to provide the tea ext~act. See P~ntauro, Tea and Soluble Tea Products ME~nufac~ure (1977), pp. 39-81, for various methods of obtaining tea extract from tea leaves. The tea leaves are typically slurried with 10 water followed by separation of the leave~ from the resulting tea extract. This extraction can be performed in a ~ingle batch fashion, as a continuous process, as a countercurrent multiple vessel process, or any combinaffon thereof.
Continuous countercurrent tea extraction i8 the mo~t 15 preferred method. If desired, tea aroma and flavor components can be volatilized from the extract, collected, condensed and added back at a later point in the process.
Also, the tea desorbate process disclosed in U . S . Patent 4,220,673 to Strobel, issued Sept. 2, 1980, can be used to 20 provide the tea extract. A tea extraction process ~ich avoids harsh tea flavors and preserves real tea flavor is desirable.
The tea extract resulting from slurry or countercurrent extraction of tea leaves produces a turbid beverage when 25 diluted with cold water. Typically, the tea extract is cooled to separate solids which form in a decreaming step. Solids which are precipitated by cooling consist chieily of tea creams resulting &om the formation vf complexes of polyphenolic compounds and caffeine. Removal of tea creams is typically 30 achieved by centrifugation, filtration or other suitable means.
Depending upon the desired concentration of tea solids in the product, the clarified extract can be further concentrated by ~uitable methods such as evaporation or rever~e osmosi~. See Pintauro, supra, pp. 82-141 (herein incorporated by 35 reference), for various representatlve methods for decreaming~, filtering and concentra'dng tea extract~.
.. ., 7, 1 31 6~53 The edible gums, solubilizers and other optional ingredients can be added at variou~ point~ in thi~ process.
For example, some or all of these product additives can be added to the tea extraction water prior to contact with the tea leaves. In particular, the addition of solubilizers to the water u3ed in tea extraction aids in the extraction of theaflavins and other tea components. Also, the previously described chelating agents such as EDTA and the polyphosphates can be added to the extraction water to sequeater undesired minerals such as calcium and magnesium typically present in hard water and tea leaves. The product additives, especially the edible gums and solubilizers, can also be added later in this process, such as before or after decreaming and clarification of the tea extract.
The tea extract, after appropriate processing to provide the desired level of tea solids and after the edible gums, solublizers and optional ingredients have been added, forms the tea concentrate of the present invention. This tea concentrate is preferably pasteurized or sterilized prior to packing in containers. The tea concentrate product can be distributed as a liquid tea concentrate or else can be chilled to provide a frozen tea concentrate product.
D. Analyffcal Methods The following analytical methods are used in the present 2 5 application to evaluate the polyphenolic profile and turbidity propertles of tea concentrates or tea beverages.
1. Polyphenols The polyphenols present in the tea concentrates or tea beverages are analyzed using a modification of the high 3 0 presaure liquid chrome.tography procedure described by Hoefler and Coggon, Journal of Chromatography, Yol. 129, (1976), pp. 460-63.
A DuPont model 8800 liquid chromatographic system (manufactured by DuPont Company, Analytical Instrument Division, Wilmington, DE 19898) with a variable wavelength ultraviolet spectrophotometlqc detector se~ at 380 nm is used.
Samples are injected onto a chromatographic column using a Dynatech Precision Sampling model LC-241 autosampler (available from Dynotech Preci~ion SampL~ng, Baton Rouge, LA
70895)~ A high pressure liquid chromatographic column, Supelco LC-18 3 um ODS, 15 cm x 4.6 mm (available from Supelco Inc., Bellefonte, PA 16823) is used. Chromato-graphic peaks are recorded using a Spectra-Physic~ model 4290 recording integrator (available from Spectra-Physics, 3333 N. Eirst St., San Jose, CA 95134). Peak integration i8 1 O accomplished u~ing a Hewlett-Packard model 1000 computer (available from Hewlett-Packard, 1820 Embarcadero Rd., Palo Alto, CA 94303).
A binary mob1le phase system i8 used. Mobile phase A
consists of O .24% glacial acetic acid in Milli-Q water (water purified in a Milli-Q Purification Unit, available from Millipore Corp. of Bedford, IIlIA 01730). Mobile phase B consi~ts of 50%
of O .24% glacial acetic acid in Milli-Q water and 50% acetone (HPLC grade3, available from Burdick ~ Jackson, 1953 S.
Harvey St., Muslcegon , ~II 49g42.
Sample~ are eluted in four timed solvent segments:
1) an isocratic segment of 80% mobile phase A and 20% mobile phase B for 2 minutes; 2) a linear gradient from 75% mobile phase A:25% mobile phase B to 25% mobile phase A:75% mobile phase B in 30 minutes; 3) an isocratic segment of 10% mobile phase A and 90% mobile phase B for 8 minutes; and 4) an isocratic segment of 80% mobile phase A and ~0% mobile phase B for 1 minute.
Tea solutions containing no carbohydrate additives are first made to drink~ng strength. An approximate volume of 2 3 0 ml is filtered through a O .45 um cellulose-scetate disposable filter, Millex HA, 25 mm diameter, available from IYlillipore Corp., Bedford, MA 01730. A 50 ul injectdon of the filtered solution is made.
Tea solutions containing carbohydrate additlves are 3 5 sequentially diluted with acetone and water to precipitate the carbohydrates insoluble in mobile phase B. For example, the ..
tea concentrate of the present inven'don is diluted as follows:
1 ) 1 ml tea concentrate is diluted with 2 ml acetone ( ~ource as above); 2~ precipitated carbohydrate material i8 removed with a pasteur pipet; 3 ) 1 ml of the resultant solution i8 S further diluted with 1. 67 ml l~lli-Q water; 4 ) 1 ml of the resulting ~olution is further diluted with 1 ml Milli-Q water to make a drinking strength solution. Approximately 2 ml of this solution is filtered through a 0 . 45 um ilter, described above, and 50 ul is injected onto the chromatographic column.
2. Turbidity The nephelometric method and nephelometric turbidity unit, as described in " Standard Methods for the Examination of Water and Waste Water", 14th ed., published by American Public Health Association, Wsshington, D. C ., is used to determine the cloudiness or turbidity of the tea beverages.
A Hach Ratio Turbidimeter, Model 18900-00, available from Hach Chemical Company , Loveland , Col ., is employed . It is calibrated prior to each measurement using Latex Standard solutions provided by Hach Chemical Company. For 2 0 refrlgerated beverages, the turbidity is measured at the refrigerated temperature, i.e. 45F (7C).
E. Specific Embodiments of Tea Concentrates of Present Invention The fo~owing specii~c embodiments are used to illustrate the tea concentrates of the present invention:
Embodiment 1 A blend of 909~ black tea leaves (Tender Lea~ blend) and 109~l Taiwanese green tea fannings was fed to a Niro~) countercurrent extractor (Model A27) at a rate of 0. 33 lbs./min. (.15 kg/min.). Distilled water wa~ treated with 0.02% sod~um hexametaphosphate and fed into the extractor at a flow rate and temperature of 3.5 lbs./min. (1.6 kg/min.) and 180F (82.2C), respe¢tively. The extract was cooled to a temperature of 124F (51.1C) at the discharge port of the 3 5 extractor . The extract was passed through a No . 200 (A.S.T.M. Standard) filter screen. This extract had a tea solids concentration of 4.~5%.
t316753 The extract was cooled to 85F (29.4C) and fed to a continuouq centrifuge (West Falia Separator Type SA-14-47-076) after a 30 minute hold time at 85F (29.4C) . The centrifuge was operated at 75~0 rpm. After clarifieation, the tea ~olid~ concentration wa~ 4.15% . The extract was diluted with distilled water to a concentration of 3.7% tea solids.
To 100 lbs. (45.4 kg~ of this tea extract were added and mixed 0.27 lbs. (276 grams) Keltrol-l~) foodgrade xanthan gum and 2.5 lbs. (1.1 kg) of maltodextrin using a contînuouq blender (Ladish Co. Triblender, Model No. F2116 ~ID-S).
Then, 4.0 lb~. (1.8 kg) of high fructose corn syrup-55, 0.49 lb. (222 grams) caramel color, and 0.0043 lbs. (1.95 grams) of FD~C Red Dye #40 were added and mixed in. The pH of the mixture was adjusted to 4.6 u~ing 0.08 lbs. (36.3 grams) of foodgrade 75% phosphoric acid. The tea concentrate was then packed into 4 oz. can~ after pasteurizing in a Crepaco UHT unit. The cans were then frozen at -10F (-23.3C).
The frozen concentrate obtained had 3% tea solids, 7%
(tea solids basis) of xanthan gum, 107% (tea solids basis) of high fructose corn syrup and 66% (tea solids bssis) of maltodextrin. One part of the tea concentrate diluted with 15 parts water provided a tea beverage having a turbidity value of 15 NTU and a viscosity of 2.7 centipoise at 45F (7C).
Embodiments 2 to 7 Six hundred and fifty (650) pounds (295.5 kg.) of distilled deaerated water at 70F (20C) is placed in a stainless steel tank. Thirty-two and one-half (32.5) pounds (14.8 kg.) of black tea leaves (Tender Lea~) blend) are mixed into the water. After constant agitaffon for 20 minutes, the glurry is allowed to settle for 20 minutes. The mixture i8 maintained at about 70F (21C) during this time.
Five hundred (500) pound~ (227.3 kg.) of the 70F
(21C) extract are then removed from the leaves by pumping the extract through a No. 200 lA.S.T.M. Standard filter screen . Five hundred (500) pounds (227.3 kg. ) of water are added to the residua~ leaves. This mixture is heated to 180F
1 3 1 67~3 (82C) while under constant agitation. Five hundred (500) pound~ (227.3 kg.) of tea extract i8 recovered fro~the heaffng tank by deleafing using a West Falia Separator (Type CA 220-010). The deleafed tea extract i8 mixed with the 70F
5 extract, then cooled to 45F (7C). The chilled solution is centrifuged with a ~iest Falia Separator (Type SA 14-47-076) at 7560 rpm. The clarified extract i9 concentrated by means of rever3e osmosis u~ing D . D . S . HR-98 membranes . To thi~
concentrated extract i3 added various quantities of xanthan 10 gum (XG), carboxymethyl cellulose (Cn~C), maltodextrin (MD), high fructose corn syrup-55 (HFCS) and glycerol ( GLY C), as shown in the following Table :
Embod-% Tea % % % % %
imentSolids XG~CMC~ MD~ HFCS~ GLYC*
2 0.8 -- 18.8 250 62.5 3 0.8 -- 25 312.5 81.3 4 o.a 6.3 -- -- 100 1.07 -- 28 280.3 56.1 6 1.0 -- 38 250 -- 60 2 0 7 1.0 0.423 250 60 --~Tea solids basis The tea concentrates (Embodiments 2 to 7 above) are acidified to pH 4.5 with foodgrade 75% pho~phorlc acid and then packed into 12 oz. c~m8 after pasteurizing in a Crepaco 25 UHT unit and frozen at 0F (-18C).
concentrated extract i3 added various quantities of xanthan 10 gum (XG), carboxymethyl cellulose (Cn~C), maltodextrin (MD), high fructose corn syrup-55 (HFCS) and glycerol ( GLY C), as shown in the following Table :
Embod-% Tea % % % % %
imentSolids XG~CMC~ MD~ HFCS~ GLYC*
2 0.8 -- 18.8 250 62.5 3 0.8 -- 25 312.5 81.3 4 o.a 6.3 -- -- 100 1.07 -- 28 280.3 56.1 6 1.0 -- 38 250 -- 60 2 0 7 1.0 0.423 250 60 --~Tea solids basis The tea concentrates (Embodiments 2 to 7 above) are acidified to pH 4.5 with foodgrade 75% pho~phorlc acid and then packed into 12 oz. c~m8 after pasteurizing in a Crepaco 25 UHT unit and frozen at 0F (-18C).
Claims (18)
1. A frozen tea concentrate having a pH of about 4.6 or less at 20°C and which comprises:
a. from about 0.4 to about 8% by weight decreamed tea solids;
b. an edible gum selected from the group consisting of xanthan gum in an amount of from about 5 to about 12% by weight of said tea solids; natural and modified gums selected from the group consisting of cellulose gums, locust bean gum, guar gum and mixtures thereof in an amount of from about 15 to about 50% by weight of said tea solids; and mixtures of from about 2 to about 5% by weight of said tea solids of said xanthan gum and from about 5 to about 25% by weight of said tea solids of said natural and modified gums;
c. the balance water.
a. from about 0.4 to about 8% by weight decreamed tea solids;
b. an edible gum selected from the group consisting of xanthan gum in an amount of from about 5 to about 12% by weight of said tea solids; natural and modified gums selected from the group consisting of cellulose gums, locust bean gum, guar gum and mixtures thereof in an amount of from about 15 to about 50% by weight of said tea solids; and mixtures of from about 2 to about 5% by weight of said tea solids of said xanthan gum and from about 5 to about 25% by weight of said tea solids of said natural and modified gums;
c. the balance water.
2. The tea concentrate of Claim 1 wherein said cellulose gum is carboxymethylcellulose.
3. The tea concentrate of Claim 2 wherein said edible gum is carboxymethylcellulose.
4. The tea concentrate of Claim 2 wherein said edible gum is xanthan gum.
5. The tea concentrate of Claim 1 which further comprises a solubilizer selected from the group consisting of sugars, polyols and mixtures thereof in a weight ratio to said tea solids of from about 0.5 to about 5.
6. The tea concentrate of Claim 5 wherein said sugars are selected from the group consisting of glucose, fructose, corn syrups, maltose, maltodextrins, polydextroses and cyclodextrins and wherein said polyols are selected from the group consisting of glycerol, sugar alcohols and polyglycerols.
7. The tea concentrate of Claim 6 wherein said solubilizer is selected from the group consisting of high fructose corn syrup, maltodextrins, glycerol and mixtures thereof.
8. The tea concentrate of Claim 1 which comprises from about 1 to about 4% by weight of said tea solids.
9. The tea concentrate of Claim 1 which further comprises a sweetening amount of a noncaloric sweetener.
10. The tea concentrate of Claim 9 wherein said noncaloric sweetener is aspartame.
11. The tea concentrate of Claim 1 which is frozen.
12. The tea concentrate of Claim 1 which further comprises an edible acid selected from the group consisting of phosphoric acid and malic acid.
13. The tea concentrate of Claim 12 wherein said edible acid is phosphoric acid.
14. A frozen tea concentrate having a pH of about 4.6 or less at 20°C and which comprises:
a. from about 1 to about 4% by weight decreamed tea solids;
b. from about 6 to about 10% by weight of said tea solids of xanthan gum;
c. a solubilizer selected from the group consisting of high fructose corn syrup, maltodextrins, glycerol and mixtures thereof in a weight ratio to said tea solids of from about 0.5 to about 5;
d. the balance water.
a. from about 1 to about 4% by weight decreamed tea solids;
b. from about 6 to about 10% by weight of said tea solids of xanthan gum;
c. a solubilizer selected from the group consisting of high fructose corn syrup, maltodextrins, glycerol and mixtures thereof in a weight ratio to said tea solids of from about 0.5 to about 5;
d. the balance water.
15. The tea concentrate of Claim 14 which further comprises a sweetening amount of aspartame.
16. The tea concentrate of Claim 14 which is frozen.
17. The tea concentrate of Claim 14 which further comprises a lemon flavoring.
18. The tea concentrate of Claim 1 which has a thearubigin to theaflavin ratio of from about 4 to about 8.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86060186A | 1986-05-07 | 1986-05-07 | |
| US860,601 | 1986-05-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1316753C true CA1316753C (en) | 1993-04-27 |
Family
ID=25333586
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000536499A Expired - Lifetime CA1316753C (en) | 1986-05-07 | 1987-05-06 | Tea concentrate having freeze/thaw stability and enhanced cold water solubility |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1316753C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113180124A (en) * | 2021-06-04 | 2021-07-30 | 杭州浙大百川生物食品技术有限公司 | High-stability concentrated tea extract and extraction method |
| CN114747642A (en) * | 2022-03-15 | 2022-07-15 | 中国农业科学院茶叶研究所 | Method for improving quality of black tea juice by using complex enzyme |
-
1987
- 1987-05-06 CA CA000536499A patent/CA1316753C/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113180124A (en) * | 2021-06-04 | 2021-07-30 | 杭州浙大百川生物食品技术有限公司 | High-stability concentrated tea extract and extraction method |
| CN113180124B (en) * | 2021-06-04 | 2024-03-01 | 杭州浙大百川生物食品技术有限公司 | High-stability concentrated tea extract and extraction method |
| CN114747642A (en) * | 2022-03-15 | 2022-07-15 | 中国农业科学院茶叶研究所 | Method for improving quality of black tea juice by using complex enzyme |
| CN114747642B (en) * | 2022-03-15 | 2024-04-02 | 中国农业科学院茶叶研究所 | Method for improving quality of black tea juice by using complex enzyme |
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