CA1201007A - Tea extraction process - Google Patents
Tea extraction processInfo
- Publication number
- CA1201007A CA1201007A CA000418858A CA418858A CA1201007A CA 1201007 A CA1201007 A CA 1201007A CA 000418858 A CA000418858 A CA 000418858A CA 418858 A CA418858 A CA 418858A CA 1201007 A CA1201007 A CA 1201007A
- Authority
- CA
- Canada
- Prior art keywords
- stage
- tea
- extract
- extraction
- tea leaf
- 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
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Classifications
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23F—COFFEE; TEA; THEIR SUBSTITUTES; MANUFACTURE, PREPARATION, OR INFUSION THEREOF
- A23F3/00—Tea; Tea substitutes; Preparations thereof
- A23F3/16—Tea extraction; Tea extracts; Treating tea extract; Making instant tea
- A23F3/18—Extraction of water soluble tea constituents
Abstract
ABSTRACT
Dry tea leaf is extracted with aqueous solvent, preferably by countercurrent procedures at atmospheric pressure, the spent tea leaf is separated from the extract, the spent tea leaf is acidified to a pH within the range of 2.0 to 3.0, the acidified spent tea leaf is further extracted with aqueous solvent at temperatures of about 140-170°C for at least 4 minutes at pressures of about 80-100 psig to provide a high temperature/high pressure acid extract, and said high temperature/high pressure acid extract is used as aqueous solvent in the earlier extraction procedures to provide a high extraction yield of good quality extract.
Dry tea leaf is extracted with aqueous solvent, preferably by countercurrent procedures at atmospheric pressure, the spent tea leaf is separated from the extract, the spent tea leaf is acidified to a pH within the range of 2.0 to 3.0, the acidified spent tea leaf is further extracted with aqueous solvent at temperatures of about 140-170°C for at least 4 minutes at pressures of about 80-100 psig to provide a high temperature/high pressure acid extract, and said high temperature/high pressure acid extract is used as aqueous solvent in the earlier extraction procedures to provide a high extraction yield of good quality extract.
Description
~IZO:lC)(~7 - 1 - Q.373 ~EA EXTRACTION PROCESS
This invention relates to the preparation of plant infusions such as tea extracts.
An ever increasing proportion of tea is marketed in the form ~f tea extracts, usually in the form of dry powders. Substantial research activity has been directed to the proplems of ob~;n; ng tea extracts in the form of dry powders that upon reconstitution provlde a high quality beverage, having a flavour and colour which is as close as possible to that obtained by brewing tea from tea leaf.
These processes may involve u~e of conditions which ~eparately collect and set a3ide the flavour components before the tea is subjected to rigorou~ extraction conditions. The flavour components are then added back to the extracted water soluble tea solids at a subsequent ~tage in the process.
Another aspect of tea extract production is yield of soluble solids. For reasons of economic~, processes which as~ure the highest pos~ible recovery of water-~oluble solids from the tea lea~ are de~ired.
Method~ of obta~ n; ng tea e~tracts using a series of countercurrent stages are well-known in the art. The Bonotto Patent US No. 3 080 237, for example, di~closes a process whereim fresh aqueous solvent is brought into ~2~0(~7
This invention relates to the preparation of plant infusions such as tea extracts.
An ever increasing proportion of tea is marketed in the form ~f tea extracts, usually in the form of dry powders. Substantial research activity has been directed to the proplems of ob~;n; ng tea extracts in the form of dry powders that upon reconstitution provlde a high quality beverage, having a flavour and colour which is as close as possible to that obtained by brewing tea from tea leaf.
These processes may involve u~e of conditions which ~eparately collect and set a3ide the flavour components before the tea is subjected to rigorou~ extraction conditions. The flavour components are then added back to the extracted water soluble tea solids at a subsequent ~tage in the process.
Another aspect of tea extract production is yield of soluble solids. For reasons of economic~, processes which as~ure the highest pos~ible recovery of water-~oluble solids from the tea lea~ are de~ired.
Method~ of obta~ n; ng tea e~tracts using a series of countercurrent stages are well-known in the art. The Bonotto Patent US No. 3 080 237, for example, di~closes a process whereim fresh aqueous solvent is brought into ~2~0(~7
- 2 - Q.373 contact first with the tea leaf which has been extracted in several earlier stages, and wherein the fresh dry tea leaf is first contacted with concentrated aqueous tea leaf extract. Temperatures of extraction varying from room temperature to elevated temperatures as high as 180C or higher have been used, together with elevated pressures needed to maintain the high temperatures. The Mishkin et al. patent, U5 No. 3 450 823, for example, discloses a two-stage extraction wherein a first extraction stage is conducted at temperatures not exceeding 110C to provide a first extract, the partially extracted leaf is comminuted and water added to form a pumpable slurry, and the slurry heated to 180C to provide a second extraction. The two extracts are combined and dried to provide the product.
It is also known that stron~ly acid conditions at elevated temperature hydrolyse plant matter cont~; n; ng cellulose to saccharides. This is disclosed, for example, in the Jelks Patent US No. 3 939 286, where the process is used to treat cellulosic plant materials to increase the digestibility thereof by L~ in~nts.
By the invention we have found that a substantial improvement in overall yield of water-soluble solid can be obtained from infusion material, especially leaf tea, if the spent infusion material obtained at the end of a traditional aqueous extraction process is subjected to a further aqueous extraction step conducted under conditions that involve both elevated pressure and low pH. The invention will hereafter be described with particular reference to the preparation of tea extracts.
In a prefered embodiment of the invention, an improved method for extracting tea from tea leaves is provided by first conducting an extraction of tea leaf with a~ueous solvent and by then subjecting the residual spent I
0~'7
It is also known that stron~ly acid conditions at elevated temperature hydrolyse plant matter cont~; n; ng cellulose to saccharides. This is disclosed, for example, in the Jelks Patent US No. 3 939 286, where the process is used to treat cellulosic plant materials to increase the digestibility thereof by L~ in~nts.
By the invention we have found that a substantial improvement in overall yield of water-soluble solid can be obtained from infusion material, especially leaf tea, if the spent infusion material obtained at the end of a traditional aqueous extraction process is subjected to a further aqueous extraction step conducted under conditions that involve both elevated pressure and low pH. The invention will hereafter be described with particular reference to the preparation of tea extracts.
In a prefered embodiment of the invention, an improved method for extracting tea from tea leaves is provided by first conducting an extraction of tea leaf with a~ueous solvent and by then subjecting the residual spent I
0~'7
- 3 - Q.373 tea leaf to acid conditions in the pH range of about 2.0 -3.0 under elevated pressure (preferably 80 to 10~ psi) and elevated temperature (preferably in the range of 140-170C) for a period of time (generally in excess of 4 minutes) sufficient to extract further solids. The slurry is then separated into spent leaf and extract. The spent leaf is discarded, and preferably the high temperature/high pressure acid extract i~ used as the aqueous solvent in an earlier stage of the extraction process.
In a more preferred embodiment of the invention, the first extraction of the tea leaf is accomplished using a multi-stage countercurrent procedure under conditions of atmospheric pressure and at temperatures not exceeding 15 about 100C. It is recognised, however, that a first extraction step which is only a single stage or one utilising temperatures above 100C and elevated pressure may be employed to advantage prior to the high temperature/high pressure/acid extraction stage, and these alternate embodiments are disclosed as part of the invention.
The process of the invention provides an exceptionally high yield of soluble tea solids. Prior art 25 processes give extraction yields ranging from 33-36% of raw tea leaf solids as soluble instant tea. By way of compari~on, the process of the present invention provides yields of ~oluble solids in the range of 47-51% on the same basis. Extraction yield is herein defined as 100 times the 30 weight of soluble solids extracted divided by the weight of the raw leaf fed to the extraction process.
It is recognised that high temperature and pressure conditions by themselves will provide some increase in 35 yield. Such conditions, i.e. 80-100 psi and 140-170C, however, yield solid~ which gel upon concentration to about '7
In a more preferred embodiment of the invention, the first extraction of the tea leaf is accomplished using a multi-stage countercurrent procedure under conditions of atmospheric pressure and at temperatures not exceeding 15 about 100C. It is recognised, however, that a first extraction step which is only a single stage or one utilising temperatures above 100C and elevated pressure may be employed to advantage prior to the high temperature/high pressure/acid extraction stage, and these alternate embodiments are disclosed as part of the invention.
The process of the invention provides an exceptionally high yield of soluble tea solids. Prior art 25 processes give extraction yields ranging from 33-36% of raw tea leaf solids as soluble instant tea. By way of compari~on, the process of the present invention provides yields of ~oluble solids in the range of 47-51% on the same basis. Extraction yield is herein defined as 100 times the 30 weight of soluble solids extracted divided by the weight of the raw leaf fed to the extraction process.
It is recognised that high temperature and pressure conditions by themselves will provide some increase in 35 yield. Such conditions, i.e. 80-100 psi and 140-170C, however, yield solid~ which gel upon concentration to about '7
- 4 - Q.373 20-25% and are not suitable for use in instant tea. On the other hand, use of even higher temperatures and pressures, in the order of 200 psi and corresponding high temperature, will reduce the molecular weight of the extracted products to provide desirable viscosities, but an undesixable scorched flavour component results. Further, while th0 use of acid has been described in the literature, it has never been proposed or suggested that the comhination of these conditions in the manner suggested would provide such a 10 substantial increase in yield. Furthermore, even though more rigorous extraction conditions are applied to the tea leaf than are applied under more moderate conditions, little or no adverse effect upon the flavour of the resulting tea is observed.
The process of the present invention may be applied to any raw tea leaf in the dired form: either green, oolong, or black tea or any desirable mixture thereof may be used. The process can also be applied to other plant 20 infusion material, such as Matté and Rooiboz.
The preferred embodiment of the process of the present invention contemplates a countercurrent multi-stage extraction of soluble solids from tea leaf using water as 25 the solvent. It is further preferred that the conventional countercurrent extraction phase comprise three atmospheric pressure stages, referred to for convenience as the first, second, and third stages. In accordance with the present invention, a fourth ~tage is provided, wherein the spent tea leaf from the third stage is acidified, and held under high pressure andtemperature conditions to extract substantial additional quantities of tea ~olids.
At leas1: three atmospheric pressure stages are 35 preferred for a number of reasons, including improved yield and the provision of neutralisation or buffering capacity.
I
3'7
The process of the present invention may be applied to any raw tea leaf in the dired form: either green, oolong, or black tea or any desirable mixture thereof may be used. The process can also be applied to other plant 20 infusion material, such as Matté and Rooiboz.
The preferred embodiment of the process of the present invention contemplates a countercurrent multi-stage extraction of soluble solids from tea leaf using water as 25 the solvent. It is further preferred that the conventional countercurrent extraction phase comprise three atmospheric pressure stages, referred to for convenience as the first, second, and third stages. In accordance with the present invention, a fourth ~tage is provided, wherein the spent tea leaf from the third stage is acidified, and held under high pressure andtemperature conditions to extract substantial additional quantities of tea ~olids.
At leas1: three atmospheric pressure stages are 35 preferred for a number of reasons, including improved yield and the provision of neutralisation or buffering capacity.
I
3'7
5 - Q.373 The extract leaving the high pressure/high temperature acid extraction stage generally has a pH in the range of 2.4 to 2.8. Passing this extract in contact with fresh batches of wet leaf in the atmospheric stages of the process raises the pH of the extract, at the rate of about 0~5 units per stage. Thus, a 3-stage atmospheric extraction raises t~e pH of the extract to the range of 4.0 to 4.5. A 2-stage atmo~pheric extraction process may be used, but in that event, neutralisation of the excess acidity by addition of 10 a base may be required. On the other hand, 4 or ~ore atmospheric pressure stages may be employed, where desired.
When conducting the high temperature/high pressure acid extraction stage of the process of the present 15 invention, a number of important considerations must be kept in mind. The pH may be adjusted by adding a strong acid of food grade quality. Hydrochloric, HCl; phosphoric, H3P04; sulphurous, H2S03; sulphuric, H2S04;
nitric, HN03; and acetic, CH3COOH acids are suitable.
20 Sulphuric acid i8 preferred, as providing a superior taste and flavour; at the same time, it is less corrosive to equipment than, e.g. hydrochloric acid.
A second factor requiring care is the pH of the tea leaf slurry- It has been established that sufficient acid should be added to bring about a pH in the slurry of below about pH 3. Subjecting the leaf solids at pH above 3 to high temperaturethigh pressure conditions yields a tea extract that, upon concentration above 20-25% solids, tend 30 to come out of solution or gel, and is therefore not suitable for use in instant tea manufacture. A p~ below about 2, on the other hand, provides undesirable flavours and degradation of the tea, as well as corrosion problems with equipment.
~5 The pH range o the tea slurry during high I
lZ~ )0~
When conducting the high temperature/high pressure acid extraction stage of the process of the present 15 invention, a number of important considerations must be kept in mind. The pH may be adjusted by adding a strong acid of food grade quality. Hydrochloric, HCl; phosphoric, H3P04; sulphurous, H2S03; sulphuric, H2S04;
nitric, HN03; and acetic, CH3COOH acids are suitable.
20 Sulphuric acid i8 preferred, as providing a superior taste and flavour; at the same time, it is less corrosive to equipment than, e.g. hydrochloric acid.
A second factor requiring care is the pH of the tea leaf slurry- It has been established that sufficient acid should be added to bring about a pH in the slurry of below about pH 3. Subjecting the leaf solids at pH above 3 to high temperaturethigh pressure conditions yields a tea extract that, upon concentration above 20-25% solids, tend 30 to come out of solution or gel, and is therefore not suitable for use in instant tea manufacture. A p~ below about 2, on the other hand, provides undesirable flavours and degradation of the tea, as well as corrosion problems with equipment.
~5 The pH range o the tea slurry during high I
lZ~ )0~
- 6 - Q.373 temperature/high pressure extraction is also an important consideration where the final product is spray dried. It has been found that tea solids obtained at this stage of the extraction when the pH ranges between about 2 and 3 serve to complement those debulXing agents normally present in tea extracts and help to decrease bulk density o~ the dried tea powder. Certain blends of tea solids are found to be deficient in these debulking agents. However, use of a pH below about pH 2 or above about pH 3 provides solids 10 which are less e*fective in their debulking characteristics.
Also important to the process of the present invention are the pressure and temperature conditions used in the high temperature/high pressure extraction stage.
Conditions within the stated ranges provide a product with an acceptable flavour. Care must be taken to maintain the pressure and temperature within the ranges of about 80 to 100 pse and 140-170C. Conditions below these ranges 20 provide products of undesirable characteristics, including a condition which causes the solids to precipitate out of ~olution in the extract when the extract is concentrated prior to drying. Conditions in excess of these ranges give scorched flavours which are undesirable.
It has been found that the acidified tea leaf slurry should be maintained under the high temperature/high pressure conditions for at least 4 minutes. Contact times longer than this are readily tolerated, and up to 12 hours 30 has been investigated without adverse changes in the product. A contact time of 15 minutes to 1 hour is generally preferred.
The process of the present invention is described 35 with reference to the attached drawing, which shows a flow / diagram of a preferred embodiment thereof.
lZ~ 7
Also important to the process of the present invention are the pressure and temperature conditions used in the high temperature/high pressure extraction stage.
Conditions within the stated ranges provide a product with an acceptable flavour. Care must be taken to maintain the pressure and temperature within the ranges of about 80 to 100 pse and 140-170C. Conditions below these ranges 20 provide products of undesirable characteristics, including a condition which causes the solids to precipitate out of ~olution in the extract when the extract is concentrated prior to drying. Conditions in excess of these ranges give scorched flavours which are undesirable.
It has been found that the acidified tea leaf slurry should be maintained under the high temperature/high pressure conditions for at least 4 minutes. Contact times longer than this are readily tolerated, and up to 12 hours 30 has been investigated without adverse changes in the product. A contact time of 15 minutes to 1 hour is generally preferred.
The process of the present invention is described 35 with reference to the attached drawing, which shows a flow / diagram of a preferred embodiment thereof.
lZ~ 7
- 7 - Q.373 The first stage of the process, Stage 1 o~ the drawing, comprises a vessel containing fresh dry tea leaf.
Fresh water or other aqueous solvent i8 added to the leaf, the extraction takes place, and the mixture of tea leaf and solvent is pumped ko a decanter lO, via line 11, where it is separated into product extract which leaves the system via line 12, and wet leaf, which is sent to Stage 2 as leaf feed via line 13.
At Stage 2, the leaf from decanter 10 is mixed with aqueous extract recovered from Stage 3 and decanter 15 via line 17; after suitable contact time, the mixture is pumped to decanter 14, where it is separated into extract, which is supplied as solvent to Stage 1 via line 18, and wet 15 leaf, which is supplied as leaf feed to Stage 3 via line 19 .
Stage 3 operates as Stages l and 2, except that the solvent used i8 extract received from the high pressure/
20 high temperature acid extraction stage via line 20, and decanter 16. The spent 1eaf from Stage 3 is separated in decanter 15 and ~upplied to kettle 4A via line 27. Tea extracts from other stages may be introduced at either the first, second, or third stages. In a preferred procedure, 25 the Stagesl, 2 and 3 are ~onducted at atmospheric pressure and at a temperature of 85-99C.
While closed columns may be used to contain the tea leaf during each of the extraction stages, an arrangement 30 comprising open kettles is preferred. One convenient process employ~3 two kettles for each stage, an upper or "A"
which receives the ~olvent from a later stage and a fresh leaf source and heats these materials to the desired temperature and a lower or "B" kettle which receives the 35 complete batch from the "A" kettle and acts as a surge for ,,~
~Z~3~
Q.373 a slurry pump which transfers the leaf and water mixture to a decanting centrifuge. The centrifuge separates the liquid and solid phases, transferring the leaf to a later stage or to a spent leaf discard system and the solvent to an earlier stage or on to the next unit operation in the process.
The "A" and "B" kettles are shown in the drawing with respect to the fourth stage. In conducting the 10 fourther stage, acid is added to the leaf and solvent coming into the "A" kettle and is then dropped as an acidified slurry to the "B" kettle where heat is provided.
A slurry pump is then used to pass the mixture in series through a steam injection heater 21, a pressurised 15 retention column 22, a pressurised water addition vessel 23 which provides initial cooling and required dilution, a heat exchange 24 to provide final cooling, and a pressure control system 25, before passing to a kettle 26 which serves as the feed to the final decanting centrifuge 16.
The addition of leaf, wa~er and acid in the fourth stage are preferably batch additions, while the transfer of solvent, leaf and slurry in Stages 1-3 is preferably continuous, this being achieved by setting the rates of the 25 slurry pump so that the contents of one batch are completely pumped out from the lower kettles precisely as the next batch is being dropped into those kettles.
Although heating of the acid tea leaf slurry with 30 steam injection is shown at 21 in the drawing, it has been ound that other methods of heating may be employed. These include scraped-surface heat exchangers, such as those sold under the trad~emark Votator. Similarly, Votator devices and other heat exchange devices may be used at 24 to cool 35 the acid extract to a temperature below its boiling point before feeding it to the decanter feed kettle 26.
o~
_ g _ Q. 373 As in prior art processes, tea aromas may be stripped from the extract, recovered, and added back at a later stage in the process. Aroma stripping is an optional feature, and, where employed, may be conveniently applied to the extract leaving decanter 10 as the product.
~ he tea extracts made according to the present invention may be concentrated and dried, as by spray drying, to a powder. It i9 generally preferred, however, 10 to subject these aqueou~ extracts to the customary treatments of d~ha7;ng and cecreaming, where desired, prior to drying. In addition, the green tea extracts may be further treated to convert them to black tea, and blends of various extracts may be madei either prior or subsequent to drying, in order to achieve desired flavours or colours in 15 the tea made by reconstituting the dried product.
In view of the acid conditions prevailing in the process of the present invention, corrosion-resistant materials should be used in fabricating the equipment used.
20 Type 316 stainless steel is suitable for the Stage 4 portion of the process, while Type 304 stainless steel will withstand the acidity in the centrifuge stream 20 supplying solvent to Stage 3.
The invention will be further described in the working examples which follow.
EX:A~PLE 1 ~0 A serie~3 of instant tea extraction processes were conducted on a pilot plant scale using a countercurrent four-stage extraction of soluble solids from tea leaf with water as ~he ~olvent. The first three stages were conducted at atmospheric pressure and at temperatures ,...
12~L0(~7 10 - Q.373 approaching the boiling point. A fourth phase in which high temperature and high pressure conditions were applied to a strongly acidic leaf slurry was then used.
Before starting the process, the retention column for the fourth stage was preheated with steam to approxima~ely 300-310F using 110 psi steam. The first three stages of the extraction were conducted in the manner normal to countercurent extraction procedures with water 10 feed until sufficient spent leaf was available from the third stage to c~ ce the fourth extraction stage.
The first three stages of extraction were started by filling the upper kettle of stage 1 with 25.7 gallons of 15 water and the water was heated to 206-210F. Fresh leaf was dropped into the kettle in the amount of 15 pounds per batch at the rate of 120 pounds per hour at 5.5% moisture.
A 7.5 minute time cycle for each batch was used, which meant that the tea leaf had a n~ ; n~ l contact time of 7.5 20 minutes at each extraction stage. Each of the second and third stages were started in the same manner, moving the spent leaf from the first to the second and from the second to the third as feed to the upper kettle. At the same time, extract from the second was used as solvent feed to 25 the next cycle of the first, and extract from the third was used as the solvent feed to the next cycle of the second.
After the three stage system was established in normal operation, it was found that the extraction yield of soluble tea solids ranged from 26-33% by weight.
~0 In starting up the fourth stage, leaf and extract from the third ~tage was decanted and separated. Clarified extract was pumped back to the ~econd stage kettle as extraction solvent for that stage. The leaf collected from ~5 stage 3 was ad~ded to a fourth stage kettle. In this fourth stage process, approximately 37~2 - 51.8 pounds per ~atch I
~ Q.373 of leaf was used. Sufficient water at 190~, 15.2 gallons per batch, was pumped to the kettle to make up a 2.4 -3.4:1 water to leaf slurry.
Sulphuric acid at 93.17 - 94.0%, 66 baume concentration was added to the :Leaf slurry at a level of 0.75% based on wet leaf weight. The combined weight of ~he completed batch varied between 164.8 - 179.2 pounds to provide a rate of 1318 - 1435 pounds per hour.
At this point, the temperature of the acid slurry was 180F. It was then dropped into the kettle "B" and pumped into the high pressure portion of the system while being heated by steam at 100 psig through a steam injector 15 to maintain a temperature of about 155C. A com~ined weight of acid slurry plus steam condensate of 1513 - 1653 pounds per hour was thus provided.
The acid slurry was flowed with steam injection into 20 a retention column wherein each tea particle is subjected to a maximum temperature of about 15SC for 15 minutes.
Thereafter, the slurry was permitted to leave the retention column flowing into a totally enclosed dilution mixing pot wherein it was mixed with 16C water suficient to provide 25 an overall water to leaf ratio of about 13.3:1. This resulted in a decrease in the mixture temperature to between about 132-134C. From the mixing pot the slurry passed through a heat exchanger which de~reased the dilution slurry temperature to 99C, up to back pressure 30 valves se~ at 63 psig. After passing through the back pressure valve, the slurry was collected ~nd passed to a decanter. The separated extract from the decanter was conveyed to Stage 3 and used as the aqueous solvent supply to that stage. The spent lea~ from the decanter was 35 discarded.
o~
- 12 - Q~373 The following Table I gives the yield obtained by conducting the four-stage extraction process set forth above using dry green tea leaf as the raw material:
Table 1 FOUR-CELL EXTRACTION PROCESS DATA (GREEN TEA PROCESS ) Average extraction ~ Solids ~ yield %
HPA Cell extract 1.50+.5 2.24-3.00 17.0 3rd Cell extract 1.69+.5 2.85-3.46 18.1 15 2nd Cell extract 2.03~.3 3.41-3.78 23.2 1st Cell extract 4.47+.5 4.11-4.50 47.1 Average cumulative extraction yield = 47.10%.
(Average 3-cell extraction yield = 26-33%.) A series of tea extraction pilot plant processes, on 25 the scale of Example 1, and following the proces~ outlined in the drawing was conducted using the followiny parameters:
30 For Stage 4:
3:1 weight ratio of water to wet spent leaf 1.5% of 50~ H2SO4, basis wet spent leaf, by weight ~20~ 7 - 13 - Q.373 c) about 155-160C; 100-120 psig steam, d) 4-5 min. time at desired temperature.
In stage 4, the spent lea~E was slurried with water, the required acid added, the batch heated to desired temperature, cooled to below the boiling point, vented to release residual pressure and pumped to decanter 16 for separation.
Stages 1-3 conditions inc:Luded a 10:1 water to fresh leaf ratio. about 98C extraction temperature, and about 7.5 - 8 minute cycle time. In one instance, the ratio of water to fresh leaf was increased to 13 1/3:1. Black tea 15 was used..
Table II below su~narises the results of the several separate runs:
~, I
- ~2~)10C~7 - 14 - Q~373 Table II
FOUR-STAGE CO~ KCURRENT EXTRACTIO~ OF BLACK TEA
High Pressure/ Run High Temperature No.
Acid Stage l. 2. 3. 4. 5.* 6. 7.
Extraction Yield ll9.3l¦l8.741lg.861l8.ll1l7.781l8.93 17.00 10 pH 1 2.5 1 2.491 2.441 2.4 1 2.601 2.l8 2.49 Stage 3 Extraction Yield ¦ 21. 22120.49 2l.l5¦20.02¦20.38122.3 1l9.35 15 pH ¦ 3.081 3.031 2.951 2.931 3-051 2.571 2.93 Stage 2 Extraction Yield 127.3g126.32 26.53126.59126.09127.23124.24 20 pH1 3.721 3.72 3.6l¦ 3.561 3.6l¦ 3.l3¦ 3.46 Stage l I l l l I
Extraction Yield 44.85143.47 43.55¦44.24¦47.79¦47.78¦46.16 25 pH1 4.431 4.4 ¦ 4.381 4.371 4.4 ¦ 4.041 4.30 * Average of these runs with water to leaf ratio of 13 l/3:l I
120~0(~
- 15 - Q.373 A series of pilot plant t:ea extraction processes, on the scale of Example 1, but using only two stayes, was conducted. The second stage wa~; the high temperature/high pressure acid extraction stage, while Stage 1 was conducted at atmospheric pressure. The conditions of each stage were as follow~:
Stage 2:
a) 3:1 water to wet spent leaf ratio, by weight b) 1.5% of 37~ HCl or 1.5% of 50% H2S04, basis wet spent leaf, by weight c) 155-160C extraction temperature, with 100-120 psig steam d) 4-5 minutes time at desired temperature e) the spent leaf was slurried with water, the required acid was added, and the slurry was heated to temperature with steam injection.
The slurry was then cooled to below its boiling point, any residual pressure was vented and the slurry then pumped to decanter 16 for evaporation. The leaf was discarded while the extract was us~d as solvent for Stage 1.
Stage 1 was a conventional atmo~pheric pressure extraction, using a 10:1 water to fresh dry leaf ratio, an extraction temperature of 98C and a cycle time of about 35 7.5 - 8 minutes. Table III below summarises the results of these runs.
~ ~L20:~L0~7 Table III
TWO-STAGE COU~TERCURRE~T EXTRACTIO~ OF BLACK TEA
Stage 2 Stage 1 High pressure/high Atmospheric temperature acid stage pressure stage Combined 10 Run Extraction Extraction extraction No. yield pHAcid yield pH yield 1. 19.62 2.92~Cl 28.322.91 47.94 15 2. 19.18 3.2H2S04 26.544.87 45.72 3. 17.8 2.99H2S04 26.284.91 44.08 A series of pilot plant tea extraction proce~ses, on the scale o~ Example 1, but using three stages, was conducted. The third stage was the high temperature/high 25 pressure/acid extraction stage, while Stages 1 and 2 were carried out at atmospheric pressure. Conditions used in each of the three stages were as follows:
Stage 3 - Same as described in Stage 2 of Example 3 30 above; both HCl and H2S04 were tested.
Stage 1 - Same as described in Stage 1 of Example 3 above.
Stage 2 - Same as described for Stage 1, using the acid extract from Stage 3 as solvent. Additional water was 12~0~37 - 17 - Q.373 added, as needed, to bring fresh leaf ratio to l~:l by weight.
Data obtained from this series of runs is given in Table IV below. ~ote that the natural buffering capacity of the additional stage accounted for an average gain of 0.9 pH unit~.
Table IV
THREE STAGE EXTRACTIO~ OF BLACK TEA
Stage 3 High temperature/High pressure/
. Acid extraction Extraction Run No. yield ~ Acid l. 21.6 2.47 HCl 2. 17.66 2.66 H2SO4 3. l9.31 2.59 H2SO4 4. 20.29 2.51 HCl I
~z~lQ(~7 Stages 2 and 3 Atmospher.ic Pressure extraction 5Extraction yields pH Combined Stage Stage S1,ageStage extraction Run No. 1 2 1 2yields __ _ 1. 27.45 21.6 5.02 3.42 49.05 26.~4 18.73 5.03 - 45.17 3. 26.48 lg.9 4.97 3.52 46.38 4. 27.05 20.14 4.77 3.31 47.1g * * * * *
Fresh water or other aqueous solvent i8 added to the leaf, the extraction takes place, and the mixture of tea leaf and solvent is pumped ko a decanter lO, via line 11, where it is separated into product extract which leaves the system via line 12, and wet leaf, which is sent to Stage 2 as leaf feed via line 13.
At Stage 2, the leaf from decanter 10 is mixed with aqueous extract recovered from Stage 3 and decanter 15 via line 17; after suitable contact time, the mixture is pumped to decanter 14, where it is separated into extract, which is supplied as solvent to Stage 1 via line 18, and wet 15 leaf, which is supplied as leaf feed to Stage 3 via line 19 .
Stage 3 operates as Stages l and 2, except that the solvent used i8 extract received from the high pressure/
20 high temperature acid extraction stage via line 20, and decanter 16. The spent 1eaf from Stage 3 is separated in decanter 15 and ~upplied to kettle 4A via line 27. Tea extracts from other stages may be introduced at either the first, second, or third stages. In a preferred procedure, 25 the Stagesl, 2 and 3 are ~onducted at atmospheric pressure and at a temperature of 85-99C.
While closed columns may be used to contain the tea leaf during each of the extraction stages, an arrangement 30 comprising open kettles is preferred. One convenient process employ~3 two kettles for each stage, an upper or "A"
which receives the ~olvent from a later stage and a fresh leaf source and heats these materials to the desired temperature and a lower or "B" kettle which receives the 35 complete batch from the "A" kettle and acts as a surge for ,,~
~Z~3~
Q.373 a slurry pump which transfers the leaf and water mixture to a decanting centrifuge. The centrifuge separates the liquid and solid phases, transferring the leaf to a later stage or to a spent leaf discard system and the solvent to an earlier stage or on to the next unit operation in the process.
The "A" and "B" kettles are shown in the drawing with respect to the fourth stage. In conducting the 10 fourther stage, acid is added to the leaf and solvent coming into the "A" kettle and is then dropped as an acidified slurry to the "B" kettle where heat is provided.
A slurry pump is then used to pass the mixture in series through a steam injection heater 21, a pressurised 15 retention column 22, a pressurised water addition vessel 23 which provides initial cooling and required dilution, a heat exchange 24 to provide final cooling, and a pressure control system 25, before passing to a kettle 26 which serves as the feed to the final decanting centrifuge 16.
The addition of leaf, wa~er and acid in the fourth stage are preferably batch additions, while the transfer of solvent, leaf and slurry in Stages 1-3 is preferably continuous, this being achieved by setting the rates of the 25 slurry pump so that the contents of one batch are completely pumped out from the lower kettles precisely as the next batch is being dropped into those kettles.
Although heating of the acid tea leaf slurry with 30 steam injection is shown at 21 in the drawing, it has been ound that other methods of heating may be employed. These include scraped-surface heat exchangers, such as those sold under the trad~emark Votator. Similarly, Votator devices and other heat exchange devices may be used at 24 to cool 35 the acid extract to a temperature below its boiling point before feeding it to the decanter feed kettle 26.
o~
_ g _ Q. 373 As in prior art processes, tea aromas may be stripped from the extract, recovered, and added back at a later stage in the process. Aroma stripping is an optional feature, and, where employed, may be conveniently applied to the extract leaving decanter 10 as the product.
~ he tea extracts made according to the present invention may be concentrated and dried, as by spray drying, to a powder. It i9 generally preferred, however, 10 to subject these aqueou~ extracts to the customary treatments of d~ha7;ng and cecreaming, where desired, prior to drying. In addition, the green tea extracts may be further treated to convert them to black tea, and blends of various extracts may be madei either prior or subsequent to drying, in order to achieve desired flavours or colours in 15 the tea made by reconstituting the dried product.
In view of the acid conditions prevailing in the process of the present invention, corrosion-resistant materials should be used in fabricating the equipment used.
20 Type 316 stainless steel is suitable for the Stage 4 portion of the process, while Type 304 stainless steel will withstand the acidity in the centrifuge stream 20 supplying solvent to Stage 3.
The invention will be further described in the working examples which follow.
EX:A~PLE 1 ~0 A serie~3 of instant tea extraction processes were conducted on a pilot plant scale using a countercurrent four-stage extraction of soluble solids from tea leaf with water as ~he ~olvent. The first three stages were conducted at atmospheric pressure and at temperatures ,...
12~L0(~7 10 - Q.373 approaching the boiling point. A fourth phase in which high temperature and high pressure conditions were applied to a strongly acidic leaf slurry was then used.
Before starting the process, the retention column for the fourth stage was preheated with steam to approxima~ely 300-310F using 110 psi steam. The first three stages of the extraction were conducted in the manner normal to countercurent extraction procedures with water 10 feed until sufficient spent leaf was available from the third stage to c~ ce the fourth extraction stage.
The first three stages of extraction were started by filling the upper kettle of stage 1 with 25.7 gallons of 15 water and the water was heated to 206-210F. Fresh leaf was dropped into the kettle in the amount of 15 pounds per batch at the rate of 120 pounds per hour at 5.5% moisture.
A 7.5 minute time cycle for each batch was used, which meant that the tea leaf had a n~ ; n~ l contact time of 7.5 20 minutes at each extraction stage. Each of the second and third stages were started in the same manner, moving the spent leaf from the first to the second and from the second to the third as feed to the upper kettle. At the same time, extract from the second was used as solvent feed to 25 the next cycle of the first, and extract from the third was used as the solvent feed to the next cycle of the second.
After the three stage system was established in normal operation, it was found that the extraction yield of soluble tea solids ranged from 26-33% by weight.
~0 In starting up the fourth stage, leaf and extract from the third ~tage was decanted and separated. Clarified extract was pumped back to the ~econd stage kettle as extraction solvent for that stage. The leaf collected from ~5 stage 3 was ad~ded to a fourth stage kettle. In this fourth stage process, approximately 37~2 - 51.8 pounds per ~atch I
~ Q.373 of leaf was used. Sufficient water at 190~, 15.2 gallons per batch, was pumped to the kettle to make up a 2.4 -3.4:1 water to leaf slurry.
Sulphuric acid at 93.17 - 94.0%, 66 baume concentration was added to the :Leaf slurry at a level of 0.75% based on wet leaf weight. The combined weight of ~he completed batch varied between 164.8 - 179.2 pounds to provide a rate of 1318 - 1435 pounds per hour.
At this point, the temperature of the acid slurry was 180F. It was then dropped into the kettle "B" and pumped into the high pressure portion of the system while being heated by steam at 100 psig through a steam injector 15 to maintain a temperature of about 155C. A com~ined weight of acid slurry plus steam condensate of 1513 - 1653 pounds per hour was thus provided.
The acid slurry was flowed with steam injection into 20 a retention column wherein each tea particle is subjected to a maximum temperature of about 15SC for 15 minutes.
Thereafter, the slurry was permitted to leave the retention column flowing into a totally enclosed dilution mixing pot wherein it was mixed with 16C water suficient to provide 25 an overall water to leaf ratio of about 13.3:1. This resulted in a decrease in the mixture temperature to between about 132-134C. From the mixing pot the slurry passed through a heat exchanger which de~reased the dilution slurry temperature to 99C, up to back pressure 30 valves se~ at 63 psig. After passing through the back pressure valve, the slurry was collected ~nd passed to a decanter. The separated extract from the decanter was conveyed to Stage 3 and used as the aqueous solvent supply to that stage. The spent lea~ from the decanter was 35 discarded.
o~
- 12 - Q~373 The following Table I gives the yield obtained by conducting the four-stage extraction process set forth above using dry green tea leaf as the raw material:
Table 1 FOUR-CELL EXTRACTION PROCESS DATA (GREEN TEA PROCESS ) Average extraction ~ Solids ~ yield %
HPA Cell extract 1.50+.5 2.24-3.00 17.0 3rd Cell extract 1.69+.5 2.85-3.46 18.1 15 2nd Cell extract 2.03~.3 3.41-3.78 23.2 1st Cell extract 4.47+.5 4.11-4.50 47.1 Average cumulative extraction yield = 47.10%.
(Average 3-cell extraction yield = 26-33%.) A series of tea extraction pilot plant processes, on 25 the scale of Example 1, and following the proces~ outlined in the drawing was conducted using the followiny parameters:
30 For Stage 4:
3:1 weight ratio of water to wet spent leaf 1.5% of 50~ H2SO4, basis wet spent leaf, by weight ~20~ 7 - 13 - Q.373 c) about 155-160C; 100-120 psig steam, d) 4-5 min. time at desired temperature.
In stage 4, the spent lea~E was slurried with water, the required acid added, the batch heated to desired temperature, cooled to below the boiling point, vented to release residual pressure and pumped to decanter 16 for separation.
Stages 1-3 conditions inc:Luded a 10:1 water to fresh leaf ratio. about 98C extraction temperature, and about 7.5 - 8 minute cycle time. In one instance, the ratio of water to fresh leaf was increased to 13 1/3:1. Black tea 15 was used..
Table II below su~narises the results of the several separate runs:
~, I
- ~2~)10C~7 - 14 - Q~373 Table II
FOUR-STAGE CO~ KCURRENT EXTRACTIO~ OF BLACK TEA
High Pressure/ Run High Temperature No.
Acid Stage l. 2. 3. 4. 5.* 6. 7.
Extraction Yield ll9.3l¦l8.741lg.861l8.ll1l7.781l8.93 17.00 10 pH 1 2.5 1 2.491 2.441 2.4 1 2.601 2.l8 2.49 Stage 3 Extraction Yield ¦ 21. 22120.49 2l.l5¦20.02¦20.38122.3 1l9.35 15 pH ¦ 3.081 3.031 2.951 2.931 3-051 2.571 2.93 Stage 2 Extraction Yield 127.3g126.32 26.53126.59126.09127.23124.24 20 pH1 3.721 3.72 3.6l¦ 3.561 3.6l¦ 3.l3¦ 3.46 Stage l I l l l I
Extraction Yield 44.85143.47 43.55¦44.24¦47.79¦47.78¦46.16 25 pH1 4.431 4.4 ¦ 4.381 4.371 4.4 ¦ 4.041 4.30 * Average of these runs with water to leaf ratio of 13 l/3:l I
120~0(~
- 15 - Q.373 A series of pilot plant t:ea extraction processes, on the scale of Example 1, but using only two stayes, was conducted. The second stage wa~; the high temperature/high pressure acid extraction stage, while Stage 1 was conducted at atmospheric pressure. The conditions of each stage were as follow~:
Stage 2:
a) 3:1 water to wet spent leaf ratio, by weight b) 1.5% of 37~ HCl or 1.5% of 50% H2S04, basis wet spent leaf, by weight c) 155-160C extraction temperature, with 100-120 psig steam d) 4-5 minutes time at desired temperature e) the spent leaf was slurried with water, the required acid was added, and the slurry was heated to temperature with steam injection.
The slurry was then cooled to below its boiling point, any residual pressure was vented and the slurry then pumped to decanter 16 for evaporation. The leaf was discarded while the extract was us~d as solvent for Stage 1.
Stage 1 was a conventional atmo~pheric pressure extraction, using a 10:1 water to fresh dry leaf ratio, an extraction temperature of 98C and a cycle time of about 35 7.5 - 8 minutes. Table III below summarises the results of these runs.
~ ~L20:~L0~7 Table III
TWO-STAGE COU~TERCURRE~T EXTRACTIO~ OF BLACK TEA
Stage 2 Stage 1 High pressure/high Atmospheric temperature acid stage pressure stage Combined 10 Run Extraction Extraction extraction No. yield pHAcid yield pH yield 1. 19.62 2.92~Cl 28.322.91 47.94 15 2. 19.18 3.2H2S04 26.544.87 45.72 3. 17.8 2.99H2S04 26.284.91 44.08 A series of pilot plant tea extraction proce~ses, on the scale o~ Example 1, but using three stages, was conducted. The third stage was the high temperature/high 25 pressure/acid extraction stage, while Stages 1 and 2 were carried out at atmospheric pressure. Conditions used in each of the three stages were as follows:
Stage 3 - Same as described in Stage 2 of Example 3 30 above; both HCl and H2S04 were tested.
Stage 1 - Same as described in Stage 1 of Example 3 above.
Stage 2 - Same as described for Stage 1, using the acid extract from Stage 3 as solvent. Additional water was 12~0~37 - 17 - Q.373 added, as needed, to bring fresh leaf ratio to l~:l by weight.
Data obtained from this series of runs is given in Table IV below. ~ote that the natural buffering capacity of the additional stage accounted for an average gain of 0.9 pH unit~.
Table IV
THREE STAGE EXTRACTIO~ OF BLACK TEA
Stage 3 High temperature/High pressure/
. Acid extraction Extraction Run No. yield ~ Acid l. 21.6 2.47 HCl 2. 17.66 2.66 H2SO4 3. l9.31 2.59 H2SO4 4. 20.29 2.51 HCl I
~z~lQ(~7 Stages 2 and 3 Atmospher.ic Pressure extraction 5Extraction yields pH Combined Stage Stage S1,ageStage extraction Run No. 1 2 1 2yields __ _ 1. 27.45 21.6 5.02 3.42 49.05 26.~4 18.73 5.03 - 45.17 3. 26.48 lg.9 4.97 3.52 46.38 4. 27.05 20.14 4.77 3.31 47.1g * * * * *
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for extracting plant infusion material, such as leaf tea, wherein spent infusion material obtained at the end of a traditional aqueous extraction process is subjected to a further aqueous extraction step conducted under conditions that involve both elevated pressure and low pH.
2. A process for extracting tea from tea leaf comprising the steps of:
a) contacting the tea leaf with aqueous solvent to extract tea leaf solids:
b) separating the aqueous extract from the spent tea leaf;
c) adding an acid to the spent tea leaf to reduce the pH thereof to within the range of about 2.0 - 3.0;
d) subjecting the acidified spent tea leaf to further extraction with aqueous solvent at pressures of about 80 - 100 psig and temperatures of about 140 - 170°C for at least 4 minutes; and e) separating the remaining tea leaf solids from the aqueous solvent to leave a high temperature/high pressure aqueous extract.
a) contacting the tea leaf with aqueous solvent to extract tea leaf solids:
b) separating the aqueous extract from the spent tea leaf;
c) adding an acid to the spent tea leaf to reduce the pH thereof to within the range of about 2.0 - 3.0;
d) subjecting the acidified spent tea leaf to further extraction with aqueous solvent at pressures of about 80 - 100 psig and temperatures of about 140 - 170°C for at least 4 minutes; and e) separating the remaining tea leaf solids from the aqueous solvent to leave a high temperature/high pressure aqueous extract.
3. The process of claim 2, wherein the high temperature/high pressure aqueous extract obtained from step (d) is used as an aqueous solvent in step (a) of the process.
4. The process of claim 2, wherein step (a) is a countercurrent extraction procedure using at least two stages and wherein the high temperature/high pressure aqueous extract obtained from step (d) is used as the aqueous solvent in at least one stage.
5. The process of claim 2, wherein step (a) is carried out at atmospheric pressure and at temperatures up to 100°C
in a time sufficient to extract essentially all of the tea solids soluble under said extraction conditions.
in a time sufficient to extract essentially all of the tea solids soluble under said extraction conditions.
6. The process of claim 5, wherein step (a) is a countercurrent extraction procedure having at least two stages and wherein the high temperature/high pressure aqueous extract from step (d) is used as the aqueous solvent in the last of said stages.
7. The process of claim 6, wherein the acid used in step (c) is H2SO4.
8. The process of claim 2, wherein step (a) is a countercurrent extraction procedure using at least two stages, the first stage of which provides for contacting raw tea leaf to an aqueous tea extract from a later stage in the procedure and a second stage of which provides for contact of partially extracted tea leaf with fresh aqueous solvent and wherein the fresh aqueous solvent used in the second stage is the high temperature/high pressure aqueous extract obtained from step (d).
9. The process of claim 2, wherein the acid used is a food grade acid selected from the group consisting of HCl, H3PO4, H2SO3, HNO3, CH3COOH and H2SO4.
10. The process of claim 2, wherein (a) is a countercurrent extraction procedure using three stages, the first stage of which provides for contacting raw tea leaf with an aqueous tea extract from a later stage in the procedure and the third stage of which provides for contacting partially extracted tea leaf with fresh aqueous solvent and wherein the fresh aqueous solvent used in the third stage is the high pressure/high temperature aqueous extract obtained from step (d).
11. A process for extracting tea from tea leaves by first conducting an extraction of tea leaf with aqueous solvent and then subjecting the residual spent tea leaf to acid conditions in the pH range of about 2.0-3.0 under elevated pressure and elevated temperature for a period of time sufficient to extract further solids.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US337,300 | 1982-01-05 | ||
| US06/337,300 US4668525A (en) | 1982-01-05 | 1982-01-05 | Tea extraction process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1201007A true CA1201007A (en) | 1986-02-25 |
Family
ID=23319959
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000418858A Expired CA1201007A (en) | 1982-01-05 | 1983-01-04 | Tea extraction process |
Country Status (11)
| Country | Link |
|---|---|
| US (1) | US4668525A (en) |
| EP (1) | EP0083570B1 (en) |
| JP (1) | JPS58139701A (en) |
| AT (1) | ATE19851T1 (en) |
| AU (1) | AU548263B2 (en) |
| CA (1) | CA1201007A (en) |
| DE (1) | DE3363555D1 (en) |
| GB (1) | GB2112624B (en) |
| IN (1) | IN158735B (en) |
| KE (1) | KE3648A (en) |
| MY (1) | MY8600731A (en) |
Families Citing this family (33)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4539216A (en) * | 1984-05-25 | 1985-09-03 | The Procter & Gamble Co. | Process for preparing tea products |
| JPS6359583U (en) * | 1986-10-07 | 1988-04-20 | ||
| JPH02145183U (en) * | 1989-05-12 | 1990-12-10 | ||
| US5196214A (en) * | 1990-06-07 | 1993-03-23 | Nestec S.A. | Water soluble tea extracts |
| US5069925A (en) * | 1990-06-07 | 1991-12-03 | Nestec S.A. | Preparation of tea products |
| DE69100127T2 (en) * | 1990-06-07 | 1993-10-07 | Nestle Sa | Water-soluble tea extracts. |
| AU664421B2 (en) * | 1992-02-14 | 1995-11-16 | Cash Engineering Research Pty Ltd | Flooded compressor system separator vessel |
| EP0654221B1 (en) * | 1993-11-18 | 2001-01-10 | Societe Des Produits Nestle S.A. | Process for preparing instant black tea |
| AU1525695A (en) * | 1994-01-10 | 1995-08-01 | Procter & Gamble Company, The | Tea extract and process for preparing |
| DE69415009T2 (en) * | 1994-09-03 | 1999-04-22 | Nestle Sa | Process for the production of instant black tea |
| AU1515095A (en) * | 1994-12-13 | 1996-07-03 | Wm. Wrigley Jr. Company | Improved chewing gum containing salatrim |
| US5532012A (en) * | 1995-06-02 | 1996-07-02 | Thomas J. Lipton Co., Division Of Conopco, Inc. | Process for preparation of purified tea components using preconcentration by cream separation and solubilization followed by medium pressure chromatography and/or preparative HPLC |
| US6063428A (en) * | 1996-02-26 | 2000-05-16 | The Procter & Gamble Company | Green tea extract subjected to cation exchange treatment and nanofiltration to improve clarity and color |
| KR100753012B1 (en) * | 1999-08-03 | 2007-08-30 | 가부시키가이샤 야쿠루트 혼샤 | Fermented milks and their production processes |
| JP3668408B2 (en) * | 2000-04-05 | 2005-07-06 | 株式会社 伊藤園 | Method for producing green tea beverage |
| US6846501B2 (en) | 2000-04-12 | 2005-01-25 | Mid-America Commercialization Corporation | Traditional snacks having balanced nutritional profiles |
| US20020012733A1 (en) * | 2000-04-12 | 2002-01-31 | The Procter & Gamble Company | Compositions for reducing hypercholesterolemia and controlling of postprandial blood glucose and insulin levels |
| US6899905B2 (en) | 2000-04-12 | 2005-05-31 | Mid-America Commercialization Corporation | Tasty, ready-to-eat, nutritionally balanced food compositions |
| US6827954B2 (en) * | 2000-04-12 | 2004-12-07 | Mid-America Commercialization Corporation | Tasty, convenient, nutritionally balanced food compositions |
| US6720015B2 (en) | 2000-04-12 | 2004-04-13 | Mid-America Commercialization Corporation | Ready-to-eat nutritionally balanced food compositions having superior taste systems |
| US6726943B2 (en) | 2000-04-12 | 2004-04-27 | Mid-America Commercialization Corporation | Nutritionally balanced snack food compositions |
| US6716462B2 (en) | 2000-04-12 | 2004-04-06 | Mid-America Commercialization Corporation | Nutritionally balanced traditional snack foods |
| US6632449B2 (en) | 2001-11-20 | 2003-10-14 | The Procter & Gamble Co. | Compositions and kits comprising a defined boron compound and methods of their preparation |
| WO2004014413A1 (en) * | 2002-07-31 | 2004-02-19 | Procyte Corporation | Compositions containing peptide copper complexes and phytochemical compounds, and methods related thereto |
| US20050260302A1 (en) * | 2004-05-19 | 2005-11-24 | The Procter & Gamble Company | Nutritionally balanced traditional snack foods having a low glycemic response |
| US7232585B2 (en) * | 2004-06-24 | 2007-06-19 | Xel Herbaceuticals, Inc. | Green tea formulations and methods of preparation |
| EA201001064A1 (en) * | 2007-12-28 | 2011-02-28 | Юнилевер Н.В. | METHOD OF EXTRACTING AROMA FROM TEA |
| US20110159121A1 (en) * | 2009-12-24 | 2011-06-30 | LifeSpan Extension, LLC | Methods and compositions for identifying, producing and using plant-derived products for modulating cell function and aging |
| CN105213414B (en) * | 2010-06-09 | 2018-01-30 | 花王株式会社 | The manufacture method of polyphenol compositions |
| US10463054B2 (en) * | 2015-05-20 | 2019-11-05 | Teaspressa Llc | Methods of tea extraction |
| AU2018332955B2 (en) * | 2017-09-13 | 2021-01-28 | Unilever Ip Holdings B.V. | Process for preparing black tea products |
| JP7210418B2 (en) * | 2019-11-05 | 2023-01-23 | 株式会社神戸製鋼所 | interaction system |
| CN110859233A (en) * | 2019-12-25 | 2020-03-06 | 湖北宇隆生物工程有限责任公司 | Production method of tea extract |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB658412A (en) * | 1946-11-28 | 1951-10-10 | Ferdinand Neef | Improvements in or relating to the production of coffee or tea-flavoured beverage powders |
| US2785979A (en) * | 1954-04-14 | 1957-03-19 | George F Mitchell | Processes for preparing tea products |
| US3080237A (en) * | 1960-02-24 | 1963-03-05 | Tea Corp | Method for producing a concentrated tea extract |
| US3224873A (en) * | 1963-02-25 | 1965-12-21 | Gen Mills Inc | Liquid-liquid recovery of copper values using alpha-hydroxy oximes |
| CH455472A (en) * | 1964-11-24 | 1968-07-15 | Nestle Sa | Process for the production of soluble extracts of plant materials |
| GB1207326A (en) * | 1967-09-19 | 1970-09-30 | Unilever Ltd | Preparation of tea |
| US3666484A (en) * | 1969-11-12 | 1972-05-30 | Lipton Inc Thomas J | Process for making a spray-dried instant tea of desired bulk density |
| US3809769A (en) * | 1970-12-31 | 1974-05-07 | Tetley Inc | Method of extracting tea |
| US3939286A (en) * | 1973-01-29 | 1976-02-17 | Jelks James W | Process for oxidizing and hydrolyzing plant organic matter particles to increase the digestability thereof by ruminants |
| US3971858A (en) * | 1973-09-05 | 1976-07-27 | Thomas J. Lipton, Inc. | Extracting tea using an aqueous solution of ammonium bicarbonate or ammonia |
-
1982
- 1982-01-05 US US06/337,300 patent/US4668525A/en not_active Expired - Lifetime
- 1982-12-23 IN IN1484/CAL/82A patent/IN158735B/en unknown
- 1982-12-31 AU AU91990/82A patent/AU548263B2/en not_active Ceased
-
1983
- 1983-01-04 CA CA000418858A patent/CA1201007A/en not_active Expired
- 1983-01-04 DE DE8383300014T patent/DE3363555D1/en not_active Expired
- 1983-01-04 GB GB08300018A patent/GB2112624B/en not_active Expired
- 1983-01-04 EP EP83300014A patent/EP0083570B1/en not_active Expired
- 1983-01-04 AT AT83300014T patent/ATE19851T1/en not_active IP Right Cessation
- 1983-01-05 JP JP58000397A patent/JPS58139701A/en active Granted
-
1986
- 1986-06-27 KE KE3648A patent/KE3648A/en unknown
- 1986-12-30 MY MY731/86A patent/MY8600731A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| US4668525A (en) | 1987-05-26 |
| EP0083570A1 (en) | 1983-07-13 |
| GB2112624B (en) | 1986-02-12 |
| JPS58139701A (en) | 1983-08-19 |
| AU9199082A (en) | 1983-07-14 |
| EP0083570B1 (en) | 1986-05-21 |
| GB8300018D0 (en) | 1983-02-09 |
| JPS6310983B2 (en) | 1988-03-10 |
| GB2112624A (en) | 1983-07-27 |
| KE3648A (en) | 1986-07-25 |
| IN158735B (en) | 1987-01-10 |
| ATE19851T1 (en) | 1986-06-15 |
| MY8600731A (en) | 1986-12-31 |
| AU548263B2 (en) | 1985-12-05 |
| DE3363555D1 (en) | 1986-06-26 |
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