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US4639375A
Expired / Lapsed
US
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Enzymatic treatment of black tea leaf
Assignee: Procter and Gamble Co
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Filing: 1983-08-12
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Granted: 1987-01-27
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Expires: 2003-08-12
Abstract
Abstract A process for the enzymatic treatment of black tea leaf is disclosed. In particular, black tea leaf is wetted with water containing tannase and one or more cell-wall-digesting enzymes, such as cellulase, pectinase, papain, or hemicellulase, prior to extraction. The enzyme-moistened tea leaf is incubated in a closed system at room temperature for a few hours. The enzyme-treated tea is then neutralized with a suitable food grade base and the enzymes are inactivated by heating. The resulting treated tea can be extracted and processed in the usual manner or dried for use in tea bags in the usual manner. As a result, a higher yield of tea is obtained and the resulting instant tea has better solubility in cold water than conventional teas. The bag tea products an infusion which does not form haze at cold temperatures.
Inventors
- 👤 Chee-Hway Tsai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:05
CPC Classifications
A; A23; A23F; A23F3/00; A23F3/06; A23F3/08; A23F3/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
130 words
A process for increasing the yield and tea solid solubility of black tea by enzymatic treatment, comprising the steps of: (1) wetting fermented black tea leaf prior to extraction with an enzyme solution comprising water, tannase and at least one cell-wall-digesting enzyme which breaks down one or more tea cell wall constituents to simpler materials wherein the tea leaf is combined with the enzyme solution at a tea:enzyme solution weight ratio of from about 4:1 to about 1:2.5; (2) incubating the enzyme-wetted tea to cause partial digestion and fermentation of the tea leaf in a closed system such that volatiles are not lost or damaged; (3) neutralizing the tea to a pH of from about 4.75 to about 5.75 with an edible base; and (4) inactivating the enzymes by heating.
Claim 2
Dependent Claim
130 words
A process for increasing the yield and tea solid solubility of black tea by enzymatic treatment, comprising the steps of: (1) wetting fermented black tea leaf prior to extraction with an enzyme solution comprising water, tannase and at least one cell-wall-digesting enzyme which breaks down one or more tea cell wall constituents to simpler materials wherein the tea leaf is combined with the enzyme solution at a tea:enzyme solution weight ratio of from about 4:1 to about 1:2.5; (2) incubating the enzyme-wetted tea to cause partial digestion and fermentation of the tea leaf in a closed system such that volatiles are not lost or damaged; (3) neutralizing the tea to a pH of from about 4.75 to about 5.75 with an edible base; and (4) inactivating the enzymes by heating.
Claim 3
Dependent Claim
25 words
A process according to claim 1 wherein the enzyme-wetted tea leaf is incubated at a temperature of from about 20° C. to about 65° C.
Claim 4
Dependent Claim
21 words
A process according to claim 1 wherein the enzyme-wetted tea leaf is incubated for from about 0.5 to about 20 hours.
Claim 5
Dependent Claim
18 words
A process according to claim 1 wherein the enzyme-wetted tea leaf is further incubated in an inert atmosphere.
Claim 6
Dependent Claim
13 words
A process according to claim 1 wherein the enzymes are inactivated by heating.
Claim 7
Dependent Claim
30 words
A process according to claim 1 wherein the cell-wall-digesting enzyme is a member selected from the group consisting of cellulase, hemicellulase, pectinase, dextranase, iysozyme, protease and lipase, and mixtures thereof.
Claim 8
Dependent Claim
11 words
A process according to claim 6 wherein the protease is papain.
Claim 9
Dependent Claim
12 words
A process according to claim 6 wherein the lipase is pancreatic lipase.
Claim 10
Dependent Claim
60 words
A process according to claim 6 wherein the enzyme solution contains from about 0.5 to about 35 units of tannase per gram of tea leaf, wherein one unit is the amount of enzyme which hydrolyzes one micromole of ester bond in 0.35% tannic acid in 0.1 m. phosphate buffer having a pH of 5.5 in one minute at 30° C.
Claim 11
Dependent Claim
63 words
An extractable tea product comprising black tea leaf which has been at least partially digested by treatment with tannase and at least one cell-wall-digesting enzyme, and which, when extracted with boiling water to yield a tea extract having a percent solids concentration of from 0.30% to 10%, produces an extract the solids of which are completely soluble in the water at 4° C.
Claim 12
Dependent Claim
63 words
An extractable tea product comprising black tea leaf which has been at least partially digested by treatment with tannase and at least one cell-wall-digesting enzyme, and which, when extracted with boiling water to yield a tea extract having a percent solids concentration of from 0.30% to 10%, produces an extract the solids of which are completely soluble in the water at 4° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-26 | 1990-07-28 | 1991-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-26 | 1994-07-28 | 1995-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-26 | 1998-07-28 | 1999-01-27 | $7700.00 | Window Closed / Lapsed |