Title of Invention	A PROCESS FOR MANUFACTUREING GREEN TEA.
Abstract	A process for the manufacture of green tea comprising the steps of subjecting harvested green tea leaves to the step of freezing and dehydration followed by a step of primary rolling to obtain rolled leaves, subjecting said rolled leaves to a first stage of drying to obtain partially dried leaves followed by separation of fines there from. subjecting the bulk of the partially dried leaves to a step of secondary rolling followed by drying in a third stage to obtain dried tea which is subjected to fibre extraction, grinding and winnowing to obtain the green tea, characterized in that the harvested green tea leaves is initially subjected to the step of freezing and dehydration.

Title of Invention

A PROCESS FOR MANUFACTUREING GREEN TEA.

Abstract

A process for the manufacture of green tea comprising the steps of subjecting harvested green tea leaves to the step of freezing and dehydration followed by a step of primary rolling to obtain rolled leaves, subjecting said rolled leaves to a first stage of drying to obtain partially dried leaves followed by separation of fines there from. subjecting the bulk of the partially dried leaves to a step of secondary rolling followed by drying in a third stage to obtain dried tea which is subjected to fibre extraction, grinding and winnowing to obtain the green tea, characterized in that the harvested green tea leaves is initially subjected to the step of freezing and dehydration.

Full Text	2 This invention relates to a process for manufacturing green tea. BACKGROUND OF THE INVENTION Green tea is made from green leaf, which is also used in making black tea. The main difference in processing of green and black tea is the prevention of withering and fermentation in the form by initial heat inactivation of the polyphenol oxidase enzyme present in tea flush.. This inactivation is achieved by steaming the flush to a temperature of l00OC as well as by a process known as panning where the flush is fed into hot rotating drum touching a temperature of 300-350oC. The steps involved in steaming process of green tea manufacture are sorting and cleaning the fresh green leaves and subjecting the same to the steps of steaming, primary rolling and drying, rolling, secondary drying, final rolling followed by final drying and refining to obtain the green tea. In the panning process of green tea manufactureed, the steps followed are similar to those for the steaming process, except that the initial inactivation is effected by dry heat. The fresh green leaf is sorted and cleaned and subjected to the step of panning, primary rolling and drying, rolling, secondary drying, final rolling and final drying followed by refining. 3. The entire exclusion of withering and fermentaion stages necessary to the manufacture of black tea, renders the whole process of green tea manufacture a simple one in comparison with that of black tea. A1though variation in weather conditions exercise little effect on manufacture, green tea making requires as much, if not more, care and supervision than that does black tea manufacture. An improved process for making green tea involving microwave technology to replace the conventional steps of steaming and panning, is known in the art. This process involves the steps of subjecting the sorted and cleaned fresh green leaf to the steps of microwave heating, cooling, dehydration, rolling, drying and refining to obtain the green tea. Thus, in all the processes mentioned hereinbefore, the tea leaves are subjected to steaming, panning or microwave heating to inactivate the enzymes for preventing oxidative changes and to retain catechins substantially unchanged during processing. It is known that the flavor of green tea is related to the intensity of astringency , bitterness, brothy taste and sweetness Caffeine contributes to the bitterness of the tea brew through complexes with phenol. The astrigency of the tea brew is a result of polyphenols in tea, such as (-) epi catechin, (-) epi catechin gallate, (-) epi gallo catechin and (-) epi gallo catechin gallate. The brothy taste of tea brew originates in the amino acid fraction, expecially the 1-theanine. Sweetness is as a result of sugar and amino acids. 4. The disadvantages associated with the use of steaming, panning and microwave treatment in the manufacture of green tea are longer duration of drying, lower turnover, poor sanitary conditions due to spillage of tea leaf component during processing and lack of quality in terras of aroma, OBJECTS OF THE INVENTION It is therefore an object of this invention to propose a process for the manufacture of green tea which is cost effective and efficient by involving reduced processing time. It is a further object of this invention to propose a process for the manufacture of green tea with improved quality. Other objects and advantages of this invention will be apparent from the ensuing description. At the outset of the description which follows, it is to be understood that the ensuing description only illustrates a particular form of this invention. However, such a particular form is only an exemplary embodiment without intending to imply any limitation on the scope of the invention. Accordingly the description is to be understood as an exemplary embodiment and reading of the invention is not to be taken restrictively. 5. DESCRIPTION OF THE INVENTION Yhus according to the invention is provided a process for the manufacture of green tea. In accordance with this invention, the harvested green leaves are subjected to the step of freezing, dehydration followed by primary rolling and secondary rolling and, finally the steps of drying,cooling, drying and cleaning to obtain the tea leaves which are finally graded and winnowed before packing In the process of the instant invention, green leaf harvest containing 65-75% of two leaf and a bud as in case of rain crop with dry matter content ranging from 18% to 26% is used for making green tea. The green tea leaf is frozen which facilitates crystallization of intro-and extra-cellular moisture in leaf causing maximum cell damage during dehydration rollign and drying process. The total processing time is reduced during dehydration and drying as a result of faster rate of moisture evaporation due to maximum cell damage caused to the leaf. The steps of freezing and dehydration help in simultaneous inactivation of enzymes and removal of moisture which weather the leaf to a satisfactory rollable condition. The biochemical changes desirable in green tea are achieved during primary rolling, roll breaing-cum-sitting and secondary rolling. The leaf after primary rolling and first stage drying is subjected to roll breaking-cum sifting to effect separation of fines from bulk and the bulk and fines are separately handled during second and third stage of drying to minimize loss in dry matter. 6. Cooling of processed leaf after second stage of drying helps in equilibrating moisture in leaf particle by internal diffusion process thereby facilitating removal of moisture during final drying. The banji and coarse leaves are processed to make green tea with improved leaf colour, bright yellow liquor and adequate aroma in infusion and cup. The invention will now be more explained in greater detail with the help of the following non-limiting example. EXAMPLE Results of a pilot scale trial for making green tea using 10 kg leaf of July crop by the new process as well as by steam treatment process are given below: 7. The process described herein above for the method of making Green tea is not only economical and superior in producing better quality product, the process parameters are illustrative without restricting the scope thereof. - 7 -WE CLAIM 1. A process for the manufacture of green tea comprising the steps of subjecting harvested green tea leaves to the step of freezing and dehydration followed by a step of primary rolling to obtain rolled leaves, subjecting said rolled leaves to a first stage of drying to obtain partially dried leaves followed by separation of fines there from, subjecting the bulk of the partially dried leaves to a step of secondary rolling followed by drying in a third stage to obtain dried tea which is subjected to fibre extraction, grinding and winnowing to obtain the green tea, characterized in mat the harvested green tea leaves is initially subjected to the step of freezing and dehydration. 2. The process as claimed in claim 1 wherein said harvested green leaves comprise 65-75% of three leaves and a bud with dry matter content ranging from 19-26% by sorting and cleaning. 3. The process as claimed in claim 1 wherein the step of freezing comprises conveying the green leaves on a continuous endless-chain-blast freezing-unit to achieve crystallization of the infra and extra-cellular moisture in leaf in 15-30 minutes. 4. The process as claimed in claim 1 wherein the step of dehydration comprises dehydration of frozen leaves in multi-tray band or through flow drier and reducing the moisture content to 30 ± 5% in 15-30 minutes by using hot air at 75-100°C. 5. The process as claimed in claim 4 wherein the moisture content is reduced upto 50% for the debittering process. 6. The process as claimed in claim 1 wherein the step of primary rolling comprises rolling of withered leaf with 30-50% moisture - 8 - in orthodox rollers with pressure for 10-20 minutes. 7. The process as claimed in claim 1 wherein the rolled leaves are dried in a first stage in multi-tray band or through flow o drier using hot air at 112 + 2 C to reduce the moisture content-to 12-15% in 10-20 minutes, 8. The process as claimed in claim 1 wherein the separation of fines from partially dried leaf is effected in rol1-breaker-cum- sifter fitted with a sieve, preferably a 5 mesh size sieve s'. The process as claimed in claim 1 wherein the step of secon dary rolling comprises subjecting the bulk of the partially dried leaves containing 12-15% moisture to rolling in orthodox rollers, using maximum pressure for 10-20 minutes, 10. The process as claimed in claim i wherein the step of drying in a second stage comprises drying of the bulk of the dried and rolled leaves and fines separately in multi-tray band or through o flout driers using hot air et 112 + 2 C to a moisture content of 6-7% . 11. The process as claimed in claim 1 wherein the dried tea is o cooled to room temperature in a current of ambient air at 25-35 C for 5-10 minutes. 12. The process as claimed in claim 1 wherein drying in a third stage comprises drying in multi-tray band drier using hot air at o 3 12 ±2 c for 8-10 minutes to a moisture content of 3-4%. 13. The process for the manufacture of green tea substantially as here in described and illustrated in the accompanying drawing. A process for the manufacture of green tea comprising the steps of subjecting harvested green tea leaves to the step of freezing and dehydration followed by a step of primary rolling to obtain rolled leaves, subjecting said rolled leaves to a first stage of drying to obtain partially dried leaves followed by separation of fines there from. subjecting the bulk of the partially dried leaves to a step of secondary rolling followed by drying in a third stage to obtain dried tea which is subjected to fibre extraction, grinding and winnowing to obtain the green tea, characterized in that the harvested green tea leaves is initially subjected to the step of freezing and dehydration.

Full Text

2
This invention relates to a process for manufacturing green tea.
BACKGROUND OF THE INVENTION
Green tea is made from green leaf, which is also used in making black tea. The main difference in processing of green and black tea is the prevention of withering and fermentation in the form by initial heat inactivation of the polyphenol oxidase enzyme present in tea flush.. This inactivation is achieved by steaming the flush to a temperature of l00OC as well as by a process known as panning where the flush is fed into hot rotating drum touching a temperature of 300-350oC.
The steps involved in steaming process of green tea manufacture are sorting and cleaning the fresh green leaves and subjecting the same to the steps of steaming, primary rolling and drying, rolling, secondary drying, final rolling followed by final drying and refining to obtain the green tea.
In the panning process of green tea manufactureed, the steps followed are similar to those for the steaming process, except that the initial inactivation is effected by dry heat. The fresh green leaf is sorted and cleaned and subjected to the step of panning, primary rolling and drying, rolling, secondary drying, final rolling and final drying followed by refining.

3.
The entire exclusion of withering and fermentaion stages necessary to the manufacture of black tea, renders the whole process of green tea manufacture a simple one in comparison with that of black tea. A1though variation in weather conditions exercise little effect on manufacture, green tea making requires as much, if not more, care and supervision than that does black tea manufacture.
An improved process for making green tea involving microwave technology to replace the conventional steps of steaming and panning, is known in the art. This process involves the steps of subjecting the sorted and cleaned fresh green leaf to the steps of microwave heating, cooling, dehydration, rolling, drying and refining to obtain the green tea.
Thus, in all the processes mentioned hereinbefore, the tea leaves are subjected to steaming, panning or microwave heating to inactivate the enzymes for preventing oxidative changes and to retain catechins substantially unchanged during processing. It is known that the flavor of green tea is related to the intensity of astringency , bitterness, brothy taste and sweetness Caffeine contributes to the bitterness of the tea brew through complexes with phenol. The astrigency of the tea brew is a result of polyphenols in tea, such as (-) epi catechin, (-) epi catechin gallate, (-) epi gallo catechin and (-) epi gallo catechin gallate. The brothy taste of tea brew originates in the amino acid fraction, expecially the 1-theanine. Sweetness is as a result of sugar and amino acids.

4.
The disadvantages associated with the use of steaming, panning and microwave treatment in the manufacture of green tea are longer duration of drying, lower turnover, poor sanitary conditions due to spillage of tea leaf component during processing and lack of quality in terras of aroma,
OBJECTS OF THE INVENTION
It is therefore an object of this invention to propose a process
for the manufacture of green tea which is cost effective and
efficient by involving reduced processing time.
It is a further object of this invention to propose a process
for the manufacture of green tea with improved quality.
Other objects and advantages of this invention will be apparent
from the ensuing description.
At the outset of the description which follows, it is to be
understood that the ensuing description only illustrates a
particular form of this invention. However, such a particular
form is only an exemplary embodiment without intending to imply
any limitation on the scope of the invention. Accordingly the
description is to be understood as an exemplary embodiment
and reading of the invention is not to be taken restrictively.

5. DESCRIPTION OF THE INVENTION
Yhus according to the invention is provided a process for the manufacture of green tea.
In accordance with this invention, the harvested green leaves are subjected to the step of freezing, dehydration followed by primary rolling and secondary rolling and, finally the steps of drying,cooling, drying and cleaning to obtain the tea leaves which are finally graded and winnowed before packing In the process of the instant invention, green leaf harvest containing 65-75% of two leaf and a bud as in case of rain crop with dry matter content ranging from 18% to 26% is used for making green tea. The green tea leaf is frozen which facilitates crystallization of intro-and extra-cellular moisture in leaf causing maximum cell damage during dehydration rollign and drying process. The total processing time is reduced during dehydration and drying as a result of faster rate of moisture evaporation due to maximum cell damage caused to the leaf.
The steps of freezing and dehydration help in simultaneous inactivation of enzymes and removal of moisture which weather the leaf to a satisfactory rollable condition. The biochemical changes desirable in green tea are achieved during primary rolling, roll breaing-cum-sitting and secondary rolling. The leaf after primary rolling and first stage drying is subjected to roll breaking-cum sifting to effect separation of fines from bulk and the bulk and fines are separately handled during second and third stage of drying to minimize loss in dry matter.

6.
Cooling of processed leaf after second stage of drying helps in equilibrating moisture in leaf particle by internal diffusion process thereby facilitating removal of moisture during final
drying.
The banji and coarse leaves are processed to make green tea
with improved leaf colour, bright yellow liquor and adequate aroma in infusion and cup.
The invention will now be more explained in greater detail with the help of the following non-limiting example.
EXAMPLE
Results of a pilot scale trial for making green tea using 10 kg leaf of July crop by the new process as well as by steam treatment process are given below:

7.
The process described herein above for the method of making Green tea is not only economical and superior in producing better quality product, the process parameters are illustrative without restricting the scope thereof.

- 7 -WE CLAIM
1. A process for the manufacture of green tea comprising the steps of subjecting
harvested green tea leaves to the step of freezing and dehydration followed by a step of
primary rolling to obtain rolled leaves,
subjecting said rolled leaves to a first stage of drying to obtain partially dried leaves followed by separation of fines there from,
subjecting the bulk of the partially dried leaves to a step of secondary rolling followed by drying in a third stage to obtain dried tea which is subjected to fibre extraction, grinding and winnowing to obtain the green tea, characterized in mat the harvested green tea leaves is initially subjected to the step of freezing and dehydration.
2. The process as claimed in claim 1 wherein said harvested green leaves comprise
65-75% of three leaves and a bud with dry matter content ranging from 19-26% by
sorting and cleaning.
3. The process as claimed in claim 1 wherein the step of freezing comprises
conveying the green leaves on a continuous endless-chain-blast freezing-unit to achieve
crystallization of the infra and extra-cellular moisture in leaf in 15-30 minutes.
4. The process as claimed in claim 1 wherein the step of dehydration comprises
dehydration of frozen leaves in multi-tray band or through flow drier and reducing the
moisture content to 30 ± 5% in 15-30 minutes by using hot air at 75-100°C.
5. The process as claimed in claim 4 wherein the moisture content is reduced upto
50% for the debittering process.
6. The process as claimed in claim 1 wherein the step of primary rolling
comprises rolling of withered leaf with 30-50% moisture

- 8 -
in orthodox rollers with pressure for 10-20 minutes.
7. The process as claimed in claim 1 wherein the rolled leaves
are dried in a first stage in multi-tray band or through flow
o
drier using hot air at 112 + 2 C to reduce the moisture content-to 12-15% in 10-20 minutes,
8. The process as claimed in claim 1 wherein the separation of
fines from partially dried leaf is effected in rol1-breaker-cum-
sifter fitted with a sieve, preferably a 5 mesh size sieve
s'. The process as claimed in claim 1 wherein the step of secon
dary rolling comprises subjecting the bulk of the partially dried
leaves containing 12-15% moisture to rolling in orthodox rollers,
using maximum pressure for 10-20 minutes,
10. The process as claimed in claim i wherein the step of drying
in a second stage comprises drying of the bulk of the dried and
rolled leaves and fines separately in multi-tray band or through
o flout driers using hot air et 112 + 2 C to a moisture content of
6-7% .
11. The process as claimed in claim 1 wherein the dried tea is
o cooled to room temperature in a current of ambient air at 25-35 C
for 5-10 minutes.
12. The process as claimed in claim 1 wherein drying in a third
stage comprises drying in multi-tray band drier using hot air at
o 3 12 ±2 c for 8-10 minutes to a moisture content of 3-4%.
13. The process for the manufacture of green tea substantially as here in described and illustrated in the accompanying drawing.

A process for the manufacture of green tea comprising the steps of subjecting harvested
green tea leaves to the step of freezing and dehydration followed by a step of primary
rolling to obtain rolled leaves,
subjecting said rolled leaves to a first stage of drying to obtain partially dried leaves
followed by separation of fines there from.
subjecting the bulk of the partially dried leaves to a step of secondary rolling followed by
drying in a third stage to obtain dried tea which is subjected to fibre extraction, grinding
and winnowing to obtain the green tea, characterized in that the harvested green tea
leaves is initially subjected to the step of freezing and dehydration.

Documents:

00021-cal-2000 abstract.pdf

00021-cal-2000 claims.pdf

00021-cal-2000 correspondence.pdf

00021-cal-2000 description(complete).pdf

00021-cal-2000 description(provisional).pdf

00021-cal-2000 drawings.pdf

00021-cal-2000 form-1.pdf

00021-cal-2000 form-18.pdf

00021-cal-2000 form-2.pdf

00021-cal-2000 form-3.pdf

00021-cal-2000 form-5.pdf

00021-cal-2000 latters patent.pdf

00021-cal-2000 reply f.e.r.pdf

21-cal-2000-granted-abstract.pdf

21-cal-2000-granted-claims.pdf

21-cal-2000-granted-correspondence.pdf

21-cal-2000-granted-description (complete).pdf

21-cal-2000-granted-drawings.pdf

21-cal-2000-granted-form 1.pdf

21-cal-2000-granted-form 18.pdf

21-cal-2000-granted-form 2.pdf

21-cal-2000-granted-form 3.pdf

21-cal-2000-granted-form 5.pdf

21-cal-2000-granted-letter patent.pdf

21-cal-2000-granted-reply to examination report.pdf

21-cal-2000-granted-specification.pdf

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Patent Number

212289

Indian Patent Application Number

21/CAL/2000

PG Journal Number

48/2007

Publication Date

30-Nov-2007

Grant Date

28-Nov-2007

Date of Filing

17-Jan-2000

Name of Patentee

A.I.N. KHANNA

Applicant Address

42/135, NEW BALLYGUNGE ROAD, CALCUTTA 700039.

Inventors:

#	Inventor's Name	Inventor's Address
1	A.I.N. KHANNA	42/135, NEW BALLYGUNGE ROAD, CALCUTTA 700039.
2	DR.S. RAMASWAMY	ROOM NO. 1/196, PLOT NO. 27/28, BALAKRISHNANAGAR, GERUGAMBAKKAM, CHENNAI

PCT International Classification Number

A61K 38/56

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA