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(19)    (11) Patent Number: KE 324
(45) Date of grant: 30/06/2009
P
Kenya Industrial Prripselty Institut..
(12) PATENT
(51) Int.Cl.7: A 23F 3/06, F 26B 11/16
(21)Application    KE/P/06/00511    (84) WO No. WO/2005/093352
Number:    06/10/2005
(22)Filing Date:    29/03/2004
(31)Priority Number:    (32) Date: (33) Country:
(73)    Owner(s): COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH of Rafi Marg, New Delhi 110 001, India
(72) Inventor(s)    GARIKAPATI, Dyva, Kiran, Babu and DESIKACHAR,
Ravindranath, Srigiripuram
(74)    Agentladdress for correspondence: Hamilton Harison &Mathews,  (54) Title:    A FIELD CONVENIENT JACKETED LEAF INACTIVATOR FOR GREEN TEA
PROCESSING
(57) Abstract: A simple, convenient tea leaf roaster for efficiently inactivate the tea shoots to produce good quality green tea with minimum use of energy. The invention comprises of roasting tank (1) provided with a heating jacket (2) and an agitator (9) operated manually or by motor. The jacket containing thermic fluid is heated under controlled conditions to generate steam out of the tea shoots charged into the inactivation tank by taking the advantage of moisture present in the fresh two and a bud leaves. The contents in the treatment tank are gently heated up to help in efficient roasting of the leaf without imparting burnt aroma to the end product. The leaves are completely inactivated without exposing to higher temperature, and due to non-loss of juice from the shoots during the process; the quality of green tea is superior to leaves processed by earlier prior arts.
 
WO 2005.03352    PCT/1N2004/000073
A HELD CONVENIENT JACKETED LEAF INACTIVATOR FOR GREEN
TEA PROCESSING
Fidel of invention
5
The present invention relates to a field convenient jacketed leaf inactivator for
green tea processing. More particularly, the present invention relates to a simple,
convenient tea leaf roasts' to efficiently inactivate the tea shoots to produce good
quality green tea having wide range of heating options to enable the operation
10 even in the fields with nailmum use of energy.
Background and Prior art references
The present invention is particularly useful during the processing of green tea
wlvse the fresh leaf harvested from the bushes of Camellia sinensis (L.) O. Kunlze
is inactivated/ fixed! roasted as soon as possible in the field itself. The use of this
15 imfention enables the improvement in the quality of the green tea as compared to trade ional/ conventional processing methods. The green tea manufactured by using this invention is devoid of smoky or roasted flavour. Other uses of the present invention are that the machine can be utilised to quickly inactivate einimatic reactions and subsequent drying of herbs as well especially having
20 medcinal or food value, where the biological activities continue for significant period otherwise processed by conventional shade drying which may results in loss of active ingredients.
Priwart 1:
Most of the green teas manufactured in China are fixed by pan firing. A double
25 roaster fixing machine as shown in figure 1 of the schematic diagram
accompanying this speacafion is used for making Chinese green tea also known
as Kamaira-cha. Reference may be made to (0 Shao-Jun Luo. Processing of tea.
In: Special issue on tea. Tei Yamanishi (ed.), Marcel Dekker Inc., Hong Kong.
Farad Reviews Intematkinal, Vol. 11(3): 409 434, 1995, (ii) T. Takeo. Green and
 
AND 2f105/093351    PCIAN2004/000073
2
semi-fermented teas. In: Tea: Cultivation to consumption. K.C. Wilson and M.N. Clifford (eds.), Chapman & Hall: London, UK, 1992; 413 — 457, wherein the machine is fitted on a frame (1) made up of mild steel (MS) or cast iron (Cl). Tea leaves are placed in the roasting room (2) and start firing in the hearth below
5 roaster (3). The process is continued for 10 — 15 min with agitation of 4 — 5 timesilinki. During firing, the greenish odour note is evaporated and the typical pan-fwed aroma is developed. After reaching the desired stage, the leaf is removed from the said roasting room by tilting the roaster with the help of transroissiciii system (4) which is operated from switch box (5). The fired leaves
10 are mardpulated to one of three shapes characteristic of Chinese green tea during 10-15 ruin: in a roller and dried at 100-150°C in a pan. The products are the gun shot type of tea which is ball-like, the chun-mee and sow-nee types which have a fine, 'Aided form and the pan-fired type which has a flat leaf form and later
polished lb a pale white colour. The  major drawbacks of this prior art are (I) the \Nfret)
15 temperature of roasting pan initially will be at 250-300°C, as a result the initial change gets charredibumt, (ii) because higher temperatures are needed to rapidly heat the baffinactive the leaf, there will be very little control to prevent charring / burning_ Lower temperature will not inactive the leaf properly resulting ttir jbrow I of the shoots, (iii) the burnt note of this kind of roasting stays with the end
20 proclucts,, (iv) handling of charge per batch it very less viz, 30 kg/batch.
Price ad 2:
Another method followed for the production of steamed, unshaded green tea in
Japan is popularly known as Sen-che consisting of a series of controlled heating
ail  oudag_a ralOjorts. The machinery as shown in figure 2A and 2B of the
25 drawings accompanying this specification is used for the manufacturing of Sm¬ola. Reference may be made to T. Takeo. Green and semi-fermented teas. In:
 
Tea: Culivation to consumption. KG. Wilson and M.N. Clifford (eds.), Chapman &
Londbn, IX, 1992; 413 — 457 wherein plucked leaves are steamed for 45  60 seconds in a steamer (a), then curled and semi-dried in hot-air at 90-110°C for 40-50 min in a primary drying tea roller (b). This primary drying and rolling process
5 reduces tie leaf moisture from 76% to about 50%. The leaves are rolled for a further 15 min without heat, and then pressed and dried for 30 — 40 min in hot air at 50 — 60°C in a secondary drying and rolling (c). This secondary drying reduces the moil ire content of the tea leaves to about 30%. A further curling is followed by the tied drying stage, in which the tea leaves are dried directly on a hot pan at
10 84-90°C and twisted for 40 Min under pressing and rolling by a cuffing machine-hand mounted en a pan. Finally, the tea leaves are dried at BOAC until a moisture content of 6% is achieved in final drying and rolling (d). The tea made with these machines, caller} Ara•claw (=crude tea) in Japan, is produced at a small-holding (1 — 2 ha) farmers factory or at a factory operated by a farmer's union which involves
IS 50-100 small-holding farmers. This crude tea is refined by the wholesalers because the leaves are not uniform and the product has poor appearance. Therefore, this crude tea is sifted repeatedly to remove stalk and dust formed during the above said series of operations. The refined leaves are dried again 6 remove be greenish odour note. The major drawback in this method is that the
20 inacdvalort and further processing involves tedious and elaborative steps for gradual dehydration and rolling. The machinery is also very expensive.
 
In the the drawings accompanying this specification figure 3 represents another
method adopted in India for the manufacture of green tea by directly steaming the
..■•■•■•
25 leaves. Reference may be made to www.workandworks.com. About 200 kg of
freshly plucked leaves are charged in to the roasting drum (1) through the doors
 
WO 2005/1193352    PCT/IN24104/0011073

(2). This roaster is connected to a motor (3) by pulleys (4) and belt (5) system. The roaster is rotated by switching on the motor. Steam generated in a separate boiler is fed into the roaster through the steam inlets (6) & (7) provided on both sides of the drum. The process of steaming continues for 6 to 7 minutes and
5 within this period the kmnies are boiled. if the leaves are not tender (i.e. plucking after 7 days), then roasting time will go up by one minute to one and a half minute. After steaming is cornett:fed, the leaves along with the condensed steam are taken out by opening the doors (2). These leaves are dried and then rolled for further processing of green Ism The major drawbacks of direct steaming are (i) the
10 processing area be nines highly wet and unhygienic because of the leaf juice (ii) during rolling, wet lealf bses the soluble ingredients along with extra water present within the leaf due to above, (iii) leaf carries extra moisture due to condensation of the steam injected for inactivation, hence needs to be semi-dried before further rolling, (iv) the loss of useful tea ingredients, the quality of final green tea is inferior
15 as compared to when there is no loss of juice, (v) generation of steam used in the inactivation of leaf and semi drying in point (iii) both results in consumption of extra energy, (vi) the maclarregy also requires an additional steam generator, (vii) the heavy machinery used kit the production requires high capital investment and high recurring costs, thereby, increasing the cost of production.
20 Thus, the machinery and the processes mentioned above have one or the other major drawbacks like inferior quality of green tea, (I) restricted mode of heating, (iii) narrow utility In the field, (iv) higher cost of the machinery, (v) unhygienic processing site and (4) involving wastage of energy.
Objects of the invention
25 The main object of the present invention is to provide a field convenient jacketed leaf iriactivator for green tea processing, which obviates the drawbacks as detailed
 
5
above.
Another object of the present invention is to quickly inactivate enzyme linked
reactions and subsequent drying of herbs which cannot be achieved in
conventional air drying under shade condition where the biological activities
5 continue for a significant tine during the process and may result in loss of active ingredients.
St* another object of the Resent invention is to provide a portable machinery for
the inactivation of green tea leaves and We herbs with wide range of heating
options to catty out the Recessing in adverse site conditions such as without
18 electricity, water etc.
Yet another object of the Resent invention is to provide a machine to make a good quality green tea with minimum use of energy.
Summary of the Invention
A simple, convenient tea leaf roaster was invented to efficiently inactivate the tea
15 shoots to produce good quality green tea having wide range of heating options to enable the operation even lithe fields with minimum use of energy. The invention comprising of roasting tank povideci with a heating jacket and an agitator operated manually or by motor. The jacket containing thermic fluid is heated under controlled conditions to generate steam out of the tea shoots charged into the
28 inactivation tank by taking the advantage of moisture present in the fresh two and a bud leaves. The contents in the treatment tank are gently heated up to help in efficient roasting of the leaf without imparting burnt aroma to the end product. The system is designed to haw a better control over the working parameters and hence, chances of and burning of leaves are minimized. In addition to
25 the inactivation of polyptienol oxidase (PPO), there is a simultaneous loss of
moisture from shoots, thus helping conservation of energy. The leaves are
 
6
completely inactivated without exposing to higher i    Aura and due to non-
lass of juice from the shoots during the process; the quality of green tea is superior
to leaves processed by earlier prior arts. Because of improvement in liquor
character, the green teas made by the present invention are likely to have wider
5 consumer acceptability.
Btrief description of figures
Figure 1: Schematic diagram of machinery used for making Chinese green tea. Figure 2: Machinery used for the manufacturing of Sen-cha (steamed, unshaded peen tea).
10 Figure 3:1achinery used for the manufacturing of Sen-cha (steamed, unshaded peen tea).
Figure 4: Machinery India for the manufacture of green tea by directly steaming
Figure 5: Construction features of the present invention.
E Figure 6: Construction features of the present invention.
Detailed Description of the hwention
Accordingly, the present invention provides a field convenient jacketed leaf
irectivator liar green tea processing, comprising: (a) treatment tank (1) having a
removably fixed external jacket (2) connected to a means (3,4) for charging (3)
20 and discharging (4) of thermic fluid; (b) the treatment tank provided with removably stable means (6, 6) for charging (5) and discharging (6) of the shoot material; (c) a shaft (7) having impellers (9) and material collecting bowls / blades (10) and connected at the center of the treatment tank and (d) a heating device (13) placed below the edema] jacket to heat the thermic fluids.
25 In an embodiment of the present invention, in (b) the removably fixable means are Bose type lids.
 
7
In another embodiment of the present invention the shaft is fixed on a ball bearing (8) and the impeders and material collecting bowls / blades connected by means selected Thorn the group consisting of nut-bolts, rivets and welding (14
In yet another mnbodiment of the present invention the shaft is connected to a
5 handle (12) fixed on the shaft to rotate the said impellers for mixing and uniform exposure of material to the heat transfer surface.
In still another emboctiment of the present invention the shaft is connected to a motor (114) by kin means (15, 16) namely V-belt driven (15) on a pulley (16) for mechanization.
10 In another embedment of the present invention the V-belt is loosened before/
duringlafter processing of the material to disengage the belt from the shaft.
In yet another mabodiment of the present invention the treatment tank is provided with means (18) for measuring parameters selected from the group consisting of temperature, humidity and pressure.
15 In still another embodiment of the present invention the external jacket is provided with means (19, 20) for measuring parameters selected from the group consisting of temperature, pressure, thermic fluid regulator and thermic fluid expansion kettle. In another embodiment of the present invention the inactivate% is fixed on a stand (21) a* wheels (22) for its easy mobility for use in remote areas.
20 In yet another embodiment of the present invention the treatment tank, jacket, shaft, impellers and bowls are made up of metals selected from the group consisting of stainless steel, brass and bronze.
In still another embodiment of the present invention the length of the treatment tank, shaft and jacket is extended to operate the system under continuous mode.
25        In another embodiment of the present invention the treatment tank is provided with
hoppers at the top extreme one end for feeding and at the opposite end for
 
discharging the material under continuous mode.
in yet another embodiment of the present invention at the end of discharging hole rotating blades are fixed for chopping the material before discharging.
In still another embodiment of the present invention the material collecting bowls 5 attached to the impellers are used with an angle to push the material away from the feeding hopper and towards discharging hole.
In another embodiment of the present invention the thermic fluid used in the inactivator is selected from the group consisting of steam, water and heat transfer oils.
10 In yet another embodiment of the present invention the heating means is selected from the group consisting of burners operated on fuel, direct firing by fuel namely
wood, briquettes and coal, electric heaters, microwave and ultrasound energy.
fin still another embodiment of the present invention the external jacket is removable and the treatment tank is heated by above said means.
In another embodiment of the present invention the treatment tank is provided with an exhaust tan mounted on a duct for removing the moisture during partial dehydration of the charge.
In yet another embodiment of the present invention continuous charging and discharging is achieved with the use of spiral metal worm of suitable diameter and 20 length.
Accordingly the present invention provides a method for inactivation of green tea shoots, said method comprising: (a) filling outer jacket of the roasting tank with water and healing; (b) charging freshly plucked tea shoots comprising two and a bud into the preheated inactivation chamber; (c) continuously mixing the leaves
25 and continuing heating and (d) removing the steamed shoots and cooling the shoots.
In another embodiment of the present invention heating is done using heating
 
9
means, said heating means is selected from the group consisting of burners operated on fuel, direct firing by fuel namely wood, briquettes and coal, electric heaters, microwave and ultrasound energy to provide heat bank.
In still another embodiment of the present invention freshly plucked tea shoots in
5 the weight range of 1000 to 7000 g was charged in slowly in the weight range of 100 to 150 g for up to 90 seconds at a time while mixing the leaves to avoid blockage of the impellers and to attain uniform heating.
In another embodiment of the present invention the charging lid is closed after complete charging of the shoot
10 In yet another embodiment of the present invention- the heating is continued for an additional time period of six minutes.
In another embodiment of the present invention continuous mixing is achieved by impellers attached to the shaft, which is rotated by the motor having speed re011ator-
15 In still another embodiment of the present invention the temperature of the leaves alter inactivation is in the range of 82 to 85 °C.
In another embodiment of the present invention the loss in weight in the inactivated leaves is In the range of 150 to 200 g.
In yet another embodiment of the present invention the green tea obtained shows .
20 no polyphenol oxidase activity and is good in taste without roast flavour.
The constructional features of the present invention as shown in the figures endears given below
A stainless steel (ss304) or brass or any biocompalible material of construction
stationery drum/tank (1) having internal diameter (ID) = 500 — 1000 mm or more;
25 length = 600 — 6000 run or more; thickness = 3 — 8 mm primarily serving as a
container for holding the material to be inactivated or partially dehydrated. The
same tank is fitted with nut-bolts or any appropriate means to a 'MS' jacket (2), ID
 
to
= 700 - 7000 min or compatible with the tank, 3.0 - 10.0 mm thickness; covering
the bottom half portion of the tank depth = 250 - 3500 mm or as per the
dimensions of the tank which wit be filled with water/ oiV thermic fluids from inlet
(3) and heated by a heat source (13) consisting of a liquefied petroleum gas (LPG)
5 burned stove length = 600 - 6000 mm in V - shape or any convenient shape in
one or more parts/pieces connected to one or more LPG cylinders depending
upon the length lithe tank. The other heating sources that can be used are direct
firing, furnace made up of fire clay/ cement and fire bricks, by fuel wood or burners
operated with pc:Welkin products or any other source of conventional fuels or
le heating sources. Water/ oii/ thermic fluids can be drained out from the out let
valve (4). To operate the system by steam, the inlet (3) can be connected to a
boiler for steam supply and the outlet (4) may be fitted with a steam trapper.
Circular, ellipsoidal or any other convenient shape such as square type charging
hole (5) having dimensions (L x W) 600 - 6000 mm x 200 - 800 mm with loose-
15 type lid 608 - 6008 mm x 208 - 808 mm and a discharging hole (6) 600 - 6000
mm x 150 - 600 rim along with loose-type fid 608 - 6008 min x 160 - 808 mm
with latch was fixed adjacent to the charging hole. A shaft (7) having diameter =
25 -100 mm, length = 900 - 6300 min made up of stainless steel (SS) or brass or
any metal, resistant to the processed chemicals/materials used in the manufacture
20 method, fixed at the centre of the axis of the tank longitudinally with the help of ball
bearings or any other suitable mechanism (8) of suitable size and compatible with
the shaft. On this shaft, impellers (9) of length = 480 - 980 mm of angle iron 50 x
50 -100 x 100 mm and 5 -12 mm thickness fixed preferably at 90° to each other
with nut-bolts or studded/ riveted (11). The number of impellers may vary from 2
25 to 25 or more depending up on length of the tank, quantity of material handled per
batch or per hour. The edges of these impellers are welded with paddles in plate
bowl shape (10), with length = 300 - 600 mm, depth = 50 - 300 mm leaving 2 - 5
 
tt
=ogee from the wall of the tank to mix/ rotate the leaf for uniform exposure to the heat for proper inactivaion of the leaf in optimum time by retaining quality. At the one end, the shaft is provided with a handle (12), length = 100 - 300 mm and diameter = 25 - 50 mmio rotate the impellers manually and at the other end a V-
5 belt (15) is connected tea pulley (16) which are fixed on the shaft of the tank and motet (14) to mechanically mix the leaf kept in the tank for inactivation. A system (17) is fitted for V - belt to tighten the latter during processing for effective =serpent of the shaft without wasting the energy and to loosen after processing for easy discharging of ire leaf by rotating the shaft manually, when needed. The
10 rear (14) operating cm single phase/ 3 phase, 50 - 60 Hz, 0.5 - 5 hp, with appropriate voltage is also provided with a switch box and reduction box to regilate the rpm of the shaft. Two temperature gauges (18, 19) range 0 - 150°C oneeach on the roasting tank and in the heating jacket are provided to monitor the temperature of the contents in the tank and thermic fluid in the jacket respectively.
15 A pressure gauge (20) is also provided to monitor the pressure of the jacket. The whale system is fixed oma compatible frame (21) of suitable dimensions along with wheels (22) at the basear easy mobility in the fields. The dimensions viz, length, diameter etc., of the roasting tank (1), jacket (2) shaft (7) and heating source (13) met be changed as mentioned earlier to operate the machine in continuous mode
20 by 'incorporating a leaf charging hopper, having a preferable length = 400 - 800 me. diameter = 300 - fi00 mm with an angle of 20 - 60° at the top left side of the tank and a discharging hole provided at the right hand bottom side of the tank with a provision to cut the discharging material by revolving blades fixed on a shaft what are attached to lie pulley by a V - belt which is again connected to the
25 sane or other motor of 1.0 - 3.0 hp and a speed regulator. The tank is placed will an angle of 2 - 8. with the base. The paddles/blades on the impellers are remove* fixed with an angle which can be changed from 0 - 90° to move the
 
12
charged leaf from one end to the other end in required time by exposing all the leaves b the heating surface of the tank. The rpm and the angle of paddlesbmpellers will be set depending upon the configuration of the machine, load and quality of the end product. The impellers and paddle can also be
5 replaced with a continuous spiral or helical shaped paddles on the shaft or any suitable arrangement which can mix the leaf uniformly and to move the material front chasing end to discharging end.
The steam is generated out of the leaf itself by taking advantage of moisture
present is the fresh shoots of two and a bud. The water jacket provided at the
10 bottom aithe tank is heated to its bolting point or slightly above its boiling point to produce wet steam which will gently heat the shoots. The steam formed in the jadoet is always wet, saturated and maintained at the same condition to help in roasting Be leaves without imparting burnt notes to the end product. The system is designed to have a better control over the working parameters and hence, the
15 chances of browning and burning of leaves are minimized. From the, table 1, anisesof the samples, it is dearly observed that the present innovation helps in effective* inactivating tea shoots without imparting smoky/bumt flavour or aroma to green lea. In addition to the inactivation of polyphenol oxidase (PPO), there is a sloultimeota loss of moisture from shoot, thus helping conservation of energy.
20 Due to mon-loss of juice from the shoots, the green tea is superior to steam inactivated shoots as described in method 3 of the text. Due to improVement in liquor character, the green teas made from the above inactivation procedure are likely to cater to a wider spectrum of consumers.
Fresh tea leaf of 1000 g to 7000 g harvested from the plantation comprising of 40 25 to 905/0 two and a bud to be used for the inactivation of PPO were charged in to the roasting tank (1) by manually feeding about 100 g to 150.g at a time. Prior to
 
13
feeding of the leaf, the inactivators jacket (2) may be filled with an oil or water as a thermic fluid theugh the inlet (3) for heating the tank. The tank can be directly heated from the hearth bellow or by firing with the burners (13) operated on petroleum products in the furnace constructed with fire brick and day/ cement.
5 The termerabse of the thermic fluid used may be kept between 90° to 120°C which as be monitored by a thermometer (19) fixed on jacket (2)_ The temperable of the contents in the inactivation tank (1) is observed from a thennomeler MO provided at the top portion of the tank. Other thermic fluid that can be used is steam, which may be generated in a separate boiler. The motor
10 (14) attached to the shaft (7) by V — belt (15) is switched on to rotate the paddles (10) fixedio the impellers (9) for uniform heating of the leaf to be inactivated. After completion of charging of shoots, the charging hole (5) is dosed and the process of heating and mixing is continued for 4 to 7 minutes to completely inactivate PPO. During the process, the moisture present in the fresh leaves charged is taken out
15 by external heating of the tank walls and the steam generated out of this moisture is further used for inactivation of PPO. After such an inactivation, both the healing and rotation me stopped and leaves are taken out of the tank by opening the discharging hole (6) and by manually rotating the shaft (7) with the help of handle (12). This manual operation is possible only when the V—belt is disengaged from
20 the pulleys (16) by the arrangement (17) provided. While manually rotating the shaft, the material in the tank is collected in the bowl (10) which is attached to the impellers (9) can be taken out and spread on sieves kept under room fan for rapid cooling di the shots to ambient temperature. After cooling to room temperature, the shoots are weighed on a weighing machine and the moisture losses were
25 calculated_ A small fraction of the batch can then be tested/ analysed for its residual PPO activity.
 
The following examples are given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention.
EXAMPLE -1
The outer jacket of the masting tank as shown in the figures. and el vr-
5 with water and heated with LPG gas burner to maintain the steam pressure at aa kgicm2. Freshly plucked tea shoot (1500 g) comprising of 60% two and a bud were charged into the inactivation chamber: which was pre-heated to 100°C. This 1500 g of leaves was not charged all in one go, but by slowly charging about 100 to 150 g at a time inki the tank to avoid blockage of the paddles and to attain
10 uniform heating. The WM time taken for charging of shoots was about 50 seconds. The charging id was closed after complete charging of the shoots. The leaves were continucustf mixed with the paddles attached to the shaft which was rotated by a motor haebg a speed regulator. Heating was continued; with the paddle continuing to able, for an additional six minutes. At the end, a few drops
15 of condensed water could be seen coming out of the lid joints. The steamed shoots were then reamed from the chamber. The temperature of the shoots at the end of the inactivation WM measured to be at 85°C. The inactivated shoots were spread on a wire mesh. kept under room fan, for rapidly cooling the shoots to room temperature. The weight of the cooled shoots was observed to be 1350 g. A
20 sample of the cooled shoots was processed for residual PPP activity. The inactivated shoots werellien processed further involving rolling and finally dried in an oven to give the final product 'Green Tea'.
EXAMPLE -2
The outer jacket of the tank was filled with water and heated with LPG gas burner
25 to maintain the steam pressure at 0.8 kg per cm2. Freshly plucked tea shoots (3000 g) comprising of 60% two and a bud were charged into the inactivation chamber which was pre-heated to 100°C. This 3000 g of leaves was not charged
 
Is
all in one go, but by slowly charging about 100 to 150 g at a time into the tank to avoid blockage of the paddles and to attain uniform heating. The total time taken for charging of shoots was about 90 seconds. The charging lid was closed after complete charging of the shoots. The leaves were continuously mixed with the paddies attached to the shaft which was rotated by a motor having speed regulator. Heating was continued; with the paddle continuing to rotate, for an additional six minutes. At the end, a few drops of condensed water could be seen corning out of the id joints- The steamed shoots were then removed from the chamber. The temperature of the shoots at the end of the inactivation was
10, measured to be at 82°G. The inactivated shoots were spread on a wire mesh, kept under room fan, for rapidly cooling the shoots to room temperature. The weight of the cooled shoots was observed to be 2800 g. A sample of the cooled shoots was processed for residual PPO activity. The inactivated shoots were then processed further involving rotting and finally dried in an oven to give the final product 'Green
15 Tea'.
The observations of the examples illustrated above along with report on the quality of the tea are tabulated:
Table t: Quality of green tea leaves.
    Initial
weight    Temp. of leaf
after
inactivation    Loss in
weight    *PPO
activity
remaining    Tasters repor
Example -1    1500 g    • 85°    150 g    Not
detectable    Good Green Tea + roast flavour
Example -2    3000 g    82°    200 g    Not
detectable    Good Green Tea , roast flavour

20 * The polyphenol oxidase (PPO) activity was followed as described by Singh and Ravindranath (Singh, H.P. and Ravindranath, S.D. Occurrence and distribution of PPO activity in floral organs of some standard and local cuttivars of tea. J. Sc?.
 
16
Food Agric., 1994, 64: 117-120). initial activity of PPO in fresh shoots was 1120 Loft fresh weight.
The main advantages of the present invention are:
1.    Improves the green tea quality where it is devoid of smoky or roasted 5    flavour.
2.    -Herbal Inactivation: The harvested crops are usually air dried under shade conditions where biological activities continue for a significantly longer time which may result in lose of active ingredients. The present invention will serve io quickly inactivate enzyme linked reactions and subsequent drying
10    of herbs.
3.    On improvisation into continuous mode, more charge can be handled per hour.
4.    Field convenient, which can be used for small batches to wide range for assessing the suitability of a germplasm for making the quality grade green 15    tea.
5.    Improvised machines can be designed and made for use by marginal. median and big growers for making green tea.
6.    The COMITIEWCial Japanese tea making machines as described in prior art 2 (Fig. 2A and 2B) are big and very expensive involving separate machines
20 for (a) inactivation viz., for flotation or roasting and (b) roiling and semi¬drying of the shoot stage-by-stage. In present invention, the above two steps are performed in one step, fence rendering it cost effective.
7.    This invention prevents loss of the juice, owing to conversion of shoot into steam, which is otherwise lost by direct steam inactivation process as 25    followed in prior art 3 (Fig. 3).
8.    The factory floor is cleaner and more hygienic when compared to the process involving steam inactivation as is followed in prior art 3 (Fig. 3).
 
17
9.    The present invention avoids wasteful use of energy involved in steaming and subsequent manufacture.
10.    Because cd wide range of options available in heating sourcesffuels,
5 manual andbr mechanical operation, and size of the unit, it can be used at different kxation under different operational conditions for inactivation of lite leaves.
 
Is
We claim
1. A field convenient jacketed leaf inactivator for green tea processing, comprising:
a)    a beatrnent tank k    a removably fixed external iefcket (2)-
5    connected to a means (3,4) for charging (3) and dischayging (4) of
thermic fluid,
b)    the treatment tank provided with removably fixable means (5, 6) for charging (5) and discharging (6) of the sho(It material,
c)    a shaft (7) having impellers (9) and material collecting bowls / blades 10    (10) and connected at the center of the treatment tank, and
d)    a heating device (13) placed below/the external jacket to heat the thermic fluids.
2    The inactivator as claimed ig,eltiim 1, wherein in (b) the removably fixable
means are loose type Ids.
15 a    The inactivator as claimed in claim 1, wherein the shaft is fixed on a bail
bearing (8) and the impellers and material collecting bowls / blades connected by means selected from the group consisting of nut-bolts, rivets and welding (11).
4    The ir►cfivator as claimed in claim 1, wherein the shaft is connected to a
20    handle (12) fixed on the shaft to rotate the said impellers for mixing and
uniform exposure of material to the heat transfer surface.
5    The inactivator as claimed in claim 1, wherein the shaft is connected to a
motor (14) by known means (15, 16) namely V-belt driven (15) on a pulley (16) for mechanization.
25 6.    The inactivator as claimed in claim 1, wherein the V-belt is loosened
before/ during/after processing of the material to disengage the belt from the shaft.
 
19
7    The inactivator as claimed in claim 1, wherein the treatment tank is
provided with means (18) for measuring parameters selected from the group consisting of temperature, humidity and pressure.
5 8.    The inactivator as claimed in claim 1, wherein the external jacket is
provided with means (19, 20) for measuring parameters selected from the group consisting of temperature, pressure, thermic fluid regulator and thermic fluid expansion kettle.
9.    The inactWatar as claimed in claim 1, wherein the inactivator is fixed on a
10    stand (21) with wheels (22) for its easy mobility for use in remote areas.
10.    The inactivator as claimed in claim 1, wherein the treatment tank, jacket shaft, impellers and bowls are made up of metals selected from the group consisting of skinless steel, brass and bronze.
11.    The inactivator as claimed in claim 1, wherein the length of the treatment 15    tank, shaft and jacket is extended to operate the system under continuous
mode.
12.    The inacfivator as suggested in claim 11, wherein the treatment tank is provided with hoppers at the top extreme one end for feeding and at the opposite end for discharging the material under continuous mode. •
20 13. The inactivator as claimed in claim 11, wherein at the end of discharging hole rotating blades are fixed for chopping the material before discharging.
14 The inactivate- as claimed in claim 11, wherein the material collecting bowls attached to the impellers are fixed with an angle to push the material away from the feeding hopper and towards discharging hole.
25 15_ The inactivator as claimed in claim 1, wherein the thermic fluid used in the Inactivator is selected from the group consisting of steam, water and heat transfer oils.
 
zo
    16_    The inactivator as rimmed in claim 1, wherein the heating means is
selected from the group consisting of burners operated on fuel, direct tiring
by fuel namely wood, briquettes and coal, electric heaters, microwave and
5    ultrasound energy.
17.    The inacivator as claimed in claim 1, wherein the external jacket is removable and the treatment tank is heated by above said means.
18.    The inacrwator as claimed in claim 1, wherein the treatment tank is provided with an exhaust fan mounted on a duct for removing the moisture
10    during pedal dehydration of the charge.
19.    The inactivator as claimed in claim 1, wherein continuous charging and discharging is achieved with the use of spiral metal worm of suitable diameter and length.
A method for inactivaion of green tea shoots, said method comprising: 15    a) filling outer jacket of the roasting tank with water and healing:
b)    charging freshly pluciced tea shoots composing two ana a oud into the preheated inactivation chamber„
c)    continuously mbayej the leaves and continuing heating, and
d)    removing the steamed shoots and cooling the shoots
    2/1) 21.    The method as claimed in claim 20, wherein heating is done using heating
means, said heatirg means is selected from the group consisting of burners cperated cutlet, direct firing by fuel namely wood, briquettes and coal, electric heaters, microwave and ultrasound energy to provide heat bank.
    r 22.    The method as chiliad in claim 20, wherein freshly plucked tea shoots in
the weight range of 1000 to 7000 g was charged in slowly in the weight range of 100 to 150 g for up to 90 seconds at a time while mixing the
 
21
leaves to avoid blockage of the impellers and to attain uniform heating.
23.    The method as claimed in claim 20, wherein the charging lid is closed after complete charging of the shoot.
24.    The method as claimed in claim 20, wherein the heating is continued for an
5    additional time period of six minutes.
25.    The method as claimed in claim 20, wherein continuous mixing is achieved by impellers attached to the shaft, which is rotated by the motor having speed regulator.
26.    The method as claimed in claim 20, wherein the temperature of the leaves
10    after inadivaion is in the range of 82 to 85
27.    The method as claimed in claim 20, wherein the loss in weight in the inactivated leaves is in the range of 150 to 200 g.
28.    The method as claimed in claim 20, wherein the green tea obtained shows no polyphenol oxidase activity and is good in taste without roast flavour

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