Title of Invention	HOT WATER SOLUBLE INSTANT TEA
Abstract	The present invention relates to hot water soluble instant tea and provides a method for preparing an extract, concentrate or powder, which is capable of being reconstituted as a tea beverage, having excellent organoleptic properties and substantially free of undesirable cloudiness and haze, and resembling conventional tea in taste and character

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Field of the Invention: The present invention relates to hot water soluble instant tea More particularly, the invention provides a method for preparing an extract, concentrate or powder, which is capable of being reconstituted to a tea beverage, having excellent organoleptic properties and substantially free of undesirable cloudiness and haze The instant tea of the invention resembles conventional tea in taste and character Background art: Black tea is generally prepared by subjecting green tea leaves to vanous process conditions such as withering, rolling, disintegrating, fermenting, firing etc, during which enzymatic reactions are initiated in the tea leaves and the characteristic aroma, colour and flavour of black tea are developed Black tea extract is produced by treating black tea leaves with warm water The extract produced contain soluble tea solids as well as insoluble solids The insoluble solids are discaided and the supernatant is processed furthei to recovei any left over desirable tea propertres such as flavor, aioma etc The characteristrc feature of tea depends on the quantity and type of polyphenols present in tea, which make up of 20 - 35% of total dry weight of freshly plucked leaves Approximately 70% of the polyphenols in the tea leaves are fermentable and take part in the chemical changes that take place during tea manufacture The most important of the polyphenols, as far as quality of tea goes, aie the epi-gallocatechrn and gallates The supernatant left after removal of tea solids is concentrated, dned and sold as powder Such a powder may be instantly soluble in hot water or cold water, as the case may be This generally is the traditional method of tea manufacture 2 One of the most serious problems laced by instant tea manufacturers is that the tea powder piepared according to traditional methods, when reconstituted tends to lose the characteristic flavour and atoma of fresh black tea The reconstituted tea leacts badly to milk and tends to take a dull coloration The characteristic aioma associated with black tea is lost during various stages of processing Ideally, hot water soluble instant tea should lesemble black tea infusion to the extent possible However, little amount of cloudiness and haze could be present in the tea However, the prior ait does not yet provide a cost effective and simple method for the production of instant hot tea And, it is desirable to provide an instant tea product, which when reconstituted in hot water retains characteristic aioma and other organoleptic properties of tea The applicant's studies have shown that the water used for tea extraction plays a ciucral role, especially in the stage pnor to stripping the black tea extract of its aroma and ptior to reconstitution The Applicant has found that the process must be modified and similarly, befoie the volatile aroma constituents are incorporated into the tea extract, they must be processed Objects of the invention: The major object of this invention is to ptepare tea which is readily soluble in hot watei and provide a method therefor Another object is to piepare instant tea pioduct which when leconstituted in hot water is substantially free of undesired turbidiry 3 Still another object is to prepate instant tea which when econstituted in warm water retams the aroma and characteristic organoleptic properties associated with fiesh black tea Yet another object of the invention is to provide instant tea which when reconstituted in hot water retains the characteristic aroma and organoleptic properties of tea Statement of Invention: Accordingly, the invention provides a novel method for the production of instant tea which when rconstituted in hot water, exhibits the chatacteristic aroma and the organoleptic properties of black tea Further, the beverage so produced is substantially free of undesired cloudiness and turbrdity The invention provides a method for the production of hot watei soluble instant tea, said method comprising the steps of a) forming an extract by treating black tea leaves with hard warm water having hardness of 10 to 140 ppm and pH of 6 8 to 7 2 at a temperature in the range of 60 to 105°C , b) shipping the extiact of its aroma volatiles by passing the tea extract through a flash evaporator under partial vacuum, wherein the residence period is about 30 seconds to 360 seconds, c) separating at least about 12% by wt as insoluble tea solids from the extract by subjecting the extract to lepeated clarification and polishing to obtain a clarified concentrate, d) separating 6-10% soluble tea solids from the clarified concentrate, e) adjusting the pH of the concentrate to neutral by adding an edible acid, f) adding the aioma volatiles obtained in step (b) to the concentrate, and 4 g) obtaining a substantially powder capable of being reconstituted in hot water to produce instant tea, substantially free of cloudiness and haze In an embodiment the tea leaves are selected from oolong or black tea leaves In another embodiment, the tea leaves are extracted with hard warm water containing calcium and magnesium salts and having hardness of 10 to 140 ppm and pH of 6 8 to 7 2 In an embodiment, the extraction of tea leaves is effected at a temperature in the range of 80 to l00°C In still another embodiment, the ratio of water to tea leaves is 1 10 In yet another embodiment, the step of polishing includes subjecting the extract of step (c) to repeated centrifugation at an optimum speed of 3000 to 5000 lpm In an embodiment, the edible acid is selected from citric acid, maleic acid or fumaric acid In an embodiment, the amount of edible acid added is 0 1% to 1% by wt In an embodiment, the concentrate obtained in step (f) and the powder of step (g) may be incorporated with additives acceptable in the food and beverage industry such as cola concentiate Thus, the invention provides an instant tea leadrly soluble in hot water and produced according to the process described above Detailed description: To describe the invention in detail, an extract of oolong tea leaves or black tea leaves such as Darjeeling tea leaves (which have been subjected to rolling, 5 withering, fomentation, etc a suitable solvent. The applicant's studies have revealed that the nature, the quality and type of liquid used for extraction influences the haze and clarity of the final instant tea product So far, although water was used, there was no emphasis on the quality and type of water used The quality of water differs at least in chemical content e g hard water contains more of Ca, Mg salts and in soft water these are removed by passing through a sodium resin filter The calcium and magnesium salts play a crucial role in the brewing of tea at the end when an infusion of the final product is prepared Therefore, if soft water, (where water has been passed through a softener) is used, then the salts in it add on to the extract and get carried till the end The use of soft water also imparts different shades to the milk Whereas, if hard water (not passed through any softener) having hardness of 10-140 ppm is used, the resultant tea product is far superior Therefore, in the present case, the solvent is hard warm water It may have pH of 6 8 to 7 2 The temperature at which the extract is prepared is also important The best results are obtained when extraction is effected at 60 to 105"C The preferred temperature is 80-100°C The amount of water in which the tea leaves are immersed can be leadily determined by a skilled artrsan However, it is found that when the tea extract may be taken once or twice and it is to be ensured that the ratio of water to tea leaves is taken at 1 10, the extract is superior in quality The resultant tea extract contains about 8-12 % tea solids Preferably, the process is a direct counter cuirent extraction with boiling water (1 10 Leaf Water) The control variables are 6 a) diffusion of soluble tea solids acioss the interphase b) volume of water used, which in turn would deteimme the extent of extraction (lower the concentration of soluble tea solids in the final extract at steady state greater than the extend of extraction, c) temperature of water used, d) period of extraction or contact time between the leaf and water, and e) usage of hard water for extraction In this invention, one may preferably use hard water of 60 - 100 ppm hardness also to extract the tea The pH of water should be 6 8 - 7 2 This is ideal for obtaining brightness in the cup The next step is the removal of the aromatic volatile components present in the tea extract For this purpose, the tea extiact obtained is passed through a flash evaporator under partial vacuum The flash evaporators conventionally used in the tea industry may also be used in this invention The flash evaporator used may preferably be equipped with a recuculation line means and means for reborling the contents to generate heat for evaporation of volatiles as mentioned earlier It is to be noted that extracted liquor is flash evaporated before centrifuging and lemoval of insoluble solids, further, the extiact enters the flash evaporator through a heater, raising the temperature between 80 -90°C prefcrably 90 -95°C Reborling is done only for cuculation to act as an vaporiser The whole of extractcd decanter liquor is passed through a tubular heater with a provision of re-circulation between 85 - 95°C before it is sprayed- inside this equipment The residence time of the extract in the flash evapoiatoi is about 30 seconds to 360 seconds 7 At this juncture, the volatrles in the tea extract such as eprgallatones, catechins"; tannins are captured and drawn out As a preferred measure, the extract may be re-borled and the re-boiled extract may be drawn out, chilled, condensed, distilled and extracted separately The aromatic volatiles are thus recovered as an aqueous soluton having pH of about 7 5 to 8 2 Once the aiomatic volatiles have been separated from the tea extiact, the extiact is subjected to further processing either chemical or otherwise, to maximize the contents thereof The extract may be subjected to clarification and repeated polishing preferably by centrifugation at least three to four times so that the insoluble components which result in the cloudiness and turbidity in the final re-constituted beverages may be removed The resultant concentrate contains soluble solids to the extent of about 12% by wt This step is carried out at 80-90°C in a self-ejecting centrifuge The extract obtained is pre-evaporated in a falling film evaporator to obtain solids concentration of 6 - 10% tea solids keeping the outlet temperature as low as possible maximum of 55°C under 640 mm vacuum pressure The resultant liquor may contain tea solids to the extent of 6 - 8% or 6-10% It is now fiee of insolubles but lacks the basic characteristics of clear infused liquor The hquoi is subject further to polishing which involves centrifugation at an optimum speed of 3000-5000 rpm Best results are obtained when centrfugation is carred out with warm extract, at 55 to 70°C This will enable lemoval of the solids, without disturbing the basic char acteristics thereof Polished tea liquor is immediately concentrated in a vacuum evaporator where residence time is shortest Here a centrifugal evaporator has been used having 8 vacuum of 80 Kpa Prime importance is to manimum a lower temperature and also not to scorch the product by over heating it The concentrate obtained is used in further steps herebelow During these processes, it is necessary to ensure that water which may be present may also be removed therefrom in any appropriate manner The aroma volatiles which were removed from the tea extract in the beginning are now mixed with the concentrate It is often observed in the prior art processes that when this aroma is immediately added to the concentrate, a coloui development occurs fiom 1 eddish to brownish and this colour changes even to black If this concentrate is carried forward to prepare the final product, the coloui of the cup is dull with milk, it turns pale The reason for the change of colour could be attributed to the fact that the pH of the aroma and the pH of the concentrate are at variance The pH of the aroma volatiles is about 7 5 to 8 2 i e alkaline and that of the concentrate is 4 8 to 5 4 If the aroma volatiles are driectly added to the concentrate, the pH rises suddenly and also forms a low intensity film in the liquor It is therefore necessary to adjust the pH of the concentrate before the aroma volatiles can be added to it The Applicant recommends that any edible acids such as citric acid, fumiaric acid or maelic acid etc, may be added to the concentrate prior to aroma addition Here, citric acid is preferred since it is a commonly available and well tested acid With this addition, the pH is adjusted to 4 5 - 4 8 The amount of acid which is added will depend on several factors such as colour development in the concentrate etc The amount of acid that may be added is about 0 1 to 1 % by wt 9 As a next step, the aioma volatiles may concentrate and pH adjusted and blended The aroma vrolatrles which are added may be about 4 -8% by volume by volume The final step is to spray dry the concentrate and pack it for sale For this, a centrifugal atomiser, spray drier may be used to spray dry the concentrate to form obtain a powder of the beverage Lower temperatures are maintained to avoid product damage and degradation Inlet temperature may be maintained at 180 - 185° C and outlet temperature at 96 - 102°C The powder is fluidised using a fluid bed cooler by injecting air conditioned de-humidifred an for obtaining optimum particle size for greater solubility The powder produced may be used as such or as a liquid concentiate or otherwise in any suitable form The beverage prepared using this concentrate is substantially free of haze and cloudiness, in that it has residual amount of tea (I. e in very small quantities) Thus, the salient features of the invention for the preparation of an instant tea product with improved turbidity, better taste and colour are a) usage of raw hard water for extraction b) usage of flash evaporator after extraction and before clarification for the entrapment and removal/separation of volatiles c) addition of pH neutralised tea aroma at concentrate stage In order more clearly to describe the nature of the present invention, specific examples are hereinafter described It should be understood, however, that this is done solely by way of illustration and thus is not limitative of the ambit of the invention or the appended claims 10 Example: Fresh green leaf plucked from the garden is withered to 70% w/w in withering trough Wrthered leaves is given for loose cuts and then transfeired to continuous f er meriting machine af ter passing through rotary shifter Fermentation time is 70 mts with 1/2" thickness in bed Fermented leaf/black tea or blend thereof are extracted hot at 90 -95°C with 110 part of Raw water having 50-100 ppm total hardness in continuous counter current process in decanter Tea aroma is collected by vapourising the volatiles using flash evaporator and subsequently concentrated and condensed in the aroma lecovery unit, collected aroma pH is alkaline 78-82 which is lowered down to 4 5 - 5 0 by using an edible acid, such as citric acid Hot extract with 4 - 6 % solid w/v is hot clarified in the DMRPX I at 1660 ltrs/hr feed late with 8mts time cycle for discharge at a tempeiature of 70° c Hot clarified liquor is frist evaporated in falling film evaporator to 8% and polished in DMRPX II Polished liquor is made concentrate to 36% w/v by CT-6 Evaporator Tea aroma is then added back to concentrate at 4% v/v mixed thoroughly and spray dried into powder at Inlet of 176° c and outlet temperature of 96° C The hot watei soluble instant powder obtained is instantly soluble m hot water and has very good organoleptic propertres Colour assessment of the liquor is done using a photoelectric colorimeter - 111 instrument, where light is passed through a filter in a wave length range of 540-610nm and peak wave length of 570nn All samples of colour analysis is measured at a solid concentration of 0 35% (w/v) 11 Turbrdrty of powder is measured by using systronics digital Nephelo Turbrdity Meter Model-132 which is an accurate and elegant mstiument designed for conducting nephelo metric and turbidity measurement of suspended particles and colloids in solution based on the law of Tyndal Effect The digital display is calibrated in NTU's, accuracy within ±2% Samples are measured at a solid concentiation of 0 35% (w/v) Results of the some trials are shown below Trial Colour Clarity (NTU) pH 1 0 24 2 5 518 206A 2 0 22 4 5 5 26 295 3 0 205 4 3 511 306A Organoleptic tasting of powder is also earred out with a solid concentration of 0 26% (w/v) All the cups are found bright with good tea flavour 12 Claims 1 A method for the production of hot water soluble instant tea, said method comprising the steps of (a) forming an extract by treating black tea leaves with hard warm water having hardness of 10 to 140 ppm and pH of 6 8 to 7 2 such as heremdescribed at a temperature in the range of 60 to 105°C , (b) snipping the extract of its aroma volatiles by passing the tea extract through a flash evaporator under partral vacuum, wherein the residence period is about 30 seconds to 360 seconds, (c) separating at least about 12% by wt as insoluble tea solids fiom the extract by subjecting the extract to repeated clarification and polishing to obtain a clarified concentrate, (d) separating 6-10% soluble tea solids from the clarified concentrate, (e) adjusting the pH of the concentiate to neutral by adding an edible acid, (f) adding the aroma volatiles obtained in step (b) to the concentiate, and (g) obtaining a substantially morsture free tea powder capable of being leconstrtuted in hot water to produce instant tea, substantially free of cloudiness and haze 2 A method as claimed in claim 1 wherein the tea leaves are selected from oolong or black tea leaves 3 A method as claimed in claim 1 wherein the hard warm water contains calcium and magnesium salts 4 A method as claimed in claim 1 wherein extraction of tea leaves is effected at a temperature in the range of 80 to 100°C 5 A method as claimed in claim 1 wherem the ratio of water to tea leaves is 110 6 A method as claimed in claim 1 wherein the step of polishing includes subjecting the extiact of step (c) to repeated centrifugation at an optimum speed of 3000 to 5000 1 pm 13 7 A method as claimed in claim 1 wherein the edible acid is selected from citric acid, malerc acid 01 fumaric acid 8 A process as claimed in claim 1 wherein the amount of edible acid added is 01% to l% by wt 9 A process as claimed in claim 1 wherein the concentrate obtained in step (f) and the powder of step (g) may be incorporated with additives acceptable in the food and beverage mdustry such as cola concentrate 10 A process for producing hot water soluble instant tea substantially as hereindescnbed and illustrated 10 Dated this 23rd day of December 2003 14 The present invention relates to hot water soluble instant tea and provides a method for preparing an extract, concentrate or powder, which is capable of being reconstituted as a tea beverage, having excellent organoleptic properties and substantially free of undesirable cloudiness and haze, and resembling conventional tea in taste and character

Documents:

01671-kolnp-2003-abstract.pdf

01671-kolnp-2003-claims.pdf

01671-kolnp-2003-correspondence.pdf

01671-kolnp-2003-description(complete).pdf

01671-kolnp-2003-form-1.pdf

01671-kolnp-2003-form-18.pdf

01671-kolnp-2003-form-2.pdf

01671-kolnp-2003-form-26.pdf

01671-kolnp-2003-form-3.pdf

01671-kolnp-2003-form-5.pdf