Title of Invention	A PROCESS FOR THE IMPROVENENT OF FLAVOUR IN BLACK TEA & BREWED LIQUOR
Abstract	This invention relates to a process for the improvement of flavour of back tea and brewed liquor. The green leaves shoots of tea bush processed by withering, rolling, fermentation and firing is referred to as black tea. The brewed infusion from black tea is referred to as beverage tea.

Full Text

The present invention relates to a process for the improvement of flavour in black tea and brewed liquor. The green leave shoots of tea bush processed by withering, rolling, fermentation and firing is referred to as bl ack tea. The brewed infusion from black tea is referred to as beverage tea. The quality of tea could not be heretobefore ascertained with much precision due to lack of knowledge on the processing technology and consequently therefore the improvement of flavour of the tea by modifications in the processing technology was not known in the art. However, extensive research in the field of process optimisation during manufacturing have demonstrated that leaf withered for about 20 h at controlled humidity and oxygen saturated atmosphere of 20- 25 cfm per kg. of green leaves were superior to those manufactured from fresh harvest. It has generally been accepted that more rapid air circulation will increase dessication and reduce respiration loss of stored leaf shoots. Low oxygen and high carbon dioxide levels which is detrimental to quality of tea could be avoided by proper ventilation in the factory layout. Post harvest quality of black tea depends on physiological age of tea shoots, withering time, temperature, humidity, the type of mechanical injury and conditions of fermentation, etc.. So long black tea manufacture is a batch process suggesting that technology and determination of quality are not unique. Furthermore, value added tea is expected to serve for an improved product likely to have additional market. This would result in the production of flavoured teas and bottled teas for perspective buyers. Characteristics of various varieties of tea flavour for the genuineness of the beverage is now known. It has also been estimated that the orthodox tea grown in hilly regions contains a three times higher amount of volatiles than does plain region orthodox tea. Moreover, the content of monoterpene alcohols is about five times higher in tea grown in hilly region as compared to tea grown in plain region. Records of volatiles and non-volatile flavoury compounds clearly indicate that biosynthetic as well as degradative reactions in the lipid fractions of the tea leaf shoots are mostly responsible for flavour of tea. Polyphenols such as catechins as also caffeine are important for contributing to bitterness and astringency property of tea. The com- ponents of essential oil in fresh leaves and volatile compounds developed during the manufacturing process form the characteristic tea flavour and aroma. Browning is the most characteristic reaction that take place during fermentation process of black tea manufacturing. Presence of important phenolic compounds found to be in the following portions : Catechins 5%, theaflavin 1-2%, thearubigin 15%. Theaflavins are bright orange in colour and formed by oxidation of catechins by polyphenol- oxidase during fermentation. Thearubigins are complex formed from polyphenols and proteins and are dark reddish in colour. Theaflavins contribute to the quality and brightness of the colour of black tea liquor, but mout feel is due to the heterogeneous thearubigins. Further such typical chemical flavour constituents/or essential oils extracted from black teas, species teas/or herbal teas and from may fruits and spices were reported to be similar. The compounds included are linalool derivatives, aliphatic and aromatic aldehydes, alcohols, etc.. In tea grade, it is also customary to blend and and recondition teas for better taste quality of consumers. However, the process of withering known in the tea industry have been found to play a vital role in improvement of flavour of tea in so far as that the process of withering and rolling is accompanied by release of flavoury compound from non -volatile precursors. It is of importance to note that the higher content of fresh and floral notes has been attributed to hydrolytic action of various enzymes and subsequent release of essential and characteristic aroma and flavours is amply highlighted. The present invention is the outcome of a modification in the processing technology in so far as the direction of utilising the release of flavour in the process of withering and rolling of tea leaves is concerned. The present invention utilises processing conditions alongwith additional flavoury compounds such as carotenes and essential oils to the advantage for imparting an added flavour to the black tea and/or the brewed liquor. It is thus an object of this invention to provide for a process for the improvement in the flavour of black tea or brewed liquor by utilising the process extrudes of tea processing technology. Another object of this invention is to provide for a method of improvement in the f lavour of tea by a process that would be less expensive as compared to the improvement that the flavour renders to the quality of tea. Another object of this invention is to provide for an improvement in the product quality of black tea and/or brewed liquor. Another object of this invention is to utilise the withering conditions of tea manufacture to the advantage in so far as improvement in flavour and quality of tea is concerned. This objective is directed to assure aroma and flavour quality of such tea/beverages by proper analysis of volatile and non-volatile compounds. Yet another object of the present invention is to provide for a process of manufacturing consumer acceptable value added teaa (other than traditional black tea/or brewed liquor). A further object of the present invention is directed towards providing technical know-how for manufacturing flavoury teas in a continuous process by oscillated withering and efficient damage of leaf cells by CTC methods. The method of the invention discloses a process for improvement in flavour of tea and/or breewed liquor by controlled withering of the tea leaves/shoots comprising :- i) spreading said leaf shoots on withering trough; ii) passing a slow drought of warm air, preferably maintaining a hygrometric difference of about 3 -4 C between the inlet and outlet end of the warm air in said trough; iii) processing said leaf shoots for atleast 8 hours by conventional CTC techniquess; iv) fermenting the process leaf shoots and subsequnetly firing at higher temperature for drying; said process stages consisting of withering to firing being controlled preferably in the temperature range of 32 C to 90 C with optional addition of flavoury compounds such as herein described at anyone of the following stages :- a) during said withering and rolling; b) after said CTC processing; c) prior to said step of firing at the end of the fermentation depending upon the required colour and flavour of tea; and d) during CTC processing or while conventional reconditioning of tea. The process of the invention thus takes into consideration the higher content of fresh and floral notes attributive to the hydrolytic action of various enzymes and the subsequent release of essential and characteristic volatile flavours. The present invention suggests an improvement in the quality of tea produced by adjustment in the withering conditions during manufacturing of the harvested leaf shoots. The present invention further discloses a process by which an improvement in the product quality of the tea can be achieved even without the use of any foreign chemicals for such improvement in flavour by suitable modifications in the withering condition. It has been found that the flavour of teas is basically attributed to the high ratio of terpenoids to non-terpenoids. In normal withering conditions where differenciation can be made by nose from fresh leaf and withered leaf where conditions providing terpenoids were retained better than those in over withered conditions. Terpenoid to non-terpenoid ratios is therefore higher in normal withered manufactured teas than those in over withered teas. It is such ratio of the terpenoid to non-terpenoid contained after the withering of the tea leaves that can determine the flavour of the final product. The storage time for effecting such chemical withering for improvement in flavour of tea was about 8-12 hours if little heat is applied alongwith air flow. In the present invention, the process for improvement in flavour of tea and/or brewed liquor is attributed to the fact that by a controlled withering process, the constituents of the tea is varied to a desired proportion by suitable conversion of the constituents of the leaf shoots into characteristic flavoury compounds by controlled hydrolytic action. In this regard, the present invention proceeds for a suitable temperature range within which the process of withering till firing may be controlled. Also, the process of the invention takes into consideration alongwith the withering temperature the hygrometric difference between incoming and outgoing warm air passed through the withering trough for the purpose of withering and cooled air during rolling and fermentation under high humid conditions of the tea leaves. The non-terpenoids consisted mainly of fatty acid mostly alkenals and alkenols etc . The terpenoids on the other hand are mainly linalool and their oxides. Apart from such terpenoid to non-terpenoid ratio, other factors that contribute towards colour and flavour of black tea are beta-carotene, lutein, violaxanthine and neoxanthine which are the major carotenoids of tea. Although a decrease is seen in all these four carotenoids during processing, only beta-carotene and lutein mostly undergo oxidative changes during withering into characteristic volatile flavoury compounds of tea. Some important character imparting compounds of black tea, such as geranylacetone, damascenones, beta- cyclocitral, theaspirone and dihydroactinidiolide, etc. (about 10% of total volatiles) are supposed to be the degraded products of carotenoids. Characteristic flavoury volatile compounds like linalool and geraniol also occurring as clycosides becomes free during withering, rolling etc stages of tea manufacture. The production of flavour volatiles especially linalool derivatives is considerably accelerated due to slight higher withering temperature of leaf shoots compared to air. The volatile n-hexenal, trans-2-hexenal, 1-genten-3-01, etc. are formed from the fatty acids released from linolenic, linoleic and palmitic acids. The impact of green flavour due to alkenals, alkenols, etc. essential but more pronounced when fresh tea leaf is processed for black tea. The presence of higher amounts of trans- 2-hexenal and depression of linalool is found to be one of the reasons why unwithered tea is less fragrant than withered tea. However, improvement in the unwithered tea can be brought about by spraying of flavoury compounds and/or aromatic plants/herbs thereby improving the flavour of tea. The addition of natural flavour volatiles of ginger, lemonpeel, cinnamon bark and leaf have been considerable significance as natural flavour additives. A particular working example of the process for improvement of black tea and brewed liquor as supposed to be disclosed by way of the present invention is discussed hereunder :- EXAMPLES IDENTIFYING PREFERRED EMBODIMENTS OF THE PROCESS OF THE INVENTION Fresh leaf shoots are plucked and sprayed in a six inch thick layer on a withering trough; a slow drought of warm air at about 30oC was passed over said spreaded leaves maintaining a hygrometric difference of 2 C between the inlet and outlet end of said trough during the passage of warm air ppassed therethrough; processing said leaf shoots for 8 hours by conventional CTC techniques; fermenting by conventional means - the thuus processed leaf shoots and subsequent firing at 90oC for drying (approximately 90oC). The leaf shoots thus processed were found to have additional flavour and aroma content not known in the processes presently known in the art. Further to the said processing steps carried on, additional further improvement in the aroma and flavour content during such improved processing of leaf shoots can be attained by following any one of the optional roots of adding aroma/f lavoury constituents during the processing of the leaf shoots as detailed hereunder :- (a) About 30 kgs. of freshly plucked tea leaves were divided into three lots and spread over a" withering trough, air was blown at 773 ft3/min for a period of 6,8, and 10h, and hygrometric difference was maintained at about 60 F. In a separate lot, 5 kgs. of green leaf shoots was placed on a hasslan cloth for natural withering for about 24h. After withering, the leaves from each lot were rolled separately in a Little Ciant Roller for 30 mins. and then passed through the CTC machine three times. (b) Another 15 kgs. of withered leaves was divided into three lots and passed through the CTC machine after mixing with 0, 2% and 4% (W/W) lemon peels and then fermented for 1 hr. 20 mins.. The fermentation was stopped by heating for 30 mins. with a blast of hot air at 180-210 F to obtain black tea with 3% moisture content. (c) In a specific embodiment, 1 kg. of the withered and rolled leaf shoots were additionally treated by spraying of 1 gm. of an aqueous of beta-carotene and fermented in the usual manner. The colour and flavour profile of such tea were found to be superior to the conventionally processed tea. (d) 110 cc of extract solution of flavoury compounds comprising of cinnamon leaf/cinnamon bark/ginger in the proportion of 0.1 mg. percent was sprayed thoroughly on 5 kgs. of black tea leaf as processed by the method of the invention just after fermentation and allowed to dry in a conventional manner, the flavour and aroma content of the black tea thus produced was found to be of superior quaIity. (e) 5 gms. of tejpat (cinnamon leaf containing 80% eugenol) was boiled with water and the extract sprayed over 600 gms. of fermented tea processed by the method of the invention. The product showed improved flavour content. (f) Raw cinnamon leaf, cinnamon bark, lemon peel, ginger of about 1% dry weight were blended during CTC processing of the leaf shoots as per the present invention, the product obtained showed improvement in genuine flavour and aroma content. Further, the present invention also provides for improvement in colour and flavour profile of black tea by spraying on the withered rolled plucked leaves beta-carotenes in water with subsequent fermentation of the same. The product obtained by the process has a quality wherein the percentage of total organic soluble solids, caffeins and minerals (ash, amino acid contents) were significantly more in adequately withered leaves within the fresh shoot moved teas. The withering process under conventional techniques are disadvantageous in that the crude fibre does not appear to get solubilized adequately into phenolic acids thereby affecting '.he organoleptic properties as well as brewed tea. A higher amount of linalool and decreased amount of hexanals were characteristics of good flavoury teas made from withered leaves and carotenes spread teas. The biogenesis of aroma compound during processing enhanced the quality of brewed tea. Additionally, the present invention also discloses that addition of essential oils (ppm level) from fresh aromatic plants and herbs such as cinnamon leaf, lemon peel, jasmin flower, etc. were shown to have improved flavour quality of black teas especially in monsoon seasons. It is to be noted that a process of the invention involves optional addition of aqueous solutions of flavoury compounds such as beta-carotenoids, solicyclic acids, cinnamaldehyde, etc. by spraying the same over the leaf shoots at any one of the following stages of processing :- a) during rolling; b) after CTC cuts; c) prior to the step of firing at the end of the fermentation and d) during CTC processing/recon- ditioning stages of tea manufacturing depending upon the required colour and flavour of tea. Furthermore, ambiguous assessment of the overall quality of black tea and brewed liquor by testing panels have been serving the industry but the actual way of assessing is by applied sensory method where the effect of chemical/attributes are being evaluated during sensory organs. Thus, alternate means of bio-chemical assessment have been used while optimising manufacturing processes of black tea. It may be mentioned that various other embodiments of the process in so far as applying optional foreign additives during the process of manufacturing of improved flavour tea of the present invention would be possible without deviating from the scope and spirit of the present invention. WE CLAIM : 1. A process for improvement in flavour of tea and/or brewed liquor by controlled withering of the tea leaves/shoots comprising :- i) spreading said leaf shoots on withering trough; ii) passing a slow drought of warm air, preferably maintaining a hygrometric difference of 3 -4oC between the inlet and outlet end of the warm air in said trough; iii) processing said leaf shoots for 8 hours by conventional CTC techniques; iv) fermenting the process leaf shoots and subsequently firing at higher temperature for drying; said process stages consisting of withering to firing being controlled preferably in the temperature range of 32 C to 90 C with optional addition of flavoury compounds such as herein described at any one of the following stages : a) during said withering and rolling; b) after said CTC processing; c) prior to said step of firing at the end of the fermentation depending upon the required colour and flavour of tea; and d) during CTC processing or while conventional reconditioning of tea. 2. A process as claimed in Claim 1 wherein said withering is carried on in the temperature range of 32 to 38 C. 3. A process as claimed in Claim 1 wherein said withering and rolling conditions are so maintained such as to obtain a high ratio of terpenoid to non-terpenoids in the withered leaves. 4. A process as claimed in Claim 3 wherein said flavoury compounds comprising of any one or more of carotenoids and cinnamalcehyde. 5. A process as claimed in any one of Claims, 1,2,3 or 4 wherein additional flavoury compounds comprising of essential oils (ppm) of fresh aromatic plants and/or herbs are used. 6. A process as claimed in Claim 5 wherein said aromatic plants and/or herbs comprise of any one or more of cinnamon leaf, lemon peel and jasmin flower. 7. A process as claimed in Claim 3 wherein said non-terpenoids comprise of any one or more of fatty acid degradation products such as cis-3-hexanals, trans-2-hexanals. 8. A process as claimed in Claims 3 or 7 wherein said terpenoids comprise of any one or more linalools or their oxides. 9. A process as claimed in any one of Claims 1 to 8 wherein beta- carotene, lutein, violoxanthine and neoxanthine are degraded by said controlled withering and rolling thereby adding colour and flavour to the tea leaves being processed. 10. A process as claimed in any one of Claims 1 to 9 wherein flavoury volatile compounds like linalool and geraniol evolve as volatile flavoury compounds by said controlled withering and rolling of the tea leaves. 11. A process as claimed in any one of Claims 1 to 10 wherein said warm air is passed through the leave shoots such that the oxygen level does not fall below 2%. 12. A process as claimed in any one of Claims 1 to 11 wherein said flavoury compounds are spread directly on top of the bulk leaves during fermentation with continued humidification after rolling and/or CTC cuts. 13. An improved black tea and/or brewed liquor obtained by the process as herein described and illustrated. 14. A process for flavoured improvement of black tea and brewed liquor substantially as herein defined and illustrated. This invention relates to a process for the improvement of flavour of back tea and brewed liquor. The green leaves shoots of tea bush processed by withering, rolling, fermentation and firing is referred to as black tea. The brewed infusion from black tea is referred to as beverage tea.

Documents:

617-CAL-1992-FORM 15.pdf

617-cal-1992-granted-abstract.pdf

617-cal-1992-granted-claims.pdf

617-cal-1992-granted-correspondence.pdf

617-cal-1992-granted-description (complete).pdf

617-cal-1992-granted-examination report.pdf

617-cal-1992-granted-form 1.pdf

617-cal-1992-granted-form 18.pdf

617-cal-1992-granted-form 2.pdf

617-cal-1992-granted-form 26.pdf

617-cal-1992-granted-form 5.pdf

617-cal-1992-granted-reply to examination report.pdf

617-cal-1992-granted-specification.pdf

617-CAL-1992-PA.pdf