ORTHODOX

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Steps involved in orthodox tea manufacture: Majority of the processing steps are identical to that of CTC manufacture. The steps involved in orthodox tea manufacture include withering, preconditioning, rolling (roller or rotorvanes), roll-breaking and green leaf sifting, fermentation, drying, grading & sorting and finally packing.

Withering

Normally withering is carried out by spreading the leaves thinly on banks of trays or “tats” made of tightly stretched jute Hessian or wire-netting. The tats are kept 12 to 15 centimeters apart, to allow free access of air. There are two types of withering; open withering and closed withering. The open or “chung” type of withering accommodation admits of no control of rate of withering except by thickness of spread and the length of time of the withering phase. This is “natural withering” in its simplest form. The average length of time for withering is 18 to 20 hours where “tats” are used. In modern trough withering system 16-18 hours is the duration of wither with normal ambient air. In rainy season, to remove the surface moisture, heaters are used along with fans for two hours. Modern methods greatly reduce the withering time but they can also lower the quality of the final product by reducing the time for chemical withering. In general, south Indian tea manufacture is carried out with withered leaves having a moisture content of 60-65% for orthodox type of manufacture.

Rolling: When a satisfactory wither has been obtained the leaf is ready for rolling, which twists the leaf, breaks it up and expresses the juices (substrates and enzymes). The machines used vary in size and design but their principles are alike, they compress and turn the leaf over. This step facilitates mixing up of cell constituents viz., enzymes and substrate, thereby starting fermentation, while the maceration is complete in CTC, in orthodox only internal injury is imparted due to rolling. Enzymic oxidation of the catechins (polyphenols) begins at this stage.

Rotor Vane: The rolled leaves are fed into the rotor vane, which mixes the leaves thoroughly aiding in the cell maceration and extraction of the juice from the leaves.This step ensures proper coating of the leaf with the juice thereby facilitating subsequent processes viz., rolling and fermentation.

Roll breaking and green leaf sifting: These two steps are involved mainly for the orthodox type of manufacture. On discharge from the roller the leaf mass is more or less compressed into lumps. These are broken up in the sifting process by the machine which usually combines the operation of roll-breaker and sifter. The roll-breaker and green-leaf sifter in the first instance cools the leaf, secondly it aerates the mass, and thirdly by sieving out particles of small size it separates leaf into portions that will be reasonably uniform in their rate of fermentation.

Fermentation: Though actual fermentation starts at rolling it is continued in the next stage. The sifted leaves are spread out in thin layers on tables or perforated aluminum trays or into aluminum drums, in order to continue the oxidative process. During fermentation, the leaf changes colour and turns into a dark coppery tone. Typical aroma develops at this stage. The ideal conditions for fermentation are dhool temperature <30oC, moisture ~55%, pH 4.5 to 5.0 and relative humidity >90%. When the fermentation is judged to be sufficient (colour & nose assessment) the fermenting dhool is transferred to the drier. Googhie cum floor Drum fermentation is extensively used in south Indian tea Industry for orthodox type of tea manufacture.

Drying: Endless chain pressure driers as described in the CTC process are also commonly used in orthodox tea manufacturing. After firing, the tea is spread out to cool and then temporarily stored to wait sorting. Modern innovations on the drier are the hot-feed drier, where hot air is supplied separately to the feeder to arrest fermentation immediately as the dhool is fed, and the fluid-bed drier where the leaf moves from one end of the chamber to the other over a perforated plate in a liquid fashion.

Grading and sorting: Grading and sorting: Grading is carried out on mechanically oscillated sieves, similar to those used in the green leaf stage and fitted with meshes of appropriate size. Finished grades are stored in air-tight bins until a sufficient quantity has been accumulated to fill a consignment. The common grades of orthodox tea are as follows.

GRADES IN ORTHODOX TEAS
FP Flowery Pekoe
Whole leaf FTGFOP Fine Tippy Golden Orange Pekoe
TGFOP1 Tippy Golden Orange Pekoe
GFOP Golden Flowery Orange Pekoe
FOP Flowery Orange Pekoe
OP Orange Pekoe
BOP Broken Orange Pekoe one
GFBOP Golden Flowery Broken Orange Pekoe
Brokens BPS Broken Pekoe Souchong
GBOP Golden Broken Orange Pekoe
FBOP Flowery Broken Orange Pekoe
BOP Broken Orange Pekoe
GOF Golden Orange Fannings
Fannings FOF Flowery Orange Fannings
BOPF Broken Orange Pekoe Fannings
OPD Orange Pekoe Dust
OCD Orange Churamani Dust
BOPD Broken Orange Pekoe Dust
BOPFD Broken Orange Pekoe Fine Dust
Dust FD Fine Dust
D – A Dust – A
Spl.Dust Special Dust
G. Dust Golden Dust

News & Events

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  • Residue analysis in other crops

    31-05-2013

    The Pesticide Residue Division is equipped with state-of-art instruments viz., Gas Chromatograph, High Performance Liquid Chromatograph, GCMS, Atomic Absorption Spectrophotometer, etc., Our lab is GLP certified by National GLP Compliance Monitoring Authority, Govt. of India for the execution of Pesticide Residue Studies. We are accredited…

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  • Vacancy 2014

    02/05/2014

    02.05.2014 UPASI TEA RESEARCH FOUNDATION NIRAR DAM P.O VALPARAI – 642 127.   1.      SENIOR ENTOMOLOGIST Ph.D. (Entomology) with 5 years of research experience in the relevant field. Pay scale : Rs.15600+DA and other allowances  2.      SENIOR PLANT PATHOLOGIST Ph.D. (Botany/Micro biology) with 5 years…

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  • Monthly circular – April 2014

    07/04/2014

       Monthly Circular April -2014  WEATHER Weather data recorded in March 2014 at the TRF observatory are given below, along with the corresponding figures for March 2013. Year Total Rainfall mm Mean Sunshine hr/day Mean Temperature ° C Mean Relative Humidity % at Mean Evaporation…

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Articles

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  • Publications 2011

    09.05.2012

    Ajay, D. and Baby, U.I. 2010. Induction of systemic resistance to Exobasidium vexans in tea through SAR elicitors. Phytoparasitica 38: 53 – 60. Babu, A. Vasanthakumar, D. Jasin Rahman, V.K. Roobakkumar, A and C. Sundaravadivelan. 2011.Potential of Mallada boninensis Okamoto (Neuroptera: Chrysopidae), as a biocontrol…

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  • Latest

    12/12/12

    The principal landmark in the history of tea research in south India, was the establishment of a Tea Experimental Station in Gudalur in 1926. During the last seven and half decades, this research organisation. Now known as the UPASI Tea Research Foundation (UPASI TRF), had…

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  • Publications and Library

    01/02/05

    Annual Report is the one among the major publications of UPASI TRF. Annual report of each year is released by September of the following year. Other publications include Research Highlights and half yearly Newsletters. The Bulletin of UPASI TRF is an occasional publication. The Handbook…

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Conferences Seminars

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  • PLACROSYM XXI

    DATE:  10-12 December 2014

    PLACE:  Kozhikode

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  • Research Extension Meeting

    DATE:  06-08 May 2013

    PLACE:  Valparai

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  • JOINT AREA SCIENTIFIC SYMPOSIA (JASS)

    DATE:  

    PLACE:  

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  • INTERNATIONAL TEA CONVENTION

    DATE:  

    PLACE:  

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  • TGLIA

    DATE:   2013

    PLACE:  

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  • Dr.C.S. Venkata Ram Annual Tea Colloquium

    DATE:  1 August 2013

    PLACE:  VALPARAI

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  • INTERACTIVE SESSIONS / WORKSHOPS

    DATE:  28/04/2012

    PLACE:  VALPARAI

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  • PLATINUM JUBILEE SYMPOSIUM

    DATE:  2001

    PLACE:  Chennai

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  • PLANTATION CROPS SYMPOSIUM 2014

    DATE:  2014

    PLACE:  

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  • UPASI ANNUAL CONFERENCE

    DATE:  September 2013

    PLACE:  Coonoor

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Research Activities

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  • residue-35x35

    Pesticide Residue

    Of late, considering the constant usage of pesticides and to monitor the residues in the final produce, a well equipped test facility was established at UPASI TRI in 1994. The pesticide residue laboratory is accredited by National Accreditation Board for testing and calibration Laboratories (NABL)…

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  • Botany

    The Tea Research Institute at Valparai has seven divisions namely Botany, Soil Chemistry, Entomology, Pesticide Residue, Plant Pathology & Microbiology, Plant Physiology & Biotechnology and Tea Technology. Botany Research activities of Botany Division include plant improvement, cultivation practices and weed research. Plant improvement programme was…

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  • Soil Chemistry

    Chemistry Division is involved in research pertaining to soil-plant nutrients of tea besides extending analytical service to the industry. The research activities include investigations on physico-chemical properties of soil, soil-plant interactions, response of tea to major, secondary and micronutrients and their interactions. The research work…

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  • Entomology

    Entomology Division involve in basic and applied aspects of insect pests, particularly, biology, ecology and evolving control measures. The division evolved and recommended physical, chemical and biological method of tea pests control. In the past, extensive studies on bioecology, crop loss due to major pests…

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  • Pathology & Microbiology

    In the division of Plant Pathology & Microbiology, research is carried out on diseases of tea and biofertilizers. Among the tea diseases, blister blight is the most important leaf disease caused by the pathogen, Exobasidium vexans affecting the tender harvestable shoots of tea resulting in…

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  • Physiology & Biotechnology

    Plant Physiology Division was established in 1980 which has been primarily concentrated on crop productivity. The division strives for excellence in applied research in tea productivity and bush health besides biotechnological studies. The research undertaken extends over a wide range of research programmes having collaborative…

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  • Tea Technology

    Besides offering the analytical services and involving in inter laboratory ring test to validate the test methods, Tea Technology Division is concerned about quality of final produce in accordance with PFA Act requirements, storage studies, value added products and manufacturing aspects. The laboratory has been…

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