Tea mfg in bd

4th International Conference on Mechanical Engineering, December 26-28, 2001, Dhaka, Bangladesh/pp. VI 85-91 TEA MANUFACTURING IN BANGLADESH: PROBLEMS AND
PROSPECTS
Pradipta Khisa*and M. Iqbal**
Department of Industrial & Production Engineering Shahjalal University of Science & Technology, Abstract Tea industry is an agro-based export oriented industry in Bangladesh for over a century.
Started from establishing Malnicherra Tea Estate in 1857 in Sylhet, now the number of tea estates
have reached at 158 and tea industry has spread over Moulvibazar, Habigonj, Rangamati and
Brahmanbaria.We produce only 2% of global tea production and we are earning near about two
hundred crore taka in every year. The various stages of tea manufacturing are: Withering, Rolling,
Fermenting, Drying/Firing, Sorting & grading, Tea tasting, Packaging etc. Now tea estates are
facing various problems, which must be solved to save the tea industry. Tea is a safe and healthy
beverage, which has also medicinal value. We have to intensify our race to reach a target of 1500
Kg/ha by 2010 A.D. to produce 90 million Kg made tea and to increase our area by about 1650 ha.
This will satisfy our increasing domestic need and at least maintain the present ratio of the export
of tea. We have to make quality tea, which must satisfy the prescribed criterion of the European
countries to restore its name and fame. This must be done for the sake of increasing export volume
and its existence. This paper includes introduction, global scenario, specification for black tea-ISO
standard 3720, manufacturing of black tea, problems of the tea industries in Bangladesh, remedies
and recommendations, prospects of the tea industry in Bangladesh, tea: its use as a medicine,
conclusion, and references.
INTRODUCTION
Moulvibazar, Habigonj &Chittagong). About 96% annual production (of which 63% of Moulvibazar Now-a-days tea is the most popular drink all over the district) is contributed by greater Sylhet obtained from -
world. Modern man can not think of starting a day 93%(of which 62% of Moulvibazar district) of without having a cup of tea. It refreshes the mind and plantation area. It is to be noted that Sterling companies gives energy. Almost all people take tea once or twice a produce about 50% of annual crop from about 42% of day. Tea is the oldest and most popular non-alcoholic beverage known to man since three centuries B. C. in China. Until 17th century, Coffee was the sole beverage Table-1: Comparative Production of world's major
known to Europe and it was only 1657 that the first tea producer countries of tea
packet was sold in Galway House in London. About 100 years later, 1784-1789 tea drinking become widespread GLOBAL SCENARIO
In the world thirty countries are producing more than 2.50 billion kilogram of teas annually (including 0.56 billion kg of green teas manufactured by eight countries) from 2.56 million hectares of plantation. After meeting their domestic consumption, 28 countries export about 1.02 billion kg of tea annually (ITC, 1997). Bangladesh is producing more than 55 million kg of tea annually from about 48000 hectares of land .It can earn foreign exchange equivalent to about 1775 million Taka annually by exporting about 25 million kg of tea. Tea cultivation in Bangladesh is spread over the hilly zones on the eastern part mainly in four districts (Sylhet, Table-2: Comparative productivity of crop (kg/ha)
MANUFACTURING OF BLACK TEA
(kg/ha) Tea manufacturing is a continuous process of removed of the moisture content from the freshly plucked tea leaves in different stages where physical and chemical a) Salient feature of tea manufacturing
The salient feature of black tea manufacture involves the following operations, viz. plucking and handling of tea shoots, withering, processing (rolling), fermentation, TEA PROCESSING
drying/firing, sorting and packaging. Tea quality is assesssed by the appearance of the leaf before and after Tea leaves are processed in the tea factories to ‘infusion with boiling water’ and overall organoleptic produce an acceptable product for human consumption. There are various kinds of tea, such as – Black tea, Green tea, Oolong tea, Flavoured tea etc. in the world b) Plucking Standard
tea market Since black tea is widely consumed Two leaves and a bud are desirable as plucking beverage, so my discussion will be confined only upon standard, because this type of leave contains high amount of tea catechins, caffeine, fermenting enzyme and less moisture that can produce grainy and bloomy SPECIFICATION FOR BLACK TEA-ISO
tea responsible for giving strong, brisk, bright red and STANDARD
aromatic brew under satisfactory manufacturing conditions. Recommended standard of plucking: At ISO defines black tea as “Tea derived solely and least 70 % fine leaf (by Ballometer count). exclusively and produced by acceptable processes, notably fermentation and drying from the leaves, buds (i) Withering. It is a process of moisture removal from
and tender stems of varieties of species Camellia leaf by the help of exhaust fan or any other means. sinensis”. The tea shall be clean and reasonably free Many bio-chemical and physical changes occur during from extraneous matters and it should comply with the the withering period. Main bio-chemical changes which requirements specified in the table below. Tea exporting have been substantiated during withering are: 1) countries also have their own standard specification for Increase of polyphenoloxidase activity.2) Increase in tea which in most cases conform with ISO standard. caffeine and permeability of cell membrane, 3) Breakdown of chlorophyl and protein to amino acids, 4) Table – 3: chemical requirements for black tea
Change in carotenoids and levels of organic acids. There are two types of withering: 1) Natural withering, Characteristics ISO
Bangladesh
requirement
(ii) Processing/ Rolling. Processing is nothing but the
leaf distortion of the withered leaf. The withered leaf is sifted through green leaf sifter to remove extraneous material before it is processed. The process of leaf distortion is aimed at bringing contact of the chemical compound; polyphenols with copper based enzyme, polyphenoxidase in the leaf cell. There are various types of tea processing in vogue in tea growing countries, viz. Orthodox, Rotorvane, CTC, LTP etc. In Bangladesh, the following types of tea processing are practiced: a) Orthodox manufacture or conventional method, b) Un- orthodox manufacture or non-conventional method. In Bangladesh widely used method is Un-orthodox or non- conventional method, which includes: i) Rotorvane, ii) CTC (crush, tear, curl), iii) BLC (Barbora Leaf Conditioner). In Bangladesh, generally used combination is between two types of machines, e.g.— Roller-CTC, Rotorvane—CTC, BLC—CTC etc. Un-orthodox manufacture
theaflavins and thearubigins. The moisture in withered leaf, the better is the fermentation. High percentage of i) BLC (Barbora Leaf Conditioner). It looks like
relative humidity(R.H.) has a positive effect on Rotorvane and it is used like Rotorvane. Generally its fermentation. There are various methods of diameter is about 38 cm and 70 cm long. It is made by fermentation as follows: 1. Floor fermentation, 2. Rack soft metal, like MS and its inner cylinder consists of a fermentation, 3. Bawl fermentation, 4. Trough lining made by brass. There is a bracket connected at fermentation/ machine fermentation. The most widely one end of the cylinder, which is made by CS, called gable. The discharge end consists of adjustable pressure plates. If feeding of green leaves have done at the mouth (iv) Drying/Firing. The last stage of tea manufacturing
of BLC, then feedworm derives the leaves to the is Drying/Firing. The main objectives of drying are as processing zone, where twisting of leaves are done. Due follows: a) Drying of moisture content in the processed to collision with battens, the leaves are become ready tea leaf or reduction of moisture content upto 2—3 %, for CTC machine use. Due to high pressure juice of the which is suitable for storage and transportation, b) To leaves comes out and again mixed with the leaves. The arrest the fermentation, c) To make quality tea. At the discharge of the leaves are controlled by adjusting commencement of drying, the fermentation reactions pressure plates. It is considered as best pre-processing proceed at an accelerate rate. Enzymic reactions decline machine due to its high capability and other outstanding steadily and cease, when the moisture content falls to characteristics. Generally 70—75 % withering is around 20 %. The change of colour of the ‘dhool’ considered best for processing of green leaves (1200— (fermenting raw material) from brown to black tea of commerce is due to a variety of reactions, viz. the breakdown of chlorophyll, formation of theaflavin etc. ii) CT C (Crush, Tear, Curl) It consists of a pair of
A high proportion (about 40% ) of volatile compounds horizontally mounted contra-rotating stainless steel that are responsible for tea aroma is lost during firing. rollers initially 210 mm in diameter. The surface of each Other reactions, the neutralisation of harshnes of liquor roller is engraved with a series of teeth ( 8 TPI or 10 and destruction of micro-organisms that play an TPI ) in the axial direction and 50 or 60 helical grooves. important role in producing better quality, are also The rollers are so mounted that their teeth mesh involved during firing. There are many types dryers, together, the gap between them being adjustable. such as – Paragon Circuit Dryer, Quality dryer, ECP 3 The leaf falls on the apex of slow moving roller rotating Circuit (6 rows) dryer, two stage dryer etc. Modern at 70 rpm. The fast roller rotating at 700 rpm in the dryers are Fluid bed dryer and Vibratory Fluid bed opposite direction imparts a relative motion between the Dryer. Fluid bed dryers are operated on the theory of surface the two rollers with leaf in between . The leaf fluidization, where the ‘dhool’ (fermenting raw comes out through the bottom crushed, torn and curled. material) floats over a layer of air and the leaf is The rollers gradually wear with passage of time, and subjected to decrease temperature. Drying of ‘dhool’ this wear should be limited to 0.012 inch of tooth has been done in a tunnel in fluid bed dryer. Base of height. It is advisable to re-sharpen the rollers after tunnel is made by perforated stainless steel plate. Hot air processing every1630 kg withered leaf (Standard 70 % flows below the perforated plate and ‘dhool’ flows over wither) per inch (2.54 cm) of roller length. The the perforated plate. ‘Dhool’ has transformed into fluid available CTC machine maybe 60 cm (24″), 76 cm bed and it flows into the tunnel. It accelerates the drying (30″), 91 cm (36″) and 112 cm (48″). Generally three or of ‘dhool’ and air flow gradually drives the dry tea to four cuts are given and the moisture contents in the the front of tunnel. Cyclone helps both drying and fibre region of 67—72 % may be employed. Dauracherra tea extraction. Density of tea has been increased in fluid estate (A property of the Bangladesh Tea Board) uses bed dryer. Vibrating fluid bed dryer is the most popular four cuts of CTC machine, whereas a neibouring sterling garden, namely Mertinga tea estate uses six / seven cuts or even more for CTC machine. (v) Sorting and Grading. After firing, teas are cooled
off quickly; If bulked hot, tea will loose briskness and (iii) Fermentation. Fermentation of tea leaf is the
may taste bakey /stewey. Main objective of sorting is to process of oxidation of various chemical constituents of produce a series of black tea having even sized particles tea leaf through a series of chemical reaction. According without any visible pale coloured stalk or fibre. Finer to scientist D.L. Sana –“ No micro-organisms are fibre and smaller stalk in CTC/ LTP/ Orthodox are involved in the so-called ‘fermentation’, but the term is generally removed by means of electrostatic attraction probably too firmly established to change it despite its of the fibre extractor machine and the teas being passed inaccuracy.” This is the stage of enzymic oxidation. beneath a series of charged rollers. Passage of the tea Colour, strength and briskness are developed during this through a series of sieves in various sorters, viz. stage. During fermentation, the tea catechins or the Myddleton, McIntosh, Trinick sorter, vibroscreen etc. polyphenols and oxygen react in presence of fermenting produces a number of grades with more or less evenly enzymes, the polyphenol oxidases, requiring four sized particle. Moisture content of graded tea should be copper atoms to form a group of compounds called within 2—3 %. All grades must be of uniform size tasters (they may be registered brokers). Tea samples brought and sold in auctions are tested and evaluated by Tea Grades
the brokers and buyers. The main considerations to a tea tasters are – appearance (colour & size), infusion and Table—4: A tentative guide for sorting teas
liquor. Tasters and blenders have over hundred special terms, which describe the test and tasting e.g. – brownish-black, blackish, even or uneven size, fibrous PROBLEMS OF THE TEA INDUSTRIES IN
BANGLADESH
There are many problems in the tea estates of Bangladesh, these problems can be furnished as follows: a) Factory: problems related with withering, processing (rolling), fermenting, drying/firing, sorting and grading, packaging & storage, tea tasting and quality control and overall managerial problems, b) Field/ Tea Estate: problems related to the field and the surrounding and also managerial problems. But, I have discussed here only the existing overall problems and remedies of the tea estates, which seemed to me important for successful tea culture. According to me, these are some of the main problems prevailing in the tea estates: 1.Unexpected natural calamity, such as—drought. The tea industry of Bangladesh had experienced a severe and prolonged drought from Nov’ 98 to till the end of April’ (vi) Packing, Storage.
99 and also around the year 1999, 2. Deterioration of Packing. Quality should be assessed before packing: a)
law and order situation of the tea estates, e.g.—log Moisture content should not exceed 3% on packing, b) stealing, shade tree cutting, illegal occupation of land, Temperature of final firing, if required 85—95° C, c) lack of security both for the management and the Chest marking must be clear and according to standard labourer, political or outsider influence on their internal arrangements, pilferage of tea from the factory etc. 3. Shortage of medicine and lack of other facilities in the Storage.Tea is an unstable and very hygroscopic
hospital. The labourer (Kuli) have no faith on hospital product, which deteriorates during storage. Several or existing staff or doctor. Mortality rate even for chemical changes occur during storage. The rate of Diarrhoea is also very high, 4.Lack of pure water and deterioration depends principally on the moisture purification process, no hygienic latrine in labourer content and temperature. The maintenance of quality quarters. Unhealthy atmosphere prevails in the labour during storage can be made by: i) Effective drying line, 5. Rate of addicted person of wine is very high. condition during drying, ii) Prevention of moisture The labourer are consuming near about 1 lakh gallon content during processing, sorting etc. Teas that are wine only in Moulvibazar and Hobigonj district. There sorted and packed with a minimum delay in the tea are many bars of wine namely ‘Patta’, which were legal chests lined with Aluminium foil may be stored in good bars since British rule, 6. Lack of infrastucture, e.g.- quality for a considerable time. All the packed teas, roads, labour line quarters, water supply network are not chests or gunny bags or both are sent to the ware houses sufficient, 7. Lack of capital and modern machineries in and then sold in auction centre through some brokers. various gardens. 8. Lower market value of made tea in comparison to increasing production cost, 9. Lower (vii) Tea tasting and quality control. Now -a -days,
yield per hectare in comparison to increasing domestic each and every commodity has to be tested (either in need,10. MRL value or maximum residue limit on laboratory or by tasting with the help of tongue) pesticides has not been followed strictly. The European whether it is food or beverage to ensure its quality countries have declared that they will not buy before its sales promotion or marketing of the product. Bangladeshi tea, if they found the MRL value beyond Tea is the most popular non-alcoholic beverage to both the prescribed level since 1998 ( Ittefaq report, 4, Dec. the rich and the poor. Since it is a beverage, so quality 2000), 11. An allegation is often heard on the air that must be maintained before and after manufacturing. It many owners of the tea gardens are not using Govt. must be manufactured in a hygienic atmosphere. Tea loans properly, e.g.—they are interested about tasting is an art and the professional tea tasters possess forestation of valuable trees (according to timber value), the knowledge of market demand with respect to grade, horticulture and some of them are giving up tea culture appearance, taste and liquoring characteristics of tea. due to high investment of money and low return/slow Tasting and valuation are carried out by Professional tea return. So, weekly payment is not regular or timely in seedling is very poor. So, we have to make clone tea many gardens. Workers afraid about loosing their with high yielding variety and also have good quality. jobs,12.Lack of perennial water source for irrigation But which is the most contradictory situation in tea during dry season and also in prolonged culture. Because of quality and yield do not exist drought,13.Lack of educational institutions/infrastucture simultaneously. It is an irony of fate in everywhere. and that is why literacy rate is poor,14.The children of Dream and reality can not be the same around the world the labourer have been suffering from malnutrition. So, 8. Shortage of capital and modern machinery can be REMEDIES AND RECOMMENDATIONS
solved by Govt. loan. But this loan should be used only for tea culture. Forestation of valuable trees, horticulture 1. Law and order situation of the tea estates must be should be stopped in the tea field for the sake of tea improved. It is in an alarming stage in various gardens. culture and for the traditional labourer, who can not quit Security of both executives and labourer must be from the scene, who do not know any other technical ensured. Shade tree cutting, log stealing, illegal work. Govt. loan should not be used in housing or any occupation of land, pilferage of tea and disturbance from the surrounding ‘Basti’ must be stopped in order to 9. Tea industry of Bangladesh had experienced a severe and prolonged drought in the beginning of the year 2.M.B.B.S. doctor and supporting staff must be 1999. The average rainfall during January to April in appointed in various gardens to ensure proper medical 1999 was 4.99″ as against 10 years average rainfall facility. Suitable fund must be allocated for medicine, 18.34″ in the same period. In order to face this natural calamity, we should adopt both short term and long term measures. Construction of more dams /reservoirs, set up 3. To set up sufficient number of deep and shallow tube of more deep tube wells with water network system are wells in the labour line is a demand of time to ensure the short term ways to combat losses of drought. We pure water. Purification of water for existing tube wells should take some long term measures as follows: a) is also important .Unhealthy atmosphere in the labour Mulching of young tea should be properly done in dry line must be eliminated by introducing hygienic latrine season, b) The pΗ of top soil of the tea area should be increased by adding Dolomite and lime, so that water holding capacity of the soil is increased by increasing 4.Wine consumption in the labour line must be reduced structure of soil, c) Systematic cattle farming may be gradually to some extent, with a target to make it zero. undertaken in the tea estates to get maximum quantity Health education can be carried out through Toki of cow dung to be applied for raising organic matter in cinema (bioscope) regarding family planning, health & the soil, d) For root development of the plants drainage hygiene by the Govt. information dept. or any other status should be improved ,e) Drought resistant variety of tea should be evolved by the BTRI scientists. More shade trees should be planted, f) To discourage forestry 5. Housing problems of the labourer must be improved extraction in tea estates in order to avoid any variation and solved. Unmetalled roads must be transformed to of rainfall in the region, g) Weather forecasting should metalled road and adequate water supply network must be projected in order to avoid eventuality of future 6.The executives of the tea estates must be conscious 10.To establish sufficient number of educational about health hazards due to pesticide residue in black institutions to improve literacy rate, to eliminate tea. Still we have no measuring instrument to measure superstition, ignorance etc. They should be conscious ‘maximum residue level’ of various pesticides. It will about cleanliness, health and hygiene, over consumption create a serious problem on export volume or sales promotion, since European countries (especially the west European countries) are very much conscious PROSPECTS OF THE TEA INDUSTRY IN
BANGLADESH
7.Production cost variables are many, e.g.—wages of Tea is the second highest foreign exchange earner labourer, fertilizer, pesticide, management and staff agro-based commodity of Bangladesh. At present tea salary, electricity, gas, depriciation of machinery, gardens comprise of 48,587 hectares of land and a total packaging material, storage & despatch cost, etc. So, it number of 158 gardens are producing 16 crore 6121 is a tough job to reduce production cost. Now, we have thousand kgs of tea every year (upto 1998). More than 1 two ways--- quality and yield. If we produce quality tea lakh 25 thousand of people are employed in this with eye catching bright orange –red colour liquor with industry. Bangladesh annually produces about 55 flavour or to increase yield. Yield of conventional million kgs of tea and our share to world production is only 2% .The share in world export is 3%, average resulting from hamful effects of strontium—90, the earning is around 1500 to 2000 million Taka, share in most dangerous isotope in radioactive fallout. Tea national export is 1.2% and contribution towards GDP leaves contain several chemical compounds having is 0.81%. Our national average yield is 1146 kg/ha. We medicinal properties, e.g.—Caffeine, catechin hope to increase our annual production to 90 million kgs (polyphenol), and alkaloid. Other non addictive drugs, by 2010.Our yield has increased per hectare from 700- e.g.—theo bromine, theophyline, useful fluorides, kg to1146 kg due to implementation of BTRP. So, we volatile oils, and vitamin B are also present. Tea hope to increase our production further more within a catechins (polyphenols) are the colourless chemical few years. Kenya’s per ha yield is 2274 kgs, India’s compounds of bitter taste. These constituents form black 1797 kgs and Sri lanka’s 1167 kgs( according to product with iron; contribute to colour, briskness, taste, Ahmed, Amiruddin it is 1430kgs). As such, we must depth and tea characteristics of aromatic flavour of increase our production at least to 1500 kgs per hectare black tea. Caffeine is a white amorphous powder of on an average to retain the existing export target after nitrogenous base. It is an alkaloid. It stimulates central meeting the increased trend of internal consumption. If nervous system effecvting better heart functions, blood we produce quality tea with flavour and which is tested circulation, respiration and removal of fatigue. and certified by the BTRI (Bangladesh Tea Research Institute) that pesticide residue level of teas are within CONCLUSION
the prescribed level of EEC/EU, then the health & hygiene conscious European countries will accept our Tea is the most popular non- alcoholic beverage, teas without confusion, like Sri lankan teas. Sri Lankan which is the second highest foreign exchange earner Tea Research Institute (TRI) has established their teas agro-based commodity of Bangladesh. Tea industries in as the cleanest teas of the world in respect of pesticide Bangladesh are facing various problems, such as – residue. So far as I know, our BTRI still does not security problems of the executives, unexpected natural possess any measuring instrument regarding calamity, deterioration of law and order situation of the measurement of pesticide residue. It is a matter of hope tea estates, log stealing, political or outsider influence that the process to procure measuring instrument is on their internal arrangements, illegal occupation of land by the outsiders, lack of medical facilities, unhealthy atmosphere in the labour lines, over TEA: ITS USE AS A MEDICINE
consumption of wine by the labourer, lack of infrastructure (road, quarter, water supply network etc), Since 500 A.D. tea is principally used as a medicine, lack of capital and modern machineries, lower market which has an exerting action on the central nervous value of made tea in comparison to increasing system, kidney and muscles. Tea is known to produce a production cost, lower yield per hectare in comparison condition of wakefulness and increase mental activity. to increasing domestic need, lack of instrument for No other beverage has such power to calm as it measuring MRL value, some owners of the tea gardens stimulates; tea is known to dispel weakness, prevent are not using Govt. loans properly, lack of parennial drowsiness, relieve fatigue, refresh body and mind. water source for irrigation during dry season and also in Wine may be the drink of conviviality and coffee of the prolonged drought, lack of educational institutions, mid night scholar, but tea brings tranquility to both body malnutrition among the children of the labour line.For successful tea culture the above problems must be solved .To reduce production cost we have to produce The glorification of tea drinking has also been put quality tea with eye catching bright orange-red colour forth by some great English poets. The great English liquor with flavour or have to increase yield.We have to poet of 18th century, William Cowper mentioned a cup make clone tea with high yielding variety also have of tea as ---“The cup that cheers, but does not inebriate”. good quality.We must remove the screen of distrust and Another poet, Nicholas brawdy has also been glorified a suspicion of the European countries by establishing a step more, in his poem ‘ The tea table’, mentioned as – “ clean image like Sri lankan Tea Research Institute. The sovereign drink of pleasure and health”. The great English poet, Alexander Pope mentioned tea as ---“The REFERENCES
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