15. Tea.pdf

Tea

1. TeaTea
((
Morphology, Processing and UsesMorphology, Processing and Uses
))
By
Hem Chander
Assistant Professor (Botany)
Career Point University Hamirpur(HP) 176041
[email protected]

2. TEA TEA --Camellia sinensisCamellia sinensis
Family -Theaceae
Genus -Camellia
Species -sinensis

3. Groups of TeaGroups of Tea
•China type -C. sinensis var. sinensis
–Northern slope of the Himalayan Mountains
–Elevated altitudes, semi-humid forest–Elevated altitudes, semi-humid forest
–Bush with small erect leaves with many
serrations
–Flowers are borne singly
–Greater tolerance to drought and low temp.
–Main tea produced in China and Japan

4. Groups of TeaGroups of Tea
•Assam type -C. sinensis var. assamica
–Southern slopes of the Himalayan
Mountains
–Found in humid dense forest
–Tree
–Leaves are larger with less serrations, less
erect, and tend to droop at tips
–Leaves lighter green color
–Flower in clusters of 2-4

5. Origin and Domestication of TeaOrigin and Domestication of Tea
China
Assam
China
1833
1930s
Trade with Europe
1600s

6. Tea DomesticationTea Domestication
•China type domesticated in south China
–4000 years ago?
–Spread throughout China and Japan•Trading with Europe beginning in early 1600s•Trading with Europe beginning in early 1600s
–Earliest maritime explorations by the Portuguese
and Dutch
–England enters trade with East India Co in mid to
late 1600s
•East India Trade Co monopoly on tea trade
ends in 1833

7. Tea DomesticationTea Domestication
•Tea growing in India investigated
–Seed of China type were planted various locations
–Grew best in Assam, NE India -so developed
plantations
–Tea-like plants grew wild throughout forest in this –Tea-like plants grew wild throughout forest in this
area -these were the Assam type tea
–Initial plantings were mixtures of China and Assam
tea plants
•Outcrossing plants
•Seed propagation
•Hybrid tea populations were developed

8. Tea DomesticationTea Domestication
•Assam region initial area of domestication of
Assam tea
–Late 1800s
•South India
•Sri Lanka (esp. after rust destroyed the coffee industry)•Sri Lanka (esp. after rust destroyed the coffee industry)
•Java and Indonesia
–1930s
•Equatorial highlands of Central and East Africa
•Current Assam tea is a hybrid type derived
from the initial mixed plantings in NE India

9. Origin and Domestication of TeaOrigin and Domestication of Tea
China
Assam
China
1833
1930s

10. Tea ProductionTea Production
27
21
25
30
Major Producing Regions
21
9
15
0
5
10
15
20
Percent of
total
production
IndiaChinaSri LankaAfrica
By weight 50% total production of coffee
Increasing

11. Tea ProductionTea Production
2168
2000
2500
Production (1000 t)
Major Producing Regions
1
395
0 57
0
500
1000
1500
Production (1000 t)
AsiaEuropeAfricaNorth
America
South
America
Much of production consumed locally

12. Tea ImportationsTea Importations
311
227250
300
350
Importations (1000 t)
Major Importers
227
187
104
16
0
50
100
150
200
250
Importations (1000 t)
AsiaEuropeAfricaNorth
America
South
America
Much of production consumed locally

13. The Tea PlantThe Tea Plant
Perennial evergreen bush/tree
Harvest young leaves

14. The Tea PlantThe Tea Plant
•Understoreytrees
•Adaptation
–Temperature
•18-30°C
•Leaf growth stops •Leaf growth stops
–Below 13°C
–Above 35°C
–Shoot replacement cycle related to temp.
•Equatorial region
–Grown in highlands (1000-3000 m)
–At low latitude/altitude need shade for best growth (Assam type)
–Rainfall
–Soil type

15. The Tea PlantThe Tea Plant
•Understorey trees
•Adaptation
–Rainfall
•1150 mm if evenly distributed•1150 mm if evenly distributed
–Soil type
•Acid soils (pH 4.0 to 5.6)
•Good drainage
•Good water holding capacity

16. Tea Plant PropagationTea Plant Propagation
•Seed
–Short period of viability
–Germinate in sun and plant into pots once begin to emerge
–2-3 years before field planting size
Tropical Horticulture -Texas A&M University
–
–Traditional approach to propagation
–Seedlings are not uniform
•Clonally
–Single node cuttings
–Ready for field in 1 year
–Rooted cuttings are uniform

17. Tea PlantingTea Planting
•Density of planting
–10,000 to 15,000/ha
•Use of shade
–Initially all tea in Assam with shade
–Now many areas without shade
Tropical Horticulture -Texas A&M University
–Now many areas without shade
•Higher yields without shade
•Greater response to fertilizer without shade
–Some exceptions
•High heat areas (lowlands of north
India/Bangladesh)
•Low input system, in highlands of Kenya,
shaded system is equal or better than unshaded

18. Tea Training and PruningTea Training and Pruning
•Training
–Head back to 20 cm at planting
–Next year to 40 cm
–Final year at 60 cm to form a level
“plucking table”“plucking table”
•Pruning
–Need to cut back periodically
–Plucking table will slowly rise
–Periodically need to rejuvenate
•Prune below branches
•Bring to bear again

19. Tea HarvestingTea Harvesting
•Harvest -Most done by hand
–Tips
•Bud only gives best product
–Fine plucking -most common
•Bud plus 2 leaves•Bud plus 2 leaves
–Coarse plucking
•Bud plus 3 leaves
•Important to begin processing
quickly

20. Tea HarvestingTea Harvesting

21. Types of TeaTypes of Tea
•Green Tea
–Not “fermented”
–Only China type tea
–Mainly China and Japan–Mainly China and Japan
•Oolong Tea
–Semi “fermented”
–Produced in Taiwan
•Black Tea
(highest production)
–“Fermented”

22. Tea ProcessingTea Processing

23. Black Tea ProcessingBlack Tea Processing
••WitheringWithering
––Thin layers of leaves in traysThin layers of leaves in trays
––Leaves allowed to dry to lose turgidityLeaves allowed to dry to lose turgidity––Leaves allowed to dry to lose turgidityLeaves allowed to dry to lose turgidity
––1818--24 hours24 hours
––50% weight loss50% weight loss

24. ••RollingRolling
––Twists and breaks up leafTwists and breaks up leaf
––Expresses leaf sapExpresses leaf sap
••Good contact with flavanols and polyphenol oxidaseGood contact with flavanols and polyphenol oxidase––Done 3Done 3--5 times5 times
Black Tea ProcessingBlack Tea Processing
Tropical Horticulture -Texas A&M University
––Done 3Done 3--5 times5 times
••1st roll = dhools, most tender parts of the leaves1st roll = dhools, most tender parts of the leaves
••2nd and 3rd rolls = mahls and fines2nd and 3rd rolls = mahls and fines
••Sticks left over = big bulkSticks left over = big bulk
––Need to keep temp between 27 Need to keep temp between 27 --32 C32 C
••Mechanical heatMechanical heat
••Heat generated by oxidationHeat generated by oxidation

25. Black Tea ProcessingBlack Tea Processing
••Fermentation = oxidationFermentation = oxidation
––Begins with rollers, dhool stagesBegins with rollers, dhool stages
––Flavor and aroma developsFlavor and aroma develops
––Leaves turn darkLeaves turn dark
••Flavanols >> colored theaflavins, thearubiginsFlavanols >> colored theaflavins, thearubigins
––Limit of 4Limit of 4--5 hours5 hours

26. Black Tea ProcessingBlack Tea Processing
••Drying = stops oxidationDrying = stops oxidation
––Time of fermentation Time of fermentation
••SubjectiveSubjective
••Important in qualityImportant in quality••Important in qualityImportant in quality––In at 82 In at 82 --94 C and finish at 53 C94 C and finish at 53 C
––Moisture levelMoisture level
••54% to 3% moisture54% to 3% moisture

27. Black Tea ProcessingBlack Tea Processing
••Grading and SortingGrading and Sorting
––Broken Orange Pekoe (high % buds)Broken Orange Pekoe (high % buds)
––Broken PekoeBroken Pekoe
––Orange Pekoe (twisted tender stalk)Orange Pekoe (twisted tender stalk)
Tropical Horticulture -Texas A&M University
––Pekoe Pekoe --compact and densecompact and dense
––Souchong Souchong --compact and densecompact and dense
––Broken Orange Pekoe FanningBroken Orange Pekoe Fanning

28. Green Tea ProcessingGreen Tea Processing
••Prevent “fermentation”Prevent “fermentation”
––Initial heating to destroy polyphenol oxidaseInitial heating to destroy polyphenol oxidase
––Rolled at 90Rolled at 90--100 C for 45100 C for 45--50 min 50 min --50% moisture50% moisture
––Rolled without heat for 15 minRolled without heat for 15 min––Rolled without heat for 15 minRolled without heat for 15 min
––Dried at 50Dried at 50--60 C (3060 C (30--40 min) 40 min) --30% moisture30% moisture
––Rolled on heated pan (80Rolled on heated pan (80--90 C), 40 min.90 C), 40 min.
––Dried at 80 C Dried at 80 C --<6% moisture<6% moisture
––Sieve to remove stems and debrisSieve to remove stems and debris
––Final dryingFinal drying

29. Quality ControlQuality Control
Use same weight of tea per cup
Allowed to steep in hot water same time
Grade indicated by cup placement

30. Quality ControlQuality Control
Judge quality of tea samples
Ensure consistent flavor of
blends
Tea judged better gets higher price

31. Top Tea VarietalsTop Tea Varietals
•Darjeeling
–First flush, light almondy, flowery scent, puckery mouthfeel
–Second flush, darker, more body, hints of muscat•Formosa Oolong•Formosa Oolong
–Champagne of teas, grown at lower altitudes
–Aroma of peach blossoms, wisp of smokiness, almost no
mouth pucker (astringency)

32. Top Tea VarietalsTop Tea Varietals
•Yunnan
–Full body, rich, wispy smokiness, hint of pepperiness•Earl Grey
–Flavored tea–Flavored tea
–Black tea with bergamot (citrus of Sicilian origin)
•Ceylon
–Clean, bright flavor

33. Health
Benefits Benefits
of Tea

34. Health Benefits of TeaHealth Benefits of Tea
•Reduce risk of Coronary Heart Disease
–Epidemiological studies
–Lowers blood levels of LDL cholesterol•Flavonoids are antioxidants•Flavonoids are antioxidants
–95% polyphenols in tea are flavanoids
–Higher anti oxidant activity than Vitamin A, C or E
-but with less bioavailability
–Combat free radicals >> reduce risk of cancer
•Much of benefits not experimentally confirmed