1. Tea
Tea
(
(Morphology, Processing and Uses
Morphology, Processing and Uses)
)
By
Hem Chander
Assistant Professor (Botany)
Career Point University Hamirpur (HP) 176041
hemchander78@gmail.com
2. TEA
TEA -
- Camellia sinensis
Camellia sinensis
Family - Theaceae
Genus - Camellia
Species - sinensis
3. Groups of Tea
Groups 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 Tea
Groups 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 Tea
Origin and Domestication of Tea
China
Assam
China
1833
1930s
Trade with Europe
1600s
6. Tea Domestication
Tea 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 Domestication
Tea 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 Domestication
Tea 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
10. Tea Production
Tea Production
27
21
25
30
Major Producing Regions
21
9
15
0
5
10
15
20
Percent of
total
production
India China Sri Lanka Africa
By weight 50% total production of coffee
Increasing
13. The Tea Plant
The Tea Plant
Perennial evergreen bush/tree
Harvest young leaves
14. The Tea Plant
The Tea Plant
• Understorey trees
• 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 Plant
The 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 Propagation
Tea 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 Planting
Tea 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 Pruning
Tea 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 Harvesting
Tea 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
21. Types of Tea
Types 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”
23. Black Tea Processing
Black Tea Processing
•
• Withering
Withering
–
– Thin layers of leaves in trays
Thin layers of leaves in trays
–
– Leaves allowed to dry to lose turgidity
Leaves allowed to dry to lose turgidity
–
– Leaves allowed to dry to lose turgidity
Leaves allowed to dry to lose turgidity
–
– 18
18-
-24 hours
24 hours
–
– 50% weight loss
50% weight loss
24. •
• Rolling
Rolling
–
– Twists and breaks up leaf
Twists and breaks up leaf
–
– Expresses leaf sap
Expresses leaf sap
•
• Good contact with flavanols and polyphenol oxidase
Good contact with flavanols and polyphenol oxidase
–
– Done 3
Done 3-
-5 times
5 times
Black Tea Processing
Black Tea Processing
Tropical Horticulture - Texas A&M University
–
– Done 3
Done 3-
-5 times
5 times
•
• 1st roll = dhools, most tender parts of the leaves
1st roll = dhools, most tender parts of the leaves
•
• 2nd and 3rd rolls = mahls and fines
2nd and 3rd rolls = mahls and fines
•
• Sticks left over = big bulk
Sticks left over = big bulk
–
– Need to keep temp between 27
Need to keep temp between 27 -
- 32 C
32 C
•
• Mechanical heat
Mechanical heat
•
• Heat generated by oxidation
Heat generated by oxidation
25. Black Tea Processing
Black Tea Processing
•
• Fermentation = oxidation
Fermentation = oxidation
–
– Begins with rollers, dhool stages
Begins with rollers, dhool stages
–
– Flavor and aroma develops
Flavor and aroma develops
–
– Leaves turn dark
Leaves turn dark
•
• Flavanols >> colored theaflavins, thearubigins
Flavanols >> colored theaflavins, thearubigins
–
– Limit of 4
Limit of 4-
-5 hours
5 hours
26. Black Tea Processing
Black Tea Processing
•
• Drying = stops oxidation
Drying = stops oxidation
–
– Time of fermentation
Time of fermentation
•
• Subjective
Subjective
•
• Important in quality
Important in quality
•
• Important in quality
Important in quality
–
– In at 82
In at 82 -
- 94 C and finish at 53 C
94 C and finish at 53 C
–
– Moisture level
Moisture level
•
• 54% to 3% moisture
54% to 3% moisture
27. Black Tea Processing
Black Tea Processing
•
• Grading and Sorting
Grading and Sorting
–
– Broken Orange Pekoe (high % buds)
Broken Orange Pekoe (high % buds)
–
– Broken Pekoe
Broken Pekoe
–
– Orange Pekoe (twisted tender stalk)
Orange Pekoe (twisted tender stalk)
Tropical Horticulture - Texas A&M University
–
– Pekoe
Pekoe -
- compact and dense
compact and dense
–
– Souchong
Souchong -
- compact and dense
compact and dense
–
– Broken Orange Pekoe Fanning
Broken Orange Pekoe Fanning
28. Green Tea Processing
Green Tea Processing
•
• Prevent “fermentation”
Prevent “fermentation”
–
– Initial heating to destroy polyphenol oxidase
Initial heating to destroy polyphenol oxidase
–
– Rolled at 90
Rolled at 90-
-100 C for 45
100 C for 45-
-50 min
50 min -
- 50% moisture
50% moisture
–
– Rolled without heat for 15 min
Rolled without heat for 15 min
–
– Rolled without heat for 15 min
Rolled without heat for 15 min
–
– Dried at 50
Dried at 50-
-60 C (30
60 C (30-
-40 min)
40 min) -
- 30% moisture
30% moisture
–
– Rolled on heated pan (80
Rolled 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 debris
Sieve to remove stems and debris
–
– Final drying
Final drying
31. Top Tea Varietals
Top 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 Varietals
Top 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
34. Health Benefits of Tea
Health 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
