standards of tea for ensuring market requirement
TRANSCRIPT
Tea Research Inst i tute of Sr i Lanka
Standards of Tea for Ensuring
Market Requirement
Nimal PunyasiriBiochemistry Division
Tea Research Inst i tute of Sr i Lanka
Standards of Tea
Related to:
Black TeaGreen Tea White Tea
TRI recommendations on Pesticides(Issue of MRLs)Adulterations
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Tea Research Inst i tute of Sr i Lanka
ISO Standards
Definition for Black Tea
Tea derived solely and exclusively, and
produced by acceptable processes, notably
withering, leaf maceration, aeration and
drying, from the tender shoots of varieties of
the species Camellia sinensis (Linnaeus) O.
Kuntze known to be suitable for making tea
for consumption as a beverage.
ISO 3720:2011
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Tea Research Inst i tute of Sr i Lanka
ISO Standards
Definition for Green Tea
Tea derived solely and exclusively, and
produced by acceptable processes, notably
enzyme inactivation and commonly rolling or
comminution, followed by drying, from the
tender leaves, buds and shoots of varieties
the species Camellia sinensis (Linnaeus)
O.Kuntze, known to be suitable for making
Tea for consumption as a beverage.
ISO 11287:2011
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Tea Research Inst i tute of Sr i Lanka
Chemical Composition – Fresh Tea Leaf
Constituent % by dry weight
Flavanols (Catechins) 17-30
Flavonols and flavonol glycosides 3-4
Leucoanthoyanins/Proanthocyanins 2-3
Phenolic acid and depsides ~5
Caffeine 3-4
Amino acids ~4
Simple carbohydrates ~4
Organic acids ~0.5
Polysaccharides ~13
Proteins ~15
Ash ~ 5
Cellulose ~ 7
Lignin ~ 6
Lipids ~ 3
Pigments ~ 0.5
Volatile substances 0.01 -0.02
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Tea Research Inst i tute of Sr i Lanka
35.8% (Bud)
35 % (1st Leaf)
27.9 (2nd Leaf)
23.1% (3rd Leaf)
15.0% (Stem)
Ideal for
Manufacture
of Black Tea
Total Polyphenol Content
in tea leaves
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Tea Research Inst i tute of Sr i Lanka
Polyphenol CompositionFresh Tea Leaf
Component g/100 g dry weight
Epigallocatechin gallate (EGCG) 9 - 13Epigallocatechin (EGC) 3 - 6Epicatechin gallate (ECG) 3 - 6Epicatechin (EC) 1 - 3Gallocatechin (GC) 1 - 2Catechin (C) 1 – 2Flavonols and their glycosides 3 – 4Leucoanthocyanins/Proanthocyanidins 2 – 4Phenolic acids 4Total polyphenols 27 – 40
T
O
T
A
L
P
O
L
Y
P
H
E
N
O
L
S
T
O
T
A
L
C
A
T
S
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Tea Research Inst i tute of Sr i Lanka
ISO Standards for Black Tea / Green Tea
Parameter Test Method Requirement
Black Tea
Water Extract % ISO 9768 32 min.
Total ash % ISO 1575 4-8
Water soluble ash % ISO 1576 45
Alkalinity of total ash % ISO 1578 1-3
Acid soluble ash % ISO 1577 1.0 max.
Crude fibre % ISO 5498 16.5 max.
Total Polyphenol % ISO 14502-1 9 min.
Parameter Test Method Requirement
Black Tea Green Tea
Water Extract % ISO 9768 32 min. 32 min.
Total ash % ISO 1575 4-8 4-8
Water soluble ash % ISO 1576 45 45
Alkalinity of total ash % ISO 1578 1-3 1-3
Acid soluble ash % ISO 1577 1.0 max. 1.0 max.
Crude fibre % ISO 5498 16.5 max. 16.5 max.
Total Polyphenol % ISO 14502-1 9 min. 11 min.
Total Catechins % ISO 14502-2 - 7 min.
Ratio of TC/TP - 0.5 min.
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Tea Research Inst i tute of Sr i Lanka
Pathway to ISO Standards
ISO appoints special committee
ISO collects the data from all producers
Worldwide inter-laboratory testing
TRI already contributed the data and ideas
The process of formulating a standard –
approx. 15 years
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Tea Research Inst i tute of Sr i Lanka
Contribution of the TRI
Parameters Standard Technique
Total Polyphenols ISO 14502-1 Spectrophotometry
Individual catechins ISO 14502-2 HPLC
Water extract (TS) ISO 9768 Gravimetry
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Tea Research Inst i tute of Sr i Lanka
Water Extract in SL Green Tea
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%
32%
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Tea Research Inst i tute of Sr i Lanka
Total Catechins
0
2
4
6
8
10
12
14
16
18
20
SLG
T –
01
SLG
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02
SLG
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SLG
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%7 %
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Tea Research Inst i tute of Sr i Lanka
Total Polyphenols
%
0
5
10
15
20
25
SLGT –01
SLGT –03
SLGT –05
SLGT –07
SLGT –09
SLGT –11
SLGT –13
SLGT –15
SLGT –17
SLGT –19
SLGT –21
SLGT –23
SLGT –25
SLGT –27
SLGT –29
SLGT –31
SLGT –33
SLGT –35
11 %
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Tea Research Inst i tute of Sr i Lanka
Ratio of TC / TPP
0
0.2
0.4
0.6
0.8
1
1.2
SLG
T –
01
SLG
T –
02
SLG
T –
03
SLG
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SLG
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SLG
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SLG
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SLG
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SLG
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SLG
T –
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Ratio
TC/TPP0.5
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Tea Research Inst i tute of Sr i Lanka
New parameter to be added
L-Theanine
TRI has already established the levels in
Sri Lankan GT and BT
The L-theanine content in Sri Lankan black tea
ranged from 0.91 – 1.29 %
and
in green tea ranged from 0.26 – 1.49 % on dry
weight basis
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Tea Research Inst i tute of Sr i Lanka
Theanine(gamma –ethyl amino L-glutamic acid)
This unique Amino Acid was discovered in 1949 by
Sakato from tea leaves. (latest research shows that
Theanine (Thea) is found in 21 spp from theaceae
family, Ashihara et al., 2010)
It is known to be a neurotransmitter in the brain and
Imparts mind relaxation-inducing effect in humans
Improved memory
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Tea Research Inst i tute of Sr i Lanka
Brain Waves
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Tea Research Inst i tute of Sr i Lanka
ISO Standards
DEFINITION
Tea derived solely and exclusively, and
produced by acceptable processes, by
harvesting and a single withering/drying
stage from the bud and tender shoots or 1-2
leaves of varieties of the species Camellia
sinensis (Linnaeus) O. Kuntze known to be
suitable for making tea for consumption as a
beverage
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Tea Research Inst i tute of Sr i Lanka
The above definition would exclude teas such as
Ceylon silver Tips, silver needles from the
classification “ White Tea “.
Sri Lanka has proposed ISO to include Ceylon
Silver Tips into a separate category and treat as
Special Tea
This would pave the way to protect the unique
identity of silver tips and produce a new type of
tea in Sri Lanka “ White Tea”
Sri Lanka - Proposal to ISO
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Tea Research Inst i tute of Sr i Lanka
TRI Recommended Pesticides and their
MRLs
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Tea Research Inst i tute of Sr i Lanka
MRL….
CODEX Maximum Limit for Pesticide Residues (MRL)
is the maximum concentration of a pesticide residue
(expressed as mg/kg), recommended by the CODEX
Alimentarius Commission to be legally permitted in
or on food commodities and animal feeds. MRLs are
based on GAP data and foods derived from
commodities that comply with the respective MRLs
are intended to be toxicologically acceptable
Codex website at: http://www.codexalimentarius.net
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Tea Research Inst i tute of Sr i Lanka
MRLs
Japan
?
0.05 mg/kg
0.01 mg/kg
0.1 mg/kg
1 mg/kg
5 mg/kg
MRL
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Tea Research Inst i tute of Sr i Lanka
MRLs of TRI Recommended Pesticides (mg/kg)
Pesticide Japanese MRL EU MRL
2,4-D 0.01 0.1
Azadirachtin Exempted 0.01
Bitertanol 0.1 0.1
Carbofuran 0.2 0.05
Carbosulfan 0.1 0.1
Chlorfluazuron 10 Exempted
Copper salts Exempted 40 as Cu
Dazomet 0.1 0.02
Diazinon 0.1 0.02
Diuron 1 0.1
Fenthion 0.01 0.05
Glufosinate am. 0.5 0.1
Glyphosate 1.0 2.0
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Tea Research Inst i tute of Sr i Lanka
Pesticide Japanese MRL EU MRL
Hexaconazole 0.05 0.05
Imidachlorprid 10 0.05
MCPA 0.01 0.1
Metam Sodium 0.1 0.02
Oxyfluorfen 0.01 0.05
Paraquat 0.3 0.05
Phenamiphos 0.05 0.05
Propargite 5.0 5.0
Propiconazole 0.1 0.1
Sulfur Exempted Exempted
Tebuconazole 30 0.05
Tebufenozide 25 0.1
MRLs of TRI Recommended Pesticides (mg/kg) contd.
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Tea Research Inst i tute of Sr i Lanka
JMPR/GAP/FAO
Supervised field trials for 17 pesticides used in
tea have been already carried out.
When the MRLs are not achievable. TRI files
application to EU/JAPAN with experimental
evidence
Analysis is done only by an accredited lab in
Germany
Expensive exercise
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Tea Research Inst i tute of Sr i Lanka
Analytical Contribution of TRI
Methods developed by TRI
1. Hexaconazole
2. Propiconazole GC-MS
3. Bitertanol
4. Tebuconazole
5. Pyraclostrobin (to be recommended)
6.MCPA Derivatization followed by GCMS
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Tea Research Inst i tute of Sr i Lanka
Heavy Metals – SLTB Standard
Heavy Metal Accepted Limitmg/kg
Test Method
Iron max 500 AOAC:975:03
Copper max 100 AOAC:971:20
Lead max 2 AOAC: 972:25
Zinc max 100 AOAC:969:32
Cadmium max 0.2 AOAC:973:34
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Tea Research Inst i tute of Sr i Lanka
Microbiological Requirements
SLTB Standard
Standard Accepted Limit Test Method
Aerobic Plate Count Max . 10,000 cfu/g ISO 4833:2003
Yeast & mould Max. 1000 cfu/g ISO 21527-2-2008
Total Coliforms Max. 10 MPN/g ISO 4831:2006
E.coli Absent/g ISO 7251:2005
Salmonella Absent/25 g ISO 6579:2002
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Tea Research Inst i tute of Sr i Lanka
Food Adulteration
A substance has been added or
mixed or packed with it to increase
its bulk or weight, or reduce its
quality or strength, or make it
appear better or of greater value
than it is.
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Tea Research Inst i tute of Sr i Lanka
Classic Examples of Food Adulteration
Black Pepper Papaya seeds
Chili powder Powdered bricks /Sudan dye
Coconut oil Palm oil
Milk fat Animal fat
Milk protein Melamine
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Tea Research Inst i tute of Sr i Lanka
Importance of Prevention of Adulteration
Authentication of food products is of primary importance for both consumers and industries, at all levels of the production process, from raw materials to finished products.
From the legislative point of view, quality standards have been established through the requirement of quality labels that specify the chemical composition of each product.
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Tea Research Inst i tute of Sr i Lanka
Detected Adulterations
28 Suspensions/Compounding of the offence
/ Cancellation – 2011 (up to May)
Made by SLTB*
* Source – Tea Commissioner
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Tea Research Inst i tute of Sr i Lanka
Ultimate Goal
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© 2011, Tea Research Institute of Sri Lanka
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