DEAS 921: 2018  
ICS 67.160.10 
 
© EAC 2018                                                                                                                               First Edition 2018   
 DRAFT EAST AFRICAN STANDARD  
Green tea — Specification  
EAST AFRICAN COMMUNITY  DEAS 921: 2018  
ii © EAC  2018  – All rights reserved  
 Copyright notice  
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© East African Community  2018  — All rights reserved  
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Violators may be prosecute d. DEAS 921: 2018  
© EAC 2018 – All rights reserved  iii 
 Foreword  
Development of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of products and services in the East African Community. It is envisaged that through 
harmonized standardization, trade ba rriers that are encountered when goods and services are exchanged 
within the Community will be removed.  
The Community has established an East African Standards Committee  (EASC)  mandated to develop and 
issue East African Standards  (EAS) . The Committee is c omposed of representatives of the National 
Standards Bodies in Partner States, together with the representatives from the public and private sector 
organizations  in the community .  
East African Standards are developed through  Technical Committees that are representative of key 
stakeholders including government, academia, consumer groups, private sector and other interested parties. 
Draft East African Standards are circulated to stakeholders through the National Standards Bodies in the 
Partner States. The co mments received are discussed and incorporated before finalization of standards, in 
accordance with the Principles and procedures for develop ment of East African Standards.  
East African Standards are subject to review, to keep pace with technological advan ces. Users of the East 
African Standards are therefore expected to ensure that they always have the latest versions of the standards 
they are implementing .  
The committee responsible  for this document is Technical Committee EASC /TC 0 02, Coffee, Tea, cocoa and 
related products . 
Attention is drawn to the possibility that some of the elements of this document may be subject of patent 
rights. EAC shall not be held responsible for identifying any or all such patent rights.  
 DRAFT EAST AFRICAN STANDARD  DEAS 921: 2018  
 
© EAC 2018 – All rights  reserved  1 
 Green tea — Specification  
1 Scope  
This Draft East African Standard specifies requirements, sampling and test methods for green tea  of Camellia 
Sinensis (L) O. Kuntze .  
This standard  is not applicable to green tea subject to further processing such as decaffeination, further 
roasting etc.  
2 Normative references  
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document.  For dated references, only the edition cited applies. For undated references, 
the latest editi on of the referenced document (including any amendments) applies.  
EAS 38, Labelling of Pre -packaged foods  — General requirements  
EAS 39, Hygiene in the food and drink industry — Code of practice  
ISO 1572: 1980, Tea — Preparation of ground sample of known dr y matter content  
ISO 1573: 1980, Tea — Determination of loss in mass at 103 degrees C  
ISO 1575: 1987, Tea — Determination of total ash  
ISO 1576: 1988, Tea — Determination of water -soluble ash and water -insoluble ash  
ISO 1577: 1987, Tea — Determination of a cid-insoluble ash  
ISO 1578: 1975, Tea — Determination of alkalinity of water -soluble ash  
ISO 1839: 1980, Tea — Sampling  
ISO 3103, Tea — Preparation of liquor for use in sensory tests  
ISO 5498: 1981, Agricultural food products — Determination of crude fibre  content — General Method  
ISO 6579, Microbiology of food and animal feeding stuffs — Horizontal method for the detection of Salmonella 
spp 
ISO 6888 -1, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of 
coagulase -posit ive staphylococci (Staphylococcus aureus and other species)  
ISO 7251, Microbiology of food and animal feeding stuffs — Horizontal method for the detection and 
enumeration of presumptive Escherichia coli — Most probable number technique  
ISO 9768: 1990, Tea — Determination of water extract   
2 © EAC  2018  – All rights reserved  
 ISO 14502 -1, Determination of substances characteristic of green and black tea — Part 1: Content of total 
polyphenols in tea – Colorimetric method using Folin — Ciocalteu reagent  
ISO 14502 -2, Determination of substances cha racteristic of green and black tea — Part 2: Content of 
catechins in green tea — Method using high -performance liquid chromatography  
ISO 15598, Tea — Determination of crude fibre content  
ISO 16649 -2, Microbiology of food and animal feeding stuffs — Horizon tal method for the enumeration of 
glucuronidase -positive Escherichia coli — Part 2: Colony -count technique at 44 °C using 5 -bromo -4-chloro -3-
indolyl -D-glucuronide  
ISO 21527 -2, Microbiology of food and animal feeding stuffs — Horizontal method for the enume ration of 
yeasts and moulds — Part 2: Colony count technique in products with water activity less than or equal to 0.95  
3 Terms and definitions  
For the purposes of this document, the following terms and definitions apply.  
green tea  
Tea derived solely and e xclusively, 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 of 
the species Camellia sinensis (Linnaeus ) O. Kuntze, known to be s uitable for making tea for consumption as a 
beverage  
4 Requirements  
4.1 General Requirements  
4.1.1  Green tea shall be:  
a) free from foreign and extraneous matter;  
b) free from taint, and shall have the characteristics, appearance, colour and taste of green tea;  
c) free from living insects, moulds,  filth and adulterants ; and 
d) free from added colouring matter and harmful substances;  
4.1.2  Green tea shall be free from taint, and shall have the characteristics, appearance, colour and taste of 
green tea, when examined by sensory analysis.  
4.1.3  The green tea shall be free from any additives such as colouring agents and flavourings  
4.2 Specific  requirements  
Green tea shall comply with the specific requirements specified in Table 1 when tested in accordance with test 
methods  specified therein.  
The requirements specified in Table 1, except for water extract, shall be determined using a ground sample 
prepared in accordance with ISO 1572.  
 
  
© EAC 2018 – All rights reserved  3 
  
Table 1 — Specific requirements for green tea  
Characteristic  Requirement  Test method  
Moisture  content , %, (m/m), max.  7 ISO 1573  
Water extract, % (m/m) , min. 32 ISO 9768  
Total ash, % , (m/m)  4-8 ISO 1575  
Water -soluble ash  of total ash,  %, (m/m) ; min. 45 ISO 1576  
Alkalinity of water -soluble ash (as KOH), % , (m/m)  1.0a-3.0a ISO 1578  
Acid-insoluble ash, % , (m/m) , max. 1.0 ISO 1577  
Crude fibre, % , (m/m) , max.  16.5 ISO 5498/15598b 
Total catechins, % , (m/m) , min. 7 ISO 14502 -2 
Total polyphenols, % , (m/m) , min. 11 ISO 14502 -1 
NOTE 1  Apart from moisture content, other parameters are calculat ed on dry basis . 
NOTE 2  The minimum ratio of Total catechins to Total polyphenols  shall be 0.5 . 
a When the alkalinity of water -soluble ash is expressed in terms of millimoles of KOH per 100g of ground sample, 
the limits shall be:  
- minimum 17.8  
- maximum 53.6 
b The specific method for the determination of crude fibre in tea is specified in ISO 15598, however for the purpose of 
routine estimation, the general method specified in ISO 5498 is adequate. In cases of dispute, the method of determination 
should a lways be that specified in ISO 15598. The requirement of 16.5 % mass fraction remains unchanged regardless of the 
method used. 
5 Hygiene  
5.1 Green tea shall be processed and handled in a hygienic manner in accordance with EAS 39.  
5.2 Green tea shall compl y with microbiological requirements specified in Table 2 when tested in 
accordance with test method stated therein.  
Table 2 — Microbiological limits for green tea  
S/N micro -organism  Maximum limits  Test method  
i.  Yeasts and Moulds , CFU/ g 104 ISO 21527 -2 
ii.  E. Coli, CFU/g  Absent  ISO 16649 -2 
6 Contaminants  
When tested in accordance with Annex A , the amount of iron filings in green tea shall not exceed 50 mg/kg . 
7 Pesticide residues  
Green tea shall comply with the maximum residue limits established by the Codex Alimentarius Commission.   
4 © EAC  2018  – All rights reserved  
 8 Sampling  
Samples shall have been taken in accordance with ISO 1839 . 
Liquor for the sensory assessment shall be prepared in accordance with ISO 3103.  
9 Packaging  
The product shall be packaged in closed, clean and dry materials whi ch do not compromise the quality and 
safety of green tea.  
10 Labelling  
In addition to the requirements specified in EAS 38, each package of the green tea shall be legibly and 
indelibly marked with the following:  
a) name of the product as “Green Tea’’;  
b) name an d physical address of the manufacturer/packer/importer/exporter;  
c) date of manufacture;  
d) best before;  
e) identification number ; 
f) net weight in g or kg;  
g) country of origin ; and  
h) instruction for use  and storage .  
© EAC 2018 – All rights reserved  5 
 Annex  A 
(normative)  
 
Annex title  
A.1 Apparatus  
A.1.1  Magnet (at least 4  000 gauss)  
A.1.2  Polythene sheet  
A.1.3  Petridish  
A.2 Procedure  
A.2.1  A known amount of (25 g) tea is spread evenly on petridish  
A.2.2  A powerful magnet wrapped in polythene sheet is run over the sample repeatedly till no more iron 
filings cling to the magnet  
A.2.3  Collect the iron filings in a clean, dry and previously weighed petridish  
A.2.4  Note down and express the mass of iron filings as mg/kg  
A.3 Calculation  
 
Where;  
M1=Mass, in g, of iron filings, and  
M2=mass, in g, of sample taken fo r the test. 
 DEAS 921: 2018    
 
© EAC 2018  – All rights  reserved