DEAS 33: 2018  
ICS 67.100.10  
HS 0403.10.00  
 
© EAC 2018                                                                                                                         Second  Edition 2018   
 DRAFT EAST AFRICAN STANDARD  
Yoghurt — Specification  
EAST AFRICAN COMMUNITY  DEAS 33: 2018  
ii © EAC  2018 – All rights reserved  
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 DEAS 33: 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 barriers that are encountered when goods and services are exchanged 
within the Commun ity 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 composed of representatives of the National 
Standards Bodies in Partner States, toge ther 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 comments 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 advances. 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 docu ment is Technical Committee EASC /TC 017, Milk and milk products.  
Attention is drawn to the possibility that some of the elements of this docume nt may be subject of patent 
rights. EAC shall not be held responsible for identifying any or all such patent rights.  
This second edition cancels and replaces the first edition ( EAS 33: 2007), which has been technically revised.  
 DRAFT EAST AFRICAN STANDARD  DEAS 33: 2018  
 
© EAC 2018 – All rights reserved  1 
 Yoghurt — Specification  
1 Scope  
This Draft East African Standard specifies requirements, sampling and test methods for yoghurt.  
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 thi s document.  For dated references, only the edition cited applies. For undated references, 
the latest edition of the referenced document (including any amendments) applies.  
AOAC 999.10, Official method for lead, cadmium, zinc, copper, and iron in foods Atom ic absorption 
Spectrophotometry after microwave Digestion  
CAC /RCP 1 , General principle s for food hygiene  
CAC /RCP 57 , Code of hygienic practice for milk and milk products  
CODEX STAN 192 , Codex general standard for food additives  
EAS 38 , Label ling of pre -packaged foods — General requirements  
EAS 69, Pasteurised milk — Specification  
EAS 803, Nutrition labelling — Requirements  
ISO 707 , Milk and milk products — Guidance on sampling  
ISO 2446 , Milk — Determination of fat content  
ISO 3728, Ice -cream and milk ice — Determination of total solids content (Reference method)  
ISO 4832 , Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of 
coliforms  — Colony count technique  
ISO 4833 -1, Microbiology of the food chain — Horizontal method f or the enumeration of microorganisms — 
Part 1: Colony count at 30 degrees C by the pour plate technique  
ISO 7889, Yoghurt — Enumeration of characteristic microorganisms — Colony count technique at 37 degrees 
C 
ISO 5764 , Milk — determination of freezing poi nt — Thermistor cryoscope method (Reference method)  
ISO 6579 -1, Microbiology of the food chain — Horizontal method for the detection, enumeration and 
serotyping of Salmonella — Part 1: Detection of Salmonella spp  
ISO 6611 , Milk and milk products — Enumerat ion of colony -forming units of yeasts and/or moulds — Colony -
count technique at 25 degrees C   
2 © EAC  2018 – All rights reserved  
 ISO 6731, Milk, cream and evaporated milk — Determination of total solids content (Reference method)  
ISO 6888 -3, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of 
coagulase -positive staphylococci (Staphylococcus aureus and other species) — Part 3: Detection and MPN 
technique for low numbers  
ISO 8968 -4, Milk and milk products — Determination of nitrogen content — Part 4: Determ ination of protein and 
non-protein nitrogen content and true protein content calculation (Reference method)  
ISO 11866 -2, Milk and milk products — Enumeration of presumptive Escherichia coli — Part 1: Most probable 
number technique using 4 -methylumbellifery l-beta-D-glucuronide (MUG)  
ISO 14501, Milk and milk powder — Determination of aflatoxin M1 content — Clean -up by immunoaffinity 
chromatography and determination by high -performance liquid chromatography  
3 Terms and definitions  
For the purposes of this docu ment, the following terms and definitions apply.  
3.1 
yoghurt  
cultured milk product obtained by lactic acid fermentation through the action of Lactobacillus bulgaricus and  
Streptococcus thermophiles  
3.2 
coagulated  milk 
product obtained by lactic acid fermen tation through the action Lactobacillus bulgaricus  and Streptococcus 
thermophillus  and other suitable bacteria of milk products which have been pasteurized prior to fermentation  
3.3 
sugar  
any carbohydrate sweetening matter  
3.4 
sweetened yoghurt  
yoghurt to which one or more sugars only have been added  
3.5 
plain yoghurt  
yoghurt to which no sugar and food additives have been added  
3.6 
flavoured yoghurt  
yoghurt to which flavouring foods or other flavouring ingredients have been added  
3.7 
fruit yoghurt  
yoghurt t o which fruits have been added  
3.8 
probiotic yoghurt  
yoghurt which contains in addition to yoghurt starter culture (S. thermophilus and L. delbrueckii subsp. 
bulgaricus.) live lactic acid bacteria which when administered in adequate amounts confer a health  benefit to 
the host  
3.9 
greek yoghurt  
yoghurt that has been strained to remove its whey resulting to a thicker and creamy consistency   
© EAC 2018 – All rights reserved  3 
 3.10 
heat-treated yoghurt  
yoghurt that has been pasteurised, thermized or sterilized  
3.10.1 
pasteurized yoghurt  
yoghurt w hich has been subjected to pasteurization process after fermentation   
NOTE  See EAS 69  
3.10.2 
thermized yoghurt  
yogurt that is heat -treated at 62 °C to 65 °C for 15 to 20 sec aimed at reducing the number of viable  
organisms and prolonging shelf -life 
3.10.3 
sterilized yoghurt  
yoghurt that is heat -treated at a minimum of 115 °C for 15 sec aimed at attaining commercial sterility and  
prolonged shelf -life. 
4 Requirements  
4.1 Types of yoghurt  
There are various types of yoghurt including but not limited to:  
a) plain y oghurt;  
b) flavoured yoghurt ; 
c) heat treated yoghurt;  
d) probiotic yoghurt;  and 
e) greek yoghurt  
4.2 Ingredients  
4.2.1 Essential ingredients  
All yoghurts shall be made from any of the following milk and milk products and essential ingredients:  
a) pasteurized milk  whole  or skimmed ; 
b) evaporated or condensed milk , whole or skimmed ; 
c) pasteurized cream;  
d) a mixture of two or more products;  and 
e) cultures of Lactobacillus bulgaricus  and Streptococcus thermophillus . 
4.2.2 Optional ingredients  
4.2.2.1 Ingredients , including but not l imited to the following, may be added to all types of yoghurts :  
4 © EAC  2018 – All rights reserved  
 a) cultures of suitable lactic acid producing bacteria;  
b) milk powder whole or skimmed;  
c) unfermented butter milk;  
d) concentrated whey;  
e) whey or whey proteins and/or their concentrates;  
f) edible casein; a nd caseinates;  
g) sugars (in sweetened types of yoghurt only), complying with CODEX STAN 212; or  
h) flavouring agents, nutritive and non nutritive sweeteners, fruits, vegetables as well as juices, purees, 
pulps and preparations and preserves derived theirfrom, c ereals, honey, chocolate, nuts, coffee, 
spices and other harmless natural flavouring foods and/or flavours.  
4.2.2.2 Where non dairy ingredients are used, they shall not be more than 50  % of the total composition.  
4.3 General requirements  
Yoghurt shall:  
a) be free from off flavours and off odours such as metallic flavour or yeast flavour;  
b) be free from foreign matter; and  
c) have the characteristic texture and taste of the type of yoghurt . 
4.4 Specific requirements  for yoghurt  
Yoghurt shall comply with the requirem ents specified in Table 1 when tested in accordance with test methods 
specified therein .  
© EAC 2018 – All rights reserved  5 
 Table 1 ▬ Specific  requirements for yoghurt  
S/N Characteristic  Whole 
Yoghurt  Low fat 
yoghurt  Skimmed 
Yoghurt  High fat  
yoghurt  Test method  
i.  Milk fat  content,  %, 
m/m 3.25 - 4.5 0.5 - 3.24 < 0.5 4.6 - 15 ISO 2446  
ii.  Milk Solids Not Fat , 
%, m/m,  min. 8.5 8.5 8.5 8.5 ISO 6731  
iii.  pH 4.2 - 4.6 4.2 - 4.6 4.2 - 4.6 4.2 - 4.6 Annex A  
iv.  Titratable acidity , %, 
lactic acid , min.  0.6 - 1.0 0.6 - 1.0 0.6 - 1.0 0.6 - 1.0 Annex B  
v.  Sum of 
microorganisms 
constituting the starter 
culture  CFU/ g in total  107 107 107 107 
ISO 7889  
vi.  Labelled 
microorganisms 
CFU/ g in total * 106 106 106 106 
NOTE 1  The requirement on Sum of microorganisms and Labelled microorganisms do not apply for heat treated 
yoghurt  
*Applies where a content cream is made in the labelling that refers to the pres ence of a specific microorganism other than Lactobacillus 
Bulgaricus  and Streptococcus Thermophillus that has been added as supplement to the specific starter culture  
 
4.5 Microbiological limits  
Yoghurt shall comply with microbiological limits in Ta ble 2  when tested in accordance with test methods 
specified therein.  
Table 2 — Microbiological limits  for yoghurt  
S/N Micro organisms  Maximum limits  Test method  
i.  E. Coli , CFU/ g  Absent  ISO 11866 -2 
ii.  Salmonella spp in 25g  Absent  ISO 6579 -1 
iii.  Staphylococcus aureu s, perg Absent  ISO 6888 -3 
iv.  Moulds  and yeasts , CFU/ g  10 ISO 6611  
 
5 Food additives  
Food additives which may be used shall comply with CODEX STAN 192.  
6 Hygiene  
Yoghurt shall be produced and handled in accordance with CAC/RCP 57 and CAC/RCP 1.   
6 © EAC  2018 – All rights reserved  
 7 Contamina nts 
7.1 Pesticide residues  
Yoghurt shall conform to maximum limits residues set by Codex Alimentarius Commission.  
7.2 Veterinary drugs residues  
Yoghurt shall conform to maximum tolerable residue limits for antibiotics  and other veterinary drugs set by 
Code x Alimentarius Commission.  
7.3 Heavy metals  
The level of Lead (Pb) shall not exceed 0.02 mg/kg when tested in accordance with AOAC 999.10.  
7.4 Mycotoxin  
When tested in accordance with ISO 14501 the level of aflatoxin M1 shall not exceed 0.50 µg/kg.  
8 Packa ging  
8.1 Yoghurt shall be packaged in food grade materials that are non -toxic and inert to yoghurt.  
8.2 The packaging material or containers shall be well sealed to protect the contents during storage . 
9 Labelling  
The containers shall be labelled in compli ance with the requirements of EAS 38  and EAS 803 . In addition, the 
following particulars shall be legibly and indelibly labelled on the container:  
a) name of the product as “yoghurt” by type and/or category of fat content ; 
b) net content in SI units;  
c) name and ph ysical address of manufacturer;  
d) batch or code number;  
e) nutritional information;  
f) the date of manufacture and expiry date;  
g) instruction for storage and use;  
h) declaration of allergens if any; and  
i) country of origin.  
10 Sampling  
Sampling of yoghurt shall be done i n accordance with ISO 707 .  
© EAC 2018 – All rights reserved  7 
 Annex A 
(informative)  
 
Determination of pH  
A.1 General  
The pH value or hydrogen ion concentration gives a measure of the true acidity of milk. The relationship 
between pH and acidity of milk is only approximate. In normal cow mil k the pH ranges from 6.6 to 6.8. The 
value is reduced by the development of acidity. On the other hand, the pH value of milk from a cow suffering 
from mastitis is alkaline in reaction, the value being over 7.0. The pH test is mainly used for the detection of 
abnormal mastitis in milk. The pH of milk may be determined rapidly by using the indicator strips.  
A.2 Indicator strips  
Indicator paper strips or discs are made by soaking strips of absorbent paper in a suitable indicator and drying 
them.  
A rough estima te of pH is obtained by dipping a strip of the prepared paper in milk and observing the colour. 
Bromocresol purple (pH range 5.2 to 6.8 colour changes from yellow to purple) and bromothymol blue (pH 
range 6.0 to 7.6 Colour changes from straw yellow to blui sh-green) are commonly used as indicators. Both 
narrow and wide range ready -made indicator papers are available over the pH range 2.0 to 10.5.  
Indicator paper strips shall always be kept in closed glass bottles and under dry conditions.  
A.3 Interpretation  
In normal milk the pH is well below 6.9. On an average, cow milk gives a pH of 6.6. Milk of pH over 6.9 should 
be regarded with suspicion as indication of some diseases of the udder or of late lactation milk.   
8 © EAC  2018 – All rights reserved  
 Annex  B 
(normative)  
 
Determination of titratable acidity  
B.1 Apparatus  
B.1.1  Incubator  
B.1.2  Burette ; with soda -lime guard tube  
B.1.3  Porcelain dishes ; white hemispherical of approximately 60 ml  
B.1.4  Stirring rods ; of glass, flattened at one end.  
B.2 Reagents  
B.2.1  Standard sodium hydroxide solution  
Prepare concentrated stock solution of sodium hydroxide by dissolving equal parts of sodium hydroxide 
(stocks or pellets) in equal parts of water in a flask. Tightly stopper the flask with a rubber bung and allow any 
insoluble sodium carbonate to settle down for three to four days.  
Use the clear supernatant liquid for preparing the standard 0.1 M solution. About 8 ml of stock solution is 
required per litre of distilled water. The solution should be accurately  standardized against acidic potassium 
phthalate or oxalic acid.  
B.2.2  Phenolphthalein indicator solution  
Dissolve 1 g of phenolphthalein in 110 ml rectified spirit. Add 0.1 M sodium hydroxide solution until one drop 
gives a faint pink coloration.  
B.2.3  Rosaniline Acetate Stock Solution  
Dissolve 0.121 g of rosaniline acetate in approximately 50 ml of rectified spirit, containing 0.5 ml of facial 
acetic acid. Make up to 100 ml with rectified spirit.  
B.2.4  Bench solution  
Dilute 1 ml of stock solution to 500 m l with a mixture of rectified spirit and distilled water in equal proportions 
by volume.  
The stock and the bench solutions shall be stored in dark brown bottles securely stoppered with rubber bungs.  
B.3 Procedure  
B.3.1  Acidity of fresh sample  
Weigh 10.0 g of the sample into each of the two white porcelain dishes of approximately 60 ml capacity; add 
to both 10 ml of water and stir to disperse the sample. Prepare from one dilution a colour control by adding  
© EAC 2018 – All rights reserved  9 
 and stirring 2 ml dilute rosaniline acetate solution . Stir 2 ml phenolphthalein solution into the other dilution and 
while stirring vigorously, add as rapidly as possible sodium hydroxide solution from a 10 -ml burette fitted with 
a soda -lime guard tube, until the colour matches the pink colour of the contro l. The titration shall be done in 
bright light.  
B.3.2  Acidity after incubation  
Incubate another 20 g of sample at 55 °C ± 1 °C for five days. Examine the flask each day, then shake and 
replace it in the incubator. If any physical alteration (as indicated i n A.2.1) of the content is observed the 
results of the test shall be considered positive and the sample as non -sterile.  
If no alteration takes place during the five days incubation remove the sample from the incubator and cool to 
room temperature. Weigh 10  g of the incubated sample and determine acidity as described in B.3.1.  
B.4 Calculation  
B.4.1  Acidity of fresh sample  
Titratable acidity (as lactic acid) per cent by weight = 
mMV.9  
Where,  
V=is the volume in ml of the standard sodium hydro xide required for titration ( see B.3.1) 
M=is the molarity of the standard sodium hydroxide solution ( see B.3), and  
m=is the mass in g of the sample taken for test ( see B.3.1).  
B.4.2  Acidity after incubation  
B.4.2.1  Titratable acidity (as lactic acid) perce nt by weight =  
wMV.9  
Where,  
V=is the volume in ml of the standard sodium hydroxide required for titration (see B.3.2.1),  
M=is the molarity of the standard sodium hydroxide solution (see B.3.2.1),  
w=is the weight in g of the sample taken f or the test (see B.3.2.1)  
B.4.2.2  Subtract the value obtained in B.4.1 from the value obtained in B.4.2 which would give increase in 
acidity.  
B.5 Interpretation of results  
A sample which does not show any physical alteration during incubation at 55 °C ± 1  °C for five days and 
where the acidity does not show a difference of more than 0.02 g from the initial acidity is considered sterile.  
 DEAS 33: 2018    
 
© EAC 2018  – All rights reserved