DRAFT UGANDA STANDARD  
  DUS 1597  
First Edition  
2017-02-08 
 
 
 Reference number  
WDUS 1597 : 2015 
© UNBS 2015 
  
Flavoured milk ─ Specification  
 DUS 1597 : 2015  
ii © UNBS 2015  – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct applicati on 
© UNBS 20 15  
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. DUS 1597 :2015  
© UNBS 2017 – All rights reserved  iii 
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade, Industry and 
Cooperatives established under Cap 327, of the Laws of Uganda, as amended.  UNBS is mandated to co -
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT Agreement of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of key stakeholders 
including government, academia , consumer groups, private sector and other interested parties.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the  draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
The committee responsible for this document is Technical Committee UNBS/TC2, [Food and Agriculture] , 
Subcommittee SC1, [milk and milk products ]. 
This secon d edition cancels and replaces the first edition (US 1597 :2015 ), which has been technically revised.  
 
 
 DRAFT UGANDA STANDARD  DUS 1597 : 2017 
 
© UNBS 2017 – All rights reserved  1 
 Flavoured Milk  — Specification  
1 Scope  
This draft Uganda standard specifies requirements and methods of sampling and test for flavoured milk from 
cow, goat, camel, buffalo, or sheep milk.   
 
This standards does not apply to raw flavoured milk . 
2 Normative references  
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited appl ies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
US 28, Hygiene in the food and drink manufacturing industry – Code of practice  
US 45, General standard for food additives  
US 163, Code of hygiene  practice for milk and milk products  
US 738, General standard for contaminants and toxins in food and feed  
US 217 -5/EAS  217-5, Methods for microbiological examination of foods – Part 5: Enumeration of coagulase -
positive Staphylococci  
US EAS 38, Labelling o f pre-packaged foods – Requirements  
US EAS 67, Raw cow milk – Specification  
US ISO 4833 -1, Microbiology of the food chain – Horizontal method for the enumeration of microorganisms – 
Part 1: Colony count at 30 C by the pour plate technique  
US EAS 68 -2-2, Milk and milk products — Methods of microbiological examination ─ Part 2 -2: Enumeration of 
coliforms ─ Most probable number technique at 30 °C  
US EAS 68 -3; Milk and milk products — Methods of microbiological examination — Part 3: Enumeration of 
colony formi ng units of yeasts and/or moulds - Colony -count technique at 25 °C  
US ISO 707;  Milk and milk products – Guidance on sampling  (2nd Edition)  
US ISO 2446 , Milk – Determination of fat content  
US ISO 5764 , Milk – Determination of freezing point – Thermistor cry oscope method (Reference method)  
US ISO 67 31, Milk, cream and evaporated milk – Determination of total solids content (Reference method)  
US ISO 6785 , Milk and milk products — Detection of Salmonella spp. DUS 1597 : 201 7 
2 © UNBS 2017 – All rights reserved  
 US ISO 8968 -3, Milk – Determination of nitrogen cont ent – Part 3: Block -digestion method (Semi -micro rapid 
routine method)  
US ISO 11866 -1, Milk and milk products — Enumeration of presumptive Escherichia coli — Part 1: Most 
probable number technique using 4 -methylumbelliferyl -beta-D-glucuronide (MUG)  
US ISO 11866 -2, Milk and milk products — Enumeration of presumptive Escherichia coli — Part 2: Colony -
count technique at 44 ° C using membranes  
3 Terms and definitions  
For the purposes of this standard, the following terms and definitions shall apply .  
3.1  
flavo ured  milk 
milk which i s heat treated  and with added permitted flavours  and other ingredients such as sugar, colour and 
stabilizers   
3.2 
raw cow milk  
normal, clean and fresh secretion obtained by practically emp tying the udder of a healthy animal , that ha s 
been properly fed and kept, but excluding that got during the first seven days after calving  
3.3 
UHT or long life milk  
milk which is ultra -high temperature treated, homogenized,  standardized,  filled and sealed aseptically in retail 
containers in order to  attain commercial sterility  
3.4  
pasteurized milk  
milk which has been efficiently heat treated at a sufficiently high temperature for appropriate period of time to 
ensure complete destruction of all pathogenic organisms, so as to enable the product to be  transported, 
distributed  under cold chain  and consumed as liquid milk   
3.5 
homogenization  
process by which milk fat globules are finely divided and interspersed to form a homogeneous product so as 
to prevent the fat from floating on the surface and adher ing to the inside of the container  
3.6 
standardization  
the process of raising or lowering of fat and solids not fat levels of milk in order to have a uniform fat content in 
the finished processed product  
3.7 
commercial sterility  
attained practical sterili ty after the product has been treated aiming at absolute sterility  
3.8 
food grade material  
packaging material, made of substances which are safe and suitable for their intended use and which will not 
impart any toxic substance or undesirable odour or flavo ur to the product  DUS 1597 : 2017 
© UNBS 2017 – All rights reserved  3 
 4 Requirements  
4.1 Essential Ingredients  
4.1.1  All ingredients used for the manufacture of flavoured milk shall be of good quality complying with the 
relevant standards .  
4.1.2  The milk used may  be whole milk, skimmed milk, reconstituted/ recombined powered milk or a 
mixture of two or more products  complying with the relevant standards . 
4.1.3  Only permitted ingredients  shall be used  in the processing of flavoured milk . 
4.2 General requirements  
Flavoured milk  shall:  
a) be normal in texture,  colour and odour ; 
b) be processed without affecting the composition of the product;  
c) be free of visible sediments other than from the ingredients  used ; 
d) be free from off flavour taints ; 
e) not be bitter ; and 
f) have a pleasant and acceptable taste.  
4.3 Specific requirem ents 
4.3.1 Flavoured  milk shall comply with the specific requirements stipulated in table 1.  
Table 1 — Specific  requirements for flavoured  milk 
S/No.  Parameter  Requirement  Test method  
UHT Flavoured 
milk Pasteurised 
flavoured milk  
i) pH variation on 5 days incubation, 
max.  0.3 - Annex A  
ii) Titratable acidity variation on 5 
days incubation, % lactic acid, 
max.  0.02 - Annex B  
iii) Milk fat %, m/m  
a) Whole milk, min.  
b) Fat reduced milk  
c) Low fat milk  
d) Fat free milk, max.   
a) 3.1 
b) 1.5- 3.25 
c) 0.5 – 1.5 
d) 0.5  
a) 3.1 
b) 1.5- 3.25 
c) 0.5 – 1.5 
d) 0.5 US ISO 2446  
iv) Density at 20 0C, g/mL  1.040 – 1.060  1.028 – 1.032   
v) Freezing point depression, 0C,  0.525 – 0.550   US ISO 5764  
vi) Milk solids -not fat, %, min.  8.5  US ISO 6731  DUS 1597 : 201 7 
4 © UNBS 2017 – All rights reserved  
 vii) Protein, %, min  3  US ISO 8968 -3 
Note: The param eter “milk solids -not fat” is determined by calculation from total solids content and fat content  
5 Food additives  
Food additives use d in the preparation of flavoured milk  shall be in  accordance with US 45.  
6 Contaminants  
6.1 Pesticide and veterinary drug  residues  
Flavoured  milk shall conform to those maximum limits for pesticide and veterinary drug residues established 
by the Codex Alimentarius Commission.  
6.2 Other contaminants  
Flavoured  milk shall conform to those maximum limits for other contaminants e stablished under US 738.  
7 Hygiene  
Flavoured  milk shall be produced , processed , handled and marketed under hygienic conditions and in 
appropriate premises in order to preve nt contamination of the product  in accordance with US 28 and US 163 . 
Flavoured  milk shall comply wit h the limits for micro -organisms  specified in table 2 . 
Table 2 — Microbiol ogical lim its for flavoured milk  
Microo rganism  Limit  Method of test  
UHT flavoured milk  Pasteurised 
flavoured milk  
Total plate count , CFU/ml, max.  10  1000  US ISO 4833 -1 
Coliform s, MPN/ml, max.  Absent  10   
US ISO   
4833  
 
E. Coli , MPN/ml, max.  Absent  Absen t US ISO 11866 -
1 
Yeast and moulds, CFU/ml  10 10 US EAS 68 -3 
Staphylococcus aureus , CFU/ml, max.  Absent  Absent  US ISO4833  
 
Salmonella  in 25 ml, max.  Absent  Absent US ISO 6785  
Listeria Monocytogenes  Absent  Absent  US ISO 10560  
 
Shigella  in 25 ml max  Absent  Absent   
8 Weights and measures  
The weight /volume of the flavoured  milk shall comply with the w eights and measures requirements . DUS 1597 : 2017 
© UNBS 2017 – All rights reserved  5 
 9 Packaging  
Flavoured milk  shall be packaged in food  contact  grade containers which conform to US 1659.  
10 Labelling  
In addition to the requirements in US EAS 38, the following specific labelling requirements shall apply and 
shall be legibly and indelibly marked:  
a) name of the  product  as “X Flavoured  milk” where  “X” is replaced by t he specific flavour used in the 
product ; 
b) type of heat treatment  
c) type of animal from which the  milk was got.  
d) complete list of ingredients to be declared in descending order of proportion;  
e) name and physical address of processor/producer ; 
f) batch or code number ; 
g) storage conditions and instructions ; 
h) date of manufacture;  
i) expiry date;  
j) net content  in metric units ; and 
k) country of origin.  
11 Sampling  
Sampling shall be done in accordance with US ISO 707.  DUS 1597 : 201 7 
6 © UNBS 2017 – All rights reserved  
 Annex A  
(norm ative)  
 
Determination of pH variation  
 
A.1 Apparatus  
A.1.1   Incubator adjusted at 55 °C ± 1 °C  
A.1.2   pH meter  
 
A.2 Procedure  
 
A.2.1 Determine the pH of 50 mL of the sample in the flask, with a glass electrode at 20 °C and note reading. 
Then incubate an other 50 mL of the 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 of the contents is observed (coagulation with, 
or without exudation, grittiness, flocculation, forma tion of bubbles or scum peptonization or proteolysis) the 
result of the test shall be considered positive and the sample as non -sterile.  
 
A.2.2 If no alteration takes place during the five days incubation at 55 °C ± 1 °C remove the sample from the 
incubato r and cool to room temperature. Take a small portion of it and measure the pH in the pH meter with 
glass electrode at 20 °C. From this pH value subtract the initial pH value (A.2.1).  
 
 
A.3 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 pH does not show a difference of more than 0.3 unit from the initial pH is considered sterile.  DUS 1597 : 2017 
© UNBS 2017 – All rights reserved  7 
 Annex B  
(normative)  
 
Determination of titratable acidity  
B.1 Apparatus  
B.1.1   Incubat or 
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 0.1 M  
Prepare concentrated stock sol ution 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 Phenolp hthalein 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 app roximately 50 mL of rectified spirit, containing 0.5 mL of glacial 
acetic acid. Make up to 100 mL with rectified spirit.  
For the Bench solution, dilute 1 mL of stock solution to 500 mL with a mixture of rectified spirit and distilled 
water in equal proport ions by volume.  
NOTE The stock and the bench solutions should 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 appro ximately 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 
and stirring 2 mL dilute rosaniline acetate solution. Stir 2 mL phenolphthalein solution into the other dilution 
and w hile 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 control. The titration shall be done 
in bright light.  
 
B.3.2 Acidity aft er incubation  DUS 1597 : 201 7 
8 © UNBS 2017 – All rights reserved  
 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 in 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  
 
9V M 
Titratable acidity (as lactic acid) per cent by weight =  --------   
m 
where,  
V is the volume, in mL, of the standard sodium hydroxide required for titration (B.3.1), M   
is the molarity of the standard so dium hydroxide solution (B.3), and  
m   is the mass, in g, of the sample taken for test (B.3.1).  
B.4.2 Acidity after incubation  
 
9V M 
Titratable acidity (as lactic acid) percent by weight =  ---------   
w 
where,  
V is the volume, in mL, of the standard sodium hydroxide required for titration (B.3.2.1), 
M   is the molarity of the standard sodium hydroxide solution (B.3.2.1),  
w   is the weight in g of the sample taken for the test (B.3.2.1)  
B.4.3 Increase in acidity  
 
Subtract the value obtained in B.4.1 from the value obta ined 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 fr om the initial acidity is considered sterile.  DUS 1597 : 2017 
© UNBS 2017 – All rights reserved  9 
 Bibliography  
[1] RS 194:2013, Flavoured milk – Specification  
[2] US 1597:2015, Flavoured UHT milk – Specification  
 
 DUS 1597 : 2015  
© UNBS 2017 – All rights reserved  11 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda Nat ional Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licensed under the certificati on mark scheme operated by 
the Uganda National Bureau of Standards and in conjunction with the relevant Uganda Standard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a system of supervision, control and testing in accordance with the 
certification mark scheme of the Uganda National Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particul ars of the terms and conditions of licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
 
 DUS 1597 : 2015    
 
ICS 67.100.10  
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