UGANDA STANDARD  
      US 702
First Edition
2009-0 9-04
 
 
Reference numbe r  
    US 702: 2009
 © UNBS 2009 
  
Fried potato chips — Specification 
 US 702: 2009 
ii © UNBS 2009 – 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 application  
© UNBS 2009  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, in cluding photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala  
Uganda 
Tel: 256 414 505 995 
Fax: 256 414 286 123 
E-mail: unbs@infocom.co.ug
Web: www.unbs.go.ug       US 702: 2009 
© UNBS 2009 – All rights reserved  iii
 Contents Page 
Foreword ............................................................................................................................................................iv  
1 Scope ......................................................................................................................................................1  
2 Normative references ............................................................................................................................1  
3 Terms and definitions ...........................................................................................................................1  
4 Essential quality and compositional requirements ...........................................................................1  
4.1 Essential ingredients ............................................................................................................................1  
4.2 Optional ingredients ..............................................................................................................................2  
4.3 General quality factors .........................................................................................................................2  
4.4 Specific quality requirements ..............................................................................................................2  
5 Food additives .......................................................................................................................................2  
6 Contaminants .........................................................................................................................................3  
6.1 Heavy metals ..........................................................................................................................................3  
6.2 Pesticide residues .................................................................................................................................3  
7 Hygiene ...................................................................................................................................................3  
8 Packaging ...............................................................................................................................................3  
9 Labelling .................................................................................................................................................3  
10 Weights and measures .........................................................................................................................4  
11 Methods of sampling .............................................................................................................................4  
Annex A (normative)  Sampling of fried potato chips ....................................................................................5  
A.1 General requirements ...........................................................................................................................5  
A.2 Scale of sampling ..................................................................................................................................5  
A.3 Test samples and referee samples ......................................................................................................6  
A.4 Number of tests and criteria for conformity .......................................................................................6  
Annex B (normative)  Determination of acid insoluble ash ...........................................................................7  
B.1 Reagents ................................................................................................................................................7  
B.2 Procedure ...............................................................................................................................................7  
B.3 Calculation .............................................................................................................................................7  
Annex C (normative) Determination of acid value of extracted fat ...............................................................8  
C.1 Reagents ................................................................................................................................................8  
C.2 Procedure ...............................................................................................................................................8  
C.3 Calculation .............................................................................................................................................8  
 US 702: 2009 
iv © UNBS 2009 – All rights reserved
 Foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry  of Tourism, Trade and 
Industry established under Cap 327, of the Laws of Uganda.  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 A limentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agr eements 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 gi ven field or area and consists of representatives of 
consumers, traders, academician s, manufacturers, governme nt and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committ ee 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.  
Committee membership 
The following organisations were represented on the Sugars, edible starches and related confectionery 
standards sub-committee (TC 2-SC 11) under the supervision of Technical Committee for Food and 
Agriculture standards, UNBS/TC 2, during the development of this standard: 
• Africa 2000 Network, Uganda 
• Consumer Education Trust (CONSENT) 
• Kachwekano Zonal Agricultural Research and Development Institute (KAZARDI) 
• Ministry of Agriculture, Anim al Industries and Fisheries (MAAIF) 
• Mukono Zonal Agricultural Research an d Development Institute (MUZARDI),  
• Nyabyumba United Farmers Ltd 
• Tomcris Enterprises Limited 
• Uganda National Bureau of Standards (UNBS) 
• Uganda National Farmers Federation (UNFF) 
• Uganda National Seed Potato Producers Association (UNSPPA) 
     US 702: 2009 
© UNBS 2009 – All rights reserved  v
 Acknowledgement 
This standard and other standards for potato and potato products were developed with support from the 
Association for Strengthening Agricult ural Research in Eastern and Cent ral Africa –Policy Analysis and 
Advocacy Programme (ASARECA-ECAPAAP)  project.  The project helped in the mobilisation of stakeholders 
and covered some of the costs involved in the process of formulation of the standards.  This support and the 
contribution of all other stakeholders is hereby acknowledged. US 702: 2009 
vi © UNBS 2009 – All rights reserved
 Introduction 
Potato chips are one of the deep-fried snack foods ava ilable on the market. Such products are very popular 
for reasons of taste and nutritional value. Fried potato chips, also known as potato French fries, are usually 
prepared by peeling and slicing or shredding potatoes and deep-fat frying the slices/shreds in suitable edible 
oil or fat, or combinations thereof. In the case of sl iced potatoes, these are sliced breadthwise to give thin 
slices. The slices/shreds are washed and fried in fat/oil or combinations thereof, held at proper temperature and time to render them ready. Salt and other seas onings are added after frying. When groundnut or other 
unsaturated oils are used, permitted antioxidants in the fr ying medium are sufficient to give protection to the 
potato chips. 
Success in deep fat frying of chips depends upon several factors, such as:  
a) use of proper raw material of optimum maturity and quality;  
b) correct method of preparation; 
c) use of suitable equipment;  
d) selection of appropriate fat or oil as frying medium;  
e) optimum time and temperature of frying; 
f) efficient packaging; and  
g) proper storage.  
This standard will assist in the manufacture and sale of standardized, nutritious , and safe hygienically 
processed products. It provides requirements for assess ing the quality and safety of potato chips. Complying 
with these requirements will enable the products to meet the minimum quality and safety expectation of 
consumers and regulators. UGANDA STANDARD                                                                                                     US 702: 2009
 
© UNBS 2009 – All rights reserved  1
 Fried potato chips — Specification 
1 Scope 
This Uganda Standard prescribes the requir ements and the methods of sampling and test for fried potato
chips. 
2 Normative references 
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies. 
US 7, General standard for labeling of prepackaged foods 
US 28, Code of practice for hygiene in the food and drink manufacturing industry  
US 45, General standard for food additives 
US 168, Edible oils and fats ─ Specification  
US 203, Specification for edible (fortified) salt  
US EAS 98, Curry powder ─ Specification 
US EAS 217-5, Methods for the microbiological examination of foods ─ Part 5: Enumeration of coagulase-
positive staphylococci 
US ISO 7251, Microbiology of food and animal feeding stuffs  — Horizontal method for the detection and 
enumeration of presumptive Escherichia coli — Most probable number technique 
US 705, Fresh potatoes — Specification 
3 Terms and definitions 
For the purposes of this standard, the fo llowing term and definition shall apply. 
fried potato chips 
product prepared from clean, mature, sound tubers of the potato pl ant of the species Solanum tuberosum L. 
and subjected to a deep frying process to make them crispy and ready for consumption  
4 Essential quality and compositional requirements 
4.1 Essential ingredients 
The following materials shall be used in the preparation of fried potato chips: US 702: 2009 
2 © UNBS 2009 – All rights reserved
 a) potatoes; conforming to US 705; and  
b) edible oil or fat conforming to US 168. 
The potatoes for making chips shall be free from insect s and insect residues, rodent hair and excreta. and 
fungal infestation. 
The oil or fat for use in frying shall be suitable for consumption. 
4.2 Optional ingredients 
In addition to the essential ingredients specified in 4.1, the following optional ingredients may be added: 
a) spices and condiments conforming to US EAS 98. These sha ll be clean, freshly ground, such as, 
chilli, pepper or others or combinations thereof, free  from infection, infestation, foreign matter and any 
undesirable odour or taste ; and 
b) salt shall conform to US 203 . 
4.3 General quality factors 
Fried potato chips shall: 
• have characteristic colour; 
• have acceptable texture;  
• have a uniform surface, free from b listers and excessive brown pigmentation; 
• not be excessively greasy; and 
• be free from rancidity, bitterness and other objectionable odours and taste. 
4.4 Specific quality requirements 
The fried potato chips shall conform to  the requirements given in Table 1. 
Table 1 — Chemical for fried potato chips 
Characteristic Requirement Methods of test 
Acid insoluble ash, % by mass (on dry basis), max. 0.15 Annex B 
Acid value of extracted fat, %, by mass max. 2.0 Annex C 
Peroxide value, meq. oxygen/kg fat, max. 10 Annex D 
 
Note 1 Chips should be made from mature pot atoes to prevent development of off odours. 
Note 2 Reuse of frying oil may promote the degradati on of oil and development of toxic compounds. 
5 Food additives 
Additives may be used in accordance with US 45.       US 702: 2009 
© UNBS 2009 – All rights reserved  3
 6 Contaminants  
6.1 Heavy metals  
Potatoes chips shall conform to those maximum levels of heavy metals recommended by the Codex 
Alimentarius Commission for this commodity. 
6.2 Pesticide residues  
Potatoes shall comply with those maximum residue limits recommended by Codex Alimentarius Commission (CAC/RS./100 – 1978). 
7 Hygiene 
The fried potato chips shall be prepared, packaged and st ored under hygienic conditions in accordance with 
US 28. The chips shall conform to the microbiological limits in Table 2. 
Table 2 — Microbiological limits for fried potato chips 
Microorganism Maximum limits Method of test 
E. coli , CFU per gm, max < 1 US ISO 7251 
Staphylococcus aureus , in 25 g Negative US EAS 217-5 
8 Packaging  
Potato chips for distribution shall be packaged in such a way to safe guard the hygienic and nutritional quality of the product.  
The container including packaging material shall not im part any toxic substance and smell to the product. 
The chips shall be packaged and distributed in such a way as to retain the contents in a fresh condition as supplied. 
9 Labelling 
In addition to the requirements of US 7, the following particulars shall be marked or labelled on each container: 
a) name of the product shall be “Fried potato chips”;, if the chips are spiced the product shall be labelled 
as “Spiced fried potato chips”; 
b) name, address and location of the manufacturer; 
c) date of manufacture; 
d) date of expiry; 
e) country of origin; 
f) list of ingredients; 
g) net weight; and US 702: 2009 
4 © UNBS 2009 – All rights reserved
 h) lot identification such as batch number or code 
10 Weights and measures 
The weights of the packages of potato chips shall be in accordance with the weights and measures 
regulations. 
11 Methods of sampling  
Representative samples for determining the conformity of the material to the requirements of this specification 
shall be drawn in accordance with the procedure given in Annex A.      US 702: 2009 
© UNBS 2009 – All rights reserved  5
 Annex A 
(normative) 
 
Sampling of fried potato chips 
A.1 General requirements 
In drawing, storing, preparing and handling test samples, the following precautions and directions shall be 
observed: 
a) samples shall be taken in a protected pl ace not exposed to damp air, dust or soot; 
b) sampling instruments shall be clean and dry; 
c) samples shall be placed in clean and dry containers; 
d) sample containers shall be of such a size that  they are almost completely filled by the sample; 
e) precautions shall be taken to protect the samp les, the material being sampled, the sampling 
instruments and the sample containers from adventitious contamination; and 
f) each sample container shall be sealed with a stopper or a suitable cl osure after filling in such a way 
that it is not possible to open and reseal it without detection, and marked with full details of sampling, 
such as, name of the material, name of the manu facturer, type of package and other important 
particulars of the consignment. 
A.2 Scale of sampling 
A.2.1 All the packages in a single consignment of the same type, manufactured under relatively uniform 
conditions of production and having similar composition shall constitute a lot. 
A.2.2  Samples shall be tested from each lot separately for ascertaining the conformity of a lot to the 
requirements of this specification. 
A.2.3  The number of packages to be selected from a lot shall depend on the size of the package as well as 
the size of the lot and shall be according to Table 2. 
These packages shall be selected from the lot at random.  US 702: 2009 
6 © UNBS 2009 – All rights reserved
 Table 2 — Number of packages to be selected for sampling 
For packages below 500 g For packages below 500 g to 1 kg For packages more than 500 g to 1 kg 
Number of 
packages in the lot Sample 
size Number of 
packages in the lot Sample size Number of 
packages in the lot Sample size 
Up to 100 8 Up to 50 3 Up to 50 2 
101 - 300 13 51 - 100 5 51 - 100 3 
301 -500 20 101 -300 8 101 -300 5 
501 - 1000 32 301 - 500 13 301 and above 8 
1001 and above         50 501 and above 20   
A.3 Test samples and referee samples 
A.3.1 Draw small portions of the material with a suitabl e sampling instrument from different parts of each 
selected package. The total quantity of material drawn fr om each package shall be sufficient to make triplicate 
determinations for all the characteri stics given in the specification. 
A.3.2  Mix all portions of the material drawn from each selected package thoroughly. Out of the mixture, a 
small but approximately equal quantity of material sh all be taken and mixed thoroughly so as to form a 
composite sample sufficient to make  triplicate determinations for all the characteristics given in this 
specification. 
The composite sample so prepared shall be divided into three equal parts, one for the purchaser, another for 
the supplier and the third for the referee. These part s shall be immediately transferred to clean and dry 
containers, which are then sealed airtight and labe lled with all the particulars given in B.1.6. 
The referee sample shall bear the seals of the purchaser and the supplier so as to be used in case of a dispute between the two. 
A.4 Number of tests and criteria for conformity 
A.4.1 All the characteristics given in this specific ation shall be tested on the composite sample. 
A.4.2  The lot shall be declared as conforming to the require ments of this specificatio n if all the test results 
on the composite sample meet the corresponding specification requirements.     US 702: 2009 
© UNBS 2009 – All rights reserved  7
 Annex B 
(normative) 
 
Determination of acid insoluble ash 
B.1 Reagents 
Hydrochloric acid, approximately 5 N, prepared from concentrated hydrochloric acid 
B.2 Procedure 
Weigh accurately about 5 g of the material in a platinum, por celain or silica dish. Ignite the material in the dish 
with the flame of a suitable burner till all the starch is carbonized. Complete  the ignition in a muffle furnace at 
550 °C ± 25 °C for 3 h. Cool in a desiccator. 
To the ash, add 25 mL of hydrochloric acid, cover wi th a watch-glass and heat on a water-bath for 10 min. 
Allow to cool and filter the contents of the dish through Whatman Filter Paper No. 42 or its equivalent. Wash 
the filter paper with water until the washings are free fr om the acid. Return the filter and the residue to the 
dish. Keep it in an electric air oven maintained at 105 °C to 110 °C for about 3 h. Ignite in a muffle furnace at 
550 °C ± 20 °C for 3 h. Cool the dish in a desiccator and weigh.  
Repeat the process of igniting in the muffle furnace,  cooling and weighing at half-hour intervals until the 
difference between two successive weighings is less than one milligram. Note the lowest mass. 
B.3 Calculation 
()()
() X MM M
−− ×=
100 12 000 10basis dry on ash insoluble Acid  
where 
M2 is the mass, in grams, of the dish with the acid insoluble ash; 
M is the mass, in grams, of the empty dish; 
M1 is the mass, in grams, of the sample; and  
X is the moisture content, percent by mass. US 702: 2009 
8 © UNBS 2009 – All rights reserved
 Annex C 
(normative) 
 
Determination of acid value of extracted fat 
C.1 Reagents 
C.1.1 Benzene-alcohol-phenolphathalein stock solution  — To one litre of distilled benzene, add one litre 
of alcohol or rectified spirit and 0.4 g of phenolphthalein. Mix the contents well. 
C.1.2 Standard potassium hydroxide solution, 0.02 N 
C.1.3 Standard potassium permanganate solution , 0.01 % 
C.1.4 Potassiun dichromate solution, 0.5 % 
C.2 Procedure 
Dissolve the residue in the extraction flask with 50 mL  of the benzene-alcohol-phenolphthalein solution. Titrate 
the dissolved extract with standard potassium hydroxide so lution to distinct pink colour, or in the case of 
yellow solution to orange pink colour. If an emulsion is formed during titration, dispel by adding a second 50-
mL portion of the benzene alcohol-phenolphthalein solu tion. The endpoint should match colour of the solution 
made by adding 2.5 mL  of standard potassium permanganate soluti on to 50 ml of potassium dichromate 
solution of proper strength to that of the original solution being titrated. (Add 0.5 % potassium dichromate solution dropwise to 50 mL of water until the col our matches. Then add 2.5 mL of standard potassium 
permanganate solution). 
Make a blank titration on 50 mL of the benezene-alco hol-phenolphthalein solution and subtract this value from 
the titration value of the sample. 
If the additional 50 mL portion of the benzene-alcohol -phenolphthalein solution is added, double the blank 
titration. 
C.3 Calculation 
()MVN4 56acid oleic as fat extractedof value Acid.=  
where 
V is the volume, in millilitres, of standa rd potassium hydroxide solution used; 
N is the normality of standard pot assium hydroxide solution; and 
M is the mass, in grams, of the material taken for the test. 
 
     US 702: 2009 
© UNBS 2009 – All rights reserved  9
 Certification marking 
Products that conform to Uganda standards may be  marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is gove rned by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licens ed under the certification mark scheme operated by 
the Uganda National Bureau of Standards and in co njunction 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 particulars of the terms and conditions of  licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
 
 US 702: 2009
 
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