UGANDA STANDARD
 
       US 703
First Edition
2009-0 9-04
 
 
Reference numbe r
     US 703: 2009
 © UNBS 2009 
  
Potato crisps — Specification 
 US 703: 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 703: 2009 
© UNBS 2009 – All rights reserved  iii
 Contents Page 
Foreword ............................................................................................................................................................iv  
1 Scope.......................................................................................................................... ............................1  
2 Normative re feren ces........................................................................................................... .................1  
3 Terms and de finiti ons .......................................................................................................... .................1  
4 Essential quality and com positional requi rements ...........................................................................1  
4.1 Essential in gredients .......................................................................................................... ..................1  
4.2 Optional ingr edients........................................................................................................... ...................2  
4.3 General qualit y fact ors .........................................................................................................................2  
4.4 Defects........................................................................................................................ ............................2  
4.5 Essential compositional requirements ........................................................................................... ....2 
5 Food additi ves .......................................................................................................................................3  
6 Contaminants................................................................................................................... ......................3  
7 Hygiene........................................................................................................................ ...........................3  
8 Packaging...................................................................................................................... .........................3  
9 Labelling...................................................................................................................... ...........................4  
10 Weights and measures ........................................................................................................... ..............4  
11 Methods of  test................................................................................................................ ......................4  
Annex A  (normative)  Determin ation of moistu re content ........................................................................ ....5 
A.1 Procedure...................................................................................................................... .........................5  
A.2 Calculation and expr ession of r esults .......................................................................................... ......5  
Annex B (normative)  Determin ation of free fatty acids......................................................................... ........6  
B.1 Apparatus...................................................................................................................... .........................6  
B.2 Reagents ....................................................................................................................... .........................6  
B.3 Procedure...................................................................................................................... .........................6  
B.4 Calculation .................................................................................................................... .........................6  
 US 703: 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 703: 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. 
 
 UGANDA STANDARD                                                                                                    US 703: 2009
 
© UNBS 2009 – All rights reserved  1
 Potato crisps — Specification  
1 Scope 
This Uganda Standard prescribes the requi rements and the methods of sampling and test for crisps
made from tubers of potato ( Solanum tuberosum  L.). 
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 705, Fresh potatoes - Specification  
US EAS 98, Curry powder ─ Specification 
3 Terms and definitions 
For the purposes of this standard, the fo llowing term and definition shall apply. 
potato crisps 
thin slices of peeled and cleaned potato tubers, deep-fried or baked until brittle 
4 Essential quality and compositional requirements 
4.1 Essential ingredients 
The following materials shall be used in the manufacture of potato crisps: 
a) potatoes, conforming to US 705; and 
b) edible oil or fat conforming to US 168. US 703: 2009 
2 © UNBS 2009 – All rights reserved
 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 shall be clea n, freshly ground, such as chili, 
garlic, onions, tomato powder, vinegar, pepper or ot hers or combinations thereof, free from infection, 
infestation, foreign matter and any undesirable odour or taste; and 
b) salt conforming to US 203. 
4.3 General quality factors 
Potato crisps shall be  
a) light yellow to golden brown in colour, 
b) generally uniform in size and symmetry, 
c) well cooked, tender and free from sogginess and excessive oil, 
d) crispy texture and the external surface shall not show any noticeable separation from the inner 
portion, 
e) free from rancidity, bitterness and any objectionable odours and flavours, and 
f) free from foreign matter, adulterants and any other blemish. 
4.4 Defects 
Potato crisps, when packed, shall not contain more than 10 % by mass of small pieces, slivers and irregular 
pieces. 
Packed potato crisps shall have not more than 1 % of the crisps with the following defects: 
a) surface or internal pigmentation; and 
b) black specks and spots. 
4.5 Essential compositional requirements 
Potato crisps shall conform to the requirements specified in Table 1.      US
© UNBS 2009 – All rights reserved  3
  703: 2009 
Table 1— Chemical requirements for potato crisps 
Characteristic Limit Method of test r 
Moisture content, %, by  mass, max. 5 Annex A 
Free fatty acids, %, by mass on dry weight basis, 
max. 0.5 Annex B 
Acid insoluble ash, % by mass on dry weight basis, max. 0.01 Annex C 
Peroxide value, meq/oxygen per gram 0. 5 mg/kg  
5 Food additives 
Food additives may be used in the preparation of  potato crisps in accordance with US 45. 
6 Contaminants 
Potato crisps shall conform to the tolerance limits for heavy metals given in Table 2 
Table 2 — Tolerance limits for trace metals in potato crisps 
Heavy metal Maximum limits, mg/kg Method of test 
Arsenic 0.1 US 240 
Lead 0.1 US 239 
Tin 250 US 233 
7 Hygiene  
Potato crisps shall be handled in hygienic manner in  accordance with Good Manufacturing Practices and US 
28. 
Potato crisps shall conform to the requirements given in Table 3. 
Table 3  — Microbiological requirements for potato crisps 
Micro-organism(s) Maximum limit Method of test 
Total viable count, CFU per gram, max 15 000 US 217-2 
Escherichia coli , CFU per  gram Not detected US ISO 7251 
Yeasts and moulds, CFU per gram 40 US 217-8 
NOTE CFU refers to colony forming units 
8 Packaging 
Before packaging, the crisps shall be de-oiled to remove the excess oil. The crisps shall be packaged within a 
short time after frying so as  to keep the crispy taste and texture of the crisps. US 703: 2009 
4 © UNBS 2009 – All rights reserved
 The product shall be packaged in well sealed containers in  order to prevent spoillage  or contamination of the 
product. 
Note Packaging materials that are air tight, moisture and light proof will extend the shelf life of the products. 
9 Labelling  
The packages of potato crisps shall be legibly and indelibly  labelled in compliance with the requirements of US 
7 and shall also include the following: 
a) name of the product shall be “Potato crisps.” If spiced the product shall be labelled “Spiced potato 
crisps”; 
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 
h) lot identification such as batch number or code. 
10 Weights and measures 
The weights of the packages of potato crisps shall be in accordance with the weights and measures 
regulations. 
11 Methods of test 
The product covered by this standard shall be tested ac cording to the methods of test indicated in this 
standard.      US
© UNBS 2009 – All rights reserved  5
  703: 2009 
Annex A  
(normative) 
 
Determination of moisture content 
A.1 Procedure 
Weigh accurately 10 g of the material in a suitable moisture dish previously dried in an electric oven and 
weighed.  Place the dish in an electric oven maintained at 105 °C ± 1 °C for 5 h.  Cool the dish in a desiccator 
and weigh with the lid on.  Repeat the process of heati ng, cooling and weighing at half-hour intervals until the 
loss in weight between two successive weighings is less than 1 mg. 
Record the lowest weight obtained. 
A.2 Calculation and expression of results 
Moisture, percent by mass =  
3 12 1100  x ) (
M MM M
−− 
where,  
M1 is the mass, in grams, of the dish and sample before drying; 
M2 is the mass, in grams, of the dish and sample after drying; 
M3 is the mass, in grams, of the dish only. US 703: 2009 
6 © UNBS 2009 – All rights reserved
 Annex B 
(normative) 
 
Determination of free fatty acids 
B.1 Apparatus 
Soxhlet fat extraction apparatus 
B.2 Reagents 
B.2.1 Petroleum ether , distilling below 65 °C, or ethyl ether 
B.2.2 Alcohol potassium hydroxide , 0.1 N (use absolute or alcohol denatured with methanol, [MeOH]) 
B.2.3 Alcohol-ether mixture , equal volumes of 96 % alcohol and ethyl ether 
B.2.4 Phenolphthalein solution , 1 % in alcohol or alcohol denatured with methanol (MeOH) 
Add 0.3 mL per 100 mL mixture of alcohol-ether and add alcoholic KOH solution to a faint pink. 
B.3 Procedure 
Extract 10.00 g ± 0.01 g of the sample taken in a thim ble with petroleum ether for about 4 h in a Soxhlet 
extraction apparatus.  Completely evaporate the solvent  from the extraction flask (weighed previously) on a 
steam bath, cool and weigh the extraction flask with the residue. Dissolve the residue in the extraction flask 
with the 50 mL of the alcohol-ether phenolphthalein solu tion. Titrate the dissolved extract, with standard 
potassium hydroxide solution, to a faint pink colour , which persists for 10 s. If emulsion is formed during 
titration, dispel by adding a second 50 mL portion of the alcohol-ether phenolphthalein solution. 
Make a blank titration on 50 mL of the alcohol-ether phenolphthalein solution and substract this value from the 
titration value of the sample.  If the additional 50 mL portion of the alcohol-ether phenolphthalein solution is 
added, double the blank titration. 
B.4 Calculation 
Calculate the acid value from the following formula: 
Acid value (as oleic acid) = 
MVN56.1 
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 703: 2009 
© UNBS 2009 – All rights reserved  7
 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 703: 2009 
 
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