UGANDA STANDARD
 
      US 708
First Edition
2009-0 9-04
 
 
Reference numbe r
    US 708: 2009
 © UNBS 2009 
  
Frozen potato chips — Specification 
 US 708: 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 2007  
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 708: 2009 
© UNBS 2009 – All rights reserved  iii
 Contents Page 
Foreword ............................................................................................................................................................iv  
1 Scope ......................................................................................................................................................1  
2 Normative references ............................................................................................................................1  
3 Terms and definitions ...........................................................................................................................1  
4. Process requirements ...........................................................................................................................2  
4.1 Freezing process ...................................................................................................................................2  
4.2 Handling practice ..................................................................................................................................3  
5 Presentation styles ............................................................................................................................... .3 
5.1 General ...................................................................................................................................................3  
5.2 Other styles ............................................................................................................................................3  
6 Compositional and quality requirements ............................................................................................4  
6.1 Ingredients .............................................................................................................................................4  
6.2 General quality requirements ...............................................................................................................4  
6.3 Moisture content ....................................................................................................................................4  
6.4 Fat content .............................................................................................................................................5  
6.5 Defects ....................................................................................................................................................5  
6.6 Tolerances for visual defects ...............................................................................................................5  
7 Food additives .......................................................................................................................................6  
8 Contaminants .........................................................................................................................................6  
8.1 Heavy metals ..........................................................................................................................................6  
8.2 Pesticide residues .................................................................................................................................6  
9 Hygiene ...................................................................................................................................................6  
10 Packaging ...............................................................................................................................................7  
11 Labelling .................................................................................................................................................7  
12 Weights and measures .........................................................................................................................7  
13 Sampling ................................................................................................................................................7  
Annex A  (normative)  Determination of moisture content ............................................................................8  
Annex B (normative)  Determination of acid value of extracted fat ..............................................................9  
 
 US 708: 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. 
This Uganda standard was based on th e Codex standards, Codex Stan, 114-1981, Quick frozen French fried
potatoes . Annex A is normative. 
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 708: 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 708: 2009
 
© UNBS 2009 – All rights reserved  1
 Frozen potato chips — Specification  
1 Scope 
This Uganda Standard specifies the requirements for frozen potato ( Solanum  tuberosum  L.) chips to be
supplied packaged either in retail packs or in bu lk for direct consumption or further processing. 
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 following terms and definitions shall apply. 
3.1 
frozen potato chips 
product prepared from clean, mature, sound tubers of the potato pl ant of the species Solanum tuberosum L. 
and subjected to a freezing process in the appropriate equipment.  
3.2 
presentation styles: 
3.2.1 
straight cut 
strips of potato with practically parallel sides and with smooth surfaces 
3.2.2 
crinkle cut  
strips of potato with practically parallel sides and in  which two or more sides have a corrugated surface US 708: 2009 
2 © UNBS 2009 – All rights reserved
 3.3 
external defects  
blemishes or discolourations (either internally or on the surface) due to exposure to light, mechanical, 
pathological or pest agents, eye material or peeling remnants 
3.3.1 
minor defect 
unit affected by disease, dark or intense discolouration, eye material, or dark peel covering an area or a circle 
greater than 3 mm but less than 7 mm in diameter; pale br own peel or light discolouration of any area greater 
than 3 mm in diameter 
3.3.2 
major defect 
unit affected by disease, dark or intense discolouration, eye material, or dark peeling covering an area or a 
circle greater than 7 mm but less than 12 mm in diameter 
3.3.3 
serious defect  
unit affected by disease, dark or intense discolouration, eye material, or dark peel covering an area or a circle 
of 12 mm in diameter or more 
3.3.4 
slight defect  
defects which in either area or intensity fa ll below the definition shown for minor defects 
3.4 
sorting defects 
3.4.1 
sliver  
very thin unit (generally an edge piece) which will pass throu gh a slot the width of which is 50 % of the 
minimum dimension of the nominal or normal size 
3.4.2 
small piece 
any unit less than 25 mm in length 
3.4.3 
scrap 
potato material of irregular form not conforming to the general conformation of frozen potato chips 
3.5 
frying defects, burnt pieces 
any unit which is dark brown and hard due to gross over-frying 
4. Process requirements 
4.1 Freezing process 
Potato tubers for making frozen chips shall be sort ed, washed, peeled, cut into strips, and treated as 
necessary to achieve satisf actory colour and en sure adequate stability of col our and flavour during normal 
marketing cycles. 
The treatment and frying operations may include deep frying or blanching in a suitable fat or oil and which 
may include the addition of any ingredient permissible in accordance with US 45. 
The prepared product shall be frozen and stored at  temperatures necessary for its preservation.     US 708: 2009 
© UNBS 2009 – All rights reserved  3
 The freezing operation shall be carried out in such a way that the range of temperature of maximum 
crystallization is passed quickly. T he quick freezing process shall not be regarded as complete unless and 
until the product temperature has reached -18 °C at  the thermal centre after thermal stabilization. 
The practice of repacking frozen potato chips un der controlled conditions may be undertaken. 
4.2 Handling practice 
The product shall be handled under such conditions as  will maintain the quality during transportation, storage 
and distribution up to and including the time of final sale. 
5 Presentation styles 
5.1 General 
The product shall be presented in one of the following styles: 
• straight cut; and 
• crinkle cut. 
The cross sectional dimensions  of strips of frozen potato chips which have been cut on all four sides shall not 
be less than 5 mm when measured in the frozen condition.  The frozen potato chips within each pack shall be 
of similar cross sections. 
The product may be identified by the approximate dimensio ns of the cross sections or by reference to the 
system for designations in Table 1. 
Table 1 — Designations for the dimensions across the largest cut surface 
Designation Dimension across the largest cut 
surface, 
mm 
Shoestring  5 - 8 
Medium 8 - 12 
Thick cut 12 - 16 
Extra large > 16 
 
5.2 Other styles 
Frozen potato chips may be presented with any other presentations based on differing cross sections 
provided that it 
a) is sufficiently distinctive fr om other forms of presentation laid down in this standard, 
b) meets all other requireme nts of this standard, and 
c) is adequately described on the label to avoid confusing or misleading the consumer. US 708: 2009 
4 © UNBS 2009 – All rights reserved
 6 Compositional and quality requirements  
6.1 Ingredients 
6.1.1 Basic ingredients 
These shall include the following: 
a) potatoes conforming  to US 705; and 
b) edible fats and oils, conforming to US 168. 
6.1.2 Optional ingredients 
These shall include the following: 
a) sugars (sucrose, invert sugar, dextrose, fructose, glucose syrup, dried glucose syrup) conforming to 
national standards; 
b) salt (sodium chloride), conforming to US 203; and 
c) condiments, such as herbs and spices conforming to US EAS 98. 
6.2 General quality requirements 
Frozen potato chips shall: 
a) be free from any foreign flavours and odours; 
b) be clean, sound and practically free from foreign matter; and 
c) have a reasonably uniform colour; 
When prepared in accordance with the manufactu rer's instructions, frozen potato chips shall: 
d) have a reasonably uniform colour; and 
e) have a texture characteristic of  the product and be neither excessively hard nor excessively soft or 
soggy. 
6.3 Moisture content 
The maximum moisture content of the whole product in  the styles and size designations when determined in 
accordance with Annex A  shall conform to the limits in Table 2.      US 708: 2009 
© UNBS 2009 – All rights reserved  5
 Table 2 — Limits for moisture content in frozen potato chips 
Style Size designation Moisture content, %, max. 
Shoestring, medium  
Thick cut 76 
Straight cut 
Large cut 78 
Shoestring, medium  
Thick cut 76 
Crinkle cut 
Large cut 78 
Other styles - 78 
 
6.4 Fat content 
The fat or oil extracted from the product shall have a free fatty acid content of not more than 1.5 % m/m 
measured as oleic acid or an equivalent fatty acid value based on the predominant fatty acid in the fat or oil. 
The test for free fatty acids shall be done in accordance with Annex B. 
6.5 Defects 
Frozen potato chips shall meet the following requirements with respect to visual defects subject to a tolerance 
in 6.6: 
a) be without excessive external defects su ch as blemishes, eyes and discolouration; 
b) be without excessive sorting defects, such as slivers, small pieces and scrap; and 
c) be reasonably free from frying defects, such as burnt parts. 
6.6 Tolerances for visual defects 
Tolerances on defects shall be determined based on the standard sample size of 1 kg (see clause 13). The visual external defects shall be classified as "minor" or "major" or "serious” depending on the cross section of 
the frozen potato chips. The standard samples shall not contain units in excess of the numbers shown for the 
respective categories, including total, in Table 3. 
Table 3 — Tolerances for external defects 
Number of units affected 
Cross section of strips Serious Serious +major Serious + major + 
minor 
5 - 16 mm 7 21 60 
Over 16 mm 3 9 27 
 
The tolerances for the other defects (not depending on cr oss section) shall not exceed the following limits: 
a) slivers max. 12 % m/m; 
b) small pieces and scraps max. 6 % m/m; US 708: 2009 
6 © UNBS 2009 – All rights reserved
 c) total sorting defects max. 12 % m/m; and 
d) frying defects max. 0.5 % m/m. 
7 Food additives 
Food additives may be used in accordance with US 45. Food additives listed in Table 4 may be used in 
accordance with, limits specified in the Table 4. 
Table 4 — Limits for food additives 
Category Food additive Maximum level in final product 
Disodium dihydrogen pyrophosphate 
Tetrasodium pyrophosphate 
Ethylene diamine tetra-acetic acid 
(Ca-diNa salt) 
Ascorbic acid 100 mg/kg singly or in combination 
(phosphates expressed as P 2O5) 
Citric acid  Sequestrants 
Malic acid Limited by GMP 
Sulphite, bisulphite, me tabisulphite (sodium 
or potassium salt) 50 mg/kg, singly or in combination, expressed as SO
2 
Sodium hydroxide 
Potassium hydroxide 
Citric acid Limited by GMP Processing aids 
Dimethylpolysiloxane 10 mg/kg on a fat basis 
 
Carry over of food additives shall co nform to the requirements in US 45.  
8 Contaminants  
8.1 Heavy metals  
Fresh potatoes shall conform to the maximum levels of heavy metals contaminants recommended by the 
Codex Alimentarius Commission for this commodity. 
8.2 Pesticide residues  
Fresh potatoes shall conform to the maximum residue limits for pesticide residues recommended by Codex 
Alimentarius Commission. 
9 Hygiene  
Fresh potatoes shall be handled in hygieni c manner in accordance with US 28.       US 708: 2009 
© UNBS 2009 – All rights reserved  7
 10 Packaging 
Frozen potato chips shall be packaged in such a way to protect the produce from damage or contamination.  
Packaging used for quick frozen potato chips shall: 
a) protect the organoleptic and other qu ality characteristics of the product; 
b) protect the product against microb iological and other contamination; 
c) protect the product from dehydration and, where appropriate, l eakage as far as technologically 
practicable; and 
d) not pass on to the product any odou r, taste, colour or other forei gn characteristics, throughout the 
processing (where applicable) and distribution of  the product up to the time of final sale. 
11 Labelling  
In addition to the requirements of US 7, the packa ge/container shall be marked with the following:  
a) name of the food: 
i) the name of the food as declared on the label shall include the designation "Frozen potato 
chips" or the equivalent designation used in t he country in which the product is intended to 
be sold; 
ii) in addition, there shall appear on the label a designation of the style as appropriate, that is 
"straight cut" or "crinkle cut" and there may also appear an indication of the approximate 
dimensions of the cross section or the appropriate designation, that is "shoestring", "medium", "thick cut" or "extra large"; 
iii) if the product is presented in styles not list ed in this standard, the label shall contain in close 
proximity to the words "Frozen potato chips" su ch additional words or phrases that will avoid 
misleading or confusing the consumer; and 
iv) the words “Frozen" shall also appear on t he label, except that the term "quick Frozen"  may 
be applied in countries where this term is customarily used for describing the product 
processed in accordance this standard; 
b) packages shall bear clear directions for keeping fr om the time they are purchased from the retailer to 
the time of their use, as well as directions for cooking; and 
c) in the case of frozen potato chips in bulk, the information required above shall either be placed on the 
container or be given in accompanying documents, except that the name of the food accompanied by 
the words " frozen" (the term " quick frozen" may be used in accordance with (a) (iv); and  
d) name and address of the manufacturer or packer shall appear on the container. 
12 Weights and measures 
The weights of the packages of potatoes shall be in accordance with the weights and measures regulations. 
13 Sampling 
The standard sample size shall be one kilogramme. US 708: 2009 
8 © UNBS 2009 – All rights reserved
 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, per cent 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; and 
M3 is the mass, in grams, of the dish only. 
       US 708: 2009 
© UNBS 2009 – All rights reserved  9
 Annex  B 
(normative) 
 
Determination of acid value of extracted fat 
B.1 Reagents 
B.1.1 Benzene-alcohol-phenolphthalein 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. 
B.1.2 Standard potassium hydroxide solution,  0.02 N 
B.1.3 Standard potassium permanganate solution , 0.01 % 
B.1.4 Potassiun dichromate solution, 0.5 % 
B.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 second 50-mL 
portion of the benzene alcohol-phenolphthalein solution.  The endpoint should match colour of the solution 
made by adding 2.5 of standard potassium permanganate solution to 50 mL of potassium dichromate solution 
of proper strength to that of the original solution be ing titrated. (Add 0.5 % potassium dichromate solution 
dropwise to 50 mL of water until the colour matche s. Then add 2.5 mL of standard potassium permanganate 
solution). 
Make a blank titration on 50 mL of the benzene-alcohol-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. 
B.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 708: 2009 
© UNBS 2009 – All rights reserved  10
 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 708: 2009 
 
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