UGANDA STANDARD
 
       US 705
First Edition
2009-0 9-04
 
 
Reference numbe r
    US 705: 2009
 © UNBS 2009 
  
Fresh potatoes — Specification 
 US 705: 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 705:2009 
© UNBS 2009 – All rights reserved  iii
 Contents Page 
Foreword ............................................................................................................................................................iv  
1 Scope ......................................................................................................................................................1  
2 Normative references ............................................................................................................................1  
3 Terms and definitions ...........................................................................................................................1  
4 General quality requirements ...............................................................................................................2  
5 Fresh potato grades ..............................................................................................................................3  
5.1 General ...................................................................................................................................................3  
5.2 Grade I ....................................................................................................................................................3  
5.3 Grade II ...................................................................................................................................................4  
5.4 Grade III ..................................................................................................................................................5  
6 Size designation of fresh potatoes ......................................................................................................6  
7 Contaminants .........................................................................................................................................6  
7.1 Heavy metals ..........................................................................................................................................6  
7.2 Pesticide residues .................................................................................................................................6  
8 Hygiene ...................................................................................................................................................6  
9 Packaging ...............................................................................................................................................6  
10 Weights and measures .........................................................................................................................6  
11 Labelling .................................................................................................................................................7  
 US 705: 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 705:2009 
© 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 705: 2009
 
© UNBS 2009 – All rights reserved  1
 Fresh potatoes — Specification  
1 Scope 
This Uganda Standard specifies the requirements for potatoes ( Solanum  tuberosum  L.) to be supplied
fresh and either packaged or sold loose for human consumption. It does not cover the requirements for
potatoes that are not fresh and are int ended for industrial processing or seed potato. 
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 
3 Terms and definitions 
For the purposes of this standard, the following terms and definitions shall apply. 
3.1 
firm 
potato that is not shrivelled or flabby 
3.2  
mature 
skin of the potato that is generally firmly set and not feathered 
3.3  
intact 
not having any part removed or damaged such that it makes the potato incomplete 
3.4  
malformed 
shape of a potato not typica l of the cultivar concerned 
3.5  
sprout 
new shoot emerging from the tuber 
3.6  
black heart 
blackening of tissues in the centre of the tuber US 705: 2009 
2 © UNBS 2009 – All rights reserved
 3.7  
hollow heart 
cavities of various sizes in the centre of the tuber 
3.8 
clean 
practically free from dirt or staining and practically no l oose dirt or other foreign matter present in the container 
4 General quality requirements 
The potatoes shall have been carefully harvested and have reached an appropriate degree of physiological 
development taking into account the characteristics of the variety and the area in which they are grown.  
The development and condition of the potatoes shall be such as to enable it to 
a) withstand normal transport and handling conditions, and  
b) arrive in a satisfactory condit ion at the place of destination.  
Fresh potatoes shall meet the following requirements: 
a) whole or full tubers 
b) firm; 
c) not affected by rot, mould or deterioration  as to make it unfit for consumption; 
d) clean, and practically free of any  visible foreign matter, except permitted substances used to prolong 
its shelf life;  
e) of colour  characteristic of variety. 
f) practically free of pests affecting the general appearance of the produce;  
g) practically free of damage caused by pests;  
h) free of excess external moisture, ad equately dried if they have been washed;  
i) free of any foreign smell and/or taste with exc eption of conservation agents allowed under US 45;  
j) practically free of mechanical damage and bruising; and 
k) free from loss of colour in the flesh. 
Tolerances for the quality requirements shall be such that  
a) a total of no more than 10 % of the potatoes in the lot may fail the requirements; 
b) no more than 3 % of the potatoes may be affected by rot, mould or deterioration as to make it unfit for 
consumption;  
c) no more than 3 % of the potatoes may be affected by damage caused by pests; and 
d) no more than 3 % of the potatoes may be affected by both rot, mould or deterioration and damage 
caused by pests in combination.      US 705: 2009 
© UNBS 2009 – All rights reserved  3
 5 Fresh potato grades 
5.1 General  
Fresh potatoes may be graded to provide for different  levels of quality attainment. Where grading is 
undertaken the grades in 5.2 - 5.4 shall be used.  
5.2 Grade I 
5.2.1 Quality requirements 
Fresh potatoes of Grade I shall be: 
a) of similar varietal characteristics;  
b) whole or full tubers; 
c) firm; 
d) free from rot or mould deterioration as to make it unfit for consumption; 
e) clean;  
f) of colour characteristic of variety; 
g) free from pests affecting the general appearance of the produce;  
h) free from damage caused by pests;  
i) free from excess external moisture, adequately dried if they have been washed;  
j) free from any foreign smell and/or taste with ex ception of conservation agents allowed under US 45;  
k) free from mechanical damage and bruising; and 
l) free of loss of colour such as browning in the flesh. 
5.2.2 Sizes 
Fresh potatoes of Grade I may be presented in any of the sizes in Clause 6.  
5.2.3 Defects 
Fresh potatoes of grade I shall have no defects except bruises. The bruises shall not cover more than two 
percent of the surface area of the tuber. 
5.2.4 Tolerances 
Fresh potatoes of Grade I may have a maximum of 5 % by number or mass of potatoes not satisfying the 
requirements of the grade, but meeting those of Grade II.  
Fresh potatoes of grade I may have a maximum of 10 % by mass or number of tubers not satisfying the 
requirements for the size designation. US 705: 2009 
4 © UNBS 2009 – All rights reserved
 5.3 Grade II  
5.3.1 Quality requirements 
Fresh potatoes of Grade II shall be  
a) potatoes that do not qualify for inclusion in Grade I; 
b) of similar varietal characteristics; 
c) whole or full tubers 
d) firm; 
e) free from rot or mould deterioration as to make it unfit for consumption; 
f) clean;  
g) of colour characteristic of variety; 
h) free from pests affecting the general appearance of the produce;  
i) free from damage caused by pests;  
j) free from excess external moisture, adequately dried if they have been washed;  
k) free from any foreign smell and/or taste with ex ception of conservation agents allowed under US 45;  
l) free from mechanical damage and bruising; and 
m) free of loss of colour such as browning in the flesh. 
5.3.2 Sizes 
Fresh potatoes of Grade II may be presented in  any of the sizes in Clause 6.  
5.3.3 Defects 
The following defects may be allowed provided the potatoes retain their essential characteristics as regards to 
quality, keeping quality and presentation: 
a) sprouts of length not more than 1 mm and surface coverage not more than 5 %; 
b) lesions not more than 2 mm in depth and not more than 5 % surface coverage; 
c) bruises not covering more than 10 % of the surface area of the tuber; and 
d) sub-epidermal stains not more than 2 mm in depth. 
5.3.4 Tolerances 
Fresh potatoes of Grade II may have a maximum of 5 % by number or mass of potatoes not satisfying the 
quality requirements of Grade II, but meeting those of Grade III.  
Fresh potatoes of Grade II may have a maximum of 10 % by mass or number of tubers not satisfying the 
requirements for the size designation.     US 705: 2009 
© UNBS 2009 – All rights reserved  5
 5.4 Grade III  
5.4.1 Quality requirements 
Fresh potatoes of Grade III consist of potatoes that do not qualify for inclusion in Grade II but meet the 
following requirements:  
a) of similar varietal characteristics; 
b) whole or full tubers; 
c) firm; 
d) free from rot or mould deterioration as to make it unfit for consumption; 
e) clean;  
f) of colour characteristic of variety. 
g) free from pests affecting the general appearance of the produce;  
h) free from damage caused by pests;  
i) free from excess external moisture, adequately dried if they have been washed;  
j) free from any foreign smell and/or taste with ex ception of conservation agents allowed under US 45;  
k) free from mechanical damage and bruising; and 
l) free of loss of colour such as browning in the flesh. 
5.4.2 Sizes 
Fresh potatoes of Grade III may be presented in  any of the sizes in Clause 6.  
5.4.3 Defects 
The following defects may occur provided the fresh potatoes  retain their essential characteristics as regards to 
quality, keeping quality and presentation: 
a) sprouts not more than 5 mm in length; 
b) lesions covering not more than 10 % of the surface ar ea of the tuber; 
c) greening covering not more than 5 % of the su rface of the tuber and greening intrusion not deeper 
than 2 mm;  
d) sub-epidermal stains not more than 2 mm in depth;  
e) internal defects in not more than 5 % by number  or mass of the tubers;  
f) common scab not extending more than 5 % of the surface area and intrusion not exceeding 10 mm.  
5.3.4 Tolerances 
Fresh potatoes of Grade III shall satisfy the general quality requirem ents in Clause 4. US 705: 2009 
6 © UNBS 2009 – All rights reserved
 Fresh potatoes of Grade III may have a maximum of ten per cent by mass or numbe r of tubers not satisfying 
the requirements for the size designation. 
6 Size designation of fresh potatoes  
Fresh potatoes may be designated by size in accordance with Table 1. When the designations in Table 1 are 
used the sizes shall be within the specification in Table 1. 
The size of the tuber shall be determined by use of an appropriate square mesh. 
Table 1 — Scale for sizing tubers 
Size Minimum, 
mm Maximum, 
mm 
Extra small less than 30 x 30 30 x 30 
Small 31 x 31 50 x 50 
Medium 51 x 51 80 x 80 
Large  81 x 81 more than 81 x 81 
7 Contaminants  
7.1 Heavy metals  
Fresh potatoes shall conform to the maximum levels of heavy metals contaminants recommended by the 
Codex Alimentarius Commission for this commodity. 
7.2 Pesticide residues  
Fresh potatoes shall conform to the maximum residue limits for pesticide residues recommended by Codex Alimentarius Commission. 
8 Hygiene  
Fresh potatoes shall be handled in hygienic manner in accordance with Good Agricultural Practices and US 28. 
9 Packaging 
Fresh potatoes may be sold packaged or loose.  Package d fresh potatoes shall be packaged in such a way to 
protect the produce from mechanical, heat and frost damage.  
Fresh potatoes containers, including packaging material shall not impart any toxic substance and smell to the product and shall safeguard the hygienic and nutritional quality of the product.  
10 Weights and measures 
The weights of the packages of potatoes shall be in accordance with the weights and measures regulations.     US 705: 2009 
© UNBS 2009 – All rights reserved  7
 11 Labelling  
In addition to the requirements of US 7, the packa ge/container shall be marked with the following:  
a) name of the product to be shown on the label shall be “Fresh potatoes”;  
b) name and location address of the expor ter and/or packer shall be declared; 
c) country of origin of the produce  
d) place of origin such as district, or region 
e) commercial identification shall be declared:  
• grade; 
• variety; 
• size (size code); 
• net weight (in metric system); and 
f) lot identification (batch number);  
 
     US 705: 2009 
© UNBS 2009 – All rights reserved  8
 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 705: 2009 
 
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