FINAL DRAFT UGANDA 
STANDARD  
  FDUS EAS 748
First Edition
2011-mm-dd
 
Referen
ce numbe r
FDUS EAS 748: 2010
 © UNBS 201 1
  
Fresh potato tuber (ware potato tuber) — Specification 
 FDUS EAS 748: 2010  
 
© UNBS  2011 – All rights reserved ii 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 201 1
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 41 505 995 
Fax: 256 41 286 123 
E-mail: unbs@infocom.co.ug
Web: www.unbs.go.ug  
 FDUS EAS 748: 2010 
© UNBS  2011 - All rights rese rved                iii National 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 U ganda. 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 limentariu s Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agr eem ents 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 Final Draft Uganda Standard, FDUS EAS 748:2010, Fresh potato tuber (w are potato tuber) — 
Specification, is identical with and has been reproduced fr om an East African Standard, EAS 748:2010, Fresh 
potato tuber (ware potato tuber) — Specification,  and is being proposed for adoption as a Uganda Standard.  
This standard was developed by the Food and Agricu lt ure Standards Technical Committee (UNBS/TC 2).  
Wherever the words, “East African Standard" appear, they sho uld be replaced by "Uganda Standard." 
 
 EAS 748:2010
 ICS 67.080.20
 
© EAC 2010                First Edition 2010  
 
EAST AFRICAN STANDARD 
 
Fresh potato tuber (ware potato tuber) — Specification 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
EAST AFRICAN COMMUNITY EAS 748:2010 9 
 
© EAC 2010 – All rights reserved               ii 
 Foreword 
 
Development of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of products and services in East Africa. It is envisaged that through harmonized 
standardization, trade barriers which are encountered when goods and services are exchanged within the 
Community will be removed.  
 
In order to meet the above objectives, the EAC Partner  States have enacted an East African Standardization, 
Quality Assurance, Metrology and Test Act, 2006 (EAC SQMT Act, 2006) to make provisions for ensuring 
standardization, quality assurance, metrology and testing of  products produced or originating in a third country 
and traded in the Community in order to facilitate industrial development and trade as well as helping to 
protect the health and safety of societ y and the environment in the Community. 
 
East African Standards are formulated  in accordance with the procedures established by the East African 
Standards Committee. The East African Standards Committe e is established under the provisions of Article 4 
of the EAC SQMT Act, 2006. The Committee is compos ed of representatives of the National Standards 
Bodies in Partner States, together with the repr esentatives from the priv ate sectors and consumer 
organizations. Draft East African Standards are circul ated to stakeholders through the National Standards 
Bodies in the Partner States. The comments received are discussed and incorporated before finalization of 
standards, in accordance with t he procedures of the Community.  
 
Article 15(1) of the EAC SQMT Act, 2006 provides that “Wit hin six months of the declar ation of an East African 
Standard, the Partner States shall adopt, without deviation from the approved text of the standard, the East African Standard as a national standard and withdraw any existing national standard with similar scope and 
purpose”. 
 
East African Standards are subject to review, to keep pace with technological advances. Users of the East 
African Standards are therefor e expected to ensure that they always hav e the latest versions of the standards 
they are implementing.  
 
© East African Community 2010 — All rights reserved *
East African Community  
P O Box 1096  
Arusha  
Tanzania  
Tel: 255 27 2504253/8 
Fax: 255-27-2504481/2504255 
E-Mail: eac@eachq.org
Web: www.each.int 
                                                      
* © 2010 EAC — All rights of exploitation in any form and by an y means reserved worldwide for EAC Partner States’ NSBs.  
 EAS 748:2010 
Acknowledgement 
This standard was devel oped with support from the Policy Analysi s and Advocacy Programme (PAAP) of the 
Association for Strengthening Agricult ural Research in Eastern and Cent ral Africa (ASARECA). This was 
possible though a grant by the United States Agency for International Development (USAID). This support 
was used in the process of formulation and mobilization of stakeholders to review the standard in national and 
regional fora. 
ASARECA is a non-political association of agricultural research institutes  in: Burundi, DR Congo, Eritrea, 
Ethiopia, Kenya, Madagascar, Rwanda, Sudan, Tanzani a and Uganda. ASARECA serves  as a platform for 
promoting regional research and in the sharing of benef its and spillovers that derive from such research. The 
mission of ASARECA is to “ Enhance regional collective action in agricultural research for development, 
extension and agricultural training and education, to pr omote economic growth, fight poverty, eradicate hunger 
and enhance sustainable use of resources in Eastern and Central Africa ”. 
Development of standards has been part of PAAP’s contribution to changing the way business is done in 
crucial agricultural sectors to increase effici ency and/or reduce waste through rationalization and 
harmonization of policies, laws, regulations and proc edures. Rationalization focuses on how countries conduct 
business in a given subsector, and determines what should be done to make the procedures and processes 
more efficient. Harmonization brings together regionally  different approaches (policies, laws, regulations and 
procedures) into unified approaches that are applied acro ss the countries. This harmonization process allows 
commodities and factors to move freely across national boundaries, thereby improving domestic and foreign investment by expanding markets beyond national borders. Over time this will lead to gradual attainment of 
seamless borders for trade in potatoes and potato products across the region. 
Removal of regulatory bottlenecks to transboundary mo vement of potato products in the region will enhance 
competitiveness of trade and value addition in the sub-se ctor. It will improve the value chains by supporting 
product differentiation and hence increased trade in pot ato products in the region.  This will ultimately 
contribute to incomes, employment generation and improved welfare in the region. This fits snugly with the 
aspirations of ASARECA as a key player contributing to economic dev elopment of the region.  
 
© EAC 2010 – All rights reserved                 iii 
 EAST AFRICAN STANDARD EAS 748:2010
 
1               © EAC 2010 – All rights reserved 
 Fresh potato tuber (ware potato tuber) — Specification 
1 Scope 
This East African standard specifies the requireme nts for ware potato tuber of varieties (cultivars) 
grown from ( Solanum  tuberosum  L.) and its hybrids to be supplied fresh and either packaged or sold 
loose for human consumption. It does not cover the requirements for potato tubers intended for 
industrial processing or seed potato tuber.  
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. 
EAS 38,  General standard for labeling of prepackaged foods 
EAS 39,  Code of practice for hygiene in the food and drink manufacturing industry  
CAC/RCP 53 , Code of Hygienic Practice for Fresh Fruits and Vegetables 
ISO 7563, Glossary of terms for fresh fruits and vegetables 
EAS 103 , General standard for food additives  
ISO 874 , Fresh fruits and vegetables — Sampling 
ISO 6561, Fruits and vegetables and derived products — Determination of cadmium content 
Flameless atomic absorpti on spectrometric method. 
ISO 6633, Fruits and vegetables and derived products — Determination of lead content — Flameless 
atomic absorption spectrometric method. 
ISO 4833, Microbiology of food and animal feeding stuffs  — Horizontal method for the enumeration of 
micro organisms — Colony — count technique at 30 °C. 
ISO 4831, Microbiology — General guidance for the enumeration of coliforms — Most probable number technique 
ISO 16654, Microbiology of food and animal feeding stu ffs — Horizontal method for the detection of 
Escherichia coli 0157. 
3 Terms and definitions 
For the purposes of this standard, the terms a nd definitions in ISO 7563 where applicable, and the 
following terms and definitions shall apply. 
 
3.1  
black heart 
blackening of tissues in the centre of the potato tuber   EAS 748:2010 9 
3.2 
badly misshapen 
potato tuber that is seriously  defo rmed relative to thee varietal shape 
 
3.3 
clean 
practically free from dirt or staining and practically no loose dirt or other foreign matter present in the 
container 
3.4 
damaged 
shall mean any defect or injury which is readily  apparent upon examination ,or which affects the 
edible quality of the potato tuber 
3.6 
defects 
defects which can be detected externally. However,  cutting may be required to determine the extent 
of the injury. 
3.7. 
firm 
shall mean potato tuber that are not soft, flabby or shrivelled 
3.8 
food grade material 
one that will not transfer non-food chemicals into the food and contains no chemicals which would be 
hazardous to human health 
3.9 
foreign matter 
any material other than that originating from the potato tuber 
3.10  
hollow heart 
cavities of various sizes in the centre of the tuber 
3.11  
intact 
not having any part removed or damaged such that it makes the potato tuber incomplete   
3.12  
malformed 
shape of a potato tuber not typical of the cultivar/variety concerned 
3.13  
mature potato tuber 
Potato tuber with the skin of potato tuber that is generally firmly set and not feathered 
 
3.14 
practically clean 
shall mean potato tuber that are free from dirt, st ain or other foreign matter, but not from unavoidable 
dirt incidental to improper harvesting and packing. 
 
© EAC 2010 – All rights reserved               2 
 EAS 748:2010 
3.15 
serious damage 
shall mean any injury or defect which seriously af fect the appearance or the edible quality of the 
potato tuber 
3.16 
similar varietal characteristics 
 potato tuber that are of the same variety and type. 
3.17  
sprout 
new shoot emerging from the tuber 
3.18 
sound  
wholesome 
free from disease, serious deterioration (such as but not limited to decay, breakdown, freezing 
damage, or soft or shrivelled specimens) or adultera tion/contamination, that appreciably affects their 
appearance, edibility, the keeping quality of the produce or market value.  
3.19 
industrial processing 
production of potato products such as starch, flour, livestock feeds, paste, granules and syrups 
4 Quality requirements 
4.1. General quality requirements 
The potato tuber shall have been carefully harvested an d 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 potato tuber shall be such as to enable it to 
a) withstand normal transport and handling conditions, and  
b) arrive in a satisfactory condition at the place of destination 
4.2 Minimum requirements 
All fresh potato tubers to be supplied to the market shall be meet the following minimum 
requirements: 
a) of normal appearance for the variety according to the producing area 
b) intact, ; 
c) sound;  
d) practically clean; 
© EAC 2010 – All rights reserved               3 
 EAS 748:2010 9 
e) firm; 
f) free of abnormal external moisture; i.e. s hall be adequately "dried" if they have been washed; 
g) free of any foreign smell and/or taste. 
h)free of loss of colour su ch as browning in the flesh 
 i) shall be covered with  well-formed skin,   
j shall be practically unsprouted, i.e.  sprouts shall be no longer than 3 mm.  practically  
k) free from pests affecting the gen eral appearance of the produce;  
l) practically free from free from mechanical damage 
m) bruise and roughness (only for varieties of which the skin is not normally rough) 
(n)Fresh potato tuber shall be practically free of extern al or internal defects detrimental to the general 
appearance of the produce, the quality, the keeping quality and presentation in the package, such as: 
i) brown stains due to heat; 
ii) cracks (including growth cracks), cuts, bites,  exceeding 5 mm in depth for ware 
potato tuber; 
iii) green colouration; pale green flush not exceeding one eighth of the surface area 
and which can be removed by normal peeling does not constitute a defect; 
iv) serious deformities(m alformation, misshape,...); 
v) grey, blue or black sub-epiderma l stains; exceeding 5 mm in depth; 
vi) rust stains, hollow or black hearts ; 
vii) deep common potato tuber scab and powdery potato tuber scab of a depth of 2 
mm or more  
viii) superficial common potato tuber scab; i.e.  scab spots in all shall not extend over 
more than a 25 % of the surface of the tuber; 
ix) frost damage; 
 
© EAC 2010 – All rights reserved               4 
 EAS 748:2010 
5 Classification 
5.1 General  
Fresh potato tuber may be classified before marketing.  
Where classification is done the following classes shall be used in accordance with the requirements of each 
class and the quality tolerances in Clause 7. 
- Extra class; 
- Class I and 
- Class II 
5.2 Extra class  
5.2.1 Quality requirements 
Fresh potato tuber of Extra Class may be presented in any of the sizes in Clause 6.  
Extra class fresh potato tuber shal l be potato tuber that meets the mi nimum requirement in Clause 4. Tubers in 
this class shall be of superior quality. The flesh s hall be perfectly sound. They shall be characteristic 
of the variety (for example, uniform shape and size ) and free of defects (f or example, sprouting, 
lesions, epidermal stains etc.) with  exception of very slight superf icial  bruises not exceeding 2% of 
the surface area of  the tuber  and provided that this will not affect t he general appearance of the produce, the 
keeping quality and the presentation in the package. 
5.3 Class I   
5.3.1 Quality requirements 
Fresh potato tuber of Class I may be present ed in any of the sizes in Clause 6   
Class I fresh potato tuber shall be potato tuber that  meet the minimum requirement in Clause 4 and 
shall be of good quality  
5.3.2  Defects 
The following defects may be allowed provided the pota to tubers retain their essential characteristics 
as regards to quality, keeping quality and presentation: 
a) defects in shape not exceeding 5% of the tubers 
b) bruising, not exceeding 10 % of the surface area of the tubers  
c) sprouts of length not more than 3 mm ; 
d) lesions not more than 2 mm in depth and not more than 3% surface coverage;  
e) sub-epidermal stains not  more than 2 mm in depth,  
f) greening covering not more than 10% of the surfac e of the tuber and greening intrusion not deeper than 
2 mm; and the affected tubers  
g) internal defects in not more than 3 % by number  or mass of the tubers;  
© EAC 2010 – All rights reserved               5 
 EAS 748:2010 9 
h) common scab not extending more than 3 % of the surface area and intrusion not exceeding 2 mm  
 
5.4 Class II  
5.4.1 Quality requirements 
Fresh potato tuber of Class III may be presented in any of  the sizes in Clause 6. They consist of 
potato tuber that do not qualify for inclusion in Cl ass II but meet the minimum requirements specified 
under clause 4. 
5.4.2 Defects 
The following defects may occur provided the fresh pot ato tuber retain their essential characteristics 
as regards to quality, keeping quality and presentation: 
a) defects in shape not exceeding 10% of the tubers 
b) bruising, not exceeding 20 % of the surface area of the tubers  
c) sprouts not more than 3 mm  in length; 
d) lesions not more than 2 mm in depth and covering not  more than 5% of the surface area of the tuber;  
e) greening covering not more than 10 % of the su rface of the tubers and greening intrusion not deeper 
than 2 mm;  
f) sub-epidermal stains not more than 2 mm in depth;  
g) internal defects in not more than 5 % by number  or mass of the tubers;  
h) common scab not extending more than 5 % of the surface area and intrusion not exceeding2 
mm  
6 Size designation  
Fresh potato tuber 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 
Small 31 x 31 50 x 50 
Medium 51 x 51 80 x 80 
Large  81 x 81 more than 81 x 81 
 
 
© EAC 2010 – All rights reserved               6 
 EAS 748:2010 
7 Provisions for tolerances   
Tolerances in respect of quality and size shall be allowed in each package for produce not satisfying 
the requirements of the class indicated. 
 
7.1. Quality 
7.1.1 General  
Tolerances for the quality requirements shall be such that; 
a) a total of no more than 10 % of the potato tuber in the lot may fail the requirements; 
b) no more than 3 % of the potato tuber may be affected by rot, mould or deterioration as to make it unfit 
for consumption;  
c) no more than 3 % of the potato tuber may be affected by damage caused by pests; and 
d) no more than 3 % of the potato tuber may be affect ed by both rot, mould or deterioration and damage 
caused by pests in combination 
7.1.2  Class tolerances 
7.1.2.1 Extra class 
Fresh potato tuber of Extra class may have a maximu m of 5 % by number or mass of potato tuber not 
satisfying the requirements of the cl ass, but meeting those of Class I or exceptionally coming within 
the tolerances of that class. 
7.1.2.2 Class I 
Fresh potato tuber of Class I may have a maximum of 10 % by number or mass of potato tuber not 
satisfying the quality requirements of Class II, but m eeting those of Class III or exceptionally coming 
within the tolerances of that class. 
7.1.2.3 Class II 
Fresh potato tubers of Class II shall satisfy the general quality requirements in Clause 4 may have a 
maximum of 20 %.1
7.2. Size tolerance 
Size tolerances for all classes shall be a maximum of Extra Class – 5%, Class I and II – 10% by number or the 
weight of potato corresponding to the size immediatel y above or below the size declared or indicated on the 
package. 
8 Contaminants  
8.1 Pesticide residues  
Fresh potato tubers shall comply with the maximum residue limits for pesticides established by the 
Codex Alimentarius Commission for this commodity. 
                                                      
1 "Partners States are required to note that the tolerance level applicable in Rwanda for Class 11 shall be 10 % in the place 
20%". 
© EAC 2010 – All rights reserved               7 
 EAS 748:2010 9 
8.2 Other contaminants  
Fresh potato tubers shall comply with the maxi mum levels of the Codex General Standard for 
Contaminants and Toxins in Food and Feed (CODEX STAN 193). 
9 Hygiene  
Fresh potato tubers shall be handled in hygieni c manner in accordance with CAC/RCP 53  
10 Packaging 
Fresh potato tubers may be sold packaged or loose. Packaged fresh potato tubers shall be packaged 
in such a way to protect the produce from mechanical, heat and frost damage.  
Fresh potato tubers shall be packaged in food grade materials  that will safeguard the hygienic, nutritional, 
and organoleptic qualities of the product.  
10 Weights and Measures 
Food grade cassava starch   shall be packag ed in accordance with Weights and Measures 
requirements of the destination country. 
12 Labelling  
12.1 In addition to the requirements of EAS 38, the following specific requirements shall apply and 
shall be legibly  and indelibly marked; 
a) name of the product to be shown on t he label shall be “Fresh potato tubers”;  
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);  
12.2  When labelling non-retail packages, informati on for non-retail packages shall either be given 
on the packages or in accompanying documents,  except that the name of the product, lot 
identification and the name and address of the manufacturer or packer shall appear on the package. 
 
© EAC 2010 – All rights reserved               8 
 EAS 748:2010 
© EAC 2010 – All rights reserved               9 
 13 Sampling  
Sampling shall be done in accordance to ISO 874 
14 Criteria for conformity  
A lot shall be declared as conforming to this standard  if each sample inspected or analysed for quality 
requirement conforms to the provision of this standard.  
 EAS 748:2010
  
© EAC 2010 — All rights reserved