PUBLIC REVIEW DRAFT DRAFT UGANDA STANDA RD  
  DUS DEAS 748 
First  Edition  
2016-mm-dd 
 
 Reference number  
DUS DEAS 748: 2016 
© UNBS 201 6 
  
Fresh potato tuber (ware potato tuber) — Specification  
 PUBLIC REVIEW DRAFTDUS DEAS 7 48:2016 
ii                © UNBS  2016  - 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 2016 
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, including 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: 256 417 333 2 50/1/2/3 
Fax: 256 414 286 123 
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  
 PUBLIC REVIEW DRAFTDUS DEAS 7 48:2016 
© UNBS  2016 - All rights reserved                iii National foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade, Industry and 
Cooperatives established under Cap 327, of the Laws of Uganda, as amended.  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 Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT Agreement 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 given field or area and consists of representatives of 
consumers, traders, academicians, manufacturers, government and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committee 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 Draft Uganda Standard, DUS DEAS 748: 2016 , Fresh potato tuber (ware potato tuber) — Specification,  
is identical with  and has been reproduced from a Draft East African Standa rd, DEAS 748: 2016, 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 agriculture  Standards Technical Committee (UNBS/TC 2). 
Wherever the words, “ East African Standard" appear, they should be replaced by "Uganda Standard." 
 
   DEAS 748: 2016  
ICS 67.080.20  
© EA C 748                                                                                                                           Second  Edition 2016   
 
DRAFT EAST AFRICAN STANDARD  
Fresh potato tuber (ware potato tuber) — Specification  
EAST AFRICAN COMMUNITY  DEAS 748: 2016  
ii © EAC  2016  – All rights reserved  
 Copyright notice  
This EAC document is copyright -protected by EAC. While the reproduction of this document by 
participants in the EAC standards devel opment process is permitted without prior permission from EAC, 
neither this document nor any extract from it may be reproduced, stored or transmitted in any form for 
any other purpose without prior written permission from EAC.  
Requests for permission to re produce this document for the purpose of selling it should be addressed 
as shown below or to EAC’s member body in the country of the requester:  
© East African Community  2016  — All rights reserved  
East African Community   
P.O.Box 1096  
Arusha  
Tanzania  
Tel: 25 5 27 2504253/8  
Fax: 255 27 2504481/2504255  
E-mail: eac@eachq.org  
       Web: www.eac -quality.net  
Reproduction for sales purposes may be subject to royalty payments or a licensing agreement.  
Violators may be persecuted  DEAS 748: 2016  
© EAC 2016  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Conformance  ................................ ................................ ................................ ................................ .........  1 
3 Normative references  ................................ ................................ ................................ ............................  1 
4 Terms and definitions  ................................ ................................ ............... Error! Bookmark not defined.  
5 Symbols (and abbre viated terms)  ................................ ............................ Error! Bookmark not defined.  
6 Clause  ................................ ................................ ................................ ......... Error! Bookmark not defined.  
6.1 Subclause (level  1) ................................ ................................ .................... Error! Bookmark not defined.  
6.1.1 Subcl ause (level  2) ................................ ................................ .................... Error! Bookmark not defined.  
6.1.2 Subclause (level  2) ................................ ................................ .................... Error! Bookmark not defined.  
6.2 Subclause (level  1) ................................ ................................ .................... Error! Bookmark not defined.  
7 Clause  ................................ ................................ ................................ ......... Error! Bookmark not defined.  
8 Special  ................................ ................................ ................................ ........ Error! Bookmark not defined.  
Annex  A (normative)  Annex title  ................................ ................................ .......... Error! Bookmark not defined.  
A.1 General  ................................ ................................ ................................ .......Error! Bookmark not defined.  
A.2 Clause  ................................ ................................ ................................ ......... Error! Bookmark not defined.  
A.2.1  Subclause (level  1) ................................ ................................ .................... Error! Book mark not defined.  
A.2.2 Subclause (level  1) ................................ ................................ .................... Error! Bookmark not defined.  
A.3 Clause  ................................ ................................ ................................ ......... Error! Bookmark not defined.  
Annex  B (informative)  Which styles correspond to which element  — Quick reference guide Error! Bookmark not defined.  
Bibliography  ................................ ................................ ................................ ................................ ........................  8 
 
. DEAS 748: 2016  
iv © EAC  2016  – All rights reserved  
 Foreword  
Development of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of pro ducts and services in the East African Community. It is envisaged that through 
harmonized standardization, trade barriers that are encountered when goods and services are exchanged 
within the Community will be removed.  
In order to achieve this objective, the Community established an East African Standards Committee mandated 
to develop and issue East African Standards.   
The Committee is composed of representatives of the National Standards Bodies in Partner States, together 
with the representatives from the  private sectors and consumer organizations. Draft East African Standards 
are circulated 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 the procedures 
of the Community.  
East African Standards are subject to review, to keep pace with technological advances. Users of the East 
African Standards are therefore expected to ensure that they always have the latest versions of the s tandards 
they are implementing .  
EAS 748 was prepared by Technical Committee EAS/TC 016 
 DRAFT EAST AFRICAN ST ANDARD  DEAS 748:2016  
 
© EAC 2016  – All rights reserved  1 
 Fresh potato tuber ( ware potato tuber) — Specification  
1 Scope  
This Draft East African standard specifies the requirements  and methods of sampling and test  for ware potato 
tuber of varieties (cultivars) grown from ( Solanum tuberosum L.) of the family Solanaceae  for human 
consumption. It does not cover the requirements for seed potato tuber.  
2 Normative refere nces  
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, Labelling of prepackaged foods — Specification  
CAC/RCP 53 -2003  Code of Hygienic Practice f or Fresh Fruits and Vegetables  
CODEX STAN 193, General standard for contaminants and toxins in food and feed.  
ISO 7558:1988 Guide to the prepacking of fruits and vegetables  
ISO 874, Fresh fruits and vegetables – Sampling  
ISO 6633, Fruits, vegetables and derived products -- Determination of lead content -- Flameless atomic 
absorption spectrometric method  
ISO 17240, Fruit and vegetable products -- Determination of tin content -- Method using flame atomic 
absorption spectrometry  
ISO 7952, Fruits, vegetables and derived products -- Determination of copper content -- Method using flame 
atomic absorption spectrometry  
ISO 6636 -2, Fruits, vegetables and derived products -- Determination of zinc content -- Part 2: Atomic 
absorption spectrometric method  
ISO 17239, F ruits, vegetables and derived products -- Determination of arsenic content -- Method using 
hydride generation atomic absorption spectrometry  
3 Terms and definitions  
For the purposes of this standard, the terms and definitions shall apply.  
3.1  
black heart   
blackening of tissues in the centre of the potato tuber   
2 © EAC  2016  – All rights reserved  
 3.2  
badly misshapen  
potato tuber that is seriously deformed relative to thee varietal shape  
3.3  
clean  
practically free from dirt or staining and practically no loose dirt or other foreign matt er 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  
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 
hazardou s 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 po tato tuber incomplete  
 
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   
free from disease, serious deterioration (such as but no t limited to decay, breakdown, freezing damage, or soft 
or shriveled  specimens) or adulteration/contamination, that appreciably affects their appearance, edibility  
3.19 
cured bruises  
  
© EAC 2016  – All rights reserved  3 
 4 Requirements  
4.1. General requirements  
4.1.1  All fresh potato tubers to be supplied to the market shall meet the following minimum requirements:  
a) of normal appearance for the variety according to the producing area  
b) intact,  
c) sound;  
d) practically clean;  
e) firm;  
f) free of abnormal external moisture; i.e. shall be adequately "dried" if they have been washed;  
g) free of any foreign smell and/or taste.  
h)free of loss of colour such as browning in the flesh  
i) shall be covered with well -formed skin,  
j shall be unsprouted ;  
k) free from pest  damage  affecting the general 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 externa l 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;   
iv) serious deformities(malformation, misshape,...);  
v) grey, blue or black sub -epidermal 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 (1/4) 
quarter of the surface of the tuber;  
ix) damage  due to low temperature ; 
4.1.2  The potato tuber shall be 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.   
4 © EAC  2016  – All rights reserved  
 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 Specific  requirements  
4.2.1  Classification  
4.2.1.1  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 4.2.3 .  
- Extra class;  
- Class I and  
- Class II  
4.2.1 .2 Extra class   
Fresh potato tuber  in this class shall be of superior qual ity. They shall be characteristic of the variety and free of 
defects  with exception of very slight superficial bruises provided  that this will not affect the general appearance of 
the produce, the keeping quality and the presentation in the package.  
4.2.1 .3 Class I  
Fresh potato tub ers in this class shall be of good quality and shall comply with the requirements in 4.1. They 
shall be characteristic of the variety and commercial type . The following slight defects  however may be 
allowed  provided that this will not affect the general ap pearance of the produce, the keeping quality and the presentation 
in the package : 
a) slight defects in shape and colour  
b) slight skin  defects  such as scratches, scars, scrapes and blemishes  and shall not exceed 5 % of the 
surface area of an individual tuber  
c) defects shall not in any case affect the flesh of the produce   
d) bruising, not exceeding 10 % of the surface area of the tubers   
e) the deep common potato tuber scab and powdery tuber scab should not extend more than 3  % of the 
surface area and intrusion not excee ding 2 mm   
 
  
4.2.1. 4 Class II  
This class shall comprise fresh potato tuber  of marketable quality, which do not qualify for inclusion in the 
other classes.  The following defects may occur provided the fresh potato tuber retain their essential 
characteristics as regards to quality, keeping quality and presentation:   
© EAC 2016  – All rights reserved  5 
 a) defects in shape not exceeding 10% of the tubers  
b) cured bruises , not exceeding 20 % of the surface area of the tubers  
d) lesions not more than 2 mm in depth and covering no t more than 5% of the surface area of the tuber;  
f) sub -epidermal stains not more than 2 mm in depth;  
g) internal defects in not more than 3 % by number or mass of the tubers;  
h) common scab not extending more than 5 % of the surface area and intrusion not exceeding2 mm  
4.2.2 Size designation  
Fresh potato tuber may be designated by size in accordance with 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  
 
4.2.3 Tolerances   
4.2.3. 1 Class tolerances  
4.2.3.1 .1 Extra class  
Fresh potato tuber of Extra class may have a maximum of 5 % by number or mass of potato tuber not 
satisfying the requirements of the class, but meeting those of Class I or exceptionally coming within the 
tolerances of that class.  
4.2.3.1 .2 Class 1  
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 meeting those of Class III or exceptionally coming within the 
tolerances of that class. .  
4.2.3.1 .3 Class 11  
Fresh potato tubers of Cl ass II shall satisfy the general quality requirements in Clause 4. May have a 
maximum of 10 % by number or mass of potato tuber not satisfying the quality requirements.  
4..2.3 .2 Size tolerance  
Size tolerances for all classes shall be a maximum of 10% by number or the weight of potato corresponding to 
the size immediately above or below the size declared or indicat ed on the package.   
6 © EAC  2016  – All rights reserved  
 5 Contaminants  
5.1 Pesticide residues  
Fresh potato tubers shall comply with the maximum residue limits for pesticides established by the Codex 
Alimentarius Commission for this commodity .  
5.2 Other contaminants  
Fresh potato tuber s shall comply with the maximum levels of the Codex General Standard for Contaminants 
and Toxins in Food and Feed (CODEX STAN 193).  
6 Hygiene  
Fresh potato tubers shall be prepared and handled in accordance with CAC/RCP 53 -2003  
7 Packaging   
7.1 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.   
7.2  Fresh potato tubers  shall also be packed in containers in accordance with ISO 7558.  
7.3 When packed,  the contents of each package shall be uniform and consist exclusively of potato tubers  of 
the same origin, variety and/or commercial type, and qual ity.  The visible part of the content of the package 
shall be representative of the entire contents.  
8 Labelling  
8.1 In addition to the requirements of EAS 38 , the following specific requirements shall apply and shall be 
legibly and indelibly marked;   
i) Name, postal and physical address of the packer or dispatcher  
ii) Name of the produce as " Fresh potato tubers  ",  
iii) Origin of produce  
iv) Harvest date  
v) Net weight (kg).  
vi) Size code  
vii) Class  
viii) Identification code and/or batch number   
ix) storage instructions  
 
8.2 When labelling non -retail packages, information for non -retail packages shall either be given on the 
packag es 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 2016  – All rights reserved  7 
 12 Sampling  
Representative samples of pineapples  shall be sampled in accordance w ith ISO 874   
8 © EAC  2016  – All rights reserved  
 Bibliography  
  DEAS 748: 2016    
 
© EAC 2016  – All rights reserved