DEAS 775: 2022  
ICS 67.080.20  
 
© EAC 2022                                                                                                                              Second  Edition 
2022  
 DRAFT EAST AFRICAN STANDARD  
Production and handling ware potato tuber  — Code of practice . 
EAST AFRICAN COMMUNITY  
 DEAS 775: 2022  
ii © EAC  2022 – All rights reserved  
 Copyright notice  
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Reproduction for sales purposes may be subject to royalty payments or a licensing agreement.  
Violators may be prosecuted . DEAS 775: 2022  
© EAC 2022 – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative referen ces ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4.1 General requirements  ................................ ................................ ................................ ...........................  2 
4.2 Agricultural input requirements  ................................ ................................ ................................ ...........  2 
4.3 Handling during production  ................................ ................................ ................................ .................  3 
4.4 Handling during harvesting  ................................ ................................ ................................ ..................  3 
5 Storage and preservation  ................................ ................................ ................................ .....................  3 
5.1 General  ................................ ................................ ................................ ................................ ...................  3 
5.2 Preparing ware potato tuber for storage ................................ ................................ .............................  4 
5.3 Control of damage  ................................ ................................ ................................ ................................ . 4 
5.4 Temperature control  ................................ ................................ ................................ ..............................  4 
5.5 Curing of ware  potato tuber  ................................ ................................ ................................ .................  4 
5.6 Storage methods  ................................ ................................ ................................ ................................ ... 4 
6 Sorting and packing for export  ................................ ................................ ................................ ............  5 
7 Packaging and labelling ................................ ................................ ................................ ........................  6 
Bibliography  ................................ ................................ ................................ ................................ ........................  7 
 DEAS 775: 2022  
iv © EAC  2022 – All rights reserved  
 Foreword  
Development of the East African Standards has been necessitated by the need for harmonizing requir ements 
governing quality of products 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.  
The C ommunity has established an East African Standards Committee  (EASC)  mandated to develop and 
issue East African Standards  (EAS) . The Committee is composed of representatives of the National 
Standards Bodies in Partner States, together with the representativ es from the public and private sector 
organizations  in the community .  
East African Standards are developed through  Technical Committees that are representative of key 
stakeholders including government, academia, consumer groups, private sector and other i nterested parties. 
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 Principles and procedures for development of East African Standards. XXXXXX.  
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 la test versions of the standards 
they are implementing .  
The committee responsible for this documen t is Technical Committee EASC/TC 016 , Fresh fruits, vegetables, 
tubers  and flowers . 
This second edition cancels and replaces the first edition (EAS 775 :2012 ), which has been technically revised.  
Attention is drawn to the possibility that some of the elements of this document may be subject of patent 
rights. EAC shall not be held responsible for identifying any or all such patent rights.  DEAS 775: 2022  
© EAC 2022 – All rights reserved  v 
 Introduction  
This code f ocuses upon issues that are specific to the primary production and packaging of ware potato  tuber 
in order to produce a quality, safe and wholesome product.  
This code addresses Good Agricultural Practices (GAPs) , Good Hygiene Practices (GHPs)  and Good 
Manu facturing Practices (GMPs) that will help control microbial, chemical and physical hazards associated 
with all stages of the production of ware potato  tuber from primary production to packaging. Particular 
attention is given to minimizing damage and deteri oration of ware potato  tuber before marketing.  
This code does not provide detailed information which is considered to be generally applicable to all fruits and 
vegetables or food products in general. Such provisions are available in other codes. As such,  this code 
should be used in conjunction EAS 39 and CAC/RCP 53,  Code of hygienic practice for fresh fruits and 
vegetables.  
 DRAFT EAST AFRICAN STANDARD  DEAS 775: 2022  
 
© EAC 2022 – All rights reserved  1 
 Production and handling ware potato tuber  — Code of practice  
1 Scope   
This Draft  East African Standard  provides recommended practices  for the production , storage,  packaging  and 
transportation of ware potato tuber  (Solanum tuberosum L.) intended for human consumption.  
2 Normative references   
The following documents are referred to in the text in such a way that some or all of their conte nt constitutes 
requirements 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 prepackage d foods   
EAS 39, Hygiene in the food and drink manufacturing industry — Code of practice  
CAC/RCP  53, Code of hygienic practice for fresh fruits and vegetables . 
3 Terms and definitions   
For the purposes of this document, the following terms and definitions apply.  
ISO and IEC maintain terminological databases for use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
3.1  
ware potato tuber  
produce of species  Solanum tuberosum  (L.) grown for its tuber  
3.2  
agricultural inputs  
any incoming material including  water, agricultural chemicals and planting material used for the primary 
production of ware potato  tuber  
3.3 
biological control  
use of competing biologica l agents (such as insects, micro -organisms and/or microbial metabolites) for the 
control of pests , plant pathogens and spoilage organisms  
3.4 
primary deterioration  
deterioration as a result of physiological changes characterised by vascular stre aking or v ascular discoloration  
3.5 
secondary deterioration  
deterioration induced by micro -organisms that cause rotting under aerobic and anaerobic conditio ns  
2 © EAC  2022 – All rights reserved  
 3.6 
curing  
operation of self -healing of wounds, cuts and bruises  
3.7 
clamp  
rectangular depression in the f ield where ware potato tubers are stacked and covered with straw/hay and soil 
to act as temporary storage 4 Primary production  and handling of ware potato tuber  
4.1 General requirements  
Ware potato tuber  is grown and harvested under a wide range of climatic  and diverse geographical conditions, 
using various agricultural inputs and technologies. Biological, chemical and physical hazards may vary 
significantly from one type of production to another.   
In each primary production area, it is necessary to consider  the particular agricultural practices that promote 
the production of safe ware potato tuber , taking into account the conditions specific to the primary production 
area, varieties of ware potato tuber  and methods used . 
During production, primary and second ary deterioration should be avoided so as to ma intain the quality of 
ware potato tuber . Procedures associated with primary production shall be conducted under good hygienic 
conditions to minimize potential hazards to health due to the contamination of ware  potato tuber  in accordance 
with EAS 39 and CAC/RCP 53 . 
4.2 Agricultural input requirements  
4.2.1  Inputs used for the production of ware potato tuber  shall conform to the relevant East African 
Standards.  
4.2.2  Agricultural inputs shall not contain microbi al or chemical contaminants at levels that may adversely 
affect the s afety and quality of ware potato tuber .  
4.2.3  Growers sh all use only agricultural inputs which are approved by the Competent Authority for the 
cultivation of ware potato tuber and sh all use them according to the product label for the intended purpose.  
4.2.4  The disposal of surplus chemical and used containers shall be in accordance to the national 
environment regulatory agency guidelines.  
4.2.5  Residues sh all not exceed levels as establi shed by the Codex Alimentarius Commission.  
4.2.6  Agricultural workers who apply agricultural chemicals sh all be trained in proper application 
procedures.  
4.2.7  Growers sh all keep records of agricultural chemical applications. Records should include informa tion 
on the date of application, the chemical used, the crop sprayed, the pest or disease against which it was used, 
the concentration, method and frequency of application, and records on harvesting to verify that the time 
between applications and harvesti ng is appropriate . 
4.2.8  Agricultural implements and equipment  shall be calibrated, as necessary, to control the accuracy of 
application . 
4.2.9  Agricultural chemicals should  be kept in their original containers, labelled with the name of the 
chemical , stor age conditions , expiry date  and the instructions for application and use .  
© EAC 2022 – All rights reserved  3 
 4.3 Handling during production  
During the primary production and post -harvest activities, effective measures shall be taken to prevent 
contamination of ware potato tuber  from agricul tural inputs or personnel who come directly or indirectly into 
contact with ware potato tuber .  
To prevent contamination, ware potato tuber  growers, harvesters and handlers shall adhere to the following:  
a) Ware potato tuber  unfit for human consumption shall  be segregated during harvesting. Those , which 
cannot be made safe by further processing should be disposed of properly . 
b) Agricultural workers should not use harvesting containers for other purposes  (including,  lunches, 
tools, fuel, etc.)  Where such contain ers have to be  used for other purposes  they shall be cleaned and 
sanitized.  
c) Care shall be  taken when packing ware potato tuber  in the field to avoid exposure to contaminati on 
with animal/ human  filth. 
4.4 Handling during harvesting  
4.4.1  Ware p otato  tubers should be harve sted when fully mature depending on the cult ivar and the method 
of planting . Maturity can be assessed by : 
a) b)d) Cut the stem and leaves 7 days to 14 days before harvesting to harden the skin of the tuber to 
minimise loss during post -harvest handling and to minimise transmission of late blight  
b) Cutting  ware potato tuber  in the field and observing the colour of the latex exud ed; latex from 
immature ware potato tuber turns black, while from mature tuber remains creamy -white  
c) rubbing the skin of th e tuber; immature tubers skin easily peel off.   
4.4.2  Careful harves ting and proper handling of ware  potato tuber is an important step towards successful 
storage.  
4.4.3  Ware p otato  tuber  can be harvested manually  or mechanically . Care should be taken duri ng the 
harvesting process to minimize damage such as bruising, scrapping or breaking of the ware potato  tuber , to 
minimize post -harvest losses.  
4.4.4  Whether harvested  manually or  mechanically, the produce shall be carefully handled and transported 
to the packing facility  immediately.  
5 Storage and preservation  
5.1 General  
Ware potato tuber s generally do not store well, except under ideal conditions and bruised ones rapidly 
deteriorate. They can last up to 3 -4 weeks.   
Ware potato tuber s are  still living o rganisms after they have been harvested and losses that occur during 
storage arise mainly from their physical and physiological condition. The main causes of loss are associated 
with mechanical damage, physiological condition (maturity, respiration, water loss), diseases and pests. To 
ensur e effective storage of tuber crops, these major causative factors need to be properly understood and, 
where appropriate, be properly controlled, taking into account the socio -economic factors which prevail in the 
areas of  production and marketing.   
4 © EAC  2022 – All rights reserved  
 5.2 Preparing ware potato tuber  for storage  
Ware potato tuber s should be harvested and handled with care to minimize deterioration during storage and 
the following should be adhered to:  
a) Retain only those tuber s that d o not show signs of injury. Tuber s that are to be kept for more tha n one 
week or more should be carefully selected since curing will not be effective on tuber s with extensive 
damage.  
b) Establish curing of the tuber s after harvest as a routine operation with, as far as possible, the 
minimum of handling.  
Severely damaged tubers should not be stored because of the following reasons:  
a) lower quality ; 
b) increased risk of subsequent pathogenic losses ; and  
c) risk of introducing disease organisms into sound produce.  
5.3 Control of da mage  
Mechanically damaged tubers will normally deteriorate rapidly and should not be stored and exported. 
Mechanical damage can occur during all handling operations, particularly harvesting and washing and 
damaged regions are more susceptible to microbial infection.  
Careful handling should be done during all handling operations and adequate drying and curing should be 
ensur ed prior to packing and storage.  
5.4 Temperature control  
Temperature has a great influence on many factors that cause loss during storag e; it influences the rate of 
sprout growth, the development of rotting micro -organisms and insect infestation .  Storage at temperatures 
below 10 °C will result in sweetening while storage temperatures above 25 °C will result in increased decay, 
water loss and sprouting.  
Ware potato tuber  meant for fries , crisps  and flour  may be stored at 10 °C - 25 °C for four months while those 
for other products may be stored in cold storage for four months.  
Temperature control methods should aim at slowing down rates of physiological and microbiological 
deterioration.  
5.5 Curing of ware potato tuber   
Ware potato tuber  shall be properly cured as soon as possible after harvest ing to promote the preservation of 
the skin as well as formation of a hard cork layer. Curing shoul d be carried out near the place where the 
tubers will be stored to minimize handling after curing. The process is carried out for 4  days  to 15 days at 
temperatures of 15 0C to 22 0C and a relative humidity of 85% to 95%.  
5.6 Storage methods  
5.6.1  General  
The g eneral storage area should be dark and well ventilated to avoid greening and accumulation of solanine.  
5.6.2  Storage in the soil before harvest   
© EAC 2022 – All rights reserved  5 
 Ware potato tuber  may be stored by leaving them un -harvested for short periods before the optimum harvest 
age. T ubers should not be left in the ground as a method of storage beyond the optimum harvest period 
because of the danger of tubers being infested by pathogens and any other physiological deterioration.  
5.6.3 Storage pits/heaps  
Storage in outdoor pits/heaps is  not recommended because the dampness encourages decay  
5.6.4 Storing ware potato tuber  in crates/  baskets/boxes  
Harvested ware potato tubers can be stored in wooden crates or baskets. The crates shall be lined with a 
layer of sawdust, wood shavings, peat o r any other suitable adsorbent materials. The spaces between the 
tubers are also filled with sawdust. Finally, the tubers are then covered with sawdust.  
To prevent the tubers drying out too early, the crate should be lined with plastic foil. The sawdust sh ould 
neither be damp nor wet. If the sawdust is too dry the tubers will deteriorate quickly. Sawdust which is too 
moist promotes the formation of mould and rot.  
The crates or baskets can simultaneously be used as containers during transport (also several times) which 
saves on handling costs and also reduces injury to the tubers during transport.  
5.6.5 The field clamp  
Ware potato tuber  may be kept in a clamp (preferably under shade) for up to eight weeks. The clamp shall be 
in a well -drained location. Tempe ratures inside a ventilated clamp will be approximately those of the ambient 
temperatures.  
5.6.6 Other methods  
Other methods of storage and preservation include refrigeration, waxing of the tubers and chemical treatment.  
5.6.6.1 Refrigeration  
Reduced tempe ratures extend the storage ability of ware potato tubers by delaying the rot processes which 
occur rapidly at normal storage temperatures. The most favourable temperature for the storage of ware potato 
tuber  is 2°C - 4°C except for ware potato tuber  meant for processing which should be stored in the range of 
10°C - 15°C.   
5.6.6.2 Waxing  
Ware p otato  tubers may be stored preserved by coating them in food grade wax.  The wax may or may not be 
supported with a fungicide.  
6 Sorting and packing for export  
With suita ble handling and storage, ware potato tuber  can be successfully transported for long distances 
including export by sea -shipment. Ware potato tuber  may be  graded in terms of size and shape , with only one 
type being packed in one carton including  small rounded,  small elongated, medium round etc.  
The suitable handling conditions for ware potato tubers are as follows:  
a) Ware potato tuber  shall be carefully cleaned and dipped in a solution of 0.05% Th iabendazole for 15  
seconds  to 30 seconds.  
b) After washing an d fungicide treatment, the ware potato tuber  should be left overnight in a well 
ventilated area to dry before packing for departure.  
c) During shipment, the required storage temperature is 10  °C to 15 °C.  
6 © EAC  2022 – All rights reserved  
 7 Packaging and labelling  
7.1 Packaging material s shall be suitable for pack ing and transporting ware potato tuber .  
7.2 Packaging  materials  shall protect the produce  against mechanical damage  and ease handling  including 
acco unting for quantity in the lot.  
7.3 The selection of suitable containers for commerc ial scale marketing requires very careful consideration. 
The following factors should be considered in choosing packaging materials:  
a) the level of losses occurring during marketing;  
b) the comparative cost of the present and improved packaging;  
c) the regularity of supply of the packaging material; and  
d) the acceptance of the packaging method to the market.  
7.4 Among the various types of packaging material that ar e available, the following are  used;  
a) natural and synthetic fibre sacks;  
b) moulded plastic boxes;  
c) wooden boxes;  
d) cardboard boxes; and  
e) paper or plastic film sacks . 
7.5 The net weight shall be:  
a) in metric units; and 
b) not more than 50 kg in line with ILO guidelines.  
Note: For sea -shipment, an additional 5% packing weight may be required due to weight loss which wi ll occur during 
storage and shipment.  
7.6 The labelling of packaged ware potato tuber  shall be in accordance with EAS 38.    
© EAC 2022 – All rights reserved  7 
 Bibliography  
 [1] EAS 775:2012 , Production and handling of fresh ware potatoes — Code of practice  
 DEAS 775: 2022    
 
© EAC 2022  – All rights reserved