Fresh sweet  potatoes – Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
NOTE: This is a draft Malawi standard and it shall neither be used nor regarded as a Malawi Standard  
________________  
 Published by  
MALAWI STANDARDS BOARD  
 ICS 67 .080.2 0           DMS 1604:2020  
                     First  edition  
          
 
 
 
 
DRAFT MALAWI STANDARD  
 
 
  
 ICS 67.080.20                 DMS 1604:2020  
 
 
 
 
 
 
 
 
 
Fresh sweetpotatoes – Specification  
 
 
 
 
 
 
 
 
 
 
 
Obtainable from the  
Malawi Bureau of Standards  
P O Box  946 
BLANTYRE  
 
Tel: +265 870 488  
Fax: +265 870 756  
       E-mail: mbs@malawi.net  
    Website: www.mbsmw.org  
Price based on 6 pages  
© Copyright reserved 
i 
 TABLE OF CONTENTS  
Contents                     Page  
Foreword  ................................ ................................ ................................ ................................ ..............................  i 
Technical Committee  ................................ ................................ ................................ ................................ ...........  i 
Notice  ................................ ................................ ................................ ................................ ................................ ... i 
Scope  ................................ ................................ ................................ ................................ .....................  ……….. 1  
Normative references …………………………………………………………………………………………………..  1 
Terms and definitions  ................................ ................................ ................................ ................................ ........  1 
Quality requirements  ................................ ................................ ................................ ................................ ..........  2 
Classification of fresh sweetpotatoes  ................................ ................................ ................................ ................  3 
Provisions concerning tolerances   ................................ ................................ ................................ ....................  4 
Size designations of fresh sweetpotatoes…………………………………………………………………………. ....4 
Food additives……………………………………………………………………………………………………………4  
Contaminants  ................................ ................................ ................................ ................................ .....................  5 
Hygiene  ................................ ................................ ................................ ................................ ..............................  5 
Packaging  and l abelling………………….…………………………………………………………………………... . . 5 
Methods of sampling and test  ................................ ................................ ................................ ............................  6 
 
 
FOREWORD  
 
This draft Malawi standard was prepared by MBS/TC 53 , the Technical Committee on  Root and tuber crops  
and their products , to provide the requirements and methods of sampling and test for fresh sweetpotatoes 
[Ipomoea batatas (L.) Lam.] for human consumption.  
 
In preparing this d raft Ma lawi standard , reference was made to  the following standard : 
 
East African Standard , EAS 771:2012 , Fresh  sweetpotatoes  – Specification . 
 
Acknowledgement is made for the use of the information.  
 
 
TECHNICAL COMMITTEE  
 
This draft Malawi  standard  was prepared by MBS/TC 53 , the Technical Committee on  Root and tuber crops  
and their products and the following companies, organizations a nd institutions were represented : 
 
Blantyre City Council;  
International Potato Center Malawi;  
Lilongwe University of Agriculture and Natural Resources;  
Malawi Bureau of Standards;  
Ministry of Agriculture, Irrigation and Water Deve lopment – Bvumbwe Agricultural Research Station;  
Ministry of Industry  – Department of Small and Medium Enterprises and Cooperatives ; 
Peoples Trading Centre;  
Shoprite Trading Limited;  
Tehilah Bakery ; and  
University of Malawi – The Polytechnic.  
 
 
NOTICE  
 
This standard shall be revised every five years or whenever necessary in o rder to keep abreast of progress . 
Comments are welcome and shall be considered when the standard is being revised.  
  
1 
  DMS 160 4:2020                                
DRAFT MALAWI STANDARD  
 
Fresh sweetpotatoes – Specification  
 
 
1 SCOPE  
 
This draft Malawi standard  specifies the requirements and methods of sampling and test for fresh 
sweetpotatoes [ Ipomoea batatas (L.) Lam .] to be supplied fresh and either packaged or sold loose for human 
consumption.  
 
 
2 NORMATIVE REFERENCES  
 
The following standards contain provisions, which through reference in this text, constitute provisions of t his 
draft Malawi standard . All standards are subject to revision and, since any reference to a standard is deemed 
to be a reference to the latest edition of that standard, parties to agreements based on this draft Malawi 
standard are encouraged to take steps to ensure the use of the most recent edition of the standard s indicated 
below. Information on current valid national and international standards can be obtained from the Malawi 
Bureau of Standards.  
 
MS 19 : Labelling of prepackaged foods – General standard;  
 
MS 237 : Food additives – General standard;  
 
MS 302 : Contaminants and toxins in foods – General standard;  
 
MS 1611 : Production and handling of sweetpotatoes – Code of practice;  and 
 
MS 1520 : Fresh fruits and vegetables – Sampling . 
 
 
3 TERMS AND DEFINITIONS  
 
For the purposes of this draft Malawi standard , the following terms and definitions shall apply.  
 
3.1  
badly misshapen   
potato tuber that is seriously deformed relative to the varietal shape  
 
3.2 
clean  
practically  free from dirt or staining or other foreign matter or extraneous matter  
 
3.3 
extraneous matter  
organic matter of plant origin other than the fresh sweetpotato  
 
3.4 
firm  
not soft, shrivelled or flabby  
 
3.5  
food grade material  
material  that is free from substances that are hazardous to human health  
 
3.6 
foreign matter  
organic and inorganic materials (such as sand, soil, glass) other than extraneous matter in the sweetpotato   
2 
 3.7 
fresh    
storage roots obtained from a plant of the spec ies ipomoea batatas (L) Lam  having visual characteristics of 
colour, texture and firmness typical of just harvested sweetpotato at the time of sale   
 
3.8 
practically free  
produce  without defects in excess of those that can be expected to result from, and be consistent with good 
cultural and handling practices employed in the production and marketing of the fresh sweetpotatoes  
 
3.9 
sound/wholesome  
free from pests, diseases, serious deterioration (such as but not limited to decay, breakdown, freezing damage,  
or softness) or adulteration/contamination, that appreciably affects their appearance, edibility and the keeping 
quality of the produce or market v alue  
 
3.10 
sprout  
new shoot emerging from the root 
 
3.11 
sweetpotato  
storage roots obtained from a plant of the species ipomoea batatas (L) Lam, primarily used for human 
consumption  
 
3.12 
whole  
fresh  storage roots which have not been subjected to any mechanical damage or peeling of its initial harvested 
mass with the exemption of trimming  
 
 
4 QUALITY REQUIREMENTS  
 
4.1 General requirements  
 
Fresh sweetpotatoes  shall have reached an appropriate degree of physiological development  and maturity  
taking into account the characteristics of the variety and the area in which they are grown. The sweetpotatoes  
shall have been carefully harvested.  
 
4.2 Specific requirements  
 
Fresh sweetpotatoes  supplied to the market shall be:  
 
4.2.1  Fresh, whole and firm ;  
 
4.2.2 Wholesome/sound  and produce n ot affected by rot, mould or deterioration as to make it unfit for 
consumption;  
 
4.2.3 Clean, and practically free of any visible extraneous matter or foreign matter, except permitted 
substances  used to prolong its shelf life;  
 
4.2.4 Of colour, taste and texture characteristic of variety;  
 
4.2.5 Practically free of pests and damage caused by pests;   
 
4.2.6 Free of excess external moisture, adequately surface dried if they have been washed;   
 
4.2.7 Free of any foreign smell and/or taste with exception of preservation agents allowed under clause 5;    
 
4.2.8 Practically  free of mechanical damage and bruising; and  
 
4.2.9 Free from greening .  
3 
 4.2.10  Free from serious deformities (i.e., malformation, bad misshape)  
 
4.3 Quality tolerances  
 
Tolerances for the quality requirements shall be such that:  
 
4.3.1  A total of no more than 10 % of the sweetpotatoes  in the lot may fail the requirements;  
 
4.3.2  No more than 3 % of the sweetpotatoes may be affected by rot, mould or deterioration as to make it 
unfit for consumption;   
 
4.3.3  No more than 3 % of the sweetpotatoes  may be affected by damage caused by pests; and  
 
4.3.4  No more than 3 % of the sweetpotatoes  may be affected by rot, mould or deterioration; and damage 
caused by pests in combination.  
 
 
5 CLASSIFICATION OF FRESH SWEETPOTATOES  
 
5.1 Types of classes   
 
Fresh sweetpotatoes  may b e classified before marketing. Where classification is done the following grades 
shall be used in accordance with the requirements of each class  and the quality tolera nces in c lause 7.  
 
5.1.1 Extra class;  
 
5.1.2 Class  I; and  
 
5.1.3 Class  II.  
 
5.2 Class requirements  
 
5.2.1 Extra class  
 
5.2.1.1  Extra class sweetpotatoes  shall me et the  specific requirements in c lause 4.2 and shall be:  
 
5.2.1.1.1 Of superior quality in terms of texture and appearance; and  
 
5.2.1.1.2 Characteristic of the variety and uniform in shape and size.   
 
5.2.1.2  Extra class sweetpotatoes  shall be free from defects, with the exception of defects on the surface 
affecting not more than 2 % of the sweetpotatoes .  
 
5.2.2 Class I  
 
5.2.2.1  Class I sweet potatoes shall me et the specific  requirements in c lause 4.2 and shall be :    
 
5.2.2.1.1  Of good quality; and  
 
5.2.2.1.2  Uniform  in shape and size that are characteristic of the variety.  
 
5.2.2.2  The following slight defects may be allowed, provided these do not affect the general appearance, the 
quality, the keeping quality and presentation o f sweetpotatoes :   
 
5.2.2.2 .1 Defects in shape not exceeding 5  % of the sweetpotatoes ;  
 
5.2.2.2.2 Bruising, not exceeding 10  % of the surface area of the sweetpotatoes ;    
 
5.2.2.2.3 Scraped areas, not exceeding 20  % of the surface area of the sweetpotatoes ; and  
 
5.2.2.2.4 Scarred and healed damage, not exceeding 5  % of the surface area of the swee tpotatoes.   
  
4 
 5.2.3 Class II  
 
5.2.3.1  Class II sweetpotatoes shall me et the specific  requirements in c lause 4.2 but may not qualify for 
inclusion in the higher classes.  
 
5.2.3.2   The following defects may be allowed:   
 
5.2.3.2.1 Defects in shape not exceeding 10  % of the sweetpotatoes;  
 
5.2.3.2.2 Bruising, not exceeding 20  % of the surface area of roots;  
 
5.2.3.2.3 Scraped areas, not exceeding 30  % of the surface area of sweetpotatoes ; and  
 
5.2.3.2.4 Scarred and healed damage, not exceeding 10  % of the surface area of the swee tpotatoes.  
 
 
6 PROVISIONS CONCERNING TOLERANCES  
 
6.1 Quality tolerances  
 
6.1.1 Tolerances in respect of quality and size shall be allowed in each package for produce not satisfying 
the requirements of the class indicated.  
 
6.1.2  The following tolerance limits may be allowed for specific classes:  
 
6.1.2.1  Extra class: 5  % by weight of sweetpotatoes  not satisfying the requirements of extra class, but meeting 
those of Class I or exceptionally coming w ithin the tolerances of class I;   
 
6.1.2.2  Class I: 10  % by weight of sweetpotatoes  not satisfying the requirements of class I, but meeting those 
of Class II or exceptionally, coming wi thin the tolerances of class II; and   
 
6.1.2.3  Class II: 20  % by weight of sweetpotatoes  not satisfying the specific  requirements, with the exception 
of produce affected by rotting or any other deterioration rendering it unfit for consumption.  
 
6.2 Size tolerances  
 
For all classes, 10  % by number or weight of sweetpotatoes  corresponding to the size immediately above 
and/or below that indicated on the package.  
 
 
7 SIZE DESIGNATION OF FRESH SWEETPOTATOES   
 
Fresh  sweetpotatoes 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. Size is determined by weight.  
 
Table 1 – Size for fresh sweetpotatoes  
 
1 2 3 4 
S/N Size code  Size Weight ( g) 
1 A  Large  > 650  
2 B  Medium  450 – 650  
3 C  Small  < 450   
 
 
8 FOOD ADDITIVES  
 
Fresh sweetpotatoes may be preserved by use of food addi tives in accordance with MS 237 .  
 
 
 
  
5 
 9 CONTAMINANTS   
 
9.1 Pesticide residues   
 
Fresh  sweetpotatoes  shall conform to those maximum residue limits for pesticide residues established by 
Codex Alimentarius  Commission for this commodity.  
 
9.2 Other contaminants    
 
Fresh  sweetpotatoes  shall conform to those maximum levels of  contaminants and toxins in food and feed in 
accordance with MS 302 .  
 
 
10 HYGIENE   
 
Fresh  sweetpotatoes  shall be handled a hygienic manner complying with MS 1611.  
 
 
11 PACKAGING  AND LABELLING  
 
11.1 Packaging  
 
Fresh sweetpotatoes  may be sold packaged or loose.  Packa ging of  fresh sweetpotatoes  shall comply  with 
requirements of  the packaging section in MS 1611.  
 
11.2 Labelling    
 
11.2.1 In additi on to the requirements of MS 19 , the following specific requirements shall apply and shall be 
legibly and indelibly marked :   
 
11.2.1.1 Name of the produce to be shown on the label shall be “Fresh sweetpotatoes ”;  
 
11.2.1.2 Name, physical and postal address of the producer and/ packer or vendor shall be declared;  
 
11.2.1.3 Country of origin of the produce;   
 
11.2.1. 4 Place  of origin such as district, or region;  
 
11.2.1.5  Name of variety;  
 
11.2.1.6 Commercial  ident ification shall be declared by:   
 
11.2.1.6.1 Grade (only when classified);  
 
11.2.1.6.2 Variety  or cultivar or type ;  
 
11.2.1.6.3 Size (size code); and  
 
11.2.1.6.4 Net weight (in metric system).   
 
11.2.1. 7. Lot identification (batch number);  
 
11.2. 1.8  Declaration  of preservatives, if used;  
 
11.2.1. 9 Date  of harvest;  
 
11.2.1. 10 Packing date;  
 
11.2.1.1 1 Storage conditions; and  
 
11.2.1.1 2 Indication “for human consumption ”. 
  
6 
 11.2.2 When labelling non -retail packages, information for non -retail packages shall either be given on the 
packages or in accompanying documents, except that the name of the produce, lot identification and the name 
and address of the producer or packer shall app ear on the package.  
 
 
12 METHODS OF SAMPLING AND TEST ING 
 
12.1 Sampling shall be done in accordance with MS 1520 .  
 
12.2 Tests for pesticide residues, contaminants and toxins shall be conducted in acc ordance with the 
recommended methods of the Codex Alimentarius Commission , AOAC and other internationally recognized 
methods of test.   
 
  
 
 
ICS 67.080.20                                     DMS 1604:2020  
 
 
 
 
 
 
THE MALAWI  BUREAU OF STANDARDS           CERTIFICATION MARK SCHEME  
The Malawi Bureau of Standards is the 
standardizing body in Malawi under the aegis 
of the Ministry of Industry and Trade .  Set up 
in 1972 by the Malawi Bureau of Standards 
Act (Cap: 51:02), the Bureau is a parastatal 
body whose activities aim at formulating and 
promoting the general adoption of standards 
relating to structures, commodities, materials, 
practices, operations and from time to time 
revise, alter and amend the same to 
incorporate advanced technology.  To bring the advantages of standardization 
within the reach of the common consumer, the 
Bureau operates a Certification Mark Scheme. 
Under this scheme, manufacturers who 
produce goods that conform to national 
standards are gran ted permits to use the 
Bureau’s “Mark of Quality” depicted below on 
their products.  This Mark gives confidence to 
the consumer of the commodity’s reliability.