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ICS 67.060                DMS 32:2014  
        Third Edition 
 
 
 
 
 
MALAWI STANDARD 
 
 
 
 
 
 
 
 
 
 
 
 
Maize grain – Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
NOTE: This is a draft proposal and it shall neither  be used nor regarded as a Malawi Standard  
  
ICS 67.060          DMS 32:2014 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Maize grain – Specification 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Obtainable from the 
Malawi Bureau of Standards 
Moirs Road 
P O Box 946 
BLANTYRE 
 
 Tel: +265 1 870 488 
Fax: +265 1 870 756 
 E-mail: mbs@mbsmw.org 
Website: www.mbsmw.org  
 
Price based on 7 pages 
© Copyright reserved  
i TABLE OF CONTENTS 
 
Contents .......................................... ................................................... ................................................... ..... Page 
Foreword .......................................... ................................................... ................................................... .............. i  
Technical Committee ............................... ................................................... ................................................... ...... i 
Notice ............................................ ................................................... ................................................... ................ ii  
Scope ............................................. ................................................... ................................................... .............. 1  
Normative references .............................. ................................................... ................................................... .... 1 
Description ....................................... ................................................... ................................................... ............ 1  
Essential composition and quality factors ......... ................................................... .............................................. 3  
Contaminants ...................................... ................................................... ................................................... ......... 4  
Hygiene ........................................... ................................................... ................................................... ............. 4  
Packaging ......................................... ................................................... ................................................... ........... 5  
Labelling ......................................... ................................................... ................................................... ............. 5  
Annex - Methods of sampling and analysis .......... ................................................... .......................................... 5  
 
 
FOREWORD 
 
Maize is the staple food for Malawi. It may be pres ented in packaged form or sold loose from the packa ge in 
a dry state to the consumer. Therefore, to ensure t hat maize supplied to consumers is safe, hygienic a nd of 
good quality, and at the same time to give guidance  to packers and distributors to supply such a good quality 
product, a request was made for this standard to be  made.  
 
This Malawi standard is a revision of MBS 32:1998, and has been prepared with reference to the followi ng 
standards: 
 
Codex Stan 153:1985, Codex standard for maize (corn) , and  
 
EAS 2:2011 , East African Standard, Maize grain – Specificatio n  (Tables 1 and 2, and definitions). 
 
Acknowledgement is made for the use of the informat ion. 
 
 
TECHNICAL COMMITTEE 
 
This Malawi Standard was prepared by the Technical Committee MBS/TC 16, Primary agricultural products  
and the following companies, organizations and inst itutions were represented: 
 
- ADMARC Limited; 
- Agricultural Commodity Exchange for Africa; 
- Auction Holdings Commodity Exchange; 
- Bakhresa Grain Milling Malawi Limited; 
- Blantyre Agricultural Development Division; 
- Bvumbwe Agricultural Research Station; 
- Lilongwe University of Agriculture and Natural Re sources (LUANAR) – Bunda Campus; 
- Malawi Bureau of Standards;  
- Malawi Investment and Trade Centre; 
- National Smallholder Farmers' Association of Mala wi (NASFAM); 
- Rab Processors Limited; and 
- Transglobe Produce Export Limited.  
ii NOTICE 
 
This standard shall be reviewed every five years, o r earlier when it is necessary, in order to keep ab reast of 
progress. Comments are welcome and shall be conside red when the standard is being reviewed.  
1                    DMS 32:2014 
 
MALAWI STANDARD 
 
Maize grain – Specification  
 
 
1 SCOPE 
 
This Malawi Standard applies to maize (corn) for di rect human consumption, i.e. ready for its intended  use as 
human food, presented in packaged form or sold loos e from the package direct to the consumer. The 
standard specifies requirements for whole grain she lled dent maize ( Zea mays indentata L.) and/or shelled 
flint maize ( Zea mays indurate L.). 
 
 
2 NORMATIVE REFERENCES 
 
The following standards contain provisions, which t hrough reference in this text, constitute provision s of this 
Malawi standard. All standards are subject to revis ion and, since any reference to a standard is deeme d to 
be a reference to the latest edition of that standa rd, parties to agreements based on this standard ar e 
encouraged to take steps to ensure the use of the m ost recent edition of the standard indicated below.  
Information on current valid national and internati onal standards can be obtained from the Malawi Bure au of 
Standards. 
 
MS 19: Labeling of prepacked foods – General standard; 
 
MS 21: Food and food processing units – Code of hygienic c onditions; 
 
MS 146: Cereals – Sampling (as grain); 
 
MS 302: Contaminants and toxins in food – General standard;  
 
ISO 5223 : Test sieves for cereals; 
 
ISO 13690 : Cereals, pulses and milled products – Sampling of  static batches.  
 
 
3 DESCRIPTION 
 
3.1 Product definition 
 
Maize is the shelled grains of the species defined in the scope. 
 
3.2 Definition of defects 
 
3.2.1  
blemished (defective) grains 
grains which are insect or vermin damaged, stained,  diseased, shrivelled (immature), broken, discolour ed, 
germinated, frost damaged or otherwise materially d amaged 
 
3.2.1.1  
broken grains 
pieces of grains or maize which will pass through a  4.5 mm round hole metal sieve according to ISO 522 3 
 
 
  
2 3.2.1.2  
discoloured grains 
include those materially discoloured by excessive h eat including that caused by excessive respiration (heat 
damage). Grains may appear darkened, wrinkled, blis tered, puffed or swollen, often with discoloured, 
damaged germs. The seed coat may be peeling or may have peeled off completely, giving grains a checked  
appearance 
 
3.2.1.3 
diseased grains 
rotting grains which can usually be detected withou t opening the grain for examination 
 
3.2.1.4 
frost damaged grains 
may appear bleached or blistered and the seed coat may be peeling. Germs may appear dead or 
discoloured   
 
3.2.1.5 
germinated grains 
grains showing visible signs of sprouting, such as cracked seed coats through which a sprout has emerg ed 
or is just beginning to emerge 
 
3.2.1.6 
insect or vermin damaged grains 
include those grains with obvious weevil-bored hole s or which have evidence of boring or tunneling, 
indicating the presence of insects, insect webbing or insect refuse, or degermed grains, chewed in one  or 
more than one part of the grain which exhibit evide nt traces of an attack by vermin 
 
3.2.1.7 
shrivelled (immature) grains 
grains which are shrivelled over the entire surface  and not just over the embryo area 
 
3.2.1.8 
stained grain 
those whose natural colour has been altered by exte rnal factors. This includes ground or weather damag ed 
grains which may have dark stains or discolouration s with a rough external appearance 
 
3.2.2 filth, foreign matter and other grains 
 
3.2.2.1 
filth   
impurities of animal origin, excluding dead or live  insects 
 
3.2.2.2  
foreign matter 
all organic and inorganic material other than maize  grains, broken grains, other grains and filth 
 
3.2.2.2.1 
inorganic matter   
include sand, stones, pebbles, dirt, lumps of earth , clay, mud, glass and metallic pieces 
 
3.2.2.2.2 
organic matter   
includes leaf or cob materials from the maize plant , other vegetable materials such as grass, wood or other 
cereals, weeds and dead insects 
 
3.2.2.3 
other grains 
edible grains, whole or identifiable broken, other than maize, (i.e. cereals, pulses and other edible legumes) 
 
3.3 Presentation 
 
3.3.1 Maize may be presented as yellow, white or a mixtur e of these colours. 
  
3 3.3.1.1 Yellow maize 
 
May contain not more than 5.0 % by mass of maize of  other colours. Maize grains which are yellow and/o r 
light red in colour are considered to be yellow mai ze. Yellow maize also means grains which are yellow  and 
dark in colour, provided the dark red colour covers  less than 5.0 % of the surface of the grain. 
 
 
3.3.1.2 White maize  
 
May contain not more than 2.0% by mass of maize of other colours. Maize grains which are white and/or 
light pink in colour are considered to be white mai ze. White maize also means maize grains which are w hite 
and pink in colour, provided the pink colour covers  less than 5.0% of the surface of the grain. 
 
3.3.1.3 Mixed maize 
 
Includes maize not falling into classes of white or  yellow maize as defined in 3.3.1.1  and 3.3.1.2 . 
 
3.3.2 Maize may also be presented as flint or dent or mix tures thereof. 
 
3.3.2.1 Flint maize 
 
Includes maize of any colour which consists of 95.0  % or more by mass of grains of flint maize. 
 
3.3.2.2 Dent maize 
 
Include maize of any colour which consists of 95.0 % or more by mass of dent maize. 
 
3.3.2.3 Flint-dent maize 
 
Include maize of any colour which consists of more than 5.0 % but less than 95.0 % by mass of flint ma ize. 
 
 
4. ESSENTIAL COMPOSITION AND QUALITY FACTORS 
 
4.1 Quality factors – General 
 
4.1.1 Maize shall be safe and suitable for human consumpt ion. 
 
4.1.2 Maize shall be free from abnormal flavours, odours and living insects. 
 
4.1.3 Maize shall be free from filth in amounts which may  represent a hazard to human health. 
 
4.2 Quality factors – Specific 
 
4.2.1 Moisture content 
 
The moisture content of maize grains shall not exce ed 14.0 % m/m as determined from samples 
representative of the lot. 
 
4.2.2 Aflatoxin content 
 
Maize shall comply with the aflatoxin limits provid ed in Table 1 below. 
 
4.3 Tolerances for defects 
 
Based on a sample, the product shall comply with th e requirements given in Table  1 below: 
  
4 Table 1: Requirements for maize 
 
S/N Characteristics Maximum limits Method of 
test Grade 1 Grade 2 Grade 3 
1 Foreign matter, % m/m 0.5 1.0 1.5 
ISO 605 2 Inorganic matter, % m/m 0.25 0.5 0.75 
3 Broken kernels, % m/m 2.0 4.0 6.0 
4 Pest damaged grains, % m/m 1.0 3.0 5.0 
5 Rotten & Diseased grains, % m/m 2.0 4.0 5.0 
6 Discoloured grains, % m/m 0.5 1.0 1.5 
7 Moisture, % m/m 12.0 13.0 14.0 ISO 711/712 
8 Immature/Shriveled grains, % m/m 1.0 2.0 3.0 
ISO 605 9 Filth, % m/m 0.1 0.1 0.1 
10 Total Aflatoxins, ppb 15 
ISO 16050 11 Aflatoxin B1, ppb 5 
12 Fumonisin, ppm 2 
13 Total Defectives Grains, % m/m 4.0 5.0 7.0 ISO 6 05 
 
Note – The worst parameter will determine the grade.  
 
4.4 Toxic or noxious seeds 
 
The products covered by the provisions of this stan dard shall be free from the following toxic or noxi ous 
seeds in amounts which may represent a hazard to hu man health: 
 
4.4.1 Crotolaria ( Crotalaria spp.), Corn cockle ( Agrostemma githago L.), Castor bean ( Ricinus communis 
L.), Jimson weed ( Datura ssp.), and other seeds are commonly recognized as h armful to health. 
 
 
5. CONTAMINANTS 
 
5.1 Heavy metals 
 
Maize shall be free from heavy metals in amounts wh ich may represent a hazard to human health, and sha ll 
comply with the requirements for this product presc ribed in MS 302 
 
5.2 Pesticide residues 
 
Maize shall comply with those maximum pesticide res idue limits as laid down by Codex Alimentarius 
Commission and adopted by the Malawi Bureau of Stan dards. 
 
 
6 HYGIENE 
 
6.1 The product covered by the provisions of this stand ard shall be prepared in accordance with the 
appropriate sections of MS 21. 
 
6.2 to the extent possible in Good Manufacturing Practi ce, the product shall be free from objectionable 
matter, having regard to the tolerances indicated i n Section 4.3 and table 1, where applicable. 
 
6.3 When tested by appropriate methods of sampling and examination, the product: 
 
6.3.1 Shall be free from microorganisms in amounts which may represent a hazard to health, and shall 
conform to the limits provided in table 2; 
 
6.3.2 Shall be free from parasites which may represent a hazard to health; and 
  
5 6.3.3 shall not contain any substances originating from m icroorganisms in amounts which may represent a 
hazard to health, . 
 
Table 2: Microbiological limits 
 
S/No.  Type of micro -organism  Limits  
1 Yeasts and moulds, max. per g 10 4 
2 Staphylococcus aureus  per 25 g Absent  
3 Escherichia coli , max. per g Absent  
4 Salmonella,  max. per 25 g Absent  
 
 
7. PACKAGING 
 
7.1 The product shall be packed in grain bags strong en ough for the conveyance of 50 kg. 
 
7.2 Grain bags shall be made only of substances which a re safe for their intended use, and shall not be 
so weathered or worn-out to avoid breakage during n ormal handling. 
 
7.3 Grain bags shall be clean and not stained by any co louring substance or impregnated by any liquid 
capable of imparting stains, excluding trade marks or normal discolouring due to exposure to the sun. 
 
 
8 LABELLING 
 
In addition to the requirements of MS 19, the follo wing specific provisions shall apply: 
 
8.1 The name of food 
 
8.1.1 The name of the food to be declared on the label sh all be “maize”. 
 
8.1.2 In addition, maize may be designated with appropria te terms indicated in sections 3.3.1  and 3.3.2  
provided it complies with the requirements defined in sections 3.3.1.1  to 3.3.1.3  and 3.3.2.1  to 3.3.2.3  
respectively. 
 
8.2 The net content shall be declared by weight in metr ic units. 
 
8.3 The container (bag) shall be permanently marked in code of clear writing to indentify the packer or 
distributor and the lot. 
 
8.4 Place of origin of the maize shall be declared. 
 
 
9 METHODS OF SAMPLING AND ANALYSIS 
 
9.1 Sampling 
 
Sampling for testing as required in this specificat ion shall be done according to MS 146. 
 
9.2 Methods of analysis 
 
Analysis of maize shall be done in accordance with ISO 13690.  
 
 
ICS 67.080.20             DMS 32:2014 
              Third Edition 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
THE MALAWI BUREAU OF STANDARDS              CERTIFI CATION 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 granted 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.