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ICS 67.060                 DMS 32:201 4 
        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  
 
__________________  
 Published by  
MALAWI BUREAU OF STANDARDS BOARD   
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  
 
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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 Ma lawi. It may be presented in packaged form or sold loose from the package in 
a dry state to the consumer. Therefore, to ensure that maize supplied to consumers is safe, hygienic and of 
good quality, and at the same time to give guidance to packers and dist ributors 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 following 
standards:  
 
Code x Stan 153: 1985,  Codex standard for maize (corn) , and  
 
EAS 2:2011 , East African Standard, Maize grain – Specification  (Tables 1 and 2 , and definitions ). 
 
Acknowledgement is made for the use of the information.  
 
 
TECHNICAL COMMITTEE  
 
This Malawi S tandard was prepared by the Technical Committ ee MBS/TC 16, Primary agricultural products  
and the following companies, organizations and institutions 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 Resources (LUANAR) – Bunda Campus;  
- Malawi Bureau of Standards;   
- Malawi Investment and Trade Centre;  
- National Smallholder Farmers' Association of Malawi (NASFAM) ; 
- Rab Processors Limited; and  
- Transglobe Produce Export Limited.   
ii NOTICE  
 
This standard shall be reviewed every five years, or earlier when it is necessary, in order to keep abreast of 
progress. Co mments are welcome and shall be considered when the standard is being reviewed .  
1                    DMS 32:2014 
 
MALAWI STANDARD  
 
Maize grain  – Specification  
 
 
1 SCOPE  
 
This Malawi S tandard applies to maize (corn)  for direct human consumption , i.e. ready  for its intended use as 
human food, presented in packaged form or sold loose from the package direct to the consumer. The 
standard specifies  requirements for whole grain shelled dent maize ( Zea mays indentata L.) and/or shelled 
flint maize ( Zea mays indur ate L.). 
 
 
2 NORMATIVE REFERENCES  
 
The following standards contain provisions, which through reference in this text, constitute pro visions of this 
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 standard  are 
encouraged to take steps to ensure the use of the most recent edition of the standard indicated below. 
Information on current valid national and internati onal standards can be obtained from the Malawi Bureau of 
Standards.  
 
MS 19: Labeling of prepacked foods – General standard ; 
 
MS 21: Food and food processing units – Code of hygienic conditions;  
 
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 scop e. 
 
3.2 Definition of defects  
 
3.2.1   
blemished  (defective) grains  
grains  which are insect or ver min damaged, stained, diseased, shrivelled  (immature) , broken, discoloured , 
germinated, frost damaged or otherwise materially damaged  
 
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 5223  
 
 
  
2 3.2.1.2   
discoloured grains  
include those materially discoloured by excessive heat including that caused by excessive respiration (heat 
damage). Grain s may appear darkened, wrinkled, blistered, 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 usual ly be detected without 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 sprou ting, such as cracked seed coats through which a sprout has emerged 
or is just beginning to emerge  
 
3.2.1.6  
insect  or vermin damaged grains  
include those grains with obvious weevil -bored holes or which have evidence of boring or tunneling, 
indicating the p resence of insects, insect webbing or insect refuse, or degermed grains, chewed in one or 
more than one part of the grain which exhibit evident 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 external factors. This includes ground or weather damaged 
grains which may have dark stains or discolourations 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 a nd 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 o r a mixture 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/or 
light red in colour are considered to be yellow maize. Yellow maize also  means grains which are yellow an d 
dark in  colour , provided the da rk 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 m ass of maize of other colours. Maize grains which are white and/or 
light pink in colour are considered to be white maize. White mai ze also means maize grains which are white 
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 a s defined in 3.3.1.1  and 3.3.1.2. 
 
3.3.2  Maize  may also be presented as flint or dent or mixtures thereof.  
 
3.3.2.1  Flint maize  
 
Includes maize of any colour which consists of 95 .0 % or more by mass of g rains of flint maize.  
 
3.3.2.2  Dent maize  
 
Include maize of any colour which consi sts of 95. 0 % or more by mass of dent maize.  
 
3.3.2.3  Flint -dent maize  
 
Include maize of any col our which consists of more than 5.0 % but less than 95. 0 % by mass of flint maize.  
 
 
4. ESSENTIAL COMPOSITION AND QUALITY FACTORS  
 
4.1 Quality factors – General  
 
4.1.1  Maize shall be safe and suitable for human consumption.  
 
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 factor s – Specific  
 
4.2.1 Moisture content  
 
The moisture content of m aize grains shall not exceed 14. 0 % m/m as determined from samples 
representative of the lot.  
 
4.2.2 Aflatoxin content  
 
Maize shall comply with  the aflatoxin  limits provided in Table 1  below . 
 
4.3 Tolerances for defects  
 
Based on a sample, the product shall comply with the 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 605  
 
Note – The worst parameter will determine the grade.  
 
4.4 Toxic or noxious seeds  
 
The products covered by the provisions of this standard shall be free from the following toxic or  noxious 
seeds in amounts which may rep resent a hazard to human 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 harmful to health.  
 
 
5. CONTAMINANTS  
 
5.1 Heavy metal s 
 
Maize shall be free from heavy metals in amounts which may represent a hazard to human health , and shall 
comply with the requirements for this product prescribed in MS 302  
 
5.2 Pesticide residues  
 
Maize shall comply with those maximum pesticide residue limits as laid down by Codex Alime ntarius 
Commission and adopted by the Malawi Bureau of Standards.  
 
 
6 HYGIENE  
 
6.1 The product covered by the provisions of this standard shall be prepared in accordance wit h the 
appropriate sections of M S 21.  
 
6.2 to the extent possible in Good Manufactur ing Practice, the product shall be free from objectionable 
matter, having regard to the tolerances indicated in 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 fre e 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 originatin g from microorganisms 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  104 
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 enough for the conveyance of 50 kg . 
 
7.2 Grain bags shall be made only of substances which are safe for their intended use, and shall not be 
so weathered or worn -out to avoid breakage during normal handling.  
 
7.3 Grain bags shall be clean an d not stained by any col ouring substance or impregnated by any liquid 
capable of imparting stains, exclud ing trade marks or normal discolouring due to exposur e to the sun.  
 
 
8 LABELLING  
 
In addit ion to the requirements of M S 19, the following specific provisions shall apply : 
 
8.1 The name of food  
 
8.1.1  The name of the food to be declared on the label shall be “maize”.  
 
8.1.2  In addition, maize may be designate d with appropriate 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 metric 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 requi red in this specification shall be done according to MS 146.  
 
9.2 Methods of analysis  
 
Analysis of maize s hall be done in accordance with ISO 13690 .  
 
 
ICS 6 7.080.20             DMS 32:2014 
              Third  Edition  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
THE MALAWI BUREAU OF ST ANDARDS              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 pa rastatal 
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 technolog y. 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 .