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ICS 67.060                 DMS 32:2022   
     Fourth  Edition  
 
 
 
 
DRAFT MALAWI STANDARD  
 
 
 
 
 
 
 
 
 
 
Maize grain – Specification  
 
 
 
 
 
 
 
NOTE: This is a draft Malawi standard  and it shall neither be used nor regarded as a Malawi standard  
 
__________________  
 Published by  ICS 67.060           DMS 32:2022   
     Fourth  Edition  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Maize grain – Specification  
 
 
 
 
 
 
 
 
 
 
 
 
Obtainable from the  
Malawi Bureau of Standards  
Ali Hassan Mwinyi  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 6  pages  
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i TABLE OF CONTENTS  
 
Contents  ................................ ................................ ................................ ................................ .....................  Page  
Foreword  ................................ ................................ ................................ ................................ .............................  ii 
Technical Committee  ................................ ................................ ................................ ................................ ..........  ii 
Notice  ................................ ................................ ................................ ................................ ................................ .. ii 
Scope  ................................ ................................ ................................ ................................ ................................ . 1 
Normative references  ................................ ................................ ................................ ................................ ........  1 
Terms and d efinitions  ................................ ................................ ................................ ................................ ........  1 
Presentation  ................................ ................................ ................................ ................................ .......................  2 
Quality requirements  ................................ ................................ ................................ ................................ ..........  3 
Contaminants  ................................ ................................ ................................ ................................ .....................  4 
Hygiene  ................................ ................................ ................................ ................................ ..............................  5 
Packaging  ................................ ................................ ................................ ................................ ..........................  5 
Labelling  ................................ ................................ ................................ ................................ ............................  5 
Methods of sampling  ................................ ................................ ................................ ................................ ..........  6 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
ii FOREWORD  
 
This draft Malawi standard  has been prepared by the MBS/TC 16, Cereals, pulses, legumes and their products,  
to provide requirements for maize. Maize  is the staple food for Malawi. 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 gu idance to packers and 
distributors to supply such a good quality product, a request was made for this standard to be made.  
 
This draft Malawi standard  is a revision of  MS 32:2017. In preparing this draft standard, reference was made 
to the following standa rds: 
 
African Standard, ARS 461:2022, Maize grains (corn) – Specification;  
 
CODEXSTAN 153:1985  (Rev 1:1995) , Codex standard for maize (corn) ; and  
 
East African Standard ,  EAS 2:2012 ,  Maize grain – Specification . 
 
Acknowledgement is made for the use of the information.  
 
 
TECHNICAL COMMITTEE  
 
This draft Malawi standard  was prepared by the Technical Committee MBS/TC 16,  Cereals, pulses, legumes 
and their products,  and the following companies, organizations and institutions were consulted:  
 
Agricultural Development and Marketing Corporation;  
Agricultural Commodity Exchange;  
Auction Holdings Limited Commodity Exchange;  
Export Trading Limited;  
Lilongwe University of Agriculture and Natural Resources;  
Ministry of Agr iculture – Department of Crop Development ; 
National Smallholder Farmers ’ Association of Malawi;  
Rab Processors Limited; and  
University of Malawi.  
 
 
NOTICE  
 
This standard shall be reviewed every five years, or earlier when it is necessary, in order to keep abreast of 
progress. Comments are welcome and shall be considered when the standard is being reviewed.   
1                    DMS 32 :2022  
 
DRAFT  MALAWI STANDARD  
 
Maize grain – Specification  
 
1 SCOPE  
 
This draft Malawi standard  specifies the requirements and methods of sampling and test for maize grains 
(corn) of  varieties grown from common maize  grains, Zea mays indentata  L., and/or Zea mays indurata  L., or 
their hybrids intended for human consumption .  
 
 
2 NORMATIVE REFERENCES  
 
The following standards contain provisions, which through reference in this text, constitute provisions of this 
Draft Malawi standard . All standards are subject to revision and, since any reference to a standard is deemed 
to be a ref erence 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 international s tandards 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 145: Cereal and cereal products – Sampling ; 
 
MS 302: Contaminants and toxins in food – General standard;   
 
MS 1796: Pulses – Determination of impurities, size, foreign odours, insects, and species and variety – Test 
methods ; 
 
ISO 711: Cereals and cereal products – Determination of moisture content (Basic reference method) ; 
 
ISO 712 : Cereals and cereal products – Dete rmination of moisture content – Routine reference method ; 
 
ISO 5223 : Test sieves for cereals;  
 
ISO 16050: Foodstuffs – Determination of aflatoxin B1, and the total content of aflatoxin B1, B2, G1 and G2 in 
cerea ls, nuts and derived products – High performance liquid chromatographic method ; and 
 
AOAC Official Method 2001.04: Determination of Fumonisins B1 a nd B2 in corn and corn flakes – Liquid 
chromatography with immunoaffinity column cleanup . 
 
 
3 TERMS AND DEFINITIONS  
 
For the purpose of this draft Malawi standard , the following terms and definitions shall apply:  
 
3.1 
maize (corn)  
shelled dried grains of the species Zea mays indentata  L, (dent maize) and/or Zea mays indurata  L, (flint maize), 
or their hybrids  
 
3.2 
flint maize (corn) - 
form of corn whose mature kernel has a smooth, vitreous, appearance and a rather round shape   
2 3.3 
dent maize (corn) - 
form of corn whose mature kernel has the shape of a horse’s tooth with a depression in the crown  
 
3.4 
insect or pest damaged grains  
grain which shows damage or owing attack by rodents, insects, mites or other pests  . 
 
3.5 
stained kernels  
kernels whose natural colour has been altered by external factors. This includes ground, soil or weather damaged 
kernels, which may have dark stains or discolourations with a rough external appearance  
 
3.6 
rotten and diseased grains  
grains made unsafe for human consumption due to decay, moulding, or bacterial decomposition, or other causes 
that may be noticed without having to cut the grains to examine them  
 
3.7 
discoloured grain/ kernel  
 kernel which is damaged by heat, frost or water  
 
3.8 
germinated kernel  
kernels showing visible signs of sprouting  
 
3.9 
frost damaged kernel  
kernels which appear bleached or blistered due to exposure of extremely low temperature and the seed coat 
may be peeling, germs may appear dead or discoloured  
 
3.10 
mouldy kernel  
maize grains with visible mycelial growth on its tip or surface  
 
3.11 
immature/shrivelled grains  
maize grains which are underdeveloped, thin and papery in appearance  
 
3.12 
broken kernels  
pieces of maize which shall pass through a 4.50 mm metal sieve  
 
3.13 
other edible grains  
edible grain, whole or broken, other than maize, that is, cereals, pulses and other edible legumes   
 
3.14 
foreign matter /extraneous matter  
all organic and inorganic materials other than maize  
 
3.14.1  
inorganic foreign matter  
inorganic matter  components, such as stone, sand and dust  
 
3.14.2  
organic foreign matter  
any animal or plant matter (e.g. dead insects, seed coats, straws, weeds) other than grain of maize and damaged 
maize grain  
 
3.15 
filth 
impurities of animal origin including dead insects   
3 3.16 
defective grains  
pest damaged, discoloured, stained, rotten and diseased, immature and shrivelled grains and broken grain  
 
3.17 
food grade packaging material  
packaging material, made of substances which are safe and suitable for their intended  use and which will not 
impart any toxic substance or undesirable odour or flavour to the product  
 
3.18 
heat damaged maize grains  
maize grains which are discoloured and damaged by excessive high temperature.  
 
3.19 
poisonous, toxic and/or harmful seeds  
seed  which if present  in quantities above permissible limit may have damaging or dangerous effect on health, 
organoleptic properties or technological performance such as Jimson weed — Datura ( D. fastuosa  Linn and 
D. stramonium  Linn.) corn cockle ( Agrostemma gi thago  L., Machai Lallium remulenum  Linn.) Akra (Vicia  
species), Argemone mexicana , Khesari and other seeds that are commonly recognized as harmful to health  
 
 
4 PRESENTATION  
 
4.1 Colour   
 
Maize may be presented as yellow, white, or red, or a mixture of these colours.  
 
4.1.1  Yellow maize shall contain not more than 5.0 % by weight 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 maize grains 
which are yellow and dark red in colour, provided the dark red colour covers less than 50 % of the surface of the 
grain.  
 
4.1.2  White maize shall contain not more than 2.0 % by weight of maize of other colours. Maize grains which 
are white and/or light pink in colour are cons idered to be white maize. White maize also means maize grains 
which are white and pink in colour, provided the pink colour covers less than 50 % of the surface of the grain.  
 
4.1.3  Red maize shall contain not  more than 5.0 % by weight of maize of other colours. Maize grains which 
are pink and white, grey or dark red and yellow in colour are considered to be red maize, provided the pink or 
dark red or yellow colour covers 50 % or more of the surface of the grai n. 
 
4.1.4  Mixed maize includes maize not falling into the classes of white, yellow or red maize as defined in 4.1.1 
to 4.1.3.  
 
4.2  Shape  
 
Maize also may be presented as flint or dent or their hybrids or mixtures thereof as follows.  
 
4.2.1  Flint maize have  kernels with a hard outer layer enclosing the soft endosperm which consist of 95  % 
or more by weight of flint maize and not more than 5% maize of other shapes by weight.  
 
4.2.2  Dent maize is maize with a concavity on the outermost face of the grain, consi sts of 95  % or more 
by weight of grains of dent maize and not more than 5% maize of other shapes by weight.  
 
4.2.3  Flint and dent maize includes maize of any colour which consists of more than 5 % but less than          
95.0 % of flint maize.  
 
 
5 QUALITY REQUIREMENTS  
 
5.1 General  requirements  
 
5.1.1  Maize shall be safe and suitable for human consumption.  
  
4 5.1.2  Maize shall be free from moulds, abnormal flavours, odours, live pests, rat droppings, toxic or noxious 
weed seeds and other injurious contaminants  as determined from s amples representative of the lot . 
 
5.1.3  Maize shall be of a reasonably uniform colour according to type, be whole and clean.  
 
5.2 Specific  requirements  
 
Maize grain shall comply with maximum limits given in Table 1  when tested in accordance with the test 
methods specified therein.  
 
5.3 Grading  
 
5.3.1  Maize shall be graded into three grades on the basis of the tolerable limits established in Table 1  
which shall be additional to the general requirements set out in this standard.  
 
Table 1: Requirements for maize  
 
1 2 3 4 5 6 
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 
MS 1796  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  14.0 14.0 14.0 ISO 711/712  
8 Immature/Shriveled grains, % m/m  1.0 2.0 3.0 
MS 1796  9 Filth, % m/m  0.1 0.1 0.1 
10 Total Aflatoxins, ppb  10 
ISO 16050  
11 Aflatoxin B1, ppb  5 
12 Fumonisin, ppm  2 AOAC Official 
Method 2001.04  
13 Total Defectives Grains, % m/m  4.0 5.0 7.0 MS 1796  
Note: The parameter, total defective grains is not the sum total of the individual defects. It is limited to 70% of the sum total o f individual 
defects  
Note: Maize grains destined for processing baby foods shall have total aflatoxin level of not more than 4 ppb.  
 
5.3.2 Ungraded maize grain   
 
These shall be maize grain  which do not fall within the requirements of Grades 1, 2, and 3 of this standard but 
are not rejected maize grains . 
 
5.3.3 Reject grade maize grain  
 
This comprises maize grain s which have objectionable odour, off flavour, living insects or which do not possess 
the quality characteristics specified in Table 1.  They cannot satisfy the conditions of ungraded maize grains  
and shall be graded as reject maize grain s and shall be rega rded as unfit for human consumption.  
 
 
6. CONTAMINANTS  
 
6.1 Heavy metals  
 
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 6.2 Pesticide residues  
 
Maize shall comply with those maximum pesticide residue limits as laid down by Codex Alimentarius 
Commission and adopted by the Malawi Bureau of Standards.  
 
 
7 HYGIENE  
 
7.1 The product covered by the provisions of this standard shall be  prepared in accordance with the 
appropriate sections of MS 21.  
 
7.2 To the extent possible in Good Manufacturing Practice, the product shall be free from objectionable 
matter, having regard to the tolerances indicated in section 5.3 and Table 1,  where applicable.  
 
7.3 When tested by appropriate methods of sampling and examination, the product:  
 
7.3.1  Shall be free from microorganisms in amounts which may represent a hazard to health, and shall 
conform to the limits provided in Table 2;  
 
7.3.2  Shall be free from parasites which may represent a hazard to health; and  
 
7.3.3  Shall not contain any substances originating from microorganisms in amounts which may represent a 
hazard to health.  
 
Table 2: Microbiological limits  
 
1 2 3 
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 Maize grains shall be packed in suitable packages which shall be clean, sound, free from insect, fungal 
infestation and the packing material shall be of food grade quality and shall be securely closed and sealed.  
 
7.2 Maize grains shall be packed in containers which will safeguard the hygienic, nutritional, and 
organoleptic qualities of the products.  
 
7.3 Each package shall contain maize grains of the same type and of the same grade designation.  
 
7.4 If maize grains are presented in bags, the bags shall also be free of pests and contaminants.  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.  
 
Note: Maximum package weight of 50 kg where human loa ding and offloading is involved.  
 
 
8 LABELLING  
 
The following specific labelling requirements shall apply and shall be legibly and indelibly marked in 
accordance with the requirements of MS 19 : 
 
8.1 Product name as “White Maize Grains, Yellow Maize Grains,  Red Maize Grains or Mixed Maize 
Grains”;  
 
8.2 Grade;  
 
8.3 Net weight in Kg;    
6 8.4 Name, address and physical location of the producer/ packer/importer;  
 
8.5 Lot/batch/code number;  
 
8.6 The declaration “Food for Human Consumption’’ ; 
 
8.7 Storage instruction  as “Store in a cool dry place away from any contaminants’’;  
 
8.8 Crop year;  
 
8.9 Packing  date and expiry date  
 
8.10 Instructions on disposal of used package;  
 
8.11 Country of origin;  and 
 
8.12 A declaration on whether the maize was genetically modified  where applicable.  
 
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 b e declared.  
 
 
9 METHODS OF SAMPLING  
 
Sampling shall be done accordance with  MS 145 . 
  
 
 
ICS 67.060              DMS 32:2022  
            Fourth  Edition  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 Trade and Industry .  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 am end 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 goo ds 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.