Ready to eat extruded snacks  – 
Specification   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Note: This is  a draft proposal and should not be regarded or used as a Malawi standards  
 ICS 67.060             DMS 1694 :2020 
        First  edition  
 
 
 
 
 
DRAFT MALAWI STANDARD   
  ICS 67.060          DMS 1694:2020 
 
 
 
 
 
 
 
 
 
 
 
 
 
Ready to eat extruded snacks  – 
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  10 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 
Essential composition and q uality requirements  ................................ ................................ ...............................  2 
Hygiene  ................................ ................................ ................................ ................................ ..............................  3 
Food additive  ................................ ................................ ................................ ................................ .....................  3 
Contaminants  ................................ ................................ ................................ ................................ .....................  3 
Packaging  and labeling ................................ ................................ ................................ ................................ ...... 4 
Methods of sampling and tests  ................................ ................................ ................................ ..........................  4 
Annex A: Sampling of ready -to eat extruded snacks  ................................ ................................ ........................  5 
Annex B: Determination of moisture content  ................................ ................................ ................................ ..... 7 
Annex C: Determination of total fat content  ................................ ................................ ................................ ....... 8 
 
FOREWORD  
 
Production of ready to eat extruded snacks , both sweet and savoury, have recently increased. To safeguard 
the health of the consumers which are mainly children, and at the same time, to provide guidelines for 
manufacture of such foods, it has been felt necessary to prescribe requirements for them.  
 
This standard does not define any particular composition of the 'ready -to-eat' extruded snack but leaves  to 
option of using different types of  raw materials in optional proportions to the manufacturers.  
 
In preparing this standard, reference was made to the following Indian  standard , and other publications:   
 
IS 12566:1989, amended 1990 , Ready to eat extruded snacks  – Specification ; 
 
M.Kavya  Reddy et el. (2014) Development of extruded ready to eat  (RTE) snacks using corn, black gram, 
roots and tuber flour blends . J Food Sci Technol (September 2014) 51 (9):1929 -1937 ;  
 
Amudha Senthil, Bharath Kumar S. Aparna Pathak (2014), Comparative quality evaluation of commercial 
extruded snacks . Wudpecker Journal of Food Technology vol 3(1) pp 001 -011, April 2015:  
 
Acknowledgement is made for the use of the information.  
 
TECHNICAL COMMITTEE  
 
This draft proposal  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 (ADMARC)  
University of Malawi – Chancellor College  
F&F Industries Limited  
HMS Foods and Grains  
Malawi Bureau of Standards  
Ministry of Agriculture – Bvumbwe Agricultural Research Services  
Ministry of Health  
Ministry of Industry  
Moon Puffs  
Unity Super Meal  
 
 
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 1694 :2020 
DRAFT MALAWI STANDARD  
 
Ready to eat extruded snacks  – Specification  
1 SCOPE  
 
This draft standard prescribes the requirements and methods of  sampling  and test for 'ready -to-eat' extruded 
snacks.  
 
 
2 NORMATIVE REFERENCES  
 
The following standards contain provisions, which through reference in this text, constitute provisions of this 
draft 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 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 standards can be obtained from the Malawi Bureau of 
Standards.  
 
MS 19: Labelling of pre -packed foods – General standard;  
 
MS 21: Food and food processi ng units – Code of hygienic conditions;  
 
MS 30: Fortified wheat flour – Specification;  
 
MS 51 : Fortified edible oils – Specification;  
 
MS 63:  Vegetable ghee – Specification;  
 
MS 63:  Mixed animal and vegetable ghee – Specification;  
 
MS 188:  Edible salt – Specification;  
 
MS 302:  Contaminants and toxins in foods  – General standard;  
 
MS 633 : Milk powders – Specification ; 
 
MS 1006: Milk fat products – Specification;  
 
ISO 6579: Methods for the microbiological examination of foods, Part 6: Examination for Salmonella Spp.;  
 
ISO 6888:  Microbiology of food and animal feeding stuffs – Horizontal method for the enumeration of 
coagulase -positive staphylococci (Staphylococcus aureus and other species);  
 
ISO 7251:  Microbiology of food and animal feeding stuffs – Horizontal method for the detection and 
enumeration of presumptive Escherichia coli – Most probable number technique;  
 
ISO 16050: Foodstuffs – Determination of aflatoxin B 1, and the total content of aflatoxin B 1, B2, G1 and G2 
in cereals, nuts and derived products – High performance  liquid chromatographic method;  
 
ISO 21527 -2: Microbiology of food and animal feeding stuffs – Horizontal method for the enumeration of yeasts 
and moulds – Part 2: Colony count technique in products with water activity less than or equal to 0.95; and  
 
 
3 TERMS AND DEFINITIONS  
 
For the purpose of this draft standard,  the following terms and definitions shall apply:  
 
  
2 
 3.1 
'Ready -to-Eat' extruded snacks  
ready  to eat extruded snacks are made by a proce ss known as 'extrusion cooking'  
 
3.2 
extrusion  
is a process by which pre -conditioned raw food material is subjected to high -temperature short -time cooking 
which results in the material becoming of plastic consistency. This material is then extruded through specially 
tapered dies. As it emerges from the d ies, it passes from a high pressure to a low pressure zone and this 
results in puffing of the product. The cooked dough is cut to the desired size; after which it is dried to the 
desired moisture. Finally, the product is coated with oil, flavours, salt, sp ices or sweetening agent, etc., and 
packed. These ingredients may  also be added before extrusion  
 
Note:  The cooker extruder configuration used for the purpose of extrusion cooking shall ensure adequate cooking of raw ingredients.  The: 
shape and size of the extruded product shall be reasonably uniform. being governed by the nature of die used for extrusion -cooking. The 
product shall be fully cooked. It shall also be free from insects, insect residues. rodent hair and excreta, fungal inf ection and any other 
extraneous and harmful material. The product shall be crisp, and free from grits or uncooked particles.  
 
 
4 ESSENTIAL CO MPOSITION AND QUALITY REQUIREMENTS  
 
4.1 Raw materials  
 
The following raw materials may be used  for the production of read y-to-eat extruded snacks:  
 
4.1.1  Dehusked and/or degermed cereals and pulses ; 
 
4.1.2  Wheat flour/semolina  complying with MS  30; 
 
4.1.3  Edible tubers and starches ; 
 
4.1.5  Edible oils complying with  MS 51 ; 
 
4.1.6  Ghee singly or in combination complying with  MS 63, MS 64 and MS 1006;  
 
4.1.7  Salt complying with MS 188 . 
 
4.1.8  Spices, spice extracts and condiments;  
 
4.1.9  Tomato, onion and garlic powder;  
 
4.10 Powder of other edible vegetables and fruits;  
 
4.11 Cheese powder ;  
 
4.12 Skimmed milk powder  complying with MS 633;  
 
4.13 Dextrins;  
 
4.14 High protein flours ; and  
 
4.14 Sugar and sugar products.  
 
4.2 Quality requirements  
 
4.2.1  The 'ready -to-eat' extruded snacks shall be of pleasant taste and sm ell, and free from rancid, soap , 
bitter or burnt taste and smell. They shall have an aroma and taste characteristic of the flavours and spices 
used.  
 
4.2.2  Ready -to-eat extruded snacks  shall conform to the composition requirements indicated in Table 1 . 
 
 
  
3 
 Table 1: Specific requirements for ready -to-eat extruded snacks  
 
1 2 3 4 
S/No.  Characteristic  Maximum limits  Methods of test  
1 Moisture content, %(m/m), max  6.0 Annex B  
2 Fat on dry basis, % m/m, max  25 Annex c  
3 Peroxide value , max  10 AOAC  
4 Total aflatoxin (AFB1+AFB2+AFG1 +AFG2 ), 
ppb, max  10 ISO 16050  
5 Aflatoxin B1 only, ppb, max  5 
6 Total fumonisin (FB1+FB 2+FB3), ppm , max  2 AOAC   
 
4.2.3  The product shall comply with the microbiological limits given in Table 2.  
 
Table 2 – Microbiological limits  for ready -to-eat extruded snacks  
 
1 2 3 4 
S/No.  Type of microorganism  Maximum limit  Method of test  
(i)  Total viable count , cfu/g , max  <104 ISO 4833  
(ii)  Salmonella  in 25 g, max  Absent  ISO 6579  
(iii)  E. coli  per g , max   Absent  ISO 7251  
(iv)  Shigella  per g , max   Absent  ISO 21567  
(v)  Coliforms  g (per 100 g), cfu/g , max  Absent  ISO 4832  
(vi)  Staphylococcus aureus  per 10 g, 
max Absent  ISO 6888  
(vii) Moulds and yeast , per g, max  < 50 ISO 21527 -2 
 
 
5 HYGIENE  
 
5.1 The product covered by the provisions of this draft standard shall be prepared and handled in 
accordance with MS 21.  
 
 
6 FOOD ADDITIVES  
 
Only those food additives listed under this product in MS 237 shall be used and only within the limits specified.  
 
 
7 CONTAMINANTS  
 
7.1 Heavy metals  
 
Ready to eat extruded snacks  shall comply with maximum limits of heavy metals in accordance with MS 302 .  
 
7.2 Mycotoxin limits  
 
Ready to eat extruded snacks  shall comply with those maximum mycotoxin limits set in Table 1  above, and 
those established by the Codex Alimentarius Commission for this commodity when tested according to                         
ISO 16050.  
 
 
 
 
 
 
  
4 
 8 PACKAGING AND LABELLING  
 
8.1 Packaging   
 
8.1.1  Ready to eat extruded snacks shall be packed in suitable  containers or  packages which will safeguard 
the hygienic, nutritional, technological and organoleptic qualities of the products . They  shall be clean , free and  
of food grade quality.   
 
8.1.2 The containers, including packaging material, shall be  made of food grade  material.  They shall not 
impart any toxic substance or undesirable odour or flavour to the product.  
 
8.1.3 Each package shall be securely closed and sealed.  The sealing shall be done hermetically with or 
without nitrogen flushing to ret ain the contents in a fresh condition.  
 
8.2 Labelling  
 
8.2.1 In addition to the requirements in MS 19 , each package shall be legibly and indelibly marked with the 
following:  
 
8.2.1.1 Name of the material and trade -mark, if any;  
 
8.2.1 .2 Name and address of the manufacturer;  
 
8.2.1.3 Batch or code number;  
 
8.2.1.4 Net mass in grams or kilograms:  
 
8.2.2.5 Date of manufacture;  
 
8.2.2.6 List of ingredients;  and 
 
8.2.2.7 Expiry  date. 
 
 
9 METHODS OF SAMPLING AND TESTS  OF 'READY -TO-EAT' EXTRUDED SNACKS  
 
9.1 Representative samples of the product shall be drawn and criteria for ascertaining conformity to the 
requirements shall be as prescribed in Annex A.   
 
9.2 Testing shall be done in accordance with the methods indicated against each requirement in Tables 
1 and 2 or other equivalent methods.  
 
 
   
5 
 ANNEX A  
(Normative)  
 
SAMPLING OF READY -TO-EAT EXTRUDED SNACKS  
 
A.1 GENERAL REQUIREMENTS OF SAMPLING  
 
A.1.1  In drawing, preparing. storing and handling samples, the following precautions and directions shall be 
observed.  
 
A.1.2  The sampling instrument shall be clean and dry when used. When talking samples for bacteriologic al 
examination, it shall be sterile.  
 
A.1.3 Precautions shall be taken to protect the samples, the material being sampled, the sampling 
instrument and the containers for samples from adventitious contamination.  
 
A.1.4 The samples shall be placed  in clean and dry containers. The sample containers shall be of such a 
size that they are almost completely filled with the sample. The sample containers shall, in addition, be sterile 
when they are used for samples for bacteriological examination.  
 
A.1.5 Each container shall be sealed air -tight after filling and marked with full details of sampling, such as, 
date' of sampling, date of manufacture and batch number or code number, if any.  
 
A.1.6 Samples shall be stored in such a manner that the temperature  of the material does not vary unduly 
from the normal temperature.  
 
 
A.2 SCALE OF SAMPLING  
 
A.2.1 Lot. In any consignment all the containers of the same size and belonging to the same batch of 
manufacture shall be grouped together to constitute a lot.  
 
A.2.2 Samples shall be tested from each lot for ascertaining conformity of material to the requirements of 
the specification.  
 
A.2.3 The number of containers to b e tested from a lot shall depend upon the size of the lot and shall be in 
accordance with Tab le 2. 
 
Table 2: Scale of sampling  
 
1 2 3 4 
S/No  Number of containers in the 
lot Sample size for tests other 
than microbiological  Sub-sample size for 
microbiological tests  
1 Up to 25  2 1 
2 26 to 50  3 2 
3 51 to 100  5 3 
4 101 to 150  6 4 
6 151 and above  8  
 
A.2.4  The containers shall be chosen at random from the lot.  
 
 
A.3 TEST SAMPLES AND REFEREE SAMPLES  
 
A.3.1 Empty the contents of the container on a sheet of paper and mix thoroughly. Take equal quantities of 
the material from each selected container and mix thoroughly as to form a composite sample weighing about 
500 g. This composite sample shall be divided int o three. equal parts, one for the purchaser another for the 
supplier and the third for the referee.  
 
A.3.2 From the remaining portion of the material from each container, draw three samples each weighing 
not less than 100 g. These will constitute individua l test samples for the container. These individual samples 
shall be separ ated into three identical size of samples in such a way that each set has an individual test sample  
6 
 representing each container selected. One of these  three sets shall be for the purchaser. another for the 
supplier and the third to be used as the referee sample . 
 
A.3.3 From the containers selected according to Table 2, the number of containers given in Table 2 shall be 
randomly selected. Drawn with a su itable sampling instrument which is  sterile, the representative  quantity of 
material under aseptic conditions to form a sample of container for microbiological examination. Divide the 
sample (taking  care not to bring in microbiological combination in the m aterial) into three equal parts, each 
part so obtained shall constitute a test sample representing the contain er and shall be transferred to sterile  
containers  sealed air -tight and labelled with full identification particulars given in A.1.5. These shall b e marked, 
in addition, with the words. 'For microbiological examination' The sample so obtained shall be divided  into three 
sets in such a way that each set has a sample representing each selected container. One of these sets shall 
be marked for the purchaser. another for the vendor and third for the referee.  
 
A.3.4 Referee samples  shall consis t of a set of individ ual sample , the composite sample and a set of samples 
for microbiological examination marked for this purpose and shall bear the seals of the purchaser and the 
vendor. These shall be kept at a place agreed to between the purchaser and the vendor to be used  in case of 
dispute between the two.  
 
 
A.4 NUMBER OF TESTS  
 
A.4.1 Tests for determination of moisture, fat and peroxide value shall be conducted on each of the samples 
constituting a set of individual samples.  
 
A.4.2 Tests for description and flavour shall be conducted on the composite sample,  
 
A.4.3 Tests for bacterial count. coliform count, Salmonella, Shigella and E Coli shall be conducted on each 
of the samples constituting a set of test samples labelled with the words "For microbiological examinat ion".  
 
 
A.5 CRITERIA FOR CONFORMITY  
 
A.5.1 For i ndividu al samples , the lot shall be declared to satisfy the requirements of moisture, fat and 
peroxide value. jf each of the test results satisfies the correspondi ng requirements given in Table 1 .  
 
A.5.2  For samples for microbiological examin ation , the test results on the sample for microbiological 
examination shall meet the corresponding requirements specified in Table 2. 
   
7 
  
ANNEX B 
(informative)  
DETERMINATION OF MOISTURE  CONTENT  
 
B.1.  PROCEDURE  
 
Weigh about 5 g of the material in a dish made of porcelain, silica or platinum, previously dried in an electric 
oven maintained at 105 ± 1°C, for 5 hours. Cool the dish in a desiccator and weigh with the lid on. Repeat the 
process of heating, cooling and weighing at half -hour intervals until the loss in weight between two successive 
weighings is less than one milligram. Record the lowest weight obtained.  
 
 
B.2. CALCULATION  
Moisture, per cent by mass   
M  M )M  M( 

12 1 100    
  
Where,  
 
M1   =   mass in g, of the dish with the material before drying;  
 
M2   =   mass in g, of the dish with the material after drying; and  
 
M    =   mass in g, of the empty dish.  
 
   
8 
 ANNEX C 
(informative)  
DETERMINATION OF TOTAL FAT CONTENT  
 
C.1 DEFINITION  
 
C.1.1  Total fat content – The whole of the substances extracted by hexane under the operating conditions 
specified in this standard, and expressed as a percentage by mass of the product as received.  
 
 
C.2 PRINCIPLE  
 
After any grinding required, hydrolysis of a test portion by hydrochloric acid in the presence of ethanol and 
formic acid, thus releasing lipids bound to proteins and sugars and producing in situ ethyl formate which is a 
lipid solvent. Extraction of the fat by hexane in a special flask, removal of th e solvent and weigh ing the residue 
thus obtained.  
 
C.3 REAGENTS  
 
The reagents used shall be of recognized analytical purity and the water used shall be distilled water of at least 
equivalent quality.  
 
C.3.1  n-Hexane , boiling between 68 °C and 70 °C  and having a residue on evaporation of less than             
0.001 g per 100 ml, or failing this, n -hexane boiling between 67 °C and 70 °C and having a residue on 
evaporation of less than 0.002 g per 100 ml (if necessary, the residue on evaporation should  be taken into 
account in the ex pression of results).  
 
C.3.2  Ethanol , 95 per cent (v/v).  
 
C.3.3  Formic Acid,  99 per cent (v/v).  
 
C.3.4  Hydrochloric acid solution,  dilute 7 volumes of concentrated hydrochloric acid p20  =  1.19 g/ml,  with 
3 volumes of water.  
 
C.3.5  Nitrogen.  
 
C.4 APPARATUS  
 
Usual laboratory apparatus and in particular:  
 
C.4.1  Mechanical grinder  
 
C.4.2  Sieve  of aperture size 500 µm.  
 
C.4.3  Water bath  capable  of being thermostatically controlled  at 75 ± 1°C.  
 
C.4.4  Analytical balance . 
 
C.4.5  Distillation apparatus , preferably  a reduced pressure rotary evaporator.  
 
C.4.6  Magnetic stirrer , with PTFE coated bar magnet approximately 0.9 cm in diameter and 4.5 cm long.  
 
C.4.7  Flask for hydrolysis and extraction,  with a ground neck and a side tube of sufficient capacity to 
retain the aqueous phase and a small portion of the hexane phase, and of dimensions and shape similar to 
that shown in Figure 1. The flask shown in Figure 1 is suitable and has a capa city of 317 ml, the capacity of 
the side tube being 51 ml.  
 
C.4.8  Reflux condenser,  to fit the flask (see C.4.7 ) (ground joint 29/32).  
 
C.4.9  Round -bottomed flask of capacity 250 ml,  to fit the distil lation apparatus (see C.4.5) 
 
  
9 
 All dimensions in millimetres  
 
 
 
 
  
Figure 1:  Flask for hydrolysis and extraction (for information only)  
 
 
C.5 PROCEDURE  
 
C.5.1  Preparation of the test sample  
 
If necessary, grind the laboratory sample in the previously well cleaned mechanical gr inder (see C.4.7) to 
produce particles such that 95 per cent shall pass through the sieve (see C.4.2). Mix well before the test 
portion.  
 
C.5.2    Preparation of the flask   
 
Dry the flask (see C.4.9) in an oven and allow it to cool to room temperature in the labora tory atmosphere. 
Then weigh it to the nearest 0.1 mg.  
 
C.5.3  Test portion   
 
Weigh, to the nearest 0.01 g, about 8 g of the test sample and transfer it to the flask for hydrolysis and                        
extraction (see C.4.7) containing the bar magnet of the magnetic stirrer (see C.4.6). 
 
C.5.4  Hydrolysis  
 
Spread the test portion in the bottom of the flask. Add 10 ml of ethanol (see C.3.2), place the flask on the 
magnetic stirrer (see C.4.6), and operate the stirrer until as homogenous a paste as possible is obtained.  
   
10 
 Add 8 ml of the formic acid (see C.3.3) and 12 ml of the hydrochloric acid solution (see C.3.4) and continue 
stirring to homogenize (see C.7). Fit the reflux condenser (see C.4.8) controlled at 75 ± 1 °C, for 20 minutes. 
Remove the reflux condenser, cool the flask and replace it on magnetic stirrer.  
 
C.5.5  Extraction   
 
Place 18 ml of the ethanol (see C.3.2) and 50 ml of the hexane (see C.3.1) in the flask, and stir the mixture for 
5 minutes at the maximum frequency of rotation of the bar magnet that can be used without risk of ejection of 
material from the flask. Allow the mixture to stand until the phases are completely separated.  
 
If necessa ry, accelerate the separation by heating the flask for 20 seconds on the water (see C.7). Transfer 
the hexane phase into the prepared flask (see C.5.2) retaining the aqueous phase in the lateral tube of the 
flask. Rinse the neck of the flask with several d rops of hexane. Place 30 ml of hexane in the flask, stir the 
mixture for 5 minutes, allow the phases to separ ate, then transfer the hexane phase into the flask containing 
the first extract. Repeat the extraction once more, using 30 ml of hexane each time.  
 
C.5.6  Removal of solvent and weighing the residue   
 
Evaporate the solvent contained in the flask, preferably under reduced pres sure; by means of the distillation 
apparatus (see C.4.5). 
 
Immediately after evaporation, pass a stream of nitrogen (see C.3.5) through the flask for 10 minutes. Carefully 
wipe the outside of the flask and allow it to cool to room temperature in the laboratory atmosphere. Then weigh 
it to the nearest 0.1 mg.  
 
C.6. EXPRESSION OF RESULTS  
Total fat content: expressed as a percentage by mass of the product as received, =  
o 
M  M  M 1001 2  
Where,  
 
Mo   =    mass, in g of the test portion ( see C.5.3 ); 
 
M1   =    mass, in g of the flask; and  
 
M2   =    mass, in g of the flask and residue (see C.5.6). 
 
Express the results to the nearest 0.01 per cent.  
 
C.7.  NOTES ON PROCEDURE  
 
If dispersion of the product in the reagents before hydrolysis (see C.5.4) is not possible, or if the decantation 
of the upper phase after extraction by hexane (see C.5.5) is difficult, it is recommended to carry out the 
determination on a test portion of mass less than 8 g, while maintaining the same quantity of reagents.
 
 
 
 
  
ICS 67.060         DMS 1694 :2020 
First  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 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 formulatin g 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.