DRAFT KENYA STANDARD     DKS 169: 2009 
                                                                                                     I CS ICS 67.060 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Wheat flour — Specification   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
©KEBS 2009            Fourth Edition 2009 
 
 
 
 
 DKS 169: 2009 
 
  © KEBS 2009 — All rights reserved  ii  
 
 
TECHNICAL COMMITTEE REPRESENTATION 
 
The following organizations were represented on the  Technical Committee: 
 
National Cereals and Produce Board 
Ministry of Health — Department of Public Health 
— Division of Nutrition 
Egerton University 
Pembe Flour Mills Ltd. 
Nestle Foods 
Unga Ltd. 
Cap[well Industries Ltd 
Proctor and Allan (EA) Ltd. 
Ministry of Trade and Industry — Department of Indu stry 
Government Chemist’s Department 
Jambo Biscuits Ltd. 
Consumer Information Network (CIN) 
Kenyatta National Hospital 
Kenya Bureau of Standards ― Secretariat  
 
 
 
 
 
 
REVISION OF KENYA STANDARDS 
 
In order to keep abreast of progress in industry, K enya Standards shall be regularly reviewed. Suggest ions for 
improvements to published standards addressed to th e Managing Director, Kenya Bureau of Standards, are  
welcome. 
 
 
 
 
 
© Kenya Bureau of Standards, 2009 
 
Copyright. Users are reminded that by virtue of Sec tion 25 of the Copyright Act, Cap. 12 of 2001  of t he Laws of Kenya, copyright subsists in 
all Kenya Standards and except as provided under Se ction 26 of this Act, no Kenya Standard produced by  Kenya Bureau of Standards may 
be reproduced, stored in a retrieval system in any form or transmitted by any means without prior perm ission in writing from the Managing 
Director. 
 
 
 
 
 
 
 
  
© KEBS 2009 — All rights reserved  iii DRAFT KENYA STANDARD                            DKS  169: 2009 
                                      ICS 67.060  
 
 
 
 
 
 
 
 
 
 
 
 
 
Wheat flour — Specification 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
KENYA BUREAU OF STANDARDS (KEBS) 
 
Head Office:  P.O. Box 54974, Nairobi-00200, Tel.: (+254 020) 605 490, 602350, Fax: (+254 020) 604031 
E-Mail: info@kebs.org,  Web:http://www.kebs.org  
 
Coast Region    Lake Region         Rift Valley Reg ion  
P.O. Box 99376, Mombasa-80100  P.O. Box 2949, Kisum u-4010                  P.O. Box 2138, Nakuru-20100  
Tel.: (+254 041) 229563, 230939/40               Te l.: (+254 057) 23549, 22396                Tel.: (+ 254 051) 210553, 210555 
Fax: (+254 041) 229448   Fax: (+254 057) 21814 
 
 DKS 169: 2009 
 
  © KEBS 2009 — All rights reserved  iv  Foreword 
 
This Fourth Edition of KS 169 was prepared by the T echnical Committee on Processed Cereals and Pulses and 
it is in accordance with the procedures of the Keny a Bureau of Standards. 
 
This standard  incorporates the specific compositio nal requirements for both fortified and non-fortifi ed wheat 
flour. The standard has prescribed the permissible levels of food additives in wheat flour. Microbiolo gical 
requirements for wheat flour have also been stipula ted. 
 
This revision was done mainly to provide a guidelin es of formulation of premix to be used in fortifica tion as well 
as to align the microbiological limits in line with  the best international practices 
 
 
During the preparation of this standard, reference was made to the following documents: 
 
Methods for microbiological examination of foods by  Mossel, D.A.A. and Taminga, S.K. ( Third Edition ). 
 
Technology of cereals by N.L. Kent ( 1998 Fourth Edition ). 
 
Guidelines on food fortification with micronutrient s, 2006, WHO/FAO 
 
Acknowledgement is hereby made for the assistance d erived from these sources. 
 
  
© KEBS 2009 — All rights reserved  1  
DRAFT  KENYA STANDARD                                                  DKS 169: 2009 
 
Wheat flour — Specification 
1 Scope  
This Draft Kenya Standard specifies the requirement s and methods of test for both fortified and non-fo rtified 
wheat flour (other than durum wheat flours) intende d for baking and other modes of human consumption . 
 
2 Definitions 
 
For the purposes of this standard, the following de finitions shall apply: 
 
2.1 
wheat flour  
is the product made from milling clean wheat grains  conforming to the requirements of KS 01-136, Speci fication 
for wheat grades 
 
2.2 
Fortified/enriched wheat flour  
product prepared from grain of common wheat, Triticum aestivum L., or club wheat, Triticum 
compactum wheat, Triticum aestivum L., or mixture thereof, by grinding or milling proc esses in which 
the endosperm is comminuted to a suitable degree of  fineness to which nutrients have been added in 
accordance with this standard 
 
2.3 
white wheat flour  
is the wheat flour obtained by milling wheat grains  at low extraction rates that  leaves negligible amounts of bran  
 
2.4 
bakers flour  
white wheat flour obtained by milling high protein wheat intended for bread making 
 
2.5 
household or home baking flour 
white wheat flour obtained by milling wheat grades or blends of hard and soft wheat intended for domes tic use 
 
2.6 
biscuit flour 
white wheat flour obtained by milling a blend of ha rd and soft wheat with a high percentage of soft wh eat for 
biscuit manufacture 
 
2.7 
cracker flour  
 {white wheat flour obtained by milling  wheat with  no improvers} 
 
2.8 
self-raising flour  
white wheat flour obtained by milling a blend of so ft and hard wheat to which raising agents are added  
 DKS 169: 2009 
 
  © KEBS 2009 — All rights reserved  2  
 
2.9 
standard flour  
wheat flour obtained by milling wheat grains at a h igher extraction than home baking flour 
 
2.10 
wholemeal flour 
wheat flour obtained by milling the entire wheat gr ain to fine particle size without any separation  
 
2.11 
atta flour 
wheat flour to which pollard or other material has been added to increase the coarseness of the flour 
2.11 
diluent  
a suitable, inert, food-grade carrier for micronutr ients  
2.12 
fortificant  
prescribed compound which provides a specified micr onutrient  
 
2.13 
Premix 
a blend of fortificants and diluents formulated to provide specified and determinable amounts of micro nutrients 
 
3 Quality requirements 
3.1 General requirements for wheat flour 
3.1.1  All types of wheat flour shall have the characteris tic colour and shall be free from any objectionable  
flavours and odours . 
3.1.2  The flour shall be free from insects, worms, fungal  infestation, rodent contaminations and foreign mat ter. 
3.1.3  The flour shall not contain flour from other cereal s. However, the addition of malted barley flour not  
exceeding 1 % is permissible in the case of baker’s  flour. 
3.1.4 The flour shall be produced under GMP conditions. 
3.1.5  The shelf life shall be three months for wholemeal , standard flour and atta, but six months for other  types 
wheat flours. 
3.2 Compositional requirements for wheat flour  
3.2.1  The types of wheat flour shall comply with the com positional requirements given in Table 1 and shall 
be free of bromates. 
 
 
 DKS 169: 2009 
 
© KEBS 2009 — All rights reserved    3 3.2.2 Self-raising flour 
In addition to the specifications in Table 1, compo sitional requirements for self-raising wheat flour may contain 
the following: 
 
3.2.2.1 Edible salt conforming to KS 05-229,  Specification for edible salt. 
 
3.2.2.2 Acid ingredients  
 
The acid ingredients shall be one or any combinatio n of the following: 
 
i) sodium acid pyrophosphate;  
 
ii) mono acid calcium phosphate; 
 
iii) sodium aluminium phosphate;  
 
iv) disodium bicarbonate shall be in sufficient amo unts to provide not less than 0.4 % of available ca rbon  
dioxide. 
 
 
 
Table 1 — Compositional requirements/limits 
 
Sl No. Types of flour Moisture 
content, 
max. %, 
m/m Fibre 
content, 
max. %, 
m/m Total ash 
content, 
max. %, 
m/m Residue on 
sieving 
through 180 
micron-sieve,  
max. % Protein 
content, 
min. %, 
m/m Mixture of acid-
ingredients and sodium 
bicarbonate added,  
max . %,  m/m  
i) 
 White wheat 
flour:       
Baker’s flour 13.5 1.0 0.70 0.80 11.0 – 
Home baking 
flour 13.5 1.0  0.70 0.80 9.0 – 
Biscuit flour 13.5 1.0 0.55 0.50 8.0 – 
Cracker flour 13.5 1.0 0.70 0.50 10.0 – 
Self-raising flour 13.5 1.0 2.0 0.80 8.0 4.5 
ii) Standard flour 13.5 1.5 1.10 30.0 11.0 – 
iii) Atta flour 13.5 2.0 2.0 55.0 12.0 – 
iv) Whole-meal 
flour 13.5   
2.0 
 2.0 30.0 12.0 – 
v) Test methods KS 171, 
Part   1 a)  KS 171, 
Part 1 KS 171: 
Part 2  b)  KS 171: Part 1 KS 171, 
Part 3 c)  KS171, Part 1 DKS 169: 2009 
 
  © KEBS 2009 — All rights reserved  4  
a)  Milled cereals products — Part 1: Moisture determi nation. 
 
b)  Milled cereals products — Part 2: Total ash determ ination. 
 
c)  Milled cereals products — Determination of protein  in animal feedstuffs, cereal and cereal products, meat and meat products 
using Kjectec auto analyzer. 
 
 
4 Heavy metal contaminants  
 
When tested in accordance to Atomic Absorption Spec trophotometry (AAS)  
 
Table 2 — Limits for heavy metal contaminants in wh eat flour 
 
Sl no Contaminant Maximum limit ppm 
i) Arsenic (As) 1.0 
ii) Lead (Pb) 0.2 
iii) Cadmium 0.2 
   
 
5 Permissible additives  
 
For improving the quality of flour, the following s ubstances may be added in quantities specified in K S 05-660, 
Specification for food additives, and those given i n the Food, Drugs and Chemical Substances Act, Cap.  254 of 
the Laws of Kenya. 
 
5.1 Improvers  
 
Improvers may be added singly or in combination, in cluding but not limited to: 
 
Maximum permitted level (mg/kg) 
 
i) L. ascorbic acid and its sodium and potassium sa lts300 ppm 
 
 
iii) mono calcium phosphate    2 500  
 
iv) chlorine dioxide      30  
 
v) L-cystein hydrochloride     90 
vi) Sulphur dioxide (In  flour for biscuits & pastr y)  200 
vii) Lecithin      2000 
 
NOTE Azordicarbonamide (ADA) shall not be used at a ll. 
 
5.2 Bleachers (added singly)     
 
Maximum permitted level 
 
i) benzoyl peroxide     60 ppm 
 DKS 169: 2009 
 
© KEBS 2009 — All rights reserved    5 5.3 Diastatically actives (singly or combined ) 
 
Maximum permitted level  
 
i) malt flour (milled from highly diastatic barley)     GMP 
  
ii) fungal enzyme (amylozyme or MYL-X)   GMP 
 
NOTE  All food additives shall be of food grade qua lity.  
 
6 Wheat flour fortification/enrichment 
 
6.1 The fortification of wheat flour with vitamins and minerals is optional. Any wheat flour that is decla red as 
fortified with vitamins and minerals shall comply w ith the specification in Table 3. 
 
6.2 Wheat flour shall only be fortified with the forms of fortificants and the number of nutrients as indi cated in 
Table 3: 
 
Table 3 — Wheat flour fortification requirements 
 
Nutrient  Fortification compound  Recom mended 
factory average 
(mg per kg) Regulatory requirements 
(mg/kg) 
Minimum  Maximum  
Vitamin A Vitamin A palm. SD 2 ± 1 0.5 3.0 
Thiamine (Vit. B1) Thiamin mononitrate 10 ± 5 5.0 1 5 
Riboflavin (Vitamin B2) Riboflavin 6 ± 3 2.5 9 
Niacin (Vitamin B3) Niacinamide 60 ± 15 40 75 
Folates Folic acid 1.5 ± 1 0.5 2.5 
Pyrodoxine (Vitamin 
B6) Pyrodoxine 6.5 ± 3.5 3.0 10 
Cobalamine (Vitamin 
B12) Vitamin B12 0.1% WS 0.015 ± 0.005 0.005 0.025 
Iron Ferrous fumerate 
 40 ± 10 30 50 
 Total iron 
 50 ± 10 40 60 
Zinc Zinc oxide 40 ± 10 30 50 
 
 
6.3 Premix Formulation 
6.3 .1 The levels provided in table 4 provides a gu ideline for fortificants in the formulation of prem ix for maize 
fortification 
6.3 .2 The activity levels of the various nutrients  shall conform to the requirements provided in tabl e 4 
6.3 .3 The premix package should be labeled with th e recommended addition rate in grams of premix per metric 
ton of wheat flour and the proposed dilution factor . 
6.3 .4 The  supplier of the premix should provide an accompani ng stability data for the fortificants and premixes . DKS 169: 2009 
 
  © KEBS 2009 — All rights reserved  6  
Table 4 – Guidelines for premix formulation 
 
Nutrient  Fortificant 
compound Activity level  
( minimum) Fortificant (g/kg of 
premix, min. 
Vitamin A  Retinyl Palmitate - 
250 IU/g (dry) 0.075  53.3  
Vitamin B1  Thiamin mononitrate  
 0.81  19.8  
Vitamin B2  Riboflavin  
 1 10  
Niacin  Niacinamide  
 0.99  121.2  
Vitamin B6  Pyridoxine  
 0.82  14.6  
Folates  Folic Acid  
 0.9  6.5  
Vitamin B12  Vitamin  B12 0.1 % 
WS 0.1  30  
Iron  NaFeEDTA  0.32  187.5  
Zinc  Zinc Oxide  0.8  75  
Diluent  477.1  
Total  1000  
Note 1:  The premix formulated based on this guidelines shal l have an addition rate of 
500 g of the premix per metric ton of maize flour ( Dilution factor 1/2000). 
Note 2:  This premix formulation is designed with minimum n utrient composition and 
does not take into consideration factory overages a nd other losses that may occur in 
the preparations of the premix. 
 
 
 
7 Hygiene 
 
7.1  flour shall be manufactured in premises complying with the hygienic practices stipulated in the Publi c 
Health Act, Cap. 242, the Food, Drugs and Chemical substances Act, Cap. 254 of the Laws of Kenya  and KS 
05-1500, Code of practice for food and drink manufa cturing industry.  
 
7.2 Microbiological limits   
 
The flour shall not contain any pathogenic microbes  and shall also comply with the microbiological lim its given in 
Table 4. 
 
 
 
 
 
 
 DKS 169: 2009 
 
© KEBS 2009 — All rights reserved    7 Table 4 — Microbiological requirements 
 
Sl no. Types of micro-organism Max. number of 
counts permissible Test method  
i) Total viable counts 10 5 per g 
KS 05-220 a)  ii) Coliforms,  per g Shall be absent 
iii) Escherichia coli, per g Shall be absent  
iv) S. aureas,  per g  Shall be absent 
v) Salmonella,  per 25 g  Shall be absent  
vi) Yeasts and moulds, per g  10 4 
vii) Bacterial rope spore count, per g  10 2 Annex A 
a)  Methods for the microbiological examination for fo ods. 
 
 
 
 
7.3 Aflatoxin  
 
The total aflatoxin level shall not exceed 10 ppb, with aflatoxin B 1 not exceeding 5 ppb when tested in 
accordance with KS ISO 16050, Foodstuffs — Determin ation of aflatoxin B 1, and the total content of aflatoxins 
B1, B 2, G 1 and G 2 in cereals, nuts and derived products — High-perfo rmance liquid chromatographic method. 
 
8 Packaging 
 
8.1  The product shall be packed in food grade material  that ensures product safety and integrity. 
 
8.2  The package fill shall comply with the Weights and  Measures Act, Cap. 513 of Laws of Kenya. 
 
9 Labelling  
 
9.1 In addition to the provisions of KS 05-40, Labe lling of prepackaged foods, the following shall be legibly and 
indelibly marked: 
 
i) name and type of product; 
 
ii) brand name; 
 
iii) name and physical address of the manufacturer/ packer/importer; 
 
iv) batch or code number;  
 
v) declaration of additives used; 
 
vi) net weight, in g or kg;   
 
vii) date of manufacture; 
 
viii) expiry date; 
 
ix) storage instruction; DKS 169: 2009 
 
  © KEBS 2009 — All rights reserved  8  
x) declared as “Human Food”; 
 
xi) where a product has been fortified, statement d eclaration, “Fortified with vitamins and minerals o r the 
fortification logo or both” shall be included on th e label. 
 
xii) country of origin; 
 
 
xiv) Caution “Store and transport away from any con taminants such as soaps, detergents, petroleum 
products, spices and other aromatic substances”. 
 
 
9.2  Any Health and/or Nutrition claim on maize flour sh all conform to the provisions of KS CAC/GL 23 
Guidelines for nutrition and health claims.  
 
 
Annex A 
(normative) 
 
Determination of bacterial rope spore count 
 
A.1 Reagents 
 
A.1.1  Peptone water , 0.1 %, sterilized. 
 
A.1.2  Tryptone glucose, (extract (TGE) agar. 
 
A.1.3  Tryptone , 5.0 g.  
 
A.1.4 Yeast extract , 2.5 g.  
 
A.1.5  Glucose (dextrose),  1.0 g. 
 
A.1.6  Sodium chloride , 6.5 g. 
 
A.1.7 Agar , bacteriological grade (see Note) 15.0. 
 
A.1.8 Wate r, distilled,1 000.0 mL. 
 
A.1.9 Final pH , 7.0 + 0.1. 
 
NOTE Granulated or chopped shreds, practically free  from thermophilic bacteria, shall be used. 
 
A.2 Procedure 
 
A.2.1  Weigh 22 g of flour in a suitable sterile containe r and transfer to 100 mL of sterile 0.1 % peptone w ater in 
a conical flask containing sterile sand or glass be ads. Disperse by blending on a shaker for about 2 m in.  Dilute 
the blended material further 1:10, 1:100, 1:1 000, 1:10 000, etc., by dilution technique, using steril e peptone 
water. 
 
A.2.2 Prepare tryptone glucose extract (TGE) agar or any  other suitable medium 100 mL per 250 mL conical 
flask.  Prepare one additional flask of medium to s erve as a sterility control.  Sterilize at 121 °C f or 15 min and 
then cool to 45 °C in a water bath.  Pipette volume s of blended material into a set of flasks of TGE a gar while DKS 169: 2009 
 
© KEBS 2009 — All rights reserved    9 they are held in the water bath; 10 mL into the fir st, 1 mL into the second and 1mL of each dilution i nto the third, 
fourth and fifth TGE flask, and so on.  Gently agit ate the flask to disperse the blended material thro ughout the 
medium. 
 
A.2.3 Transfer the flask without delay to a water bath a djusted to 85 °C to 90 °C and hold for 30 min with 
gentle shaking occasionally to assist heat distribu tion. After 30 min of heat treatment, cool the flas ks to about 45 
°C without allowing the agar to congeal. Pour the 1 00 mL medium in each flask representing the test ma terial 
and sterility control into a set of 5 sterile petri  dishes in approximately equal volumes that is abou t 20 mL per 
plate.  When agar has solidified, invert the plates  and incubate at 35 °C for 48 h. 
 
A.2.4 Count the surface and sub-surface colonies.  The s um of the colonies on the set of 5 plates poured fr om 
TGE agar, containing 10 mL of blended food material  represent the number of aerobic and mesophilic spo res 
per gram of material.  Similarly, 1 mL of the blend ed and 1 mL of each dilution are equal to 0.01, 0.0 01 per gram, 
and shall be multiplied by the respective dilution factor. Generally, the set of plates showing about 30 – 60 
colonies per plate are to be chosen for counting pu rposes. 
 
 
A.3 Precautions and limitations 
 
A.3.1  The procedure permits enumeration of aerobic and m esophilic spores in food samples containing 
relatively higher number of spores by higher diluti on of the sample prior to heat treatment. 
 
A.3.2 Certain thermophilic strains may also be indicated  in this method in which case these shall be 
determined with an additional pre-heat treatment at  150 °C – 200 °C (to knock off all spores and accou nt only for 
thermophiles) and their numbers be subtracted from the spore count.