DRAFT KENYA STANDARD  DKS 3011:2024    
ICS 67.060   
First Edition  
 
 © KEBS 2024  
 Nixtamalization of maize grains  — Code of Practice  
 
 DKS 3011:2024   
ii © KEBS 2024– All rights reserved  
 TECHNICAL COMMITTEE REPRESENTATION  
The following organizations were represented on the Technical Committee:  
Agriculture and Food Authority (AFA)  
Agriculture Sector Development Support Programme (ASDSP)  
Farm Concern International  
Egerton university  
Nairobi County -Division of Public Health  
Government Chemist's  
Kenya Agriculture and Livestock Research Organization (KALRO)  
Kenya Industrial Research and Development Institute (KIRDI)  
Kenya Medical Research Institute (KEMRI)  
Mennonite Economic Development Associates (MEDA)  
Ministry of Agriculture, Livestock, Fisheries and Irrigation  
Ministry of Health — Division of Food Safety  
Ministry of Health — Division of Nutrition and Dietetics  
National Cereals and Produce Board (NCPB)  
National Public Health Labs (NPHL)  
University of Nairobi  
Ministry of Investments, Trade and Industry — State Department for Industry  
World Food Programme (WFP)  
Salim Wazaran Limited  
Nestle Kenya Limited  
Kenya Bureau of Standards — Secretariat  
REVISION OF KENYA STANDARDS  DRAFT KENYA STANDARD                 DKS 3011:2024   
ICS 67.060  
First Edition  
 
© KEBS 202 4 – All rights reserved  iii 
 In order to keep abreast of progress in industry, Kenya Standards shall be regularly reviewed.  
Suggestions for improvements to published standards, addressed to the Managing Director, 
Kenya Bureau of Standards, are welcome.  
© Kenya Bureau of Standards  2023 
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 130 of 2001 
of the Laws of Kenya, copyright subsists in all Kenya Standards and except as provided under 
Section 25 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 mea ns without prior 
permission in writing from the Managing Director.  
  DKS 3011:2024   
iv © KEBS 2024– All rights reserved  
 Nixtamalization of maize grains - Code of Practice  
 
 
  Kenya Bureau of Standards, Popo Road, Off Mombasa Road,  
P.O. Box 54974 - 00200,  Nairobi, Kenya  
 +254 020 6948000, + 254 722202137, + 254 734600471  
 info@kebs.org  
 @KEBS_ke  
 kenya bureau of standards (kebs)  
DRAFT KENYA STANDARD                 DKS 3011:2024   
ICS 67.060  
First Edition  
 
© KEBS 202 4 – All rights reserved  v 
 Foreword  
This draft Kenya Standard has been prepared by the Processed Cereals and Pulses Technical Committee under guidance 
of the Standards Projects Committee, and it is in accordance with the procedures of the Kenya Bureau of Standards. . 
This code stipulates the best practices for nixtamalization of maize grains to ensure that hygiene, health and safety aspects  
are taken into account during preparation and processing of nixtamalized maize products. This Code of Practice is intended 
to prov ide guidance to all stakeholders in the value chain in order to ensure food safety and quality, employee safety and 
welfare, environmental protection, and sustainability. It also intends to improve compliance with Kenyan statutory and 
regulatory  requiremen ts. 
During the development of this standard, reference was made to the following documents:  
a. CXC 1 -1969, General Principles of Food Hygiene  
b. CXG  60 – 2006, Principles for traceability/product tracing as a tool within a food inspection and 
certification system  
Acknowledgement is hereby made for the assistance derived from these sources.  
                                                                                        DKS  
© KEBS 202 4 – All rights reserved  i 
 Contents  ................................ ................................ ................................ ..................  Error! Bookmark not defined.  
Foreword  ................................ ................................ ................................ ................................ ................................ . v 
1. Introduction  ................................ ................................ ................................ ................................ .....................  1 
2. Scope ................................ ................................ ................................ ................................ ..............................  1 
3. Normative References  ................................ ................................ ................................ ................................ .... 1 
4. Definitions  ................................ ................................ ................................ ....... Error! Bookmark not defined.  
5. Acquisition and storage of raw materials  ................................ ................................ ................................ ........  3 
5.1. Maize grains  ................................ ................................ ................................ ................................ ..............  3 
5.2. Calcium hydroxide/Lime  ................................ ................................ ................................ ............................  3 
5.3. Optional ingredients  ................................ ................................ ................................ ................................ .. 3 
6. The nixtamalization process  ................................ ................................ ................................ ...........................  4 
6.1. Preparation of ingredients  ................................ ................................ ................................ .........................  4 
6.2. Boiling  ................................ ................................ ................................ ................................ .......................  4 
6.3. Steeping  ................................ ................................ ................................ ................................ ....................  4 
6.4. Washing  ................................ ................................ ................................ ................................ ....................  4 
6.5. Handling nixtamalized maize products  ................................ ................................ ................................ ...... 5 
6.5.1.  Nixtamalized maize grains  ................................ ................................ ................................ ........................  5 
6.5.2.  Nixtamalized maize flour  ................................ ................................ ................................ ...........................  5 
6.5.3.  Nixtamalized maize dough  ................................ ................................ ................................ ........................  5 
6.5.4.  Nixtamalized fried/baked maize products  ................................ ................................ ................................ .. 5 
7. Packaging and storage of nixtamalized products  ................................ ................................ ...........................  5 
8. Hygiene ................................ ................................ ................................ ................................ ...........................  6 
8.1. Personal hygiene  ................................ ................................ ................................ ................................ ...... 6 
8.1.1.  Health status  ................................ ................................ ................................ ................................ .............  6 
8.1.2.  Personal cleanliness  ................................ ................................ ................................ ................................ . 6 
8.1.3.  Personal behaviour  ................................ ................................ ................................ ................................ ... 6 
8.1.4.  Visitors  6 
8.2. Establishment and equipment  ................................ ................................ ................................ ...................  6 
9. Traceability  ................................ ................................ ................................ ................................ .....................  7 
10. Legal and contractual obligations  ................................ ................................ ................................ ...............  7 
11. Waste management……………………………………………………………………………… …………  7 
 
 DRAFT KENYA STANDARD                             DKS 3011:2024   
 
© KEBS 202 4 – All rights reserved  1 
 1. Introduction  
Maize (Zea Mays L.) is a key food crop in Kenya, benefitting millions of households on food security and economic 
development. It accounts for 31% of the total calories intake  and 28% of the protein intake. Despite depending on maize as 
staple food in Kenya, there are limited ways of processing and utilizing maize, which reduces opportunities for trade and 
health, availability of key nutrients, and increases the exposure to mycotoxins. Macronutrients, mineral s, and antioxidant 
compounds in maize can be reta ined and be made available through nixtamalization or fermentation methods adding 
nutritional benefits to the consumers of the final products.   
Nixtamalization is the  process of preparing maize, in which the grain is boiled  and steeped  in food grade calcium hydroxide 
(, washed, and then dehulled. Nixtamalization offers several benefits to producers and consumers: it broadens and 
diversifies maize utilisation, improves nutritional value, and reduces aflatoxins and fumonisins in the maize grains. 
Additionally, entrepreneurs have found a profitable business venture in the production of nixtamalized products . 
This draft Kenya  code of practice specifies and recommends the best practices for the responsible procurement of raw 
materials, nixtamalization process, safe production  and handling of nixtamalized maize products. These recommendations 
when followed will enhance compliance to legal requirements.  
This Code of practice for the nixtamalization of maize grains recommends practices based on Good Manufacturing Practices 
(GMP) and are generally consistent with Hazard Analysis Critical Control Points (HACCP) principles . These  are incorporated 
into current food safety practices and certification schemes now in  use in the production,  handling, transportation, 
processing, storage, distribution,  and trade of nixtamalized maize products.  
2. Scope  
This Code of practice provides recommended good practices for the acquisition and storage of raw materials, nixtamalization 
process, packaging and handling of finished products of nixtamalized  maize intended for human consumption.  
This code applies to all players involved in nixtamalization of maize including but not limited to households, community,  and 
commercial Food Business Operators (FBOs).  
 
3. Normative References  
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 
of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the 
reference d document (including any amendments) applies. . 
KS EAS 38, Labelling of Prepackaged Foods — Specification  
KS EAS 803, Nutrition Labelling — Requirements  
KS EAS 2, Maize grains - Specifications   
CXS 192, Codex general Standard for Food Additives  
CXC 1, General Principles of Food Hygiene  
CXG  60, Principles for traceability/  Product tracing as a tool within a food inspection and certification system  DKS 3011:2024   
2 © KEBS:2024 – All rights reserved  
 Environment Management and Coordination (Water Quality) Regulation 2006, Section 13 – Fifth Schedule  
Public Health Act Cap 242  
 
4. Terms and definitions  
4.1.  
Nixtamalization   
the process of preparing maize in which the grain is boiled and steeped in food grade calcium hydroxide, washed, 
and then dehulled.  
4.2.  
Steeping   
Soaking of maize  grain in water containing Calcium Hydroxide  
4.3.  
Food grade calcium hydroxide  
is high purity calcium hydroxide acceptable for use in food products.  
4.4.  
Nixtamalized maize grains   
maize grains obtained from nixtamalization.  
4.5.  
Nixtamalized maize products   
 products obtained from nixtamalization of maize grains and/or processing of nixtamalized maize grains.  
4.6.  
 Nixtamalized maize dough  
 the product obtained from the wet grinding of nixtamalized maize grain or kneading of the nixtamalized maize 
flour.  It is also known as masa.  
4.7.  
Dried nixtamalized maize grain   
the product obtained from the drying of nixtamalized maize grains.  
4.8.  
Nixtamalized maize flour   
the product obtained from the milling of dried nixtamalized maize grain  or drying of nixtamalized maize dough.   
4.9.  
Nixtamalized fried/baked products   
 fried/baked products made from nixtamalized maize dough.  
4.10.  
Food Business Operators  
The entity responsible for operating a business at any step in the food chain.  
4.11.  
Good Manufacturing Practices  
a prerequisite programme that establish the basic environmental and operating conditions that ensure production 
of safe and hygienic  food products.  
4.12.  
Establishment   
any building or area in which food is handled and the surroundings under the control of the same management.  
4.13.  
HACCP   
 a system which identifies, evaluates, and controls hazards which are significant for food safety.  
4.14.  
Food handler                                                                                                     DKS 3011:2024  
 
© KEBS 202 4 – All rights reserved  3 
 any person who directly handles packaged or unpackaged food, food equipment and utensils, or food contact 
surfaces and is therefore expected to comply with food hygiene requirements.  
4.15.  
Food safety   
 assurance that food will not cause harm to the consumer when it is prepared and/or eaten according to its intended 
use. 
4.16.  
Contaminant   
Any biological, chemical or physical agent, foreign matter or other substances not intentionally added to food that 
may compromise food safety or suitability.  
4.17.  
Contamination   
The introduction or occurrence of a contaminant in the food or food  environment.  
4.18.  
Traceability  
the ability to follow the movement of a food through specified stage(s) of production, processing and  distribution.   
4.19.  
Potable water  
 Water either in its original state or after treatment , intended for human drinking, cooking, food preparation or other 
domestic purposes, food production, regardless of its origin whether it is supplied from a distribution network, from 
a tanker or in bottles.   
4.20.  
Plasti city 
the ability of the dough to deform under applied pressure.  
5. Acquisition and storage of raw materials  
5.1.  Maize grains  
5.1.1. The maize to be used for nixtamalization shall be sourced from suppliers that comply with prevailing safety 
and quality regulations.  
5.1.2. The specification of the raw maize grain for nixtamalization shall  conform to  KS EAS  2.  
5.1.3. Maize gra ins shall  be stored hygienically and in conditions that will maintain safety and quality status prior to 
nixtamalization. Appropriate storage facilities include metal or plastic silos, hermetic  bags or gunny bags and 
kept abov e the ground and in well-ventilated  rooms.  
5.1.4. Storage facilities shall  be cleaned prior to receiving grain to re move dust, fungal spores, grain/ crop residues, 
animal and insect excreta, soil, insects, foreign material such as stones, metal and broken glass, and other 
sources of contamination.  
5.2.  Calcium hydroxide  
Calcium hydroxide  used for nixtamalization shall  be of food grade quality.  
5.3.  Optional ingredients   
Where optional ingredients such as salt, edible oils/fat, spices, herbs and condiments have  been used, their quality shall  
comply with relevant standards.  DKS 3011:2024   
4 © KEBS:2024 – All rights reserved  
 6. The nixtamalization process  
6.1.  Preparation of ingredients   
6.1.1. Maize grains should  be cleaned by sieving and sorting to remove dust, foreign materials, shrivelled, mouldy 
and damaged grains.  
6.1.2. The cleaned maize grains shall  be thoroughly washed with potable water .. 
6.1.3. Water used in steeping maize shall  be potable.   
6.1.4. The ingredients should be weighed in the appropriate ratios. To steep 1 kg of maize, it is recommended to 
add 10-20 grams  of calcium hydroxide in 3 litres of w ater. 
6.1.5. Care should be taken to avoid contamination of the ingredients.  
6.2.  Boiling  
6.2.1. Boiling of maize in c alcium hydroxide solution shall  be done in non -reactive food grade cooking equipment.  
6.2.2. The required quantities of potable water should be brought to boil before addition  of calcium hydroxide and 
mixed  to dissolve.  
6.2.3. The cleaned maize grains should be added immediately,  and the mixture boiled for approximately 20 - 50 
minutes until slightly cooked depending on grain hardness and type of equipment used. The boiling time per 
hardness is indicated in Table 1.   
Table 1:  Boiling time for different maize grain hardness  
Grain hardness  Boiling  time (mins)  
Soft (flourly maize)  20-25 
Medium (dent maize)  30-35 
Hard (flint maize)  40-50 
 
6.3.  Steeping  
6.3.1. After boiling, the cooking equipment should be removed from  f source of heat  or source of heat  put off.   
6.3.2. The maize grains should be covered and steeped  for a m inimum of 8 hours and a maximum of  of 12 hours.  
6.3.3. A minimum of 8 hours is required for sufficient absorption of calcium  hydroxide ,  reduction of mycotoxin s, and 
enhanced functional properties. .  
6.3.4. The steeping also softens the pericarp, making it easy to remove.  
6.4.  Washing  
6.4.1. After steeping, the pericarp should be removed by hand rubbing the kernels or stirring the mixture  using an 
appropriate equipment . 
6.4.2. The steeping wastewater  should be drained  and the grains thoroughly rinsed 2 to 3 times with similar ratios of 
potable water (1 kg maize: 3 litres water) to remove residual calcium hydroxide.  
6.5     Drying of nixtamalized maize grains  
6.5.1 The nixtamalized maize grains should be dried using  appropriate methods to a moisture content of not more  than 
13.5% within a maximum of two days . 
6.6    Milling nixtamalized maize grains  
6.6.1 Wet Milling  
6.6.1.1  The nixtamalized maize grains shall be ground in a n appropriate   wet milling equipment.                                                                                                    DKS 3011:2024  
 
© KEBS 202 4 – All rights reserved  5 
 6.6.1.2  Controlled amounts  of water should be added during grinding to increase the nixtamalized maize dough 
moisture to the desired level , and to  prevent excessive generation of heat that may lead to  starch over 
gelatinization . 
6.6.1.3  Kneading is required , to ensur e plasticity and cohesiveness of  the nixtamalized maize dough . 
 
6.6.2 Dry Milling  
6.6.2.1   Dried nixtamalized maize grains should be milled using appropriate milling equipment  depending on the 
required particle sizes . 
6.7   Handling nixtamalized maize products  
6.7.1 Nixtamalized maize g rains  
Nixtamalized maize grains should be handled hygienically to  prevent contamination and/or deterioration during storage or 
handling in later processing stages.  
6.7.2 Nixtamalized maize flour  
6.7.2.1  Nixtamalized maize flour should be prepared from properly dried nixtamalized maize grains.  
6.7.2.2  The flour can be prepared through hammer or roller milling to ensure the particle sizes are attained as per 
the flour standard KS EAS 768.  
6.7.2.3  Flour may absorb water on exposure to air  and should therefore be protected from air and moisture  using 
appropriate methods. This  will prevent mould growth and  enhance shelf life of the flour.  
6.7.3 Nixtamalized maize dough  
6.7.3.1     Nixtamalized maize dough should be prepared from the nixtamalized maize grain  through wet milling 
immediately after nixtamalization or  kneading of nixtamalized flour  
6.7.3.2    The dough should be handled hygienically  to prevent any contamination from the handler and environment.  
6.7.4 Nixtamalized fried/baked maize products  
The fried or baked products may be prepared from nixtamalized maize grain, flour or dough. The raw material should be 
sound and of good quality.  
7 Packaging and storage of nixtamalized products  
7.1  Nixtamalized products should be packaged in food grade materials and sealed in a manner that will  safeguard the 
hygienic, nutritional,  and organoleptic properties of the products.  
7.2 The packaging materials should comply with environmental legislation Act Cap 387.  
7.3 The nature of the packaging material should ensure the quality, safety and integrity of the product and should conform 
to KS EAS 38.  
7.4  Nixtamalized maize products should be stored at the recommended storage conditions.  The grains and flour should 
be stored in cool dry places off the floor while the dough should be stored under refrigerated conditions to avoid 
spoilage.  
7.5 Packaged products should be labelled in accordance with KS EAS 38 and KS EAS 803.  DKS 3011:2024   
6 © KEBS:2024 – All rights reserved  
 8 Hygiene  
8.1  Personal hygiene  
8.1.1 Health status  
8.1.1.1   Personnel working in a food facility should have full medical check -ups as per the Public Health Act Cap 2 42 
and the records of the examination well documented.  
8.1.1.2   People known, or suspected, to be suffering from, or to be a carrier of a disease or illness likely to be 
transmitted through produce, should not be allowed to enter the food handling area. Any person so affected 
should immediately report illness or symptoms of illness to the management.  
8.1.2 Personal cleanliness  
8.1.2.1   Food handlers should maintain a high degree of personal cleanliness and, where appropriate, wear 
protective equipment.  
8.1.2.2   Cuts and wounds, where personnel are permitted to continue working, should be covered with suitable 
waterproof dressings.  
8.1.2.3   Personnel should always wash their hands with soap and running water before and after handling foods.  
8.1.3 Personal behaviour  
Food handlers should refrain from behaviour which could result in contamination of products. These may include but not 
limited to:  
i. Smoking;  
ii. Spitting;  
iii. Touching body parts;  
iv. Chewing or eating;  
v. Sneezing or coughing over unprotected food products and;  
vi. Wearing jewellery, watches, pins or other items.  
8.1.4 Visitors  
8.1.4.1  Access to food handling areas shall be restricted and no unauthorised person shall be allowed access to the 
Food stores.  
8.1.4.2  Visitors to food facilities should wear protective clothing and adhere to the other personal hygiene provisions 
in this section.  
8.1.4.3  A record of visitors to the food processing establishment  shall be maintained.  
8.2   Establishment and equipment  
8.2.1 Establishment and equipment used for nixtamalization should be maintained in an appropriate condition to:  
i. facilitate cleaning and disinfection procedures;  
ii. function as intended; and  
iii. prevent food contamination.  
8.2.2 Cleaning products approved for food contact surfaces should be used in food preparation and storage areas.                                                                                                    DKS 3011:2024  
 
© KEBS 202 4 – All rights reserved  7 
 8.2.3 Cleaning and disinfection chemicals should be handled and used carefully and in accordance with 
manufacturers’ instructions, for example, using the correct dilutions and contact times, and stored , separate 
from food, in clearly identified container s to avoid contamination . 
9 Traceability  
9.1 The FBOs should put in place a traceability system by way of designing, implementing,  and monitoring a detailed 
process flow.   
9.2 The system should help the food business operator to trace the product a step before and after.  
10 Legal and contractual obligations  
10.1  The production of nixtamalized maize products shall comply with relevant existing laws and regulations.  
10.2   FBOs shall comply with all applicable licenses, permits and other legal requirements.  
11 Waste management  
11.1   Waste from nixtamalization process may include but not limited to residual calcium hydroxide, waste water, grain 
pericarp, unwanted grains, organic and inorganic materials.  
11.2    An establishment should have adequate provisions for waste management. The  FBO shall ensure that wastewater 
from nixtamalization should be pretreated  before disposal.  
11.3   Construction of wastew ater treatment facilities should be environmentally acceptable  and subject  to National 
Environmental Management Authority (NEMA) regulations.  
 
 
 
 
 DKS 3011:2024    
 
© KEBS 2024 – All rights reserved