Diversity of Micro, Small and Medium Cereal Milling Enterprises in Nairobi County, Kenya and Levels of Aflatoxins in Their Milled Products

Abstract

In Kenya, aflatoxicosis is a major public health problem and several outbreaks have occurred in the past due to the consumption of contaminated maize and maize products. Even when there are no reported cases of illness or deaths, it is believed that the consumer is constantly exposed to sub-lethal doses of the toxin. The maize products consumed include meals and flours either pure or in admixture with other cereal flours. The mixes are manufactured by small scale millers found widespread in the county who do very little quality control on their products. This study was designed to establish the nature, diversity and usage of milled flour products from Micro, Small and Medium Enterprises (MSMEs) in Nairobi County and also assess levels of aflatoxin contamination in the products. Questionnaires were administered to 107 MSMEs and a total of 32 flour samples of maize, sorghum, finger millet and peanut were collected for analysis of aflatoxin. Results showed that of the 168 MSMEs registered by the Nairobi City Council in the year 2013, most were Micro enterprises. The total aflatoxin levels in the flour samples ranged from 2,190.30–<1µg kg-1. Of each of the 8 flour samples of maize, sorghum and peanut tested, 3, 6 and 5 respectively had aflatoxins levels above the national tolerable level of total aflatoxin in human food of 10 µg kg-1 (Kenya Bureau of Standards 2013). Peanut flour had the highest mean total aflatoxin level contamination at 304.51 µg kg-1. The mean total aflatoxin levels in maize, sorghum and millet flours were 59.73 µg kg-1, 39.21 µg kg-1 and 34.80 µg kg-1 respectively. The study established that there is a great diversity of flours and their mixes supplied by MSMEs in Nairobi. The individual pure flours were however contaminated with aflatoxins above the tolerable limits. The flour mixes would also have similarly high levels of aflatoxin.