| dc.description.abstract | Maize is the basic staple of the Kenyan diet. Ugali, a thick porridge of maize meal, is the main dish. Other maize based dishes include boiled mixture of maize and beans (githeri) which when the maize kernels are decorticated, is referred to as muthokoi, and cooked mash of maize, beans, vegetables and potatoes, referred to as irio. Other staple fO,ods include cereals like sorghum, millet, legumes, pulses and rice, cassava, sweet potatoes, fruits and vegetables. Milk and dairy products are also important items in the country, but especially among the pastoral communities. A wide variety of agricultural products worldwide, have been found to be contaminated by aflatoxins. Aflatoxicosis has repeatedly occurred Kenya.
This study was designed to examine the consumption patterns of maize products and other foods in Kibwezi District and assess the exposure of households to aflatoxins through consumption of maize and maize products. Multi-stage sampling was used to select 72 households for the study from the three (3) divisions of the district with 24 households being randomly sampled from each division using a sampling interval of 2 households. A previously pretested structured questionnaire was used to collect data on the socio-demography of the household, diversity of foods consumed and the frequency of their consumption. Twenty samples, each of maize kernels, muthokoi and maize meal were randomly sampled from households in the three divisions of Kibwezi District.
The samples were transported to the laboratory for aflatoxins analysis. Each sample was qualitatively screened for the presence of aflatoxins using Thin Layer Chromatography method and then the positive samples analyzed quantitatively for the toxins using High Performance Liquid Chromatography. Total aflatoxins exposure (ug/kg body weight (bw)/day) was determined from multiplying the average daily per capita maize and maize products consumption (kg) by the total aflatoxins level in maize and maize products (ug/kg).
For each household the figure was divided by an average body weight of an adult of 60 kg. The results on socio-demography showed that the households had a total of 298 residents of which 45 % were males and 55 % females with an average family size of 4ﾱ1.3. Those aged below 5 years were 15 %, while those aged between 6 - 12 years and 13 - 18 years were 18 % and 12 % respectively. The results further showed that 9 % of the residents had attained college and university education while 20 % had completed secondary education. Those who had completed primary education only were 27 % and those without formal schooling were 9 % .
Results on diversity of foods consumed revealed that 44 % of the respondents consume ugali seven times in a week, and about 10 % of the households consumed it more than ten times a week. Githeri was consumed seven times a week by 35 % of the families. Consumption of muthokoi was once a week by 25 % of the families, and porridge was consumed seven times by 21 % of the families. Of the other foods, the most commonly consumed 'foods included rice and finger millet, roots and tubers. Less than 50 % of families consume sorghum, irish potatoes, cassava, sweet potatoes, bananas mash in a week. Sorghum was rarely consumed by 86 % of the respondents, while 6 % consumed it once a week.
The consumption of fruits and vegetables was varied. Kales were highly consumed by 47 % of respondents seven times a week. Less than 50 % of the families consumed pawpaw, mangoes, oranges, carrots, cowpeas, amaranth black and nightshade. Milk had high frequency of consumption with 79 % of the respondents taking milk seven times a week. Fish was poorly consumed by 7 % of families Of the 20 samples, each of maize kernels, muthokoi and maize meal, 45 % maize kernels were found to be contaminated with aflatoxins while 20 % and 35 % of muthokoi and maize meal, respectively, were also contaminated.
The maize kernels, muthokoi and maize meal were found contaminated with aflatoxins at levels between 18000 - 480000 ng kg', 12000 - 123000 ng kgI, and 6000 - 30000 ng kg' respectively. The uncertainty and variability in dietary exposure was quantitative modeled in Ms Excel spreadsheet using Monte Carlo simulation in @Risk software. The mean probability of dietary exposure to aflatoxin in maize kernels was 291.66 ﾱ 1566.70 ng kg-I body weight day -I while the mean probability of dietary exposure to aflatoxin in maize meal and muthokoi were 59.31 ﾱ..62.45 ng kg' body weight day -I and 27.23 ﾱ 154.44 ng kg-I body weight day -I respectively.
The study established that the community in the district consumes a diversity of foods but maize was found to be the most commonly consumed by the families as ugali, but also as githeri, muthokoi, porridge and irio. According to the present results, individuals who would be exposed to total aflatoxins levels above the national maximum tolerable limits of 1 0 ug kg' would be 28 % of the households which participated in this study. According to the findings of this study, we recommend that the diversity of maize and other foods and their frequency of consumption by households should be considered when developing official food control measures and food safety policies; consumers should be educated on precooking practices such as thorough sorting of kernels and washing of kernels before preparation of githeri, muthokoi and irio or milling of maize flour; and the government-food safety regulators should initiate a national study on dietary exposure in order to generate data for the development of science based maximum tolerable limits for aflatoxins and implementation of feasible strategies in prevention and control of aflatoxins exposure in Kenya.
Keywords: maize kernels, githeri, muthokoi, maize meal, diversity, aflatoxins, Kibwezi | en_US |
