| 1. |
- Atsa'am, Donald Douglas, et al.
(author)
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K-means cluster analysis of the West African species of cereals based on nutritional value composition
- 2021
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In: African Journal of Food, Agriculture, Nutrition and Development. - : Africa Scholarly Science Communications Trust (ASSCAT). - 1684-5358 .- 1684-5374. ; 21:1, s. 17195-17212
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Journal article (peer-reviewed)abstract
- The K-means algorithm was deployed to extract clusters within the prevalent cereal foods in West Africa. The West Africa Food Composition Table (WAFCT) presents all the 76 food sources in the cereals class as a single group without considering the similarity or dissimilarity in nutritional values. Using K-means clustering, the Euclidean distance between nutritional values of all cereal food items were measured to generate six subgroups based on similarity. A one-way analysis to validate the results of the extracted clusters was carried out using the mean square values. For every nutrient, the “within groups” and “between groups” values of the mean squares were examined. This was done to ascertain how similar or dissimilar data points in the same or different clusters were to each other. It was discovered that the P values for all “between groups” and “within groups” mean squares for every nutrient was P < 0.01. Additionally, it was observed thatin all cases, the mean square values of the “within groups” were significantly lower than those of the “between groups”. These outcomes are indications that clustering was properly done such that the variability in nutrient values for all food sources within the same clusters was significantly low, while those in different clusters were significantly high. Thus, the ultimate objective of clustering, which is to maximize intra-cluster similarity and minimize inter-cluster similarity was effectively achieved. Cluster analysis in this study showed that all food items within a particular cluster are similar to each other and dissimilar to food items in a different cluster. These findings are valuable in dietaries, food labeling, raw materials selection, public health nutrition, and food science research, when answering questions on the choice of alternative food items. Where original choices are not available or unaffordable, the clusters can be explored to select other similar options within the same cluster as the original choice.
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| 2. |
- Lindahl, Johanna
(author)
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Aflatoxin B1 occurrence in millet, sorghum and maize from four agro-ecological zones in Kenya
- 2016
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In: African Journal of Food, Agriculture, Nutrition and Development. - 1684-5358 .- 1684-5374. ; 16, s. 10991-11003
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Journal article (peer-reviewed)abstract
- Aflatoxin-contaminated food is a public health concern. Contamination of staple foods in Kenya has in the past led to loss of human lives as well as condemnation of large quantities of food, contributing to food insecurity. This study investigated the occurrence of aflatoxins in maize, millet and sorghum from five counties in Kenya (Kwale, Isiolo, Tharaka-Nithi, Kisii and Bungoma) representing four agro-ecological zones (AEZs). Samples were collected from rural households in two phases between February and October 2014. Using competitive enzyme-linked immunosorbent assay (ELISA), 497 maize, 205 millet and 164 sorghum samples were screened for the presence of aflatoxin B1. Overall, 76% of maize, 64% of millet and 60% of sorghum samples were positive for aflatoxin B1. Of these, the proportion of samples with aflatoxin B1 levels above the Kenya Bureau of Standards limit of five parts per billion was 26% for maize, 10% for millet and 11% for sorghum. In samples collected during the second phase, there were significant differences in the mean levels of aflatoxin contamination between the agro-ecological zones (p < 0.05); maize from Kisii and Bungoma, representing temperate AEZ, had the lowest mean contamination, whereas millet and sorghum from Tharaka-Nithi (humid) and Isiolo (semi-arid), respectively, had the highest mean contamination. Continued exposure to aflatoxins via food in Kenya poses a threat to human health.
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| 3. |
- Lindahl, Johanna
(author)
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Aflatoxin exposure among young children in urban low-income areas of Nairobi and association with child growth
- 2016
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In: African Journal of Food, Agriculture, Nutrition and Development. - 1684-5358 .- 1684-5374. ; 16, s. 10967-10990
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Journal article (peer-reviewed)abstract
- Populations in tropical and subtropical developing countries are exposed to largely uncontrolled levels of aflatoxins through food. These countries (especially in Africa and Asia) also present a high prevalence of stunting. Studies have reported an association between aflatoxin exposure and growth impairment in children but there is not yet conclusive evidence that aflatoxins are a significant cause of stunting in children, thus further research is warranted. In this cross-sectional study, 204 low-income households were randomly selected in two low-income areas of Nairobi, Kenya. Korogocho is a higher population density area and Dagoretti a lower population density area. We asked questions about household demographics and a 24-hour dietary recall was conducted in children aged 1-3 years. Child anthropometric measurements were also conducted. Height-for-age Z-scores (HAZ), weight-for-age Z-scores (WAZ) and weight-for-height Z-scores (WHZ) were calculated for each child using World Health Organization (WHO) growth standards reference data. Samples of foods were taken from the household or from the retailer for analysis using competitive enzyme-linked immunosorbent assay (ELISA). Laboratory results for aflatoxin levels in the food samples collected were used to calculate the daily aflatoxin intake, according to the results from the dietary assessment. The study found 41% of children sampled had stunted growth. Boys were more stunted than girls (p=0.057) and Korogocho had more stunted children than Dagoretti (p=0.041). In all, 98% of food samples collected tested positive for aflatoxin and there was an average exposure to aflatoxins of 21.3 ng/kg bodyweight per day. Exposure to aflatoxin M1 (AFM1), location and sex were significantly associated with HAZ, with boys and children from Korogocho having lower HAZ, and AFM1 was negatively associated with HAZ (p=0.047), indicating that AFM1 was associated with stunting. There was no association between total aflatoxins (aflatoxin B [AFB] and aflatoxin G [AFG]) and HAZ, WAZ and WHZ. The study showed a high prevalence of malnutrition, especially stunting, in two low-income urban sites, and this was most pronounced in the high-density area. The reported association between AFM1 and stunted children indicates that more research is needed on the health impacts of this aflatoxin in growing children.
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| 4. |
- Lindahl, Johanna
(author)
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Mycotoxin hazards in the Kenyan food and feed market-a retrospective study
- 2022
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In: African Journal of Food, Agriculture, Nutrition and Development. - : African Journal of Food, Agriculture, Nutrition and Development. - 1684-5358 .- 1684-5374. ; 22, s. 19306-19325
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Journal article (peer-reviewed)abstract
- Mycotoxins are toxic fungal metabolites naturally found in food and feed as contaminants. Animal feed and human food samples (n=1818) from three major Kenyan laboratories were categorized as compliant and non-compliant according to Kenya, America (USA) and Europe (EU) mycotoxin regulatory limits. Quantitative risk assessment of dietary aflatoxin intake in maize, wheat, peanut and dairy products in relation to human hepatocellular carcinoma was carried out employing deterministic approach. Non-compliant samples’ proportions were calculated, and logistic regression and chi-square test used to compare different commodities. Animal feed were least compliant, with 64% and 39% having total aflatoxin (AFT) levels above Kenya and USA standards, respectively. Peanuts were the most non-compliant food, with 61% and 47% samples failing Kenya and USA AFT standards respectively, while wheat was least compliant (84%) according to EU threshold for AFT. Half of baby food sampled had AFT level above Kenya and EU standards. High non-compliance rate with Kenya, USA and EU regulatory thresholds with respect to seven different mycotoxins (summarized as “mycotoxins”), and also AFT and aflatoxin M1 alone in edible materials is reported. Significant non-compliance is reported for compound animal feed, peanuts, wheat, baby food, feed ingredients, herbal healthy drink, maize and fodder feed in that order. High levels of aflatoxin residues in animal feed and human food was also observed. Lifetime human consumption of wheat and maize leads to high additional risk for primary liver cancer, human hepatocellular carcinoma (HCC) associated with dietary aflatoxin, wheat and its products causing the highest disease burden. Subsequent implications and limitations of current food safety standards are discussed. Humans and animals in Kenya appear to be chronically exposed to mycotoxin hazards: this calls for surveillance and risk management. There is urgent need for enhanced and consistent surveillance of the dietary mycotoxin hazards observed in this study employing representative sampling plans. Regulation and future research need to focus on reliable analysis techniques, collection of data on toxicological effects of mycotoxins and food consumption pattern, and regulatory limits accordingly set and compliance enforced to protect vulnerable groups such as paediatric, geriatric and sick members of the society to reduce cancer burden in Kenya
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| 5. |
- Lindahl, Johanna
(author)
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Prevalence of aflatoxin in feeds and cow milk from five counties in Kenya
- 2016
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In: African Journal of Food, Agriculture, Nutrition and Development. - 1684-5358 .- 1684-5374. ; 16, s. 11004-11021
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Journal article (peer-reviewed)abstract
- Mycotoxin-producing fungi contaminate food and feeds before, during and after harvest. Aflatoxins are important mycotoxins and aflatoxin B1 (AFB1) is a class 1 human carcinogen (definitely carcinogenic). Aflatoxin M1 (AFM1) is a class 2B (possible) human carcinogen. Aflatoxin B1 in feeds can decrease milk production, reduce fertility and increase susceptibility to infections. A cross-sectional study of aflatoxin contamination of milk and dairy feeds was carried out in five counties in Kenya representing different agro-ecological zones: Kwale, Isiolo, Tharaka-Nithi, Kisii and Bungoma. Dairy feed concentrates and cattle milk were collected twice (dry season and rainy season) from 285 dairy farmers in the five counties and analysed for AFB1 and AFM1, using competitive enzyme-linked immunosorbent assay (ELISA). In the five counties, the proportion of farmers who fed cattle with dairy concentrates varied from zero to 68%. The dairy feed concentrates from farmers had AFB1 levels ranging from less than one part per billion (ppb) to 9661 ppb and the positive samples ranged from 47.8 to 90.3%. The percentages of dairy feeds from farmers with AFB1 above the World Health Organization/Food and Agriculture Organization of the United Nations (WHO/FAO) limit of 5 ppb varied from 33.3% to 87.5 % while 83.3% to 100% of the feeds from retailers and 28.6% to 100% of the feeds from manufacturers exceeded the WHO/FAO limit. Aflatoxin M1 prevalence in milk was lowest in Kwale (13.6%) and highest in Tharaka-Nithi (65.1%). The proportion of milk samples with AFM1 above the WHO/FAO standard of 50 parts per trillion (ppt) varied from 3.4% (Kwale) to 26.2% (Tharaka-Nithi); the highest was 6999ppt. This study shows that aflatoxin contamination is common in dairy feeds and in milk and concentrations may be high. This may contribute to ill health effects in both humans and animals and, therefore, there is need for better understanding of the impacts of aflatoxins in the feed-dairy value chain and appropriate interventions to control aflatoxin contamination in animal feeds.
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| 6. |
- Magaia, Telma Leví J., et al.
(author)
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Composition of amino acids, fatty acids and dietary fibre monomers in kernels of Adansonia digitata and Sclerocarya birrea
- 2017
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In: African Journal of Food, Agriculture, Nutrition and Development. - : African Journal of Food, Agriculture, Nutrition and Development. - 1684-5358 .- 1684-5374. ; 17:3, s. 12441-12454
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Journal article (peer-reviewed)abstract
- There is increasing demand for sources of energy and non-meat protein with balanced amino acid profiles worldwide. Nuts are rich in protein and essential amino acids, and have a high energy value due to their high fat content. Kernels from two wild fruits in Mozambique, Adansonia digitata and Sclerocarya birrea, were selected for this study to determine their amino acid and fatty acid composition, as well as the monomeric composition of their dietary fibre. The fat content in Adansonia digitata kernels was around 32% and in Sclerocarya birrea kernels 49%. Both kernels were rich in unsaturated fatty acids. The dominating fatty acids in Adansonia digitata kernels were palmitic, linoleic and oleic acid; varying from 25.7% to 34.9% of the total fatty acids content. In Sclerocarya birrea kernels the main fatty acid was oleic acid, 72.4%. The Adansonia digitata kernels contained the two essential fatty acids linoleic (around 30%) and linolenic acid (2%). Sclerocarya birrea kernels contained linoleic acid (around 7%). The protein content in Adansonia digitata kernels was 35% and in Sclerocarya birrea kernels 29%. Glutamic acid was the most abundant amino acid, comprising more than 20% of the protein in both kernels. The contents of essential amino acids in the kernels were compared with the requirements stated by the WHO, and the findings indicate that Adansonia digitata and Sclerocarya birrea kernels can provide good, cheap sources of protein, especially when combined with foods with high lysine content. Regarding the dietary fibre fractions, the main constituent in the insoluble fraction of Adansonia digitata kernels was glucose, while in the soluble fraction arabinose was the dominating component. In kernels of Sclerocarya birrea, uronic acids constituted more than 90% of both dietary fibre fractions. The results of this study suggest that intake of these kernels can help providing a great part of the fatty acids and amino acids required in the daily diet, especially for people living in rural areas of Mozambique. The data could be used for intake estimates, and to encourage increased consumption and utilization of these kernels.
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| 7. |
- Ramesh, Vetukuri
(author)
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Assessment of the effects of liquid and granular fertilizers on maize yield in Rwanda
- 2021
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In: African Journal of Food, Agriculture, Nutrition and Development. - : African Journal of Food, Agriculture, Nutrition and Development. - 1684-5358 .- 1684-5374. ; 21, s. 17787-17800
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Journal article (peer-reviewed)abstract
- Maize (Zea mays L.) is the most widely grown cereal in the world, accounting for 1,116.34 MT of production in 2019/2020. In Africa, this crop represented approximately 56% of the total cultivated area from 1990 to 2005. About 50% of the African population depends on maize as a staple food and source of carbohydrates, protein, iron, vitamin B, and minerals. Lately, maize has become a cash crop which contributes to the improvement of farmers' livelihoods. For example, the Strategic Plan for Agricultural Transformation (SPAT) III outlined that fertilizer availability in Rwanda should increase to 55,000 MT per year, while fertilizer use should increase from 30 kg/ha in 2013 to 45 kg/ha for the 2017/18 cropping season. Only inorganic fertilizers are currently being used in maize production in Rwanda. This research was conducted to assess the effects of liquid (CBX: Complete Biological Extract) and granular fertilizers on maize crop yields in Rwanda. The study was conducted in the fields of the Rwanda Agriculture and Animal Resources Development Board (Rubona Station) during the 2018/2019 cropping season. Analysis of variance (ANOVA) was used to determine whether differences between treatments were statistically significant, with the threshold for statistical significance set at p < 0.05. Aboveground biomass differed significantly between treatments, with maximum and minimum values of 11,475 kg and 7,850 kg, respectively, being observed. Furthermore, the harvest index differed significantly between treatments, with minimum and maximum values of 0.2136 and 0.33, respectively, being observed. Grain yield also differed significantly between treatments, with the highest value (3,053 kg/ha) observed for a treatment which applied liquid and granular fertilizer at equal proportions (treatment 8), and the lowest one was found in treatment 3 with 1,852 kg/ha. In this study, the gap between the lowest and highest grain yields was about 39.3%. In conclusion, the combination of organic liquid fertilizer and granular fertilizer can significantly increase the grain yield of maize in Rwanda.
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| 8. |
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