Traditional fermented foods and beverages of Namibia

Background: Although traditional fermented foods and beverages play an important role in contributing to the livelihoods of Namibians through enhanced food security and income generation, there is a scarcity of information regarding their traditional production methods, microbiological and biochemical characteristics, nutritional value, and safety. Research into the processing technologies of these foods and beverages is still in its infancy; thus, there is a need to document their traditional production methods, microbiology, and biochemistry in order to evaluate their nutritional value and safety, standardize and industrialize them, where possible, and preserve them for future generations. Methods: The socioeconomic importance, traditional production methods and, where available, microbiological, biochemical, and nutritional properties and safety evaluation of commonly consumed fermented foods and beverages in Namibia are documented. Recommendations are made for potential research areas. Results: Commonly produced fermented foods and beverages in Namibia include milk-based products (omashikwa, mashini ghakushika, mabisi, and âudaï), cereal-based beverages (oshikundu, omalodu, otombo, epwaka, okatokele, oshafuluka, maxau, and /Ho ≠Goas), vegetable-based fermented food, mudhika, and fruit-based beverages (ombike, omagongo, and omalunga). Conclusion: Fermented foods and beverages play a major role in the diet, socioeconomic, and cultural activities of the Namibian population. Most are spontaneously fermented. Research is scarce and should be conducted on the microbiology, biochemistry, nutritional value, and safety of the fermented foods and beverages to ensure the health of the population

Adsorption of heavy metals by agroforestry waste derived activated carbons applied to aqueous solutions

Activated carbons prepared from macadamia nut shells, baobab shells, pigeon pea husks, rice husks, Moringa oleifera husks, and marula stones were investigated for their abilities to adsorb Pb(II), Zn(II), Cu(II), Ni(II), Fe(II), Mn(II), Hg(II), Cr(III), As(III) and Cd(II) from aqueous solutions. Batch adsorption experiments were conducted at pH values of 4, 5 and 6. Metal ion adsorption generally increased as the pH was increased from 4 to 6. Percentage adsorption values were above 60% for adsorption of Hg(II) by all the activated carbons at pH 6. The adsorption of Pb(II) by carbons from Baobab shells, pigeon pea husks, Moringa oleifera husks and Marula stones was at least 22% higher than that of the commercial carbons used for comparison. Carbons derived from pigeon pea husks and baobab shells showed better metal ion adsorption compared to the other carbons and were used to determine the effects of initial metal concentration, contact time and adsorbent quantity on metal adsorption. The metal ion adsorption data fitted the Langmuir adsorption model.Keywords: Agroforestry, wastes, activated, carbon, adsorption, metalsAfrican Journal of Biotechnology, Vol 13(14), 1579-158

Variation of Fungal Metabolites in Sorghum Malts Used to Prepare Namibian Traditional Fermented Beverages Omalodu and Otombo

Sorghum malts, which are important ingredients in traditional fermented beverages, are commonly infected by mycotoxigenic fungi and mycotoxins may transfer into the beverages, risking consumers’ health. Liquid chromatography–tandem mass spectrometry was used to determine variation of fungal metabolites in 81 sorghum malts processed for brewing of Namibian beverages, otombo (n = 45) and omalodu (n = 36). Co-occurrence of European Union (EU)-regulated mycotoxins, such as patulin, aflatoxins (B1, B2, and G2), and fumonisins (B1, B2, and B3) was detected in both malts with a prevalence range of 2–84%. Aflatoxin B1 was quantified in omalodu (44%) and otombo malts (14%), with 20% of omalodu malts and 40% of otombo malts having levels above the EU allowable limit. Fumonisin B1 was quantified in both omalodu (84%) and otombo (42%) malts. Emerging mycotoxins, aflatoxin precursors, and ergot alkaloids were quantified in both malts. Notably, 102 metabolites were quantified in both malts, with 96% in omalodu malts and 93% in otombo malts. An average of 48 metabolites were quantified in otombo malts while an average of 67 metabolites were quantified in omalodu malts. The study accentuates the need to monitor mycotoxins in sorghum malts intended for brewing and to determine their fate in the beverages

Mycotoxins in stored cereals from rural households in central northern Namibia

Cereal contamination by mycotoxins is a significant food safety concern globally. To date, the spectrum of mycotoxins in stored cereals in Namibia was not yet studied. Therefore, this study aimed to gather data on grain storage practices and mycotoxin awareness using validated questionnaires as well as determine by LC-MS/MS analysis the types and levels of mycotoxins present in 100 samples of stored cereal flour in rural households in two regions (Oshana and Oshikoto) of central northern Namibia. In both regions, cereal grains were predominantly stored in traditional silos and for longer periods of more than 12 months under poorly aerated conditions. One hundred and ninety-four metabolites of fungal, bacterial and plant origins, including 30 regulated and emerging mycotoxins, were positively identified in at least one sample. About 42% of all samples were contaminated with aflatoxins, and 14% and 9% samples exceeded the European Union’s maximum acceptable limit of 2 μg/kg AFB1 and 4 μg/kg total aflatoxin limit, respectively. Only five emerging mycotoxins (moniliformin, alternariolmethylether, tenuazonic acid, 3-nitropropionic acid (3-NPA) and enniatin B) contaminated at least 50% of all samples. 3-NPA had the highest concentration in all flour samples (max: 54,400 μg/kg; mean: 5420 μg/kg). In view of the consumption of the flour by children and adults, the extremely high levels of 3-NPA and evident co-contamination by different toxin classes, urgent mitigation interventions that include educational awareness campaigns and provision of better storage facilities are required to minimize mycotoxin contamination in the staple cereals in central northern Namibia

Association of food consumption patterns and nutritional status of children under 5 years from rural households in Northern regions, Namibia

Many developing countries, Namibia included, have a high prevalence of malnutrition among children, especially in rural subsistence farming areas where inadequate food supply is common. Poor diets in children under 5 years may result in negative health impacts. This study determined the association of food consumption patterns and nutritional status of children under 5 years from rural households in Oshana and Oshikoto regions in Namibia. Employing a cross-sectional descriptive design, 377 children under 5 years participated in this study using purposive sampling. Validated dietary diversity and food frequency questionnaires were used to obtain information on demographic characteristics, commonly consumed food per week, and meal frequencies for the recruited children. Anthropometric measurements BackgroundMany developing countries, Namibia included, have a high prevalence of malnutrition among children, especially in rural subsistence farming areas where inadequate food supply is common. Poor diets in children under 5 years may result in negative health impacts. This study determined the association of food consumption patterns and nutritional status of children under 5 years from rural households in Oshana and Oshikoto regions in Namibia.MethodEmploying a cross-sectional descriptive design, 377 children under 5 years participated in this study using purposive sampling. Validated dietary diversity and food frequency questionnaires were used to obtain information on demographic characteristics, commonly consumed food per week, and meal frequencies for the recruited children. Anthropometric measurements were obtained to assess nutritional status of children using Emergency Nutrition Assessment (ENA) software. Descriptive and inferential statistics were computed using the IBM® SPSS® Statistics (Statistical Package for Social Sciences) version 27.ResultsStaple foods, mostly grains, roots and tubers, along with flesh foods, legumes and nuts were commonly consumed. Vitamin A-rich fruits and vegetables were solely consumed in Oshana region (10.7%) and not in Oshikoto. Oshana exhibited a lower dietary diversity score (4±1 SD) compared to Oshikoto (5±1 SD). The prevalence of adequate feeding practices varied, with Oshana having 38.8% meeting minimum milk feeding frequency (MMFF), 55.6% minimum dietary diversity (MDD), 69.8% minimum meal frequency (MMF), and 27% minimum acceptable diet (MAD). In Oshikoto, these figures were lower at 2%, 7%, 32%, and 0.5%, respectively. Stunting, underweight, wasting, and overweight were also documented, with slight differences between the two regions. The study did not find association between nutritional status and MMFF, MDD and MAD. However, significant associations were found between specific food types, amount of food, breastfeeding length, MMF and malnutrition indicators in both regions (p<0.05).ConclusionMost study participants consumed locally available staple foods. Stunting, underweight, and wasting were prevalent among children in the two regions which were significantly associated to the amount of food consumed, MMF and/ some food types. Improving food environments and eliminating access barriers to diversified diets can mitigate high prevalence of malnutrition among rural children

Glucose-6-phosphate dehydrogenase deficiency genotypes and allele frequencies in the Kavango and Zambezi regions of northern Namibia

Background: Namibia has made significant gains in the fight against malaria, with a target of elimination by 2023. We examined the genotype and allele frequencies of glucose-6-phosphate dehydrogenase (G6PD) deficiency to inform decisions on primaquine use, as we recently detected clusters of Plasmodium ovale curtisi in Kavango. Methods: A multistaged cross-sectional sampling method was used to enrol 212 children 2-9 y of age from schools and clinics in the Okavango and Zambezi regions of northern Namibia. Genotypes for the 202 G→A and 376 A→G mutations were assigned by polymerase chain reaction restriction fragment length polymorphism. Results: Of the 212 subjects enrolled, genotypes were available for 210, made up of 61 males and 149 females. G6PD-deficient males (hemizygotes) and females (homozygotes) constituted 3.27% (2/61) and 0.0% (0/149), respectively. Female heterozygotes (AA- and BA-) constituted 10.07% (15/149), while G6PD wild-type males (with A or B haplotype) and females (with AA, BB or AB haplotypes) consisted of 96.72% (59/61) and 89.93% (134/149), respectively. The A-, A and B allele frequencies were 0.0474, 0.3036 and 0.6490, respectively. Hardy-Weinberg equilibrium tests for female genotype frequencies did not show deviation (p=0.29). Conclusions: The frequency of G6PD deficiency alleles in males in the Kavango and Zambezi regions of northern Namibia constitute 3.27%, a first report to inform policy on primaquine role out

Traditionally processed beverages in africa: a review of the mycotoxin occurrence patterns and exposure assessment

African traditional beverages are widely consumed food-grade liquids processed from single or mixed grains (mostly cereals) by simple food processing techniques, of which fermentation tops the list. These beverages are very diverse in composition and nutritional value and are specific to different cultures and countries. The grains from which home-processed traditional beverages are made across Africa are often heavily contaminated with multiple mycotoxins due to poor agricultural, handling, and storage practices that characterize the region. In the literature, there are many reports on the spectrum and quantities of mycotoxins in crops utilized in traditional beverage processing, however, few studies have analyzed mycotoxins in the beverages themselves. The available reports on mycotoxins in African traditional beverages are mainly centered on the finished products with little information on the process chain (raw material to final product), fate of the different mycotoxins during processing, and exposure estimates for consumers. Regulations targeting these local beverages are not in place despite the heavy occurrence of mycotoxins in their raw materials and the high consumption levels of the products in many homes. This paper therefore comprehensively discusses for the 1st time the available data on the wide variety of African traditional beverages, the mycotoxins that contaminate the beverages and their raw materials, exposure estimates, and possible consequent effects. Mycotoxin control options and future directions for mycotoxin research in beverage production are also highlighted