Hydrological and Water Quality Characteristics of Rivers Feeding into Small Earth Dams for Rural Water Supply: A Case Study of Traditional Authority Kalolo in Lilongwe District

The obligation to ensure adequate and clean water supply to everyone, has necessitated the development of small earth dams for rural water supply in developing countries. In Malawi, there are approximately 750 small and medium dams most of which are used multiple purposes. However, in most cases, the sustainability of these dams is challenged by gross catchment mismanagement and improper designs and set up. In this study, FDC analysis, in conjunction with water quality assessment, was used to evaluate the reliability of rivers flows that supply small earth dams designed for rural water supply in Malawi, using Kalolo area in Lilongwe district as a case study. FDC analysis showed that over 80% of the time, all rivers in the study area would not meet the target community’s water demand, without the dams in place. Water quality assessments show biological contamination as the major water quality problem. Significant seasonal variation in water quality is evident, with the dry season having generally better biological water quality. Further, the study categorized the catchments areas as moderately to largely modified using rapid ecological assessment method. Therefore, the low biological water quality may be attributed to uncontrolled anthropogenic activities in the catchment, arising from lack of proper catchment management. It is then recommended that construction of such small earth dams should be preceded by thorough scientific design through appropriate engineering and environmental studies, encompassing hydrological, geological, ecological and socio-economic factors, if the small earth dams are to result into long term outputs.Keywords: River flow; small earth dams; flow duration curve; water quality; rural water supply

Evaluation of the bright greenish yellow fluorescence test as a screening technique for aflatoxin-contaminated maize in Malawi

The bright greenish yellow fluorescence (BGYF) test has been used with varying success in screening for aflatoxins in maize. This test was applied to 180 maize samples collected from different markets within 12 districts of Malawi in order to evaluate its performance against high performance liquid chromatographic analysis. The number of BGYF grains in 2.5 kg unground samples ranged from 0 to 35 and about 49% of all tested samples had aflatoxin concentrations ranging from 1 to 382 mu g/kg. A total of 65 (36%) of the examined unground samples showed no BGYF. The European Commission recommends a false negative rate of less than 5% for a screening technique to be acceptable. In this study, four BGYF grains per 2.5 kg unground maize sample successfully indicated an aflatoxin contamination of >10 mu g/kg (10 mu g/kg being the maxium tolerable level proposed by the Common Market for Eastern and Southern Africa), with a 4.4% false negative rate. In this case, the amount of confirmatory analyses would be reduced by 63%, if the BGYF test was employed as a screening method. The screening technique therefore offers a practical tool for Malawi and possibly for the Sub-Saharan region

Volatile constituents of fruit pulp of Strychnos cocculoides (Baker) growing in Malawi using solid phase microextraction

Volatile constituents of the edible pulp of Strychnos cocculoides (Monkey orange) were extracted using solid phase microextraction (SPME) and their identity established by GC–FID and GC–MS systems. Six compounds were extracted and identified: isobutyl acetate, 53.2%; 2-methylbutyl acetate, 12.8%; ethyl-2-methylbutyrate, 10.5%; 2, 6-ditetrabutyl-4-methyl-phenol, 8.4%; butyl-2-methyl butyrate, 6.7% and geranyl acetate, 3.1%. These accounted for 94.7% of the volatile constituents in the pulp. Thus, the acetate and butyrate esters were the most abundant volatiles in the edible pulp of the ripe fruit.Carnegie Regional Initiative in Science Education (Carnegie-RISE) through the Southern Africa Biochemistry and Informatics for Natural Products (SABINA) network and the ACP EU through the POL-SABINA network. Open Access funded by SAAB.http://www.elsevier.com/locate/sajbhb2016Biochemistr

Large-scale survey of seasonal drinking water quality in Malawi using in situ tryptophan-like fluorescence and conventional water quality indicators

Faecally-contaminated drinking water is a risk to human health, with the greatest risks to those living in developing countries. UN Sustainable Development Goal 6 aims to address this issue. Tryptophan-like fluorescence (TLF) shows potential as a rapid method for detecting microbial contamination in drinking water, which could reduce the spread of waterborne diseases. This study is the first to investigate the effectiveness of TLF for a large-scale survey using a randomised, spot-sampling approach. The large-scale survey took place in Malawi, sub-Saharan Africa, in the dry season (n = 183). A subset of sources were revisited at the end of the following wet season (n = 41). The effectiveness of TLF was assessed by comparing TLF results to thermotolerant coliforms (TTC), humic-like fluorescence (HLF), inorganic hydrochemical data and sanitary risk scores. The most prominent differences in microbial water quality were observed between source types, with little variation between districts and seasons. TLF, TTCs, turbidity and sanitary risk scores were all elevated at alternative sources (shallow wells and tap stands) compared to hand-pumped boreholes. In the dry season, 18% of hand-pumped boreholes showed TTC contamination, which increase to 21% in the wet season. Groundwater recharge processes are likely responsible for seasonal variability of inorganic hydrochemistry at hand-pumped boreholes. TLF was able to distinguish no and low WHO risk classes (TTC 0–9 cfu/100 mL) from medium, high and very high risk classes (TTC 10 – >1000 cfu/100 mL). TLF failed to distinguish between no and low risk classes, which limits the use of TLF for assessing water quality to drinking water standards. This dataset indicates that HLF may raise baseline TLF for samples with low TLF values, increasing false positives. Therefore, TLF is better suited as a rapid high-level water quality screening tool to assess moderate and high levels of faecal contamination

Effects of genotype by environment interaction on agronomic and functional flour properties among cassava genotypes targeted for industrial use

Open Access ArticleThe study was carried out to evaluate the genotype by environment (G × E) interaction on physicochemical and functional properties of ten (10) cassava advanced genotypes and improved varieties. The genotypes and varieties were collected from a multi-location trial (Uniform yield) of the IITA breeding program at four research stations in Malawi. Based on the results, G × E interaction was highly significant (P ≤ 0.001) in explaining the variance of the physicochemical parameters and functional properties. Thus, G × E interaction highly influenced starch and amylopectin contents, swelling power, and water binding capacity. Additive main effect and multiplicative interaction (AMMI) analysis identified I010040, MM06/0045 and TMSL110080 genotypes and Mbundumali, Mpale and Sagonja varieties as the most stable with high yield performance hence recommended for cultivation in a wide range of environments for the production of high quality cassava flour (HQCF) and starch for various industrial applications such as the production of ethanol, biofuels, starch and glucose syrup in chemical industries; thickeners, stabilizers, and texture modifiers in food, bakery and confectionery industries

Data on assessment of flours from advanced genotypes and improved cassava varieties for industrial applications

Open Access Journal; Published online: 28 Aug 2021The data presented in this article are related to the research paper “Physicochemical parameters and functional properties of flours from advanced genotypes and improved cassava varieties for industrial applications” [1]. The genotypes were collected from a multi-location (Uniform yield Trial) trial of the IITA breeding program in Malawi. The data were obtained using multiple analytical techniques and methodology such as oven-drying, sieving, colorimetry, titration, acid hydrolysis method, the Kjeldahl procedure, UV/VIS spectrophotometry, and centrifugation.The data set contains physicochemical parameters described dry matter (on fresh weight basis), moisture content, pH and total titratable acidy, the content of ash, bulk density; chemical properties were described by total cyanogen potential, total starch, amylose, amylopectin, crude protein and total carbohydrates; functional properties were described by swelling power, water solubility, water binding capacity and oil absorption capacity. The presented data are valuable for cassava breeders, food scientists, nutritionists, and other researchers working on breeding and processing cassava for innovative product development from cassava flour

Tryptophan-like fluorescence as a high-level screening tool for detecting microbial contamination in drinking water

Regular monitoring of drinking water quality is vital to identify contamination of potable water supplies. Testing for microbial contamination is important to prevent transmission of waterborne disease, but establishing and maintaining a water quality monitoring programme requires sustained labour, consumables and resources. In low resource settings such as developing countries, this can prove difficult, but measuring microbial contamination is listed as a requirement of reaching the UN's Sustainable Development Goal 6 for water and sanitation. A nine-month water quality monitoring programme was conducted in rural Malawi to assess the suitability of tryptophan-like fluorescence (TLF), an emerging method for rapidly detecting microbial contamination, as a drinking water quality monitoring tool. TLF data was compared with thermotolerant coliforms (TTCs, E. coli) and inorganic hydrochemical parameters. A large (n = 235) temporal dataset was collected from five groundwater drinking water sources, with samples collected once or twice weekly depending on the season. The results show that TLF can indicate a broader contamination risk but is not as sensitive to short term variability when compared to other faecal indicators. This is likely due to a broad association of TLF with elevated DOC concentrations from a range of different sources. Elevated TLF may indicate preferential conditions for the persistence of TTCs and/or E. coli, but not necessarily a public health risk from microbial contamination. TLF is therefore a more precautionary risk indicator than microbial culturing techniques and could prove useful as a high-level screening tool for initial risk assessment. For widespread use of TLF to be successful, standardisation of TLF values associated with different levels of risk is required, however, this study highlights the difficulties of equating TLF thresholds to TTCs or E. coli data because of the influence of DOC/HLF on the TLF signal

Aflatoxin risk management in commercial groundnut products in Malawi (Sub-Saharan Africa): a call for a more socially responsible industry

This study was performed as a follow-up to a study from 2013, to assess the impact of management interventions on aflatoxin incidence and levels in commercial groundnut products in Malawi. Sixty-seven samples of commercial groundnut products were analyzed for aflatoxin using a fluorometric method. Total aflatoxin levels ranged from 1.5 to 1200 μg/kg in raw groundnuts and 83–820 μg/kg in groundnut flour from vendors. In branded groundnut flour and peanut butter from supermarkets, aflatoxin levels ranged from 13 to 670 μg/kg and 1.3 to 180 μg/kg, respectively. About 93, 88, 78 and 72% of the samples analyzed contained aflatoxin levels above regulatory limit used in Malawi (3 μg/kg), EU (4 μg/kg), most developing countries (10 μg/kg), and the USA (20 μg/kg), respectively. Despite much effort, aflatoxin levels remain persistently high in commercial groundnut. Considering the difficulty of achieving an efficient government regulation system due to resource constraint, the authors recommend the promotion of a socially responsible groundnut processing industry that has consumer welfare as its central feature

Knowledge, attitude, and practices concerning presence of molds in foods among members of the general public in Malawi

This study assessed knowledge, attitude, and practices (KAP) of the public in Malawi on issues related to molds in foodstuffs. A survey involving structured questionnaire was conducted with 805 respondents from seven districts of Malawi. Descriptive statistics, t tests, and analyses of variance were calculated. A majority of respondents recognized that molds were dangerous to human health (88 %); however, about 50 % of respondents were not informed that mold toxins are thermally stable and that they are not destroyable by normal cooking processes. About 33 % of the respondents asserted that they buy moldy maize, while approximately 20 % of respondents reported that they consume moldy fruits having discarded moldy fraction. There were significant differences in knowledge scores among different demographic groups. Females had significantly (p < 0.05) lower knowledge scores on issues related to molds in foods. Additionally, the respondent’s location had a significant effect. However, respondent’s education had subtle effect on knowledge score and the overall population’s knowledge score was generally low (3.55 ± 1.32 score out of 9). Results of the study underline the need to raise public’s knowledge about health risks associated with spoilage molds in food and prevention and management options