Maurice Monjerezi

Fungal metabolites diversity in maize and associated human dietary exposures relate to micro-climatic patterns in Malawi

This study investigated the diversity of fungal metabolites in maize across four agro-ecological zones of Malawi. A total of 90 maize samples (for human consumption), collected from farmsteads, were analysed for 235 fungal metabolites using liquid chromatography-tandem mass spectrometry. A total of 65 metabolites were found in the samples. 75% of samples from the hottest agro-ecological zone contained either aflatoxins, fumonisins, deoxynivalenol, zearalenone; or a combination thereof in levels exceeding European Union (EU) maximum levels, whereas the related fraction was only 17% in the cool temperature zone. Aflatoxins, citrinin, 3-nitropropionic acid, monocerin and equisetin were most prevalent and in higher levels in samples from hot agro-ecological zones, whereas deoxynivalenol, nivalenol, zearalenone and aurofusarin were most prevalent in cool agro-ecologies. On the basis of per-capita maize consumption, estimated daily intakes for all samples from hot ecologies were well above the JECFAs provision...

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 μg/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 μg/kg (10 μg/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%...

Binding Effect of Cassava Starches on the Compression and Mechanical Properties of Ibuprofen Tablets

Starch is the most common binder in tablet formulations and important sources include cassava tubers. Using cassava starches extracted from three different cultivars (Mbundumali, Mulola and Sauti), the effect of native cassava starches as binders on the compression and mechanical properties of ibuprofen tablets was studied. The starches were used as binders for 400 mg ibuprofen tablets produced by wet granulation at the various concentrations (2-8 %w/w) and compressed at different punch settings (23-27). The formed tablets were evaluated for hardness, friability and disintegration. Cassava starches, derived from the three cultivars can be used as binders in uncoated ibuprofen tablets under the following operating conditions: punch setting of 24 and binder concentration of 2% w/w. Under such conditions, less friable tablets were produced and reduced amounts of materials were used. Mulola starch is the most appropriate binder for ibuprofen tablets while Sauti starch could be useful when fast disintegration is more essential and a requirement.

Climate change in semi-arid Malawi : perceptions, adaptation strategies and water governance

Climate change and variability are a threat to sustainable agricultural production in semi-arid areas of Malawi. Overdependence on subsistence rain-fed agriculture in these areas calls for the identification of sustainable adaptation strategies. A study was therefore conducted in Chikwawa, a semi-arid district in southern Malawi, to: (1) assess community’s perception of a changing climate against empirical evidence, (2) determine their local adaptive measures, (3) evaluate the potential of irrigated agriculture as an adaptive measure in household food security and (4) challenges over access to available water resources. The study employed focus group discussions and key informant interviews to assess people’s perceptions of climate change and variability and their desired interventions. To validate the people’s perceptions, rainfall and temperature data for the period 1960–2010 were analysed. A participatory complete randomised experimental design in both rain-fed and dry season–irrigated conditions was conducted to assess a maize cropping system that would improve adaptation. The study established persistent declining yields from rain-fed production in part because of perennial rainfall failure. In response, the community has shifted its focus to irrigation as an adaptation strategy, which has in turn triggered water conflicts in the community over the control of the resource. Water legislation however fails to adequately provide for rules governing sharing of water resources between various stakeholders. This article therefore recommends development of an appropriate institutional framework that forms a strong basis for equitable distribution of water for irrigation in areas most vulnerable to extreme climate events – including droughts and floods.