In this knowledge compendium a series of contributions illustrates how Wageningen UR cooperates with African organizations in finding innovations to combat water scarcity and to deliver the scientific knowledge necessary for future actions. In most of these activities, the integration of the formal knowledge of WUR with the tacit knowledge of the local stakeholders plays an important role. The Dutch Ministery of Economic Affairs, Agriculture and Innovation (EL&I) has stimulated the preparation of this compendium to disseminate the knowledge on these innovations among stakeholders throughout the African continent. This knowledge compendium presents a selection of recently finished research projects or on-going projects on water challenges in African food security. They are clustered under four themes: (1) challenges; (2) advances in research; (3) adaptation and implementation; (4) knowledge transfer. The contributions aim to stimulate further research and cooperation as a basis for the development of further management measures.

Sixty–six (66) food and ten (10) water samples from Nsukka metropolis were screened for the presence of coliforms using the Most probable number (MPN) technique and direct plate count on MacConkey agar/broth and Eosin Methylene Blue (EMB) agar for isolating those from both faecal and human origin. The isolates were characterized biochemically analysed using standard conventional methods. The geometric mean counts (GMC) using MPN ranged from 1-180 faecal coliforms per 100 ml for both food and water samples. However, food samples (66.7%) served in plates and water sources (83.3%) showed apparent signs of contamination probably from the human and water sources, handling and storage unlike foods from the pots that had no trace of contamination. Faecal coliforms were E. coli (42.4%) and Klebsiella pneumonia (37.4%) and others(20.20%)of non-human origin. The E. coli count ranged between 22.2% (“abacha”) and 83.3% (beans ,rice, yam) as well as water(50.0% ).Thus, there was no significant difference (p>0.05) between the indicator organisms (E. coli) in the food, storage vats and water sources. The faecal and human coliforms in foods and water were indications of foodborne diseasesKeywords: Food, Water, Coliforms, Vending, Contamination

Large seasonal water-level fluctuations may influence isotopic signatures of primary producers and the types and amounts of these potential food sources accessible to aquatic fauna of Poyang Lake, the largest freshwater lake in China. In this study, the isotopic signatures of primary producers and consumers were determined, stable carbon and nitrogen isotope analysis and mixing models were combined to investigate the influence of water levels on the diet and isotopic composition of Poyang Lake fish and invertebrates. Five potential food sources (seston, benthic organic matter, aquatic macrophytes, attached algae, and terrestrial plants), 4 species of invertebrates, and 10 species of fish were collected from the lake area during dry and wet seasons between January 2009 and April 2010. The δ 13C values of invertebrates and most fish were within the range of δ 13C values of the potential food sources for both seasons. The δ 13C values of invertebrates and most fish were lower in the dry season than in the wet season, whereas the δ 15N values exhibited different patterns for different species. Mixing models indicated that the most important food sources for common lake fauna were seston in the dry season and aquatic macrophytes and terrestrial plants in the wet season. The fauna were more omnivorous in the wet season than in the dry season. The food web dynamics of Poyang Lake are strongly influenced by changes in the abundance and accessibility of different basal food sources that occur because of seasonal flood pulses. The trophic links within the aquatic communities of Poyang Lake are modified by water-level fluctuations.

In this knowledge compendium a series of contributions illustrates how Wageningen UR cooperates with African organizations in finding innovations to combat water scarcity and to deliver the scientific knowledge necessary for future actions. In most of these activities, the integration of the formal knowledge of WUR with the tacit knowledge of the local stakeholders plays an important role. The Dutch Ministery of Economic Affairs, Agriculture and Innovation (EL&I) has stimulated the preparation of this compendium to disseminate the knowledge on these innovations among stakeholders throughout the African continent. This knowledge compendium presents a selection of recently finished research projects or on-going projects on water challenges in African food security. They are clustered under four themes: (1) challenges; (2) advances in research; (3) adaptation and implementation; (4) knowledge transfer. The contributions aim to stimulate further research and cooperation as a basis for the development of further management measures.

The total phenol content, antioxidant and pro-oxidant activities of deodourised, water-soluble aniseed, basil, caraway, cardamon, fennel, ginger, juniper, laurel and parsley extracts were estimated using a number of in vitro assays. The laurel and basil extracts contained the highest phenol content of 107.3±1.3 GAE [mg gallic acid equivalents/g (dry wt.) extract] and 98.5±1.4 GAE, respectively, whilst the ginger extract contained the lowest content at 14.9±0.9 GAE. Juniper, laurel and basil extracts were consistently better than the other extracts in terms of iron(III) reducing activity, inhibition of β-carotene-linoleate thermal co-oxidation and N,N-dimethyl-p-phenylenediamine and hydroxyl radical scavenging assays. Potential pro-oxidant activities of the extracts were assessed using both DNA and bovine serum albumin (BSA) as substrates. None of the extracts were capable of stimulating hydroxyl-mediated DNA fragmentation; however, the extracts could be categorised in the protein oxidation assay as extracts with (i) no significant (p>0.05) effect, (ii) a significant (p<0.05) protective effect or (iii) a significant (p<0.05) pro-oxidant effect. The extracts from juniper, laurel and basil had a pro-oxidative effect upon BSA at a dose of 2mg/ml, as estimated from the degree of carbonylation measured.

Rainfed farming needs to be supported by appropriate water harvesting technologies to mitigate the moisture stress during critical crop growth stages during the main season and to increase opportunities for irrigated horticultural production. With this aim, a wider scale of water harvesting technology dissemination program was carried out in some areas of Ethiopia since 2002/03. This research was conducted with the aim of evaluating the implementation of the program and its impacts thus far, and to identify the major technical and socio-economic constraints to the wider utilization of on-farm level household ponds. Detailed analysis of the case of model farmers show that acceptable economic returns are possible from pond technologies given that farmers are able to follow appropriate cropping patterns and irrigation techniques to improve water use efficiency. It is recommended that the technologies should be disseminated in the region in a more farmer participatory approach.

The water intake in 45 male (27.50 ± 0.48 kg of mena body weight) Santa Ines sheep fed with increasing levels (0, 25, 50, 75, 100% DM basis) of prickly pear (Opuntia ficus indica Mill) to replace corn was studied. A completely randomized block design with nine replications per treatment was used. Quadratic behavior was observed for the intake of dry matter, hitting the final weight, which decreased with increasing the cactus in the diet. There was an increase in the intake of natural material and a decrease in voluntary water intake; total water intake increased, and the ratio of intakes: water/dry matter, decreased in the treatment with larger cactus proportion. The pryckly pear constitues a water reservoir for Santa Inês sheep in Brazilian semiarid conditions. | En 45 ovinos machos Santa Inés (peso vivo medio de 27,50 ± 0, 48 kg) se evaluó el consumo de agua, al consumir raciones con niveles crecientes (0, 25, 50, 75, 100%) de nopal (Opuntia fícus indica Mill) en sustitución al maíz molido. El diseño fue en bloques al azar con nueve repeticiones. El consumo de materia seca respondió de modo cuadrático, perjudicando el peso final, que disminuyó, con el aumento del nopal en la dieta. Aumentó el consumo de materia natural disminuyendo el de agua, el consumo total de agua aumentó en el tratamiento con mayor cantidad de nopal. La relación de consumos: agua voluntaria/materia seca, disminuyó al aumentar el nopal. El nopal constituye una reserva de agua para ovinos Santa Inés en condiciones semiáridas de Brasil.

Scarce use of physically based models for simulating foodstuff rehydration is related, inter alia, to difficulties in determining their hydraulic characteristic curve (water content vs. matric potential under equilibrium conditions). Its direct determination is not feasible for foodstuffs as it requires extended contact time with water to reach equilibrium that may cause microbial spoilage, swelling and physical destruction of the sample. To circumvent these difficulties, an alternative indirect method for determining the characteristic curve over the entire water-content range is proposed. It is based on the hypothesis that the end-parts of this curve, the air-entry value and saturated water content for the wet-end and water sorption isotherm for the dry-end, are relatively easily determined. The predicted characteristic curve was successfully verified for a model food material by comparing it with an independently measured values. Then, it was utilized for simulated rehydration by solving the Richards equation.

Proper management of water in the food industry will depend, to a large extent, on economic incentives regulated by legislation. The influence of water cost and wastewater discharge taxes is analyzed, as factors that encourage the implementation of water recycling systems and wastewater treatments within the food industry. Two Spanish taxation models are taken into account: at the national level, the Waste Control Tax; and at the local level, the autonomous Sanitary Tax. The cost reduction obtained in the Waste Control Tax by investing 68,305€ in minimizing water consumption from 193,200m³/year to 142,417m³/year is negligible since it is not a quantitatively elevated tax (from 2262€/year to 1407€/year). With regard to the Sanitary Tax, diversity affects the tax quantity and, consequently, the pressure exerted on the effluent quality in each case. In the Region of Murcia, the sanitary tax reduction was 8885€/year; and in La Rioja, the saving is greater (38,642€/year) given that this tax is considerably higher. Designing more stringent environmental regulation will markedly enhance the development of new technologies for improving wastewater treatment towards the goal of environmentally acceptable discharging and water reuse.