In order to assess the physicochemical and heavy metal properties of groundwater consumed in Edéa (Cameroon), 8 boreholes were randomly chosen from 8 sites and their suitability was evaluated using three norms viz Cameroonian Norm (NC207:2003-02) and International standards including (CODEX: 108-1981 and European Union, EU:1998). Water samples were collected in triplicates bimonthly and analyzed using standard methods. Physicochemical analysis showed high temperatures with a mean value of (30.26 ±2.4) °C, acidic pH 5.94±0.34 and very weak mineralization leading to an electrical conductivity value of (134, 96 ± 49.59) µS/cm. The relative abundance of major ions was Ca 2+ >Mg 2+ >Na + > NH 4 + >K + for cations and NO -3 > HCO -3 -> PO 4 3-> SO 4 2->Clfor anions. All these ions fell within acceptable limits recommended by NC207:2003-0 boreholes 2, CODEX: 108-1981 and EU: 1998 with an exception for nitrates, ammonium and phosphate contents which were above acceptable limits. Among heavy metals analyzed, results showed that only lead and manganese values were above the standards'; all boreholes were contaminated by Lead while only 32.5% was contaminated by Manganese. The main water types were Mg-Ca-SO 4 3--Cland Mg-Ca-HCO 3 can't result to an alteration of the aquifer matrix (dissolution of Gypsum chloride) and influence of anthropogenic activities through infiltration of agricultural, industrial and domestic waste water. These results showed that water of Edéa is not suitable for human consumption and must be appropriately treated before any usage.

Au Cameroun, l’accès aux systèmes d’alimentation en eau potable en milieu urbain apparaît sélectif. Les populations des quartiers situés en périphérie ont recours aux puits et sources pour assouvir leurs besoins. La présente étude a pour objectif d’évaluer la qualité physico-chimique et bactériologique des eaux souterraines couramment utilisées dans quelques quartiers de l’arrondissement de Yaoundé VII. 24 échantillons d’eaux prélevés dans 6 sources (S1 à S6) et 2 puits (W1 et W2) ont été analysés suivant des méthodes normalisées. Les températures relevées, proches de celle de l’air, révèlent le caractère libre des nappes étudiées. Celles-ci subiraient l’influence directe des eaux d’infiltration. Les stations S1, W1 et W2 présentent des valeurs en nitrates supérieures à 50 mg/l (norme OMS). La consommation de leurs eaux expose la population jeune à la méthémoglobinémie. Contrairement aux recommandations de la norme camerounaise, les indicateurs de pollution fécale et les bactéries du genre Salmonella, ont été isolées dans les eaux analysées. Une analyse en composante principale ainsi qu’un dendrogramme ont permis de classer les points d’échantillonnage, selon l’ordre croissant de pollution organique suivant : {S6}, (S3, S4, S5), (S1, S2), {W1}, {W2}. Cependant, du point de vue pathogénique, S6, S3, S4, S5 sont les plus à craindre.Mots clés : Qualité des eaux, puits, sources, Yaoundé, risques sanitaires. English Title: Physico-chemical and bacteriological quality of groundwater and health risks in some districts of Yaoundé VII, CameroonIn Cameroon, access to drinking water supply systems in urban areas appears to be selective. The populations located in the peripheral zone use wells and springs to satisfy their needs. This study aims to assess the physico-chemical and bacteriological quality of the groundwater commonly used in some districts of Yaoundé VII. 24 water samples taken from 6 sources (S1 to S6) and 2 wells (W1 and W2) were analyzed according to standardized methods. The temperatures recorded, close to that of the air, reveal the free nature of the aquifers studied which are directly influenced by the infiltration waters. Samples points S1, W1 and W2 presented concentration of nitrate above 50 mg/l (WHO standard). The consumption of their waters exposes young people to methemoglobinemia. On contrary to the recommendations of the cameroonian standard, the indicators of faecal pollution and bacteria of the genus Salmonella, were isolated in the waters analyzed. A principal component analysis as well as a dendrogram permit to classify the sampling points, according to the following increasing order of organic pollution: {S6}, (S3, S4, S5), (S1, S2), {W1}, {W2}. However, from a pathogenic point of view, S6, S3, S4, S5, are the most to be feared.Keywords: Water quality, Dug wells, spring, Yaoundé, sanitary risks.

This study emphasizes the formulation of three types of cookies viz potato flour with date powder and bean milk (PDBM), potato flour with sugar and bean milk (PSBM), and potato flour, sugar, and eggs as control. After the substitution, the highest protein content was observed in PDBM (1.78 ± 0.12)% followed by PSBM, (1.35 ± 0.01)% and the lowest was in the control (0.91 ± 0.55)%. Moreover, cookies fortified with date palm powder increased the carbohydrate and fat contents compared to the control and significantly increased the calorific value of PDBM. The formulated cookies were significantly higher (p < 0.05) in iron (39.95 ± 3.00) mg/100 g and zinc (13.65 ± 1.61) mg/100 g in PDBM compared to other cookies. The date palm powder incorporated in cookies significantly increases the darkening of biscuits during cooking. The organoleptic characteristics of PDBM and PSBM were rated overall best when specific parameters were tested. With the shortage of wheat and importation constraints, an alternative provides a great market opportunity for local products like potatoes and beans. In addition, fortifying food products as cookies eaten by all will contribute to a more food and nutrition-secured world.

Une gestion efficace de la fertilité des sols en zone urbaine est un grand défi pour la production alimentaire dans les villes sub-sahariennes. La présente étude évalue l'effet de l'utilisation des engrais organiques sur les paramètres de croissance, le rendement en feuilles et la composition chimique de la morelle noire. Cette expérimentation a été faite au jardin maraîcher de Nkolbisson. Le dispositif expérimental concernait quatre traitements : le témoin sans engrais (T1), 195 kg de N/ha d'engrais chimique (T2), 6,67 t/ha de fiente de poule (T3) et 6,67 t/ha de bouse de vache (T4). Les paramètres agronomiques de croissance ont été mesurés. Des différences très significatives (P <0,05) ont été observées entre les traitements. La tendance générale a montré une augmentation de la majorité des paramètres mesurés pour les traitements aux engrais. Les valeurs les plus élevées ont été obtenues pour T4. La classification des traitements en fonction de leur influence positive sur le rendement en feuille est T4(8,77 ± 1,15) t/ha> T3(6,38 ± 0,51) t/ha = T2(5,88 ± 1,06) t/ha> T1(4,09 ± 1,07) t/ha. L’utilisation d’engrais organiques produits dans la ville peut fournir des quantités de nutriments nécessaires pour la production des légumes feuilles noires et, par conséquent améliorer leurs rendements. Mots clés : Bouse de vache, engrais minéral, fiente de poule, Solanum nigrum. English title: Effects of amendments on growth, yield and chemical composition of black nightshade in suburban areas of Yaoundé, CameroonEfficient soil fertility management in urban areas is a big challenge for food production in sub-Saharan cities. This study assesses the effect of using organic fertilizers on growth parameters, leaf yield and chemical composition of black nightshade. This experiment was carried out at the Nkolbisson market garden. The experimental set-up involved four treatments: the control without fertilizer (T1), 195 kg of N / ha of chemical fertilizer (T2), 6.67 t / ha of chicken droppings (T3) and 6.67 t / ha of cow dung (T4). Agronomic growth parameters were measured. Very significant differences (P <0.05) were observed between the treatments. The general trend has shown an increase in the majority of the parameters measured for fertilizer treatments. The highest values were obtained for T4. The classification of treatments according to their positive influence on leaf yield is T4 (8.77 ± 1.15) t/ha> T3 (6.38 ± 0.51) t/ha = T2 (5.88 ± 1.06) t/ha> T1 (4.09 ± 1.07) t/ha. The use of organic fertilizers produced in the city can provide quantities of nutrients necessary for the production of black leafy vegetables and therefore improve their yields.Keywords: Chicken droppings, cow dung, mineral fertilizer, Solanum nigrum.

No abstract