In the tropics, conversion of woodland and forest into cropland and pasture has risen drastically during the last decade. Rapid population growth and poverty are believed to be the main factors of change in land use in these zones. Southern Burkina Faso experienced rapid population growth due to massive peasants' migration from the north and central regions of the Country, exacerbated by decreasing rainfall and arable land in the area of origin. This paper assessed the impact of such increased population on land use change in the attracting zones from 1986 to 2006. Satellite images were used to measure changes in land cover types over time and national population census data were used to examine the population dynamics over the same time. Results showed that the forest land was progressively converted to croplands at an annualized rate of 0Á96 per cent, while the population density shifted from 17 inhabitants per km 2 in 1986 to 30 inhabitants per km 2 in 2006. Pearson correlation analysis revealed the positive role of population size and distribution in explaining land cover change. Policy initiatives that will lead to better environmental management are recommended.

La culture de l’oignon contribue fortement à la sécurité alimentaire et à la lutte contre la pauvreté au Burkina Faso. Cependant, plusieurs contraintes dont les pertes post-récoltes entravent le développement de cette filière. L’objectif de cette étude était d’évaluer l’impact d’un procédé de séchage sur la qualité de l’oignon. L’oignon après parage, a été prétraité (NaCl à 5%) ou non, puis séché avec un séchoir à gaz Atesta (60-65 °C, 10-12 h). Les caractéristiques nutritionnelles et microbiologiques des produits frais et séchés ont été déterminées par des méthodes standardisées. Sur la base de la matière sèche, les résultats ont donné pour l’oignon frais, 5,19%, 1,7%, 12,16% et 47,56%, respectivement pour les cendres, matières grasses, protéines et sucres totaux. Après séchage, les teneurs ont varié respectivement de 2,96 à 31,31%, de 0,59 à 0,77%, de 3,58 à 7,78% et de 36,88 à 49,56% pour les cendres, matières grasses, protéines et sucres totaux. Malgré l’effet du prétraitement et du séchage, les teneurs en fer, manganèse, magnésium, zinc et calcium sont restées intéressantes. Les oignons séchés, en l’occurrence ceux prétraités avec le sel étaient de bonne qualité microbiologique. La vulgarisation de cette technologie permettra une meilleure valorisation de l’oignon au Burkina Faso.Mots clés : Séchoir à gaz, procédé, qualité, Burkina Faso.   English Title: Impact of pretreatment with salt (NaCl) and drying on the nutritional and microbiological characteristics of onion bulb The production of onion greatly contributes to food security and the fight against poverty in Burkina Faso. However, several constraints including post-harvest losses hinder the development of this sector. The objective of this study was to assess the impact of drying process on the quality of onion. Onion after trimming, was pretreated (NaCl at 5%) or not and dried with a gas dryer Atesta (60-65 °C, 10-12h). Nutritional and microbiological characteristics of fresh and dried products were determined using standard methods. Based on the dry mater, results showed that fresh onion contains 5.19% of ash, 1.7% of fat, 12.16% of proteins and 47.56% of total sugars. After drying, ash, fat, proteins and total sugars content varied from 2.96 to 31.31%, 0.59 to 0.77%, 3.58 to 7.78% and 36.88 to 49.56%, respectively. Despite the effect of pretreatment and drying process, the content of iron, manganese, magnesium, calcium and zinc remained interesting. The dried onions, in particular those pretreated with salt presented good microbiological quality. The dissemination of onion drying technology will allow to add value to onion in Burkina Faso.Keywords: Gas-drier, process, quality, Burkina Faso.  

The aim of this study was to determine the technological properties of sorghum and millet malt produced under controlled conditions in Burkina Faso. Two types of steeping were carried out: steeping at normal pH (6.5) and at alkaline pH (8). Analyzes of the functional properties (diastatic power, alpha and beta amylase activity) of the samples of malts produced were carried out using Bernfeld modified methods. From the results, it appeared that the values of diastatic power, alpha and beta amylase and amylase activity increased significantly during the malting process (p˂0.001). The highest values for the diastatic power of the malts were obtained with millet malt (378.86 UPD and 336.45 UPD respectively for normal steeping and alkaline steeping). As for the diastatic power of sorghum malts, it varied from 79.14 UPD to 266.17 UPD. A negative correlation emerged between the diastatic power and the pH (R = -0.88), it also emerged that the diastatic power was much more correlated with the activity of alpha amylase (R = 0.99) than that of beta amylase (R = 0.6). Overall, the different types of malts exhibited satisfactory diastatic power and functional properties in accordance with standards for cereal malt production. These malts could therefore be used for the production of infant porridge in order to increase the energy density of porridge and also used in bread making to replace commercial enzymes often not appreciated by consumers.

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Isolation and morphological characterization of fungi producing antibacterial substances from local food in Burkina FasoABSTRACT Bacterial resistance to the actual antibiotic is mostly in dangerous progress, why we have interest in isolation and characterization of fungi strains producing antibiotics using local food in Burkina Faso. Fifty (50) isolated strains were used in the antibiosis trial which revealed twenty (20) strains producing antimicrobial substances. This trial concerned the strains cell as well as its aqueous and organic extracts. Three (03) strains had average inhibition diameters of 20 mm on the testing germs. Their characterization focused on the H. COMPAORE et al. / Int. J. Biol. Chem. Sci. 10(1): 198-210, 2016 199 morphological and culture criteria. After five days of incubation in Potato Dextrose Agar (PDA), the strain S 1 shows a flat colony, white on the front, with a yellow reverse. The strain S 2 shows an olive-green colony, velvety texture, more dense in the center. As for the strain S 3 , it shows a round green colored colony. In optical microscopy, strains S 1 and S 2 showed numerous round and refractive conidia, conidiophores are hyaline, long and not partitioned. S 3 strain showed uncommon conidia, penicillus made of phialides which are directly linked to the end of partitioned conidiophores. Analysis of these characteristics indicates that S 1 , S 2 and S 3 belong respectively to the Aspergillus and Penicillium genera.