Roger DARMAN Djoulde

University of Ngaoundéré · IUT

Le rÈchauffement climatique et ses consÈquences amËnent ‡ mettre en lumiËre la perception du changement par les travailleurs des organisations paysannes dans le sahel. L'objectif de la présente étude est d‟examiner les caractéristiques et les perceptions des travailleurs au sein des organisations paysannes en zones humide et semi-aride, et leurs st...

The increase in temperature, floods and globalized declines in agriculturalproductivity observed in the Sahel zone of Cameroon shed light on the perception ofclimate change by women workers within peasant organizations. The objective of thisstudy is to analyze the perceptions of women workers within peasant women'sorganizations and the direct impac...

In Sahelian cities, desertification with its climatic corollary is due to the excessive use of firewood by increasingly growing populations. However, the dead biomasses of Azadirachta indica swept away from households and unnecessarily buried in urban waste dumps could be recycled into ecological charcoal. But, it is necessary to know the binder be...

The Mangara petroleum field is made up of three superimposed reservoirs (C, D, E) with approximately 2500 m depth. These are unconsolidated sandstone reservoirs with an underlying active aquifer. The petrophysical properties of the reservoirs are relatively good as it’s a self-sourced unconventional reservoir based on its organic richness character...

L’acceptation des messages liés à la préservation et conservation de l’environnement par la population dépend en partie des méthodes de formation utilisées en zone sahélienne. L’objectif de cet article est de mesurer le degré d’atteinte du but de la formation via les méthodes pédagogique et andragogique au travers de la perception que les parti...

The management of invasive plants such as Eichhornia crassipes and the fruits of Azadirachta indica on the banks of the waters of Lake Chad in the Far North of Cameroon remains a challenge to overcome. On the other hand, given the urgency of finding other sources of energy following the scarcity of fossil fuels, it becomes appropriate to turn to re...

The objective of this study is to evaluate the economic quality of charcoal based on Prosopis juliflora linked to Eichhornia crassipes and to determine its index economic value. The density of the charcoal based on Prosopis juliflora (50≤%) and Eichhornia crassipes (50≥%) is 0.395±0.037g/cm 3 with the average humidity rate before drying of 48.89±14...

Eichhornia crassipes is an invasive plant in the waters of Lake Chad. The ecological problems caused by its permanent and invasive presence lead to search solutions. Thus its valuation as cooking energy is an option whose objective is to assert the effect of production processes of ecological coal based on Eichhornia crassipes on their performance...

Hydrogen, volatile fatty acids (VFAs), and methane coproduction from sweet sorghum stems using bacterial consortium was investigated as an efficient and sustainable pre-treatment strategy to improve energy recovery. Integrated two-stage dark fermentation and methanization approach aimed to reduce fractionation, juice extraction, and pre-treatment s...

The acceptance of messages related to the preservation and conservation of the environment within populations depends in part on the training methods used in the Sahel zone. The objective in this article is to measure the achievement of the training goals via educational and andragogical methods by analyzing the perception that the participants hav...

L'objectif de ce travail est d'évaluer les quantités résiduelles d'huiles et de gaz des eaux de production pétrolière (EPP) générées par le projet de Petrochad (mangara) limited à badila avant leur acheminement dans l'usine de traitement et déversement dans la nature. Il a été estimé que sur les 58.898.940 de bbl des eaux de production pétrolière e...

Demulsifiers such as VX champion, BAD-106 and others injected into the Petrochad(Mangara) Limited field between 2014 and 2023 only recovered 43,501,365 barrels out of a forecast of 91,250,000 barrels, or 42.48%. The mean surface and interfacial tension related to this recovery is 56.42 and 59.8 mN/m respectively. The inadequacy of this recovery is...

Taken separately, a single sweet sorghum stem bioconversion process for bioethanol and biomethane production only leads to a partial conversion of organic matter. The direct fermentation of crushed whole stem coupled with the methanization of the subsequent solid residues in a two-stage process was experimented to improve energy bioconversion yield...

The objective of this article aims to reduce indoor air pollution through the use of ecological fire starter (EFS) made from sawdust and vegetable oils. In the Far North region of Cameroon, plastic waste is used to ignite and stoke solid fuels fires, exposing mainly women and children who are responsible for cooking to health risks from indoor air...

Sweet sorghum stalks energy recovery is one of the most interesting alternatives to meet the current challenge of energy security. The usual ethanol production process from this biomass proves to be less profitable due to very expensive juice extraction step. This study aims to improve the performance and efficiency of this process experimenting ne...

Sorghum (Sorghum bicolor L. Moench) is a flowering plant in the grass family (Poaceae) characterized by a great genotypic and phenotypic diversity, making it a cereal species of major interest cultivated in warm climate worldwide. Fifth most cultivated cereal in the world and second in Africa, sorghum is the main cultivated species in the Sahelian...

The objective of this article was to assess the level of substitution of wood fuel with briquettes in Minawao refugees’ camp. The chosen methodology combines survey tools for data collection and practice. The results show that the refugees need 18,339 tons of wood fuel that must be substituted by 19,654 tons of biomass briquettes per year. Thus, si...

The objective of this paper was to determine the effects of binders on the physical and energetic properties of briquettes as well as their accessibility. Proximate analysis and investigation on binder cost on local market were conducted. The results show that the addition of binder increases the durability and density, but decreases the LHV of bri...

The purpose of this study was to evaluate the sensory property and shelf life of the processed mpedli beer using aqueous leaves extract of Vernonia amygdalina (VA) and heat treatment. The white sorghum beer was made at the laboratory scale using home-made procedure (Control). Following filtration, the beer was blended with an aqueous leaf extract (...

Combustibles briquettes are energetics resources, which could be use to substitute other types of energy. Optimization of energetic efficiency of combustible briquette lead us to made it so that to contribute to thrift wood resources and local sustainable development. Valorization of dry dead leaves of Azadirachta indica associated to dry stems of...

Total phenolic (polyphenols, flavonoids, and condensed tannins) contents and antioxidant property (DPPH, ABTS, FRAP) were evaluated in hexane (HE), acetone (AC), ethanol (ET), 70% (v/v) ethanol/water (EW), and powder extracts of Jatropha gossypifolia leaves using spectrophotometric methods. The lowest and highest contents of polyphenols (10.27 ± 0....

There are many opportunities in the global food market for innovations, through the valorization of artisanal technologies based on the local raw material. In this context we were interested in the development of cookies based on a local variety of sorghum from northern Cameroon, the so-called S35 sorghum variety and a local cowpea from northern Ca...

This study aimed to evaluate the quality and antimicrobial activity of soaps and ointments enriched with aqueous ethanol extracts from barks of Ziziphus mauritiana and Ziziphus mucronata. The galenic formulation allowed the development of ointments as well as soap based on aqueous ethanol extract (70%, v/v) using some excipients. The consistency of...

Fermented cereal-based drinks as “kounou” are among the most popular indigenous beverages in Northern Cameroon. Because they are made in a primitive way, they are ready to be served while still actively fermenting. Therefore, some physicochemical properties of “kounou” were tested in the current study during 4 days of storage at room and refrigerat...

Le riz est une céréale cultivée et consommée partout en Afrique. Au Cameroun, il est cultivé en système irrigué, pluvial et bas fond. Sa production par an estimée à 360 000 t, est très inférieure à la demande estimée à environ 800 000 t de paddy. L'Est-Cameroun présente des riches potentialités favorables à la riziculture pluviale, qui reste cepend...

The objective of this study was to determine the phytochemical profile and antimicrobial activity of leaf and bark extracts of Ziziphus mauritiana and Ziziphus mucronata. For this purpose, an extraction by maceration using ethanol was carried out and the extracts were subjected to antibacterial activity assessment through qualitative and quantitati...

ABSTRACT This article aims to assess the potential production of ecological charcoal (briquette) which is a combustible made from the agricultural residues, Agro-industrial and household waste in substitution of wood fuel in Far North Region of Cameroon. Fragile ecosystems of the Region incur in recent years a strong combined pressure by the local...

Fermented alcoholic beverages play a major role in the socio-cultural lives of people of Northern Cameroon. However, reports of shelf-life and health problems associated with indigenous sorghum-based alcoholic beverages are a major call for concern. This study aimed to highlight the additional effects of sublethal temperatures (no thermal treatment...

Ce volume axé sur la transformation de la viande du poisson et les produits carnés fait suite au précédent sur les céréales les légumineuses et fruits. Il présente, des informations sur les procédés artisanaux de transformation à petite échelle avec comme souci de contribuer à la valorisation sur le plan sous régional et international des ressource...

Ce livre vient à propos, mettre à la disposition des principaux acteurs de la filière, notamment les producteurs et les transformateurs, un paquet de nouvelles technologies mises au point par la recherche développement dans le domaine de la culture, la transformation et la filière arachide au Nord Cameroun. Il ne vient surtout pas se substituer, ma...

La région soudano sahélienne du Cameroun est fréquemment sujette aux intempéries diverses allant des catastrophes naturelles extrêmes (inondations, sècheresses …) aux crises sociales (guerre, terrorisme…) ce qui impacte fortement le développement humain dans la région. On observe cependant une résilience de ces populations face à ces catastrophes,...

Le Fond Mondial Pour la Nature (WWF) et ses partenaires (le MINFOF et l’AfricaBiodiversity Collaborative Group (ABCG)) ont commandé cette étude qui vise à évaluer la sécurité alimentaire des ménages riverains à la périphérie du parc national de Lobéké au Cameroun. Il est question d’identifier les déterminants de l’insécurité alimentaire et de propo...

The objective of the study was to evaluate in vitro inhibitory effect of methanolic and methanolic-aqueous mixture extracts of Plectranthus neochilus Schltr (P. neochilus) and Bauhinia rufescens Lam (B. rufescens) on the growth of Escherichia coli 25922 and Proteus mirabilis. A phytochemical screening was carried out to highlight compounds (phenoli...

Fish is an extremely perishable food item and requires preservation for future use. Several methods including drying, are used round the world for preserving fish and to extend its shelf-life. The microbial quality of sun-dried fish locally called "soudamouka" was investigated. Commercially available "soudamouka" samples were collected from retaile...

This work deals with the energy recovery of paper waste for the production of a domestic fuel (white coal). In the city of Maroua, paper waste produced in large quantities is not recycled and most often burned in an opened area. However, this has a high calorific value. The aim is to produce a fuel made of paper and clay used as a binder. For this...

The present work was carried out with the aim to establish the influence of hydrothermal treatments on physical and microbiological characteristics and Peleg’s prediction of soaking behavior of tiger nut tubers. For this purpose, tigernut tubers (Cyperus esculentus) Ø≥1cm, were differently soaked in tree solutions: acid solution (vitamin C) and alk...

The depletion of fossil energy and his consumption in cooking as the use of firewood are contributing to increase the problem of climate change. It is urgent to find alternative energy sources to take over the situation when the areas are being blessed with higher solar energy potential. The present work concerns design and realization of a mixed s...

In order to produce biscuits from off‐season sorghum, a local “Muskwari” sorghum was milled and sieved. This flour was used to produce shortbread biscuits with different substitutions rates of wheat flour to that of sorghum. The standard formulation of this same type of shortbread biscuits was used and biscuits were produced with incorporation rate...

Bread is one of the food items which drive the change in consumption patterns in central Africa. This bread is made basically of wheat, however, Africa does not produce enough wheat to fulfill growing demand. In order to overcome this obstacle, the idea here is to characterize some local sorghum variety the, so called "muskwari" and then substitute...

This article is focused on the production of biodiesel from the waste cotton seed oil (WCSO), after purification, as an alternative to fossil fuels. Waste oil was collected from Sodecoton, a factory producing cotton seed oil in the Far North Cameroon. The WCSO was subjected to purification using activated coal, followed by transesterification under...

Aims: “Foléré” beverage is a refreshing locally made drink much appreciated by the populations of the hottest parts of Cameroon. This paper aims at investigating microbial contamination of “Foléré” beverage and highlights impact of the sublethal temperatures on the hygienic quality the beverage. Study Design: Design used for describing physicochemi...

This study was propose to elucidate the traditional process production, biochemical, and microbiological parameters of the " red kapsiki " beer locally called " Te. " Direct interviews are conducted on the basis of questionnaires in four localities of the Far‐North region of Cameroon. At each site, beer samples are collected, labeled, and undergo p...

Dead leaves of neem trees in the Sahelian urban zone are among the wastes that are underutilized, since it is either buried or burnt, and thus, contribute to increased environmental pollution. Unfortunately, the lack of information on the biomass and energy potentials of these wastes empedes any initiative for its industrial biomethanization. This...

The kapsiki beer locally called "Mpedli" is a traditional white and occasionally brownish beer produced in the plains of "Mandara" mountains in Far-North province of Cameroon. Despite the importance of this homemade drink for the local population, the production process and the physicochemical and microbiological characteristics of this beverage ar...

The potentials of dead neem leaves for the production of the biogas was investigated as key measure to reduce the deforestation mainly caused by firewood cuttings in the Far-North Cameroon. Biomass collected was allowed to undergo biological pretreatment to facilitate its hydrolysis during anaerobic co-digestion with the cow dung. Samplings of dead...

Cassava retting is one of the main step for cassava processing. This step involve some microorganisms which activity impact on the quality of cassava derived products. With the aims of ensuring a good quality of cassava products, tree strains of microorganism namely Lactobacillus sp., Saccharomyces sp., and Rhyzopus sp., were tested as starter cult...

“Lakh vzla” is one of the most interesting food flavour enhancer used for notabilities amongst Mafa people from Northern Cameroon. With the aims at valorizing this African food enhancer, we studied artisanal processing production and investigated the principal microbiological activities and biochemical modifications which occur during its processin...

Street-vended meat samples were purchased from street food sellers in five major town from soudano-sahelian zone of northern Cameroon. Standards methods of microbiological control were used with the aims of determining their sanitary status. Total aerobic microflora, Staphylococcus aureus, Bacillus cereus, Salmonella, Escherichia colitype 01 non-01...

Aims: Mandara is a chain of Mountains located in northern Cameroun with the border of the republic of Nigeria. This area is populated by " kapsiki " an indigenous populations living. This non moslem population is brewing an opaque beer, which has both a symbolic and nutritional. This paper aims at investigating the physicochemical and microbial qua...

The "foléré" juice (Hibiscus sabdariffa) is one of the most consumed handcrafted drinks in the Far North region of Cameroon. However, an eventual contamination of this drink could significantly affect its quality and severely harm the health of the consumer. It is strong of this observation that a study was performed in order to evaluate the influe...

This work has been led in view to find the influence of sublethal heat (45°C, 50°C, 60°C) on acid resistance of B. subtilis NCTC 3610 and B. stearothermophilus CNCH 5781 spores. Firstly, we have submitted Bacillus spores to 0.4% acetic acid pH 4.5 during the times of 1, 2 and 3 hours. Then another spores group were preheated at various sublethal te...

With the aim of ameliorating its preservation capacity, silver nanoparticles (0 -100 nm) with 99.9% purity and 35 nm average particle size, were use as building material for earthenware jar, an ex-tremely old container which is still used in rural African villages specifically in North Cameroon. Earth material was dissolved in water at the weight r...

Concerns of Africans with transgenic foods and genetically modified organisms seem to have minor repercussions in general on the use and the commercialisation of these products on African markets and particularly in the northern sudano-sahelian zone of Cameroun. In this line, different crops (cotton, and maize) and some commercialized branded food...

Central Africa Francophone coun-tries are a group of states geographi-cally located in the center of Africa. They are grouped for the majority; within the community of states of Central Africa whose acronym in French is CEMAC. The CEMAC zone includes six countries: Cameroon, Congo, Gabon, Equatorial Guinea, the Central African Republic and Chad. Th...

This paper aims at valorising an artisanal honey based alcoholic beverage from northern Cameroon (Africa). The studied process production involved most of stage required for production of mead with difference in starter preparation and handling which include a step of drying and smoking. The must preparation also present light difference with the o...

Milk powder was substituted by 0, 10, 20, 30 and 40% (w/w) cocoa powder, and used for yoghurt production. Microbiological and physico-chemical analyses were carried out during fermentation and sensory profile of fermented products evaluated in comparison to plane commercial yoghurt. Adding cocoa powder induced an increase of the initial pH (p<0.05)...

To favor a better accessibility to biogas, it becomes indispensable to find new substrates of production having little or no negative influence on food security. It is the objective of this work which aims at valorizing dead neem leaves assimilated to waste. These leaves have undergone three treatments and mixed at different proportions to cow dung...

The food multimix (FMM) concept is one of the attempts used successfully by international programmes to meet the food insecurity challenges in poor African rural area (Amuna, 2009). Despite its success the current FMM formulation concept target mainly common nutrient as carbohydrates, protein and vitamins thus lacking some bioactive compounds (Zoto...

Kossam" is a set of milk based beverage from northern Cameroon presenting great symbolic and social values for local population. They have high economic value for women as most important source of income for the family in rural area. In order to ameliorate process production with the view of industrialization some of their physicochemical propertie...

La ville de Maroua, dans le Nord Cameroun, constitue un important centre de commerce pour les produits maraîchers. La demande est croissante du fait de l’augmentation de la population. La chaîne d’approvisionnement du marché de la ville est entretenue par un réseau de grossistes, d’intermédiaires et de détaillants qui s’appuient sur des circuits de...

Les stratégies de commercialisation des produits maraîchers sur le marché de Maroua, au Cameroun La ville de Maroua, dans le Nord Cameroun, constitue un important centre de commerce pour les produits maraichers. La demande est croissante du fait de l'augmentation de la population. La chaine d'approvisionnement du marché de la ville est entretenue p...

The earthenware jar is an extremely old container still used in Rural African villages. Women used to carry it on their backs to fetch and keep water from spring, to prepare and keep foods, to keep leftovers fresher. Despite its importance, food spoilage is one major drawback which limits its use in African rural area. One of the most promising inn...

Sustainability and Effectiveness of Artisanal Approach to Control Mycotoxins Associated with Sorghum Grains and Sorghum Based Food in Sahelian Zone of Cameroon