Comparing Smoked Fish Quality of Traditional and Improved Modern Ovens Using Dendro-Energy from Mangrove and Tropical Forest Woods and Implications for Conservation in Central African Atlantic Coast, Cameroon

Smoked fish qualitative organoleptic parameters (color, smell, texture and taste) and quantitative proximate parameters (protein and ash content and salt mineral: Ca, Iron, Mg, Zn content in ash) of two species (Ethmalosa fimbriata and Pseudotolithus elongatus) smoked in traditional and modern ovens with wood from mangrove (Rhizophora racemosa) and two tropical forest (Sacoglottis gabonensis and Albizia glaberrina) species in Douala-Edea Atlantic coast, Cameroon are presented. Women processors significantly spend more time, consume more wood and consequently release significant amount of carbon dioxide (CO2) to the environment with traditional smoking system. Organoleptic characteristics were significantly different with ovens types but not with different wood species except color (black and marron from inland forest wood species and preferred brownish and golden brown colored smoked fish from mangrove wood). Fish food constituents yielded for improved smoked oven:  Protein content (65.52%; 69.45%), ash content (6.21%; 5.57%) and traditional oven: Protein content (70.65%; 75.00%), ash content (5.73%; 6.33%) for Ethmalosa fimbriata and Pseudotolithus elongatus respectively. Results also confirmed good dietary quality of fish samples (source of calcium, iron and magnesium). Some energy efficient management techniques and conservation implications were proposed regarding qualitative and quantitative improvement of smoked fish

Development of expressed sequence tags-simple sequence repeats (EST-SSRs) for Musa and their applicability in authentication of a Musa breeding population

Maintaining identity of clones is essential in breeding programs. New EST-SSR markers have been developed for banana and used to screen a diploid population for clonal identity. A total of 410 primer pairs were designed from an EST database, validated using polyacrylamide gel electrophoresis (PAGE) and a subset was optimized for accurate genotyping on a capillary genetic analyzer. Combining PAGE and capillary electrophoresis, about 44% of the designed primers were informative in the diploid population. The majority of markers produced two alleles as expected in a diploid population. However, some showed three to four alleles, possibly indicating closely-related members of gene families. Screening of field samples using SSR markers revealed genotype identity issues in the target population. The present study demonstrates the applicability of SSRs in the  establishment of parentage and relatedness between accessions. The newly-developed SSRs will be valuable tools in the understanding of Musa genetics, in marker-trait associations, thereby enhancing the effectiveness of breeding programs.Key words: EST, SSRs, markers, Musa, breeding

Antioxidant and Antifungal Activities of Cocoa Butter (Theobroma cacao), Essential Oil of Syzygium aromaticum and a Combination of Both Extracts against Three Dermatophytes

To contribute in the research of better drugs against dermatophytosis, we evaluated the antioxidant and antidermatophytic activities of cocoa butter, cloves essential oil, and a mixture of both extracts. The cocoa butter was obtained by boiling the cocoa paste. The essential oil extracted by hydrodistillation was chemically analysed by gas chromatography and gas chromatography coupled with mass spectrometry. The antioxidant activity was determined using the DPPH scavenging method, and  the antidermatophytic activity was evaluated using the agar dilution method. The essential oil, majoritary constituated by eugenol (87.62%), β-caryophyllene (5.88%), and β-bisabolene (4.41%), had an antiradical power (4.22 x 10-2) higher than that of BHT (4.00 x 10-3), like the cocoa butter and essential oil mixture (6.06 x 10-3). The essential oil was more active than the griseofulvin: it was fungicidal at 400 ppm against Trichophyton rubrum, and at 900 ppm against Microsporum gypseumand Trichophyton tonsurans. The cocoa butter activity was low, but the mixture with the essential oil had an important activity with inhibitory percentages of 78.69 %, 88.27 %, 91.20% against T. rubrum (at 400 ppm), T. tonsurans(at 900 ppm)and M. gypseum (at 900 ppm)respectively. Cloves essential oil and the mixture with cocoa butter can be used to formulate new drugs against dermatophytes.

Antiplasmodial volatile extracts from Cleistopholis patens Engler & Diels and Uvariastrum pierreanum Engl. (Engl. & Diels) (Annonaceae) growing in Cameroon

In a search for alternative treatment for malaria, plant-derived essential oils extracted from the stem barks and leaves of Cleistopholis patens and Uvariastrum pierreanum (Annonaceae) were evaluated in vitro for antiplasmodial activity against the W2 strain of Plasmodium falciparum. The oils were obtained from 500 g each of stem barks and leaves, respectively, by hydrodistillation, using a Clevenger-type apparatus with the following yields: 0.23% and 0.19% for C. patens and 0.1% and 0.3% for U. pierreanum (w/w relative to dried material weight). Analysis of 10% (v/v) oil in hexane by gas chromatography and mass spectrometry identified only terpenoids in the oils, with over 81% sesquiterpene hydrocarbons in C. patens extracts and U. pierreanum stem bark oil, while the leaf oil from the latter species was found to contain a majority of monoterpenes. For C. patens, the major components were α-copaene, δ-cadinene, and germacrene D for the stem bark oil and β-caryophyllene, germacrene D, and germacrene B for the leaf oil. The stem bark oil of U. pierreanum was found to contain mainly β-bisabolene and α-bisabolol, while α- and β-pinenes were more abundant in the leaf extract. Concentrations of oils obtained by diluting 1-mg/mL stock solutions were tested against P. falciparum in culture. The oils were active, with IC50 values of 9.19 and 15.19 μg/mL for the stem bark and leaf oils, respectively, of C. patens and 6.08 and 13.96 μg/mL, respectively, for those from U. pierreanum. These results indicate that essential oils may offer a promising alternative for the development of new antimalarials

Effect of different smoking processes on the nutritional and polycyclic aromatic hydrocarbons composition of smoked Clarias gariepinus and Cyprinus carpio

The effect of different smoking processes on the nutritional value and polycyclic aromatic hydrocarbon (PAHs) content of Clarias gariepinus and Cyprinus carpio has been assessed in this study. After smoking processes, the finish products were analyzed to determine the nutritional quality and the PAHs content. Different smoking processes significantly decreased (p < 0.05) lipids content of fish. The smoked fish with unfiltered Psidium guajava has revealed higher lipid contents of 14.17 ± 0.15% and 14.96 ± 0.05%, respectively, for SNE GSF and SE GSF. A significant reduction (p < 0.05) in protein content (% DM) has been observed in the two fish's species submitted to smoking processes. We found that evisceration of fish before smoking leads to increase the level of naphthalene, acenaphthene, and benzo (a) pyrene in smoked C. gariepinus and C. carpio. The use of metallic filter in the smoking of noneviscerated fish leads to the significant reduction (p < 0.05) of the PAHs content in smoked fishes. Higher levels of PAH such as naphthalene and acenaphthene with values of 1,451.54 ± 49.58 and 709.91 ± 8.12 ng/kg were found in smoked C. carpio and 1,841.1 ± 11.41 and 809.91 ± 1.10 ng/kg were found in smoked C. gariepinus obtained in the case of traditional smoking. The PAHs content was higher in fish smoked using traditional ovens. Therefore, the quality of smoked fish was improved using a metallic filter during different smoking processes

Impacts des actions anthropiques sur les zones humides de la ville de Douala et solutions de gestion durable: Cas de la rivière Kondi

Objectif: Les observations faites au Cameroun notamment dans la ville de Douala montrent que, l’état des écosystèmes aquatiques où sont déversées les eaux résiduaires provenant des différents dépotoirs des industries et des agglomérations et même du lessivage des terres environnantes, est assez démonstratif de l’impact des activités anthropiques. L’objectif du présent travail est d’inventorier les différentes formes d’anthropisation, ainsi que leurs effets sur le milieu, afin de proposer des solutions de gestion durable.Méthodologie et résultats: La méthodologie adoptée est celle basée sur les enquêtes. Les types d’enquêtes adoptés sont les enquêtes face à face et par observation directe. Les résultats des enquêtes ont montré que plus de la moitié des riverains de la rivière Kondi se sont installées dans cette zone à cause des difficultés financières ont été averties des menaces éventuelles au moment de leur installation sur ce site. L’inondation apparaît comme la première menace subie par les populations. L’élevage et la construction des maisons en bordure du cours d’eau sont les activités anthropiques à l’origine des catastrophes le long du cours d’eau. De manière générale, les populations affirment déverser leurs déchets dans les bacs à ordures et la majorité des domiciles ne possèdent pas des latrines aménagées. Par ailleurs, plus de la moitié de la population connait les noms des espèces végétales et les utilise à des fins alimentaire et sanitaire. Enfin, la proposition du drainage du cours d’eau est la plus avancée par les populations riveraines.Conclusion et application des résultats: L’analyse des données obtenues a permis de recenser différentes formes d’activités anthropiques menées par les populations et, d’en évaluer leurs conséquences. Les propositions de gestion durable découlant de ces effets donnent une indication sur la perception qu’ont les populations sur la qualité des milieux aquatiques de la ville de Douala, et une orientation de l’assainissement des cours d’eau.Mots clés: Rivière Kondi, écosystème aquatique, activités anthropiquesEnglish Title: Impacts of human actions on the wetlands of the city of Douala and sustainable management solutions: case of Kondi RiverEnglish AbstractObjectives: Observations in Cameroon including Douala show that the status of aquatic ecosystems where wastewater discharged from various dumps industries and cities and even leaching of surrounding land, is quite demonstrative of impact of human activities. The objective of this work is to inventory the various forms of human impact and their effects on the environment, to propose sustainable management solutions.Methodology and results: The methodology is based on the investigations. The kinds of surveys are adopted inquiries face to face and by live observation. Survey results showed that more than half of the residents of the river into this area Kondi moved because of financial and difficulties were warned of feasible threats at their installation on that site; appears the flood as the first threat faced by populations. Farming and building houses on the edge of the river are the anthropogenic activities causing disaster along the river. In general, people say their dump waste in the garbage bins and the majority of homes-have only improved latrines. Furthermore, over half of the population know the names of plants and used in food and health Purposes. Finally, river drainage of the proposal is the most advanced by local residents.Conclusion and application of results: The analysis of data has identified different forms of human activities and populations assess their consequences. The sustainable management proposals resulting from these effects give an indication of the perception of people about the quality of aquatic environments of the city of Douala, and guidance for remediation of waterways.Keywords: Kondi River, aquatic ecosystem, human activitie

Comparative essential oils composition and insecticidal effect of different tissues of Piper capense L., Piper guineense Schum. et Thonn., Piper nigrum L. and Piper umbellatum L. grown in Cameroon

This study compared the chemical composition of the essential oils obtained by hydrodistillation of different tissues of Piper capense, Piper guineense, Piper nigrum and Piper umbellatum grown in Cameroon. The GC and GC/MS analysis showed qualitative and quantitative differences between these oils. Oils from the fruits were rich in a-pinene (5.6 - 12.3%) and b-pinene (6.7 - 59.3%). The other major constituents were sabinene (14.7%) for P. capense, limonene (15.8%) and b-caryophyllene (20.8%) for P. guineense. The oil from the fruits of P. nigrum contained sabinene (11.2%), d-3-carene (18.5%),limonene (14.7%) and b-caryophyllene (12.8%) while that of P. umbellatum content linalool (14.4%) and (E)-nerolidol (10.0%) as major constituents. The essential oil obtained from the leaves of P. capense was largely composed of a-pinene (12.8%), -pinene (50.1%) and b-caryophyllene (12.4%). The most abundant constituents identified in the oil from the leaves of P. guineense were limonene (10.3%) and germacrene B (25.1%) while that from P. nigrum was characterized by its high amount of a-selinene (16.5%) and -selinene (14.6%). -pinene (10.8%), -caryophyllene (28.2%) and (E)-nerolidol (16.5%) were the quantitative important constituents of the essential oils from the leaves of P. umbellatum. Theoils from the lianas of P. guineense was rich in (Z, E)-a-farnesene (28.7%), limonene (19.7%) and myristicine (10.9%), while those from P. nigrum contained d-3-carene (14.4%) and -caryophyllene(36.0%). The oil from the stems of P. capense contained mostly a-pinene (14.3%) and -pinene (61.4%). The distillation of those from P. umbellatum did not produce any essential oil. Oils from the three fruits showed variable contact toxicity against Sitophilus zeamais with P. guineense being more toxic (LD50 =10.0 ± 0.3 ìl/g) than P. capense (LD50 = 16.1 ± 0.6 ìl/g) and P. nigrum (LD50 = 26.4 ± 1.5 ìl/g). Poudrox (5%) used as a standard insecticide exhibited 100% mortality

Proximate composition, mineral content and fatty acid profile of two marine fishes from Cameroonian coast: Pseudotolithus typus (Bleeker, 1863) and Pseudotolithus elongatus (Bowdich, 1825)

Background: Knowledge of chemical composition of fish from Cameroon is poor. The genera Pseudotolithus are nutritionally and economically important in Cameroon. Thus the knowledge on their chemical composition could help in functional food elaboration. Purpose: In this study, Proximate composition, fatty acid profiles and mineral composition were determined in two fish species, Pseudotolithus typus and Pseudotolithus elongatus from Cameroonian coasts. Basic procedure: AOAC standard method was used. Fatty acids were identified by GC/MS as N-acylpyrolidides. Mineral compositions were determined by atomic absorption spectrophotometry for Ca, Na, K, Mg, Fe, Zn, Cu, Mn, and by UV spectrophotometry for phosphorus (P). Main finding: Results indicated that chemical composition was not similar in the two fish species. Results also showed that water is the main constituent in the edible parts and in the bones with 76.17% to 78.24% and 51.21% to 55.28% respectively. Pseudotolithus typus and Pseudotolithus elongatus were good sources of proteins with 16.17% and 13.4% respectively. All the fish analyzed for fat were lean with fat contents less than 0.5%. These species of fish were poor in ω6PUFA and were rich in ω3PUFA with about one third of total fatty acids. The main ω3 fatty acids were eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The most abundant main elements were the potassium in the edible parts (1.39%) and calcium in the bones (18.26%). The most abundant trace elements were Zn and Fe in the edible parts and in the bones. Principal conclusion: The Na/K ratio values and ω3 fatty acids contents suggest that consumption of these two fish species could be recommended to prevent cardiovascular diseases. Keywords: Proximal composition, Mineral content, Fatty acid profiles, Pseudotolithus typus, Pseudotolithus elongate

Conditions to access of Drinking Water, Waterborne Diseases and Link with Socio-Environmental Aspects in Peri-Urban Areas Of Douala Littoral Cameroon, Sub-Saharan Africa

Les conditions d’accès à l’eau potable et le risque d’apparition de maladies hydriques dans les localités périurbaines de Dibombari, Bonaléa et Mbanga ont été étudiés. Des enquêtes ont été menées dans le cadre de cas de santé afin d’identifier les personnes souffrant de maladies d’origine hydrique; les ressources en eau consommées par ces individus ont été examinées dans leur environnement immédiat, puis leurs paramètres physico-chimiques in situ ont été mesurés à l’aide d’un multiparamètre portable Hanna HI98192. Les tests statistiques d’association du Chi2 et du Rho de Spearman couplés à des modèles de régression logistique binaire ont été utilisés pour prédire les risques d’apparition de maladies d’origine hydrique. Il est apparu que les maladies d’origine hydrique étaient significativement (P<0,05 et P<0,01) associées au traitement, à l’âge, au sexe, à l’assainissement et à la proximité des sources de pollution. Les personnes de plus de 15 ans et les femmes étaient les plus touchées par les maladies d’origine hydrique avec des proportions de 67,71% à Dibombari, 65,38% à Bonaléa et 64,19% à Mbanga. Du côté pédictif, les facteurs associés à un risque accru de maladie d’origine hydrique étaient l’âge (6,39[1,05 ;38,89] à Dibombari ; 4,88[1,07 ;30,33] à Bonaléa et 5,79[1,99 ;16,78] à Mbanga) et la distance aux sources de pollution (1,13[1,02 ;1,25] à Dibombari ; 1,22[1,01 ;1,33] à Bonaléa et 1,17[1,09 ;1,26] à Mbanga). Les facteurs de protection étaient: le type d’eau (0,80 [0,70 ; 0,90] à Dibombi) et le traitement (0,75 [0,65 ; 0,86] à Dibombari ; 0,76 [0,66 ; 0,89] à Bonaléa et 0,05 [0,007 ;0,38] à Mbanga) Il est conseillé aux acteurs du développement dans ces localités de mettre l’accent sur la protection des ressources en eau et l’assainissement car la santé des populations est en jeu