Evaluation of the fungal microflora infesting pigeon pea (Cajanus cajan L. Millspaugh) in southern Benin and associated mycological hazards

Pigeon pea is a perennial legume with a good nutritional value. Unfortunately, it is also a substrate for fungi contamination. Then, a qualitative semi-structured survey was carried out in the main production areas of pigeon pea in southern Benin. This survey was coupled with samples collection. A total of 60 samples of pigeon pea were collected and analyzed for associated fungal microflora by using a taxonomic schemes primarily based on morphological characters of mycelium and conidia. Obtained results indicated a low technological valorization of pigeon pea seeds in southern Benin and their used only in direct consumption after cooking. Microbiological analyses revealed the high contamination of pigeon pea seeds by fungi, with the most occurrence of Aspergillus (71.42%), followed by Fusarium (26.19%). Fungal species such as Aspergillus ochraceus, A. parasiticus, A. flavus and Fusarium oxysporum were also detected in analyzed samples. Taking into account the toxicity of the secondary metabolites produced by these fungi, mycological hazards are discussed and important methods for the control of mycotoxin-contamination are further provided. More attention should be paid to the mycological quality of this legume, in order to protect the consumers’ health

Aspect botanique, profil nutritionnel et implications du pois d'Angole (Cajanus cajan (L.) Millspaugh) dans le développement communautaire en Afrique subsaharienne

Le pois d’Angole est une importante légumineuse à graines appartenant à la famille des Fabaceae. Il représente une culture intéressante pour l’agriculture africaine grâce sa richesse en éléments nutritifs, son adaptabilité aux conditions climatiques, sa capacité exceptionnelle de régénération des sols et ses usages très diversifiés pour l’homme et le bétail. C’est donc une culture à promouvoir dans la lutte contre la malnutrition et l’insécurité alimentaire en Afrique subsaharienn

EFFECT OF ESSENTIAL OIL OF MENTHA SPICATA L. FROM BENIN ON THE QUALITY OF MANGO PUREE IN STORAGE MODEL FOOD SYSTEMS AT 4° AND 25°C

The present study aims to evaluate the effect of essential oil from fresh leaves of Mentha spicata L. on the quality of mango puree in storage model food systems at 4°C and 25°C. The results of physico-chemical characterization of mango puree underlined its high nutritional potential, with carbohydrates, carotenoids and vitamin C contents of 9.5±0.4%, 20.05±0.03 mg/100g and 21.03±0.05 mg/100g respectively. The microbiological analyses using taxonomic schemes primarily based on morphological characters of mycelium and conidia revealed that Aspergillus parasiticus, Fusarium versicolor and Mucor spp. were the most common fungi identified in mango puree in the southern Benin. Antifungal assay, performed by the agar diffusion assay, indicated that essential oil exhibited high antifungal activity against the growth of fungi. The minimal inhibitory concentration (MIC) of the essential oil was found to be 2.0 μL.mL-1for Aspergillus parasiticus and Fusarium versicolor; and 1.0 μL.mL-1 for Mucor spp. The chemical analysis of the oil made by GC/MS led to the identification of 35 components, characterized by carvone (67.5%), and limonene (12.0%) as major components. The results obtained during the evaluation of the microbiological, physico-chemical and sensorial characteristics of the mango puree stored by adding essential oil, revealed the high potential of the essential oil of Mentha spicata L. in food quality preservation. This essential oil offers a novel approach to the management of fruit derivate products during storage

Dialium guineense Willd. Parkia biglobosa (Jacq.) R. Br. Ex Benth. and Tamarindus indica L.: Review of known and synergetic bioactive compounds

International audienceNative from Africa, Dialium guineense Willd. Parkia biglobosa R. Br. Ex Benth. And Tamarindus indica L. grow in tropical regions, and are very widespread in West Africa, particularly in Benin. They are simultaneously used in the traditional healing of infectious diseases but there is a lack on their bioactive compounds description. This work places a special emphasis on inventory of known bioactives compounds from the three plants and their mechanism of action in order to identify the need for further research. It emerges from this work that numerous studies confirm the biological activities of the plants extracts. Nevertheless, few bioactive molecules are described as well as the mode of action of the active extracts

Effects of essential oil from Cymbopogon citratus leaves and its susceptibility on the quality of fresh orange juice during storage

The present study aims to evaluate the effect of essential oil (EO) from Cymbopogon citratus leaves against the spoilage flora of fresh orange juice. Thus, the EO was extracted by hydrodistillation from fresh leaves of Cymbopogon citratus collected in southern Benin and its chemical composition was determined by gas chromatography, coupled to mass spectrometry (GC/MS). Orange samples were collected from large production areas of South and Central Benin and juices were extracted by mechanical pressing. After identification of spoilage flora of fresh orange juice, antimicrobial tests were carried out with the EO of Cymbopogon citratus to evaluate its antimicrobial activity on spoilage flora of fresh orange juice.  Results indicate that the spoilage flora of fresh orange juice is mainly composed of fungi belonging to the genera of Cladosporium, Penicillium and Fusarium. Bacteria such as Enterobacter cloacae and Enterobacter aerogenes were also identified in some samples. The major compounds identified in the EO by GC/MS are Neral (33.0%) and geranial (41.3%) with a predominance of oxygenated monoterpenes (85.5%). Antimicrobial tests have revealed a high antibacterial activity of the EO, with minimum bactericidal concentrations (MBC) between 0.1 and 0.15 μL.mL-1. Antifungal tests revealed that fungi are also susceptible to this EO with minimum fungicidal concentration (MFC) between 0.15 and 0.25 μL.mL-1. Results obtained during the evaluation of the physicochemical characteristics of the orange juice stored by adding EO, indicated a significant decrease in the pH and vitamin C content. However, with EO concentration of 0.250 μL.mL-1, the pH of stored juice was 6.4 ± 0.1 after 15 days of preservation, with a best vitamin C content of 28.06 ± 0.03 mg / 100mL. The EO of Cymbopogon citratus, with high antimicrobial activity, could be used as an alternative in the preservation of fruit juices, replacing antimicrobials from chemical synthesis

GC-MS screening and evaluation of the anti-inflammatory and antioxidant activities of ethanolic leaves and stem barks extracts from Dialium guineense Willd, Parkia biglobosa (Jacq.) R. Br. ex Benth. and Tamarindus indica L

International audienceInflammation has been shown to be greatly involved in the degenerative processes of human skin such as photo aging and atopy. Reduction of low-grade inflammatory reactions by topical products may be necessary in case of skin aggression, to obtain an optimal wound healing and restore the physiological balance of human skin. Present work evaluated the antioxidant, anti-inflammatory and phototoxic properties of ethanolic extracts from leaves and stem barks of Dialium guineense Willd., Parkia biglobosa (Jacq.) R. Br. Ex Benth. and Tamarindus indica L. The antioxidant power of the extracts, measured in vitro by the KRL method, showed that each gram of D. guineense bark extract, P. biglobosa leaves extract and T. indica bark and leaves extracts has an antioxidant capacity equivalent to 1585, 2092, 5071 and 2246 mg of Trolox respectively. Simultaneously with their actions on cell viability, the anti-inflammatory activity of the extracts was monitored measuring their effects on NO production by mouse macrophages submitted to LPS from E. coli to determine the anti-inflammatory ratio of each extract. The bark and leaves of D. guineense Willd., the leaves of P. biglobosa (Jacq.) R. Br. Ex Benth. and the bark of T. indica L. have anti-inflammatory ratios from 161 to 458.2, whereas Dexamethasone (positive control) has a ratio of 37.87. The in vitro 3T3 NRU test was used on mouse fibroblasts to determine the phototoxicity of the six extracts. Only D. guineense Willd. stem bark was photo-toxic with a photo-irritation factor greater than 5 (PIF = 8.39). Our study report some molecules such as lupeol, amaryn, sitosterol for the first time in the extracts and shows that the use of these plants in traditional medicine is justified

Efficacité des huiles essentielles de trois plantes aromatiques contre la mycoflore d’altération du niébé (Vigna unguiculata L., Walp) collecté dans les magasins de vente du Sud-Bénin

Objectif : La présente étude vise à évaluer l’activité antimicrobienne des huiles essentielles extraites des feuilles fraîches de Cymbopogon citratus (L.), de Cymbopogon nardus (L.), et de Eucalyptus saligna (S.), sur les moisissures isolées des stocks de niébé de quelques magasins de vente du sud-Bénin.Méthodologie et Résultats : Pour ce faire, un échantillonnage a été réalisé dans les grands magasins de stockage du niébé situés dans les marchés de Ouando (Porto-Novo) et de Dantokpa (Cotonou) suivi de la recherche et l’isolement de la mycoflore d’altération. Des tests antifongiques ont été réalisés avec les huiles essentielles de Cymbopogon citratus (L.), Cymbopogon nardus (L.), et de Eucalyptus saligna (S.), afin d’évaluer leur potentiel antifongique. Des résultats obtenus, il ressort que les souches fongiques isolées des échantillons de niébé sont essentiellement Aspergillus flavus (L.), Aspergillus tamarii (K.) et Penicillium roqueforti (T.). Les tests antifongiques ont permis de démontrer l’activité des huiles essentielles testées contre la flore fongique contaminant le niébé, avec des concentrations minimales d’inhibition (CMI) dépendantes du type fongique et de la dose d’huile essentielle testée. Les fortes activités antifongiques sont obtenues avec les huiles essentielles de Cymbopogon citratus (L.) et de Cymbopogon nardus (L.) avec des CMI comprises entre de 0,05 et 1Al/ml.Conclusion : Le potentiel antifongique de ces plantes offre donc une approche novatrice dans la gestion intégrée des stocks de niébé au Sud du Bénin.Mots clés : niébé, moisissures, huiles essentielles, activité antifongique

Essential oils as natural antioxidants for the control of food preservation

Despite advancements in food preservation ways, the nature of preservatives remains one of the real problems that must be taken into account for the preservation of consumer health. To cope with the problems of contamination and oxidation of foodstuffs, the chemistry development has favored the appearance and application of new chemical substances such as benzoates, sulphites, calcium chloride, acid citric etc. used as synthetic food preservatives. Subsequently, several of these synthetic preservatives have been banned in some countries because of their long-term adverse toxicological effects. The current trend of consumers seeking healthier diets is forcing them to use natural products with antimicrobial and antioxidant activities such as essential oils. These aromatic plant extracts, whose antioxidant power has been widely proven in the literature, also contain substances with very interesting biological activities, less polluting for the environment, with minor effects on the health of consumers. In this review, we have highlighted the antioxidant potential of essential oils for food quality improvement and preservation

Antifungal Properties of Pimenta racemosa (Mill.) and Mentha x piperita (L.) Essential Oils against Fusarium oxysporum Causing Tomato Fruit Rot

peer reviewedFungal pathogens are responsible for the rot of tomatoes and cause health hazards to consumers as well as economic loss. The aims of this study were to evaluate the efficacy of essential oils from Pimenta racemosa (Mill.) and Mentha x piperita (L.) leaves as plant-based fungicide against Fusarium oxysporum strains associated with tomato rot. The chemical composition of the essential oils was determined by GC-MS analysis. Antifungal effects of essential oils against strain of F. oxysporum obtained from rotted tomato, were evaluated through the determination of Minimal Fungicide Concentration (MFC) and the Minimal Inhibitory Concentration (MIC). Results indicated that β-myrcene (19.48%), chavicol (15.39 %), and eugenol (46.65%) were the major components of the essential oil of Pimenta racemosa (Mill.). L-menthone (17.19 %), menthol (24.79%), and menthofuran (26.78 %) were the major components of the essential oil of Mentha x piperita (L.). Essential oil of Pimenta racemosa (Mill.) exhibited the highest antifungal activity against the growth of Fusarium oxysporum strain tested with a MIC and MFC of 0.75 and 1.25 μl.ml-1 respectively. These results provide an experimental basis for further research on the use of these plant extracts in the development of eco-friendly preservatives against fungi causing rots of tomato in post-harvest