Yann Adjovi - Academia.edu (original) (raw)

Papers by Yann Adjovi

European Scientific Journal, ESJ, Mar 31, 2022

Resume Dans la lutte contre les aflatoxines, le recours aux méthodes alternatives est de plus en ... more Resume Dans la lutte contre les aflatoxines, le recours aux méthodes alternatives est de plus en plus préféré. Cette étude a consisté à évaluer l'efficacité des huiles essentielles de six plantes aromatiques (Mentha spicata, Mentha piperita, Cymbopogon citratus, Illicium verum, Cinnamomum verum, Myristica fragrans) extraites sur le développement des moisissures d'une part et sur leurs capacités anti-aflatoxinogènes d'autre part. Les huiles essentielles ont été extraites par hydrodistillation. L'activité antifongique de ces dernières ont été évaluées in vitro par les tests de diffusion directe, de micro-atmosphère et de test en puits. L'huile essentielle de C. verum a présenté la meilleure activité antifongique par inhibition totale à des concentrations de 0,01mg/µl sur A. novoparasiticus (AF32) et de 0,1 mg/µl sur A. flavus (AFc5) et A. novoparasiticus (NCPT280). Les huiles essentielles d'I. verum et de C. citratus ont eu une importante activité antifongique par les méthodes de

Journal of AOAC INTERNATIONAL, 2010

A new method that uses HPLC with a photochemical reactor for enhanced detection was developed and... more A new method that uses HPLC with a photochemical reactor for enhanced detection was developed and validated for the determination of aflatoxins in cassava flour. Samples were spiked with a mixture of four aflatoxins at 5, 10, and 20 g/kg mixed with either 1 or 5 g NaCl and extracted with methanolwater (80 20, v/v) by shaking for 10 or 30 min. An immunoaffinity column was used for cleanup. HPLC with postcolumn derivatization, for enhancement of aflatoxin fluorescence, and fluorescence determination were used for quantitation of the toxin concentration. The method was validated for recovery, linearity, and precision at the three concentrations tested. Recovery ranges were 5270, 6985, and 8089 for the spiking levels of 5.0, 10.0, and 20.0 g/kg, respectively. It appears that the amount of salt (NaCl) and the shaking time are critical factors in this method; optimal performance was obtained when 1 g salt was used and the shaking time was 10 min. The good linearity and precision of the me...

Journal of Medicinal Plants Research, Mar 25, 2014

Journal of Pharmacognosy and Phytotherapy

The dichloromethane, methanol and hydroethanolic extracts from leaves of Vitex doniana and stem b... more The dichloromethane, methanol and hydroethanolic extracts from leaves of Vitex doniana and stem bark of Adansonia digitata have been investigated for their antibacterial, antifungal, antioxidant activities and toxicity. The antifungal activity has been investigated against six species of Aspergillus by measuring the mycelial and sporulation inhibitions. The antimicrobial activity was investigated against six Gram positive and Gram negative strains using the microplate dilution method. The phytochemical study was performed on thin layer chromatography and antioxidant activity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging test. The sporulation inhibition percentage was 70% while mycelial inhibition was less than 40%. The minimum inhibitory concentration ranged from 0.039 to 2.5 mg/ml. In DPPH radical scavenging assay, the effect on reducing free radicals increased in a dose dependent manner. Three extracts out of six were very active compared to quercetol, with in...

Critical Reviews in Food Science and Nutrition, 2012

This article may be used for research, teaching, and private study purposes. Any substantial or s... more This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.

Fungal infection and aflatoxin contamination were evaluated on smoked or dried fishes sold in sur... more Fungal infection and aflatoxin contamination were evaluated on smoked or dried fishes sold in surrounding markets of Cotonou. These fishes are traditionally processed to avoid losses and rapid perishability and preserve them from a longer period. Fungal contamination was evaluated after plating on selective media with a total of 175 fungal isolated from 56 samples. Fungi identification shown high prevalence of Aspergillus genus that represent 44, 56% followed by Mucors (30%), Rhizopus and Rhizomucor (9.14%; 5.14%, respectively), Penicillum sp. (6.85%) and another minority. In Aspergillus genus, A. flavus represented 29.48% after A. niger that was 37.17%. A. parasiticus, A. fumigatus, A. wentii, A.clavatus and A. ochraceus had 10.25%, 7.69%, 5.12%, 3.84% and 2.56% respectively followed by A. tamarii, A. candidus and A. versicolor that had 1.28% each. In aflatoxin pathway gene cluster, we investigated three specific genes AflD, AflO and AflP to 18 stumps of A. flavus isolated. This sh...

The emergence of new diseases due to recurrent food poisoning nowadays in the face of excessive u... more The emergence of new diseases due to recurrent food poisoning nowadays in the face of excessive use of conventional antibiotics leads to the search for new bioactive molecules. Thus, the objective of this work was to investigate the antibacterial activity of fungal metabolites on contaminants responsible for food poisoning. To do this, Eight (08) fungal strains belonging to the genera Aspergillus, Penicillium and Nigrospora were used and antibacterial tests were performed on 4 bacterial strains (Staphylococcus aureus ATCC 25923, Shigella sp, Escherichia coli sp and Salmonella sp) using the agar cylinder method (antibiotic). The results showed that seven (07) fungal isolates have high antibacterial activity with inhibition diameters ranging from 18 to 29 mm on Staphylococcus Aureus ATCC 25923; Shigella sp; Salmonella sp and Escherichia coli. Synergistic tests have shown that the combination of 4 to 5 fungal strains could increase bacterial inhibition of Staphylococcus, Salmonella, Sh...

Legumes such as cowpea (Vigna ungiculata) and Bambara groundnut (Vigna subterranean) are the most... more Legumes such as cowpea (Vigna ungiculata) and Bambara groundnut (Vigna subterranean) are the most sought in Benin and in the West Africa sub-region. These legumes are an important protein source because of their high content of essentials amino acids. But, like many dried agricultural and food products, they are subject to contamination by molds and mycotoxins during storage. In order to assess the contamination of Bambara groundnuts, by the most dangerous and widespread mycotoxins in Africa (aflatoxins), especially in Benin, this study was conducted in Cotonou (Benin) main markets. Thirty-five (35) samples of Bambara groundnuts were collected from six (6) different markets in Cotonou. The fungi are isolated and identified morphologically on different media after direct culture. The species of Aspergillus section Flavi aflatoxigenic potential are evaluated and the contamination of samples by aflatoxins was determined by Thin Layer Chromatography (TLC). The results of this study show...

Food and Nutrition Sciences, 2017

Increasing consumer awareness regarding the health benefits of different nutrients in food has le... more Increasing consumer awareness regarding the health benefits of different nutrients in food has led to the requirement of assessing the effect of food processing approaches on the quality attributes. The present work focuses on understanding the effects of ultrasound (US) processing, mild heat pasteurization (65˚C for 15 min), thermal pasteurization (80˚C for 15 min) and their combination on physicochemical, microbiological properties and nutritional quality of pineapple juice through 60 days of storage at room temperature. Ultrasound treatment showed significantly lower browning degree. Ultrasound followed by ultrasound combined with mild heat pasteurization (UMP) treatments was effective in retaining the total phenolic content of pineapple juice as compared to the thermal treatment or the untreated juice sample at room temperature during 60 days of storage. Thermal pasteurization (TP) followed by ultrasound combined with mild heat pasteurization (UMP) and ultrasound (US) treatment, in increasing order, was found to be effective in delaying microbial growth in pineapple juice. This study demonstrates that ultrasound combined with mild heat pasteurization treatments could be able to effectively inactivate the microorganisms and pectin methylesterase in pineapple juice whilst preserving relatively high amount of phenols.

International Journal of Food Safety, Nutrition and Public Health, 2015

Contamination of foods with mycotoxins represents an important limit to the income of farmers and... more Contamination of foods with mycotoxins represents an important limit to the income of farmers and a major public health concern especially in tropical countries. Cassava represents an important part of the diet of many people in this part of the word and the most important smallholder crop in Africa. Fungal contamination of cassava products can occur at pre-harvest level or after, during processing, according to the conditions (moisture, temperature, competition with other microorganisms). Such fungal contamination can also lead to mycotoxin accumulation. The most common fungi found in cassava products belong to genera Rhyzopus, Aspergillus, Fusarium, Phoma and Penicillium. Their corresponding mycotoxins could also be found in cassava. However, until now, the correlation between the presence of Aspergillus flavus and its toxins aflatoxins remains unclear. In this review, we broadly report data about mycotoxins contamination of cassava (Manihot esculenta Crantz) and its derivatives, with a special emphasis on aflatoxins.

Journal of Pharmacognosy and Phytotherapy, 2012

Journal of Medicinal Plants Research, 2014

Journal of Food Safety, 2011

... Tokpo for technical assistance. The authors are grateful to Drs. Delphin Koudande, Guy Apolli... more ... Tokpo for technical assistance. The authors are grateful to Drs. Delphin Koudande, Guy Apollinaire Mensah, Pascal Fandohan, Kerstin Hell and Professor Joseph Hounhouigan for their comments and advice. REFERENCES. ...

Food Control, 2013

ABSTRACT Fungal infection and aflatoxin contamination were evaluated on 114 samples of dried and ... more ABSTRACT Fungal infection and aflatoxin contamination were evaluated on 114 samples of dried and milled spices such as ginger, garlic and black pepper from southern Benin and Togo collected in November 2008–January 2009. These products are dried to preserve them for lean periods available throughout the year. Fungal contamination was evaluated after plating on selective media with a total of 20 fungal genera identified, ranging from 7 in garlic to 14 in ginger. Ginger and pepper showed high incidence of fungal contamination compared to garlic that had lower levels of fungal contamination. Species of Aspergillus were dominant on all marketed dried and milled spices irrespective of country. Gene characterization and amplification analysis showed that most of the Aspergillus flavus isolates possess the cluster genes for aflatoxin production. Aflatoxin B1 assessment by Thin Layer Chromatography showed that only garlic (1 sample) and ginger (4 samples) were naturally contaminated with aflatoxin B1 ranging from 390 μg/kg to 1045 μg/kg respectively. Previous reports have mostly highlighted the risk of mycotoxin exposure from staple crops and vegetables in Africa, but such risks now need to be evaluated further for other products such as dried and milled spices.