Microbiological Safety and Quality Assessment of Maize (Zea mays L) Produced and Stocked from Rural Conditions in Côte D’ivoire

Abstract

Aims: Fungal pathogens are one of the main biological agents causing maize post-harvest loss and affect food security in the country. Thus, this study was conducted to assess fungal pathogens associated to post-harvest maize (Zea mays L.) with especial focus to mycotoxin-producing fungi at producer’s storage condition in different regions of Côte d’Ivoire. Study Design: A total of 1 500 samples of maize as grains, cobs and husks were collected at rate of 500 samples by region (Gbêkê, Poro, Hambol, Indénié-Djuablin and Gontougo) and sent to the laboratory in order to analyse their sanitary quality. Place and Duration of Study: This study was carried out during March 2016 to January 2017. The analyses of the collected sample carried out at the Biotechnology, Agriculture and Valorisation of Biological Resources Laboratory of the Félix Houphouët-Boigny’s University, Abidjan. Methodology: Microbiological analysis was assessed by recording the number of colony in the plate. The contents of aflatoxin and ochratoxin A in the different samples were determined using standard methods. Results: The total microbial species isolated ranged from 104 to 1011 cfu/g with thermotolerants coliforms (103 – 104) and fecal coliforms (102 – 103). The stored maize samples contained also high amount of yeast and molds (104 to 107 cfu/g). Aspergillus genus was the predominantly fungal isolated in all maize samples with tree species which are A. flavus, A. niger and A. versicolor potential producers of mycotoxins. More importantly, stored maize sample as grain, cobs and husks were affected by aflatoxins (B1, B2, G1 and G2) and ochratoxin A. Sixty per cent of the maize samples, mostly husks, showed aflatoxin B1 (from 12.73 to 130.31 µg/kg) and OTA (from 16.75 to 134.21 µg/kg) concentrations above the Maximum Authorized Limit of 5 µg/kg. Conclusion: A significant variability from one region to another can be noticed at level of maize quality regardless the type of maize. The sanitary quality of maize seems to be tied to postharvest treatments (drying), type of storage (grains, cobs and husks) and structure of storage.