Occurrence of mycotoxins and microbial communities in artisanal infant flours marketed in Cote d'Ivoire

The aim of this study was to determine the microbial diversity and mycotoxin profile of artisanal infant flours commonly vended in public healthcare centres and retail markets in Cote d'Ivoire. Thus, maize, millet, sorghum, soya and multigrain (mix of different cereals) flour samples collected from different localities were first, analysed for nutritional composition, then for microbial communities using high-throughput sequencing and for mycotoxins through UHPLC-MS/MS method. Firmicutes was the most abundant bacterial phylum and the dominant genera were Weissella, Staphylococcus, Pediococcus. Potential pathogenic genera such as Bacillus, Enterobacter, Acinetobacter and Burkholderia were also found. The fungal community was composed of two dominant phyla (Ascomycota and Basidiomycota) and 31 genera with > 0.1% relative abundance. In samples from public healthcare centres, Candida, Hyphopichia, Trichosporon, and Cyberlindnera were the most dominant genera according to the flour type while in samples from retail markets, they were Cyberlindnera, Clavispora, Nakaseomyces, Aureobasidium and Candida. Possible toxigenic genera Fusarium and Aspergillus were also detected. Aflatoxin B1 (AFB1), Ochractoxin (OTA), Fumonisin B1 (FB1) and B2 (FB2) were the mycotoxins found in the analysed flours. AFB1 was detected in 100% of maize (range 1.2-120.5 mu g/kg; mean: 44.2 mu g/kg) and 50-83.3% of millet flours (range 0.2-31.5 mu g/kg; mean: 31.5 mu g/kg). Its level in all maize and rice flour samples exceeded EU standard (0.1 mu g/kg). For OTA and fumonisins, millet and maize flours showed the highest levels of sample exceeding the EU standard. Thus, artisanal infant flours marketed in Cote d'Ivoire, mainly maize and rice flours, although containing potentially beneficial bacteria, represent potential health risks for children.