Health Risks Linked to Microbial and Mycotoxic Contamination of Local Infant Flours in Bukavu

Abstract

This study assessed the health risks associated with microbial and mycotoxicological contamination of locally produced and marketed infant flours in the city of Bukavu (DRC). Ten samples of locally produced infant flours, including simple cereal flours (EBT, EPT, ESZ), cereal-legume flours (EBM, ADNU), and fortified flours (UJNZ1, UJNZ2, EFM, EAB, EKM), were analyzed using standardized microbiological colony counting methods and mycotoxicological methods. The results showed widespread microbiological contamination of all the flours. Total mesophilic aerobic flora (TMAF) counts ranged from 8.58 × 10⁴ ± 14 CFU/g in simple cereal flours (SEF) to 2.4 × 10⁵ ± 0.02 CFU/g in cereal-legume flour (CEF). Total coliforms were present in all samples, with counts ranging from 7.9 × 10² ± 7 in SEF flour to 3.1 × 10⁵ ± 0.014 CFU/g in ADNU flour. Staphylococcus aureus was detected in the majority of flours, reaching 9.8 × 10³ ± 3 in SEF and 1.2 × 10⁶ ± 0.14 CFU/g in ADNU. Yeasts and molds were absent in some simple cereal flours, but reached 1.5 × 10³ ± 7 CFU/g in the EBM cereal-legume flour and 2.5 × 10⁶ ± 0.3 CFU/g in the ADNU flour. The presence of Salmonella spp. was confirmed only in some cereal-legume flours, with a load of 9.0 × 10² ± 3 CFU/g in the EBM flour and 5.7 × 10⁴ ± 0.014 CFU/g in the ADNU flour, rendering these products non-compliant with the applicable criteria for infant foods. Aflatoxin analysis revealed that 60% of samples were positive, primarily among cereal-legume flours and certain fortified flours (EBM, ADNU, EFM, UJNZ1, UJNZ2 EAB), while plain cereal flours (EBT, EPT, EKM, and ESZ) were free of aflatoxins. These results indicate significant but variable exposure of infants to microbiological and mycotoxin risks, strongly influenced by flour formulation and processing and storage conditions.