Impact of Technological Treatments on the Hygienic Quality of Local Milk from the Niamey Region

This study evaluates the effectiveness of three technological treatments, including spontaneous fermentation (T1), fermentation with inoculum (T2), and filro-fermentation (T3), in improving the microbiological quality of raw milk (T0) collected in the municipality of Kollo (Niger). A total of 31 milk samples were collected and subjected to each treatment. Microbiological analyses focused on the enumeration of Fecal Coliforms (FC), Escherichia coli, Staphylococci, Sulfite-Reducing Anaerobic bacteria (SRC), and the detection of Salmonella spp. The results show that all treatments significantly reduced FC contamination (p = 0.000) compared to raw milk (1.71 log CFU/mL). Treatments T1, T2, and T3 were similarly effective, with average reductions to 0.55, 0.00, and 0.41 log CFU/mL, respectively. Regarding E. coli, only treatment T2 (0.46 log CFU/mL) showed a statistically significant reduction compared to the control (1.71 log CFU/mL). For Staphylococci and SRC, no significant difference was observed between the raw milk and the treated samples (p > 0.05). Although the prevalence of Salmonella decreased from 58.06% in raw milk to approximately 42% in treated samples, this reduction was not statistically significant according to the chi-square test (p = 0.531). The study’s main limitation lies in its in vitro experimental design; the effectiveness of these treatments under real-world conditions and their impact on the organoleptic properties of the milk were not assessed. In conclusion, fermentation, particularly with the addition of an inoculum (T2), appears to be the most effective treatment for significantly reducing the main fecal contamination indicators in local milk. These results support the promotion of controlled fermentation practices to enhance food safety in the local dairy value chain.