Introduction: Powdered infant milk play a crucial role in infant nutrition when breastfeeding is not available. However, both dairy companies and consumers encounter challenges related to the physicochemical stability, as well as the microbiological quality throughout storage/ distribution.
Objective: Study aimed to evaluate microbiological quality and physicochemical stability of eleven imported first-age milk samples from various brands, collected in Algiers city, during spring season.
Methods: Samples stability will be assessed by various physicochemical tests (density, pH, titratable acidity, viscosity, protein and lactose levels, etc). Microbiological quality will be explored by research involving colony forming units (CFU) counting on conventional selective culture media, the evaluation of the pathogenic floras/species. Salmonella Enumeration, in addition to conventional method, on three differential selective broths.
Results & discussion: Chemical tests indicated that samples remained stable, with the following mean values: Density (1.024), pH (6.655), Acidity (17.628), Viscosity (2.574), Conductivity (1805.72 µS/cm), Total Dissolved Solids (TDS) (85 mg/L), Protein Content (1.66 g/100ml of milk), and Lactose Content (1.5509 g/100ml of milk). Microbiological analysis, apart from absence of Staphylococcus, Cronobacter, revealed following results: yeasts and molds were present in 36.36 % (4/11) of samples, total bacterial count exceeded standards in 27.27 % (3/11) of samples, total coliforms were observed in 9.09 % (2/11) of samples, total fecal coliforms were detected in 9.09 % (1/11) of samples, Escherichia coli was present in 9.09 % (1/11) and D-Streptococcus was found in 18.18 % (2/11) of samples.
Research Implications: The entire set samples demonstrated chemical stability throughout storage and distribution, with no packaging or labeling defects noted. However, microbiological quality sample’s fell below local/international standards. In light of these findings, further investigation is warranted through expanded sampling approach, targeting additional PIF brands, conducting a wider array of physicochemical and toxicological tests, and examining a wider of bacterial flora/species.