Vol. 7, Issue 11, Part H (2025)

The Codex Alimentarius, established by the FAO/WHO Committee, defines yoghurt as a fermented dairy product produced via the symbiotic metabolic activity of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Recently, there has been growing interest in non-traditional sources, such as human fecal samples, for isolating lactic acid bacteria (LAB) strains with probiotic potential. In this study, three LAB strains were isolated from human fecal samples, molecularly identified, and incorporated into yoghurt formulations both individually and in combination as probiotic LAB cultures. The experimental yoghurts were compared to a Y1 made with traditional starter cultures to evaluate physicochemical, microbial, and sensory properties. Results revealed significant differences in microbial counts between Y1 and experimental yoghurts, while all samples maintained favorable physicochemical properties within acceptable ranges. Color analysis indicated that ingredient variations influenced the lightness (L), red-green (a), and yellow-blue (b) values. Texture parameters, including hardness, adhesiveness, and cohesiveness, were affected by culture concentration and incubation time; however, these differences were not statistically significant, suggesting consistency across formulations. Among the experimental samples, one showed improved syneresis, indicating enhanced water-holding capacity These findings underscore the potential of human-derived LAB strains for developing probiotic yoghurt while maintaining desirable quality attributes. The study highlights the importance of strain selection, culture concentration, and formulation parameters in optimizing product characteristics and consumer appeal.