Evaluating Physicochemical Parameters and Microbial Communities of Functionalized in Fermented Milk

This study evaluated the quality and microbial composition of commercial fermented dairy products marketed with functional claims by integrating physicochemical analyses, microbial viability assays, and 16S rRNA gene sequencing. A total of 74 commercial samples of yogurt, fermented milk, and kefir marketed with functional claims, combining physicochemical characterization, microbial viability assays, and 12 representative samples, were selected for high‐throughput sequencing to characterize microbial communities. Physicochemical analyses indicated overall compliance with regulatory standards for pH, titratable acidity, ash content, and lactose levels, although variability among brands was observed, as well as the presence of starch‐based thickeners consistent with label declarations. High‐throughput 16S rRNA sequencing enabled a comprehensive assessment of the microbial communities and revealed product‐specific microbial profiles. Yogurt samples were predominantly characterized by the genera Streptococcus and Bifidobacterium , fermented milk samples by Streptococcus and Lactobacillus , and kefir samples exhibited higher microbial diversity, with Lactococcus as the dominant genus, followed by Bifidobacterium and Leuconostoc . Importantly, sequencing results confirmed the consistency between labeled probiotic claims and the microorganisms effectively present in the products. Microbial viability assays demonstrated that the detected microorganisms remained viable until the end of the shelf life, with growth mainly observed up to dilutions of 10 −4 and 10 −5 , although significant differences among brands were identified, particularly in M17 medium. Overall, these findings demonstrate that 16S rRNA sequencing is a robust and reliable tool for validating probiotic claims and strengthening quality control strategies for fermented dairy products with functional attributes.