Effects of Bifidobacterium animalis subsp. lactis IMAU12267 on milk fermentation, subsequent storage, and functional properties

This study investigated the effects of co-fermentation with Bifidobacterium animalis subsp. lactis IMAU12267 and the commercial starter culture PYS-010 on the quality characteristics of fermented milk. Comparative evaluation of micro-rheological properties, storage stability, and untargeted metabolomic profiles among the co-fermentation (I + P), IMAU12267 (I), and PYS-010 (P) groups demonstrated that the I + P group significantly shortened fermentation time and enhanced gelation performance of the final product. The I + P group also showed higher viable counts of IMAU12267, reduced post-acidification, and superior texture, viscosity, water-holding capacity, and sensory attributes. By day 7, 14 key metabolites were identified in the I + P group, primarily linked to galactose and riboflavin metabolism and to glycolysis/gluconeogenesis pathways, indicating improvements in flavor, product quality, and nutritional value. These results reveal a synergistic metabolic interaction between IMAU12267 and PYS-010 and offer valuable insight for the development of high-quality, functionally enhanced fermented dairy products. • IMAU12267 increases α-lactose and D-galactose to improve fermented milk quality. • IMAU12267 elevates riboflavin and capric acid to enhance nutritional functionality. • IMAU12267 lowers acetic acid levels to support balanced flavor profiles.