Improvement of yogurt quality characteristics by Limosilactobacillus fermentum and stachyose

As health awareness continues to rise, yogurt has gained increasing consumer favor due to its rich nutritional profile and probiotic functions. This study investigated the effects of a synbiotic formulation combining Limosilactobacillus fermentum (L. fermentum) and stachyose on yogurt quality characteristics over a 21-d storage period at 4°C. Four experimental groups were established: Con (0.02% starter culture), Sta (0.02% starter culture and 0.5% stachyose), L.F (0.02% starter culture and 1.0 × 10⁷ cfu/mL L. fermentum), and Sta + L.F (0.02% starter culture, 0.5% stachyose, and 1.0 × 10⁷ cfu/mL L. fermentum). Results indicated that, compared with the Con group, the synbiotic yogurts exhibited a denser gel network structure, a 17.35% higher viscosity, and improved textural properties, rheological characteristics, and microstructure. Meanwhile, peptide content increased significantly and antioxidant activity was markedly enhanced; the DPPH radical scavenging rate of the Sta + L.F group reached 72.26%, versus 68.89% for the Con group. At the end of storage, the Sta + L.F group exhibited significantly higher viable bacterial counts (9.06 log cfu/g) and water-holding capacity (83.39%) than the Con group (8.98 log cfu/g and 76.45%, respectively; P < 0.05). The pH and titratable acidity on d 21 were 4.26 and 91.96 °T for the Sta + L.F group, compared with 4.28 and 89.79 °T for Con, all remaining within consumer-acceptable ranges. The results indicated that the yogurt with synbiotics had good product quality and storage stability. This study provides theoretical support for developing novel functional dairy products.