Abstract: In this paper, 5 yogurts fermented by 2 Lactobacillus acidophilus and 3 Bifidobacterium were used as the experimental subjects to explore their pH, titratable acidity, dynamic rheology and texture profile. The results indicated that the acid-producing capacity of Lactobacillus acidophilus fermented milk was stronger than that of Bifidobacterium fermented milk. Texture profile analysis showed that texture of Lactobacillus acidophilus fermented milk was hard. All samples showed a strong thixotropic loop behavior in the rising and decline curve of shearing force, and the size of thixotropic loop was decreased according to the order of B. infantis KLDS 2.0604, B. longum KLDS 2.0001, Lb.acidophilus KLDS AD2, B. infantis KLDS 2.0002 and Lb. acidophilus KLDS AD1, which suggested that the recoverability of B. infantis 2.0604 fermented milk was the weakest under the condition with the damage of shearing force. A sudden increase in the pattern of apparent viscosity was not observed in KLDS 2.0002 fermented milk, which revealed the poor elasticity of KLDS 2.0002 fermented milk. All of these investigations showed that the texture and viscoelasticity of KLDS AD2 fermented milk should be the best.

Key words: Lactobacillus acidophilus, Bifidobacterium, thixotropic looptexture, profile analysis, rheological properties