Abstract: In this study, we evaluated the feasibility of using a mixed starter culture of Streptococcus thermophiles (St), Lactobacillus bulgaricus (Lb) and Lactobacillus kefiranofaciens subsp. kefiranofaciens ZW3 to make ropy yogurt without any added thickener or emulsifier. St + Lb was used as a control. The results showed that L. kefiranofaciens subsp. kefiranofaciens ZW3 shortened the fermentation time, improved water-holding capacity, reduced whey syneresis, increased viscosity, improved rheological properties, and enhanced hardness, gumminess, chewiness, cohesiveness and resilience of yogurt compared with the control group. The results of electronic nose analysis and sensory evaluation showed that ZW3 increased the contents of volatile flavor components and improved the flavor and taste of yogurt without any food additives.

Key words: ropy yogurt; Lactobacillus kefiranofaciens subsp. kefiranofaciens; rheological properties; texture characteristics; flavor analysis