In this study, Propionibacterium freudenreichii was used for in situ production of conjugated linoleic acid (CLA) yogurt. Firstly, effects process variables, including strain type, percentage milk fat, inoculum, quantity sunflower oil, concentration inulin, temperature fermentation and time storage at 4°C, on CLA by were investigated using screening method the Plackett–Burman design. Then optim...