Effect of type and level of starter culture on the rheological properties of set yogurt during gelation process

The effect of type and level (2, 3. 5%) of starter cultures on the rheological properties of set yogurt during gelation process was studied using a cylindrical rotational viscometer. At the beginning of the gelation process the viscosity was constant after which the viscosity rose rapidly and reached a maximum value and then gradually decreased. The results indicate that the starter type and level have a definite effect on yogurt viscosity during gelation process. The Ostwald-de Waele power-law model was used to characterize the flow behavior of the curd.