In this research, fortification was applied to milk by adding different amounts of CaCO₃. Fortification was performed before and after pasteurization of milk with different levels (200, 400, 600 mg/100ml) of calcium carbonate. The effect of adding calcium carbonate to fortified yoghurt samples was determined throughout the storage period (throughout the storage period 21 day at 4 °C). Added calcium carbonate has increased the pH and viscosity values and also decreased the titration acidity and serum separation values of the yoghurt.

The results were found to be statistically significant ( P <0.05). The best results were obtained with the calcium carbonate added before pasteurization. As a result of sensory evaluation, samples in which CaCO₃ has been added before pasteurization and control samples have obtained higher scores than the others. While increasing values of added calcium carbonate positively have affected physical and chemical properties of yoghurt, it has negatively affected the sensory properties of yoghurt. Additional concentrations should not exceed 400 mg/100ml.