Effects of Homogenization and Heat Treatment of Milk with Different Fat Content on Physical Properties of Ayran

Abstract In this research, the effects of different homogenization pressure levels (15, 40, 15/3 and 40/8 MPa) and heat treatments (95°C for 90 s and 300 s) of milk containing 1.5 and 2.5% of fat on some physical properties of ayran were investigated during storage at 4°C for 30 days. The individual effects of fat content of milk, homogenization, heat treatment, and storage period on the syneresis, apparent viscosity, consistency constant and thixotropy values of the ayran samples were statistically significant. Based on the results of rheological analysis, the power law model was more appropriate for all ayran samples.