摘要:This research was conducted to determine the effects of different heat treatments of milk (at 75, 85 and 95 °C for 5 minutes) on the physical, chemical, microbiological and sensory properties of Ayran on the 1, 7 and 14th days of storage (at 4-5 °C). Different heat treatments had no significant effect (P>0.05) on pH, titrat¬able acidity and lactic acid content, the number of yoghurt bacteria and sensory properties (body, texture and overall) of ayran samples. However, results showed that acetaldehyde, whey separation and viscosity of samples were affected significantly by different heat treatments (P<0.05). The highest viscosity and the least whey separation values were gained in ayran samples produced by milk heat treated at 95 °C for 5 minutes.