The effects of ultra-filtered milk proteins on chemical and sensory properties of yoghurt

The chemical composition، sensory attributes and acetaldehyde content of yoghurts produced from ultrafiltered milk retentates and normal yoghurt made with SMP were studied and compared. UF yoghurts had more content of acetaldehyde، protein، lactic acid and total solid than control but lactose content and syneresis were at lower level. The amount of produced acetaldehyde was dependent to the protein amount and by increasing the latter the acetaldehyde got higher. The quantity of acetaldehyde decreased during the storage of yoghurt. Scores for sensory analysis of UF yoghurts were higher than control. Yoghurt made from UF retentate with 13. 5 % TS and 5. 3% protein got the highest rating for all sensory properties and was comparable with one of the most acceptable yoghurts produced in Iran.