Mastitis is one of the most serious diseases that can affect quality of milk and milk products, it’s derived from it.  In the present study, yoghurts were made from cows’ milk with four different somatic cell count (P1: 3.6 × 105 cells/ml; P2: 4.5 × 105 cells/ml; P3: 5.4 × 105 cells/ml; P4: 7.2 × 105 cells/ml). The yoghurts made from different range of SCC were analyzed for chemical parameters (dry matter, ash, fat, protein, total sugar, reducing sugar content and titrable acidity), physical parameter (pH and syneresis) and sensory evaluation during the storage period. Yoghurt made with different SC counts of milk except reducing sugar and total protain  had no significant effects on the dry matter, ash, fat, reducing sugar, total sugar, pH and titratable acidity at day 1 but  syneresis was gradually increased in yoghurt made milk with higher  SC counts.

During the storage period, dry matter, ash, fat, total protein, total sugar, reducing sugar, pH, and titratable acidity were (p < 0.05) varied yoghurts made from milk with different SC counts.  At the end of storage yoghurt made from milk with 5.4 × 105 cells/ml showed higher average value of dry matter content (25.83±0.06%) and yoghurt made from milk with 3.6 × 105 cells/ml SC counts range showed higher average value of fat (2.67±0.06%), reducing sugar (2.02±0.09%),  total sugar (11.89±0.02%) and pH (4.09±0.08) while yoghurt made from milk with 7.2 × 105 cells/ml showed higher values of total protein (3.72±0.10%) and titratable acidity (1.18±0.03%).  During the storage period, dry matter, ash and titratable acidity contents of yoghurt were (p < 0.05) increasing with storage period while reducing sugar, total sugar and pH were (p < 0.05) decreasing with storage period. The sensory evaluation of the produced yogurts revealed that milk with high SC counts yoghurt received the lowest grading score of attributes and all sensory scores of yoghurts were significantly reduced from week 1 to week 4 of storage. Based on the sensory evaluation most of the pannelist prefer or higher score obtained, yoghurt made from milk with low SC counts (3.6 × 105 cells/ml) at the 1st week of storage.