The Quality of Raw Milk Produced in Saudi Arabia

The study covered 12 days dairy plants which produce over 90% of the total fresh milk produced in Saudi Arabia. Results showed that moisture was relatively high (88.42%) in raw milk, whereas total milk solids was law (11.42). Fat content was lower than the minimum required by the Saudi standards in over 40% of the plants. Freezing point of raw milk was relatively high (-0.52ºC) and it was in accordance with the high moisture content. Ash (0.73%), tiratable acidity (0.16%), pH (6.7) and proteolysis (2.65 mg tyrosine/100 g milk), were within the normal values. However, lipolysis was high (Acid Degree Value "ADV" = 0.81). Season and storage had some effects on the physiochemical characteristics of raw milk. Moisture content and lipolysis were higher in summer, whereas fat, protein, pH and proteolysis were higher in winter. pH, freezing point and lipolysis were higher in plant's samples than in farm's samples. The microbiological quality of raw milk was good as far as the total count is concerned (3 x 104). However, coliforms amount (2 x 103) exceeded the American standards in most of the plants. Other microbial groups were low. Season had no effect on microbial groups except for lipolytic and psychrotrophic counts. Lipolytic count was higher in summer than in winter, whereas psychrotrophic cound had opposite direction. Coliform count was nearly three times higher in winter than in summer; however, differences were not statistically significant. Storage had an effect only on lipolytic count which increased in plant's samples