EFFECT OF STORAGE PERIOD ON THE CONTENT OF FULL AND LOW FAT PASTEURIZED COW’S MILK

Pasteurized milk samples packaged in 2 liter plastic containers were collected from four factories in Riyadh city, named(1- A) ,( 2-A) ,(3- A), and (4-A)for full fat milk and(1- B) ,( 2-B),(3- B) , and(4- B) for low –fat milk. All samples were  stored in the refrigerator at 4°C for 1, 3 and 8 days of production. Effect of refrigeration storage on  the  chemical composition of full and low – fat milk  was followed. Vitamins (A) and Vitamin (D) contents were also determined in all samples during the same storage period. Effect of refrigeration storage was quite clear. Protein ,fat ,total solids and solids-not fat as well as vitamins (A) and (B) significantly decreased as the storage period progressed. Some samples were free from vitamins (D). so , consumption of pasteurized milk in the first days of production  is the better.