Nutritional Quality of Pasteurized Milk. Vitamin B-12, Folate and Ascorbic Acid Content during Storage

Changes in the vitamin B-12, folate and ascorbic acid content of pasteurized, packaged milk, containing 1.5 or 3% fat, under conditions simulating retail and domestic handling and storage, were studied. The storage conditions were similar to those in a dairy and in a retail store (light during day time), the milk thereafter being held in a domestic refrigerator. When milk packages had been opened, they were reopened twice a day and were placed in light at room temperature for 30 rain each time. Samples were taken daily and analyzed for vitamin B-12, folates and ascorbic acid. Similar analyses were performed on the milk prior to pasteurization. The milk was stored for at most 9 days, which was beyond the expiration date. The experiment was replicated in March, August and October. No marked loss of vitamins due to pasteurization was found. There were no general or appreciable changes in vitamin B-12 or folate content during storage. About 25-45% of the ascorbic acid was lost during storage.