THE EFFECT OF DIFFERENT STORAGE CONDITIONS ON THE COMPOSITION AND KEEPING QUALITY OF PROCESSED MILK

Résumé

Samples of four major brands of tinned evaporated milk purchased from the local markets in Ibadan and cartons of pasteurized fresh milk from the Iwo Road dairy were left sealed or unsealed after opening. The samples were then stored on the shelf, in a bowl of water or in a refrigerator (storage conditions commonly used in many Nigerian homes). At 0, 24, and 48 hours, the samples were assessed for percentage fat and protein as well as bacterial quality using the plate count and the dye reduction tests. The results showed that percentage milk fat remained unchanged after 48 hours of storage under the different conditions. Changes in percentage milk  protein were also minor. Keeping quality in terms of total counts and dye reduction times, were poorest under shelf storage and best under refrigeration. Sealing the samples resulted in better keeping quality.