EFFECT OF CHILL STORAGE TIME ON PROTEOLYSIS AND LIPID OXIDATION IN VACUUM-PACKED MUSCLES FROM DUCK

Proteolysis and lipid oxidation in the vacuum-packed leg and breast muscles from Mullard drakes stored at 1°C were studied. As proteolysis indicators there were determined proteolytic activity, contents of amino nitrogen and free amino acids (FAA), and TBARS values as indicators of oxidative changes. Changes were also determined in the proteolytic activity, TBARS values and contents of: amino nitrogen and FAA. As a result, 18 FAA were found in breast muscles and 19 in leg and their total contents after 1 day of storage were 184.39 mg/100 g tissue, and 233.33 mg/100 g tissue (respectively). In the case of breast muscles a significant increase in the content of detected FAA (except Pro) was noted after 13 days of storage and in the leg muscles (except Asp) after 5 days of storage. It was established that the proteolytic activity decreased (ca. 38%) in breast after 18 days and in leg (ca. 30%) after 5 days of storage. The content of amino nitrogen significantly increased in breast muscles after 18 days and in leg muscles after 5 days of storage. During storage, TBARS values were observed to increase continuously in breast muscles, whereas in legs they first increased after 5 days and then were observed to decrease