Effect of nitrate/nitrite on the quality of sausage (sucuk) during ripening and storage

The effects of nitrate/nitrite on the microbial and chemical properties and sensory quality of Turkish-style sausage (sucuk) were investigated during 15 days of ripening and 45 days of storage. Aerobic plate count, mould and yeast count, pH, 2-thiobarbituric acid value, residual nitrite level, nitrosomyoglobin conversion and sensory characteristics (flavour, colour and cutting scores) were monitored. Aerobic plate count increased (P (less than) 0.05) during the first 8 days of ripening and decreased (P (less than) 0.05) during further ripening and storage. Mould and yeast count increased (P (less than) 0.05) during the first 4 days of ripening and decreased (P (less than) 0.05) during further ripening and storage. Overall sensory quality increased (P (less than) 0.05) during the first 12 days of ripening and decreased (P < 0.05) during further ripening and storage. Increasing the nitrate/nitrite concentration increased (P (less than) 0.05) the overall sensory quality. During the first 4 days of ripening, the pH of all sausages decreased (P (less than) 0.05) from 5.98 to 4.53-4.81, owing to the action of lactic acid bacteria. Residual nitrite level decreased (P (less than) 0.05) sharply during the first 8 days of ripening, from 150 to about 2 mg kg^-1 in sausage samples B3 (prepared with 150 mg kg^-1 nitrite, 300 mg kg^-1 nitrate and starter culture) and from 75 to about 1 mg kg^-1 in samples B2 (prepared with 75 mg kg^-1 nitrite, 150 mg kg^-1 nitrate and starter culture). The conversion of haem pigments to nitrosomyoglobin increased (P (less than) 0.05) during the first 12 days of ripening and decreased (P (less than) 0.05) during further ripening and storage.