Shelf-life studies on fresh sardine packaged with carbon dioxide-nitrogen gas mixture.

Changes in sensory evaluation, K-value, 2-thiobarbituric acid (TBA) value, trimethylamine (TMA), pH and viable bacterial numbers were examined for sardine Sardinops melanostictus packed under air, 20% CO2-80% N2 (v/v) or 80% CO2-20% N2 in plastic bags with low gaspermeability during 5°C-storage. Shelf-life was affected mainly by the appearance of rancid taste; samples packed under modified atmospheres had double the shelf-life of samples packed under air. The TBA number had high correlation with sensory analyses of the samples, while K-values showed no significant differences. The amounts of TMA decreased depending upon the enriched CO2, concentration. Growth of aerobic bacteria was inhibited in samples containing 80% CO2, although it was not significantly inhibited in samples containing 20% CO2, Anaerobic bacterial numbers were little affected by CO2.