Quality changes in depurated and undepurated green mussels (Perna virides) at ambient storage conditions

Results were correlated with sensory and acceptability scores of the cooked green mussels. Thiobarbituric acid (TBA) value and fat content were determined at the start and end of storage. Presence of mercury, cadmium, and lead was determined. Tests for the presence of coliforms and pathogenic bacteria such as Shigella, Salmonella, Vibro cholera, Vibro parahaemolyticus and Staphylococcus aureus were conducted. K-value and Hx [hypoxanthine] value in both the depurated and undepurated green mussels generally fluctuated with time of storage. The trimethylamine (TMA) and the total volatile base-nitrogen (TVB-N) contents were better indices in evaluating the degree of freshness of sorted green mussels TMA and TVB-N contents of the undepurated green mussels had significant linear relationship with odour, flavour and acceptability scores. Significant linear relationship also existed between TMA content and flavour, and acceptability scores of the depurated green mussels. The total viable count (TVC) and the number of H2S-producers increased with time of storage. The log of TVC and the log of the number of H2S-producers of the undepurated green mussels both had significant linear relationship with odour and acceptability scores. Depuration and storage had no significant effect in the TBA value and fat content of the mussels. Mercury, cadmium, and lead were not removed by depuration. Depuration had little effect on the lowering of the coliforms of the mussels. Pathogenic microorganisms were not detected in the depurated and undepurated green mussels. Depurated mussels had a longer shelf-life compared to the undepurated mussels. Exposing the mussels to conditions more or less similar to the culture area during the depuration process had prolonged the shelf-life of the shellfish.