Mollusc oysters and other bivalves quality
The quality assessment checks listed below are specific to bivalves. Please refer also to the general quality assessment checks for all sensory criteria, which cover all seafood.
Appearance
Check | Higher quality | Lesser quality | Comment |
---|---|---|---|
Shell |
Clean, intact |
Chipped or dirty |
Mussels have byssal threads (filaments) that are used to attach the mussel to a surface. These may be present but do not affect the eating quality. |
Liquid (liquor) |
Clear |
Slightly opalescent (oysters), or slightly milky in colour |
|
Flesh Texture |
Juicy, moist, plump and firm |
Starting to shrink and look flat |
Oysters are often turned over when shucked to give a "plump" look. |
Colour |
Mussels are either white or orange; oysters vary naturally from greenish grey to white or ivory |
Mussels fade; oysters darken (but may be a brilliant white or greenish) |
Living environment and feed can influence flesh colour. |