The eating qualities of seafood (including texture and flavour) vary widely between different species and when cooked you should taste the flavour characteristics for the particular species. If the seafood is spoiled, the flavours will typically become sour, bitter or rancid. As a general rule, the texture of seafood should be firm and juicy. Seafood which has been frozen then thawed properly should be indistinguishable from fish that has never been frozen. If something has gone wrong during the freezing and thawing process, it is often indicated by texture changes - such as the flesh being either too wet and mushy or too dry.
While readily available, fantastic to eat and relatively easy to prepare, one considerable issue to consider with all forms of fresh seafood is that it starts to spoil quickly. While it is impossible to prevent this natural spoilage process, good temperature control and handling can greatly slow down the rate of spoilage and ensure the product is of as good quality as it can possibly be.
To maintain shelf life and quality, seafood should be constantly stored in chilled conditions, via the use of either ice or refrigeration. Even a short amount of time at room temperature will affect seafood's quality and reduce its shelf life, so this should be avoided or kept to an absolute minimum. As with the storage of most other fresh foodstuffs, the lower the storage temperature, the better.
Certain fish species, including tuna, mackerel and herring, are also susceptible to the formation of histamine at elevated temperatures - for such species, storage at temperatures lower than 4°C is especially important.
Humane handling is an important issue to consider with regards to live shellfish:
They should be handled carefully. Do not allow them to dry out and never drop them as this causes physical shock. Ideally, live shellfish should be stored at consistent temperatures, as extreme changes in temperature can cause thermal shock.
When storing chilled fish in a refrigerator, always cover with plastic overwrap to prevent any drying out. Ice can also be used in conjunction with refrigeration to reduce product temperature and maintain shelf life. If using ice, ensure that excess melt water is removed periodically, so that the fish does not stay in contact with any water. However, there are some exceptions and tuna, salmon and smoked fish products should not be directly iced.
As with all foods, cooked and raw seafood should always be stored separately.