According to the Food and Drug Administration, seafood that isn't stored or transported properly could have high levels of naturally occurring histamines, which could lead to illness if consumed. To prevent problems when adding scallops to your favourite seafood dishes, make sure the scallops you choose are fresh before you purchase them. You can determine the freshness of the scallops at your local seafood market by using three of your primary senses.
Smell your scallops. Fresh scallops should emit an odour that is slightly sweet. If you smell an odour that is similar to sulphur your scallops have already spoiled and should be discarded immediately.
Look at your scallops. Fresh scallops will be a light cream colour, and should have very little surface moisture on them. You should avoid any scallops that are stored in a cream coloured liquid, or have a pink tint on their outer layer. These are both signs that the scallops are no longer fresh, and could cause illness if ingested.
Feel your scallops. A scallop should have a firm texture, and should be relatively dry. If your scallops are slimy, rubbery or mushy, they should be discarded immediately. Scallops that have a mushy texture have already started decaying, and have a high probability of causing illness if eaten.
Scallops should be cooked to an internal temperature of 62.8 degrees Celsius in order to kill any harmful bacteria that they may house. Scallops that are fresh when purchased should be cooked within two days in order to prevent spoilage.