Learn why cooked seafood can sometimes develop a stronger fishy smell in the fridge. Discover the chemical changes that occur during storage.
1 Answer
The fishy smell in cooked seafood stored in the refrigerator is primarily caused by the breakdown of trimethylamine oxide (TMAO) into trimethylamine (TMA) by bacteria. TMA is a volatile compound responsible for the unpleasant odor.
Detailed Explanation:
Fresh seafood naturally contains trimethylamine oxide (TMAO). This compound is odorless and helps marine animals regulate their buoyancy and cope with osmotic stress in saltwater environments. However, after the seafood is cooked and begins to degrade, bacteria present in the seafood start to break down the TMAO. This breakdown process converts TMAO into trimethylamine (TMA). TMA is a volatile amine compound, meaning it easily evaporates and becomes airborne. It's this TMA that we perceive as the 'fishy' smell. The colder temperatures of refrigeration slow down, but don't completely stop, the bacterial activity and the conversion of TMAO to TMA. Therefore, even in cold storage, the process continues, albeit at a reduced rate, leading to the development of the fishy odor over time. The longer the cooked seafood sits in the refrigerator, the more TMA is produced, and the stronger the fishy smell becomes. Different types of seafood contain varying levels of TMAO, which can influence the intensity of the fishy smell.
Pro Tip:
To minimize the fishy smell, store cooked seafood in airtight containers in the coldest part of your refrigerator and consume it within 1-2 days. This will help slow down bacterial growth and the production of TMA.