Storage of off-flavors in adipocytes of salmon muscle

Understanding the storage locations of off-flavors in tissues of aquatic organisms is an important step in finding solutions of effectively removing and depurating off-flavors from fish and shellfish in the aquaculture industry. Experiments were carried out in exposing Atlantic salmon to the water-soluble fraction (WSF) of crude petroleum hydrocarbons, and in depurating the hydrocarbon off-flavors in exposed fish in clean water. Muscle tissue, adipocytes isolated from muscle tissue, and subdermal fat were collected and analyzed for WSF hydrocarbon content at the end of exposure and during depuration. Both white muscle tissue and adipocytes were heavily tainted with WSF hydrocarbons at the end of exposure, but adipocytes in the muscle tissue accounted for about 55% of accumulated WSF hydrocarbons. The non-adipocyte portion of muscle tissue was freed of WSF hydrocarbons rapidly during depuration in clean water, while the depuration of WSF hydrocarbons from adipocytes was much slower. As a result, adipocytes became the predominant storage sites for the remaining WSF hydrocarbons in muscle tissue after 4 days of depuration in clean water. The accumulation and depuration of WSF hydrocarbons from subdermal fat were similar to those from adipocytes.