ABSTRACTThe potential role of α‐tocopherol in protecting the muscle lipids of smoked, farmed Atlantic salmon (Salmo salar) and of Atlantic mackerel (Scomber scombrus) from oxidative degradation was examined over a period of 12 weeks. One smoked salmon sample had much more α‐tocopherol than the other, but this higher tocopherol level dropped in parallel to the decrease in α‐tocopherol in the mackerel, a species known to be very susceptible to the development of rancidity. The other salmon sample started with less α‐tocopherol but showed no decrease in α‐tocopherol. The salmon samples developed a similar level of peroxides over 12 weeks, both being less than the peroxides in the 12‐week sample of the mackerel lipid where α‐tocopherol could not be mea