Retention of the synthetic antioxidant butylated hydroxyanisole in Atlantic salmon (Salmo salar) fillets

Butylated hydroxyanisole (BHA) is a phenolic antioxidant that is used as a food additive, particularly in fats and oils, and it is also authorized as a feed additive in the European Union for all animal species with a maximum concentration of 150 mg kg(-1) feed (alone or in combination with ethoxyquin and/or butylated hydroxytoluene). Information on the BHA levels in food of animal origin is scarce, as is literature on the transfer of BHA from feed to animal products. Consequently, the current feeding trial was conducted under realistic rearing conditions to determine the retention of BHA in Atlantic salmon (Salmo salar) fillets. Four different concentrations of BHA in feed were tested (0, 48.5, 92.5 and 225 mg BHA kg(-1) feed), and fish were sampled after 4, 8 and 12 weeks dietary exposure, and after a 2-week starvation period, which is representative of commercial salmon farming in Norway. The levels of BHA in salmon fillets were fairly dose dependent during the feeding period. A steady state in fillet residues was reached after 4 weeks of administration of BHA. After the 2-week withdrawal period, BHA was not detectable (< 7 mu g kg(-1)) in either fish fillets or livers.