The effects of the addition of transglutaminase to heated or ultrasound-treated whey protein coatings on quality parameters of frozen Atlantic salmon (Salmo salar) were evaluated. The influence of the type of denaturation treatment (heating or sonication) was also studied. The addition of microbial transglutaminase to the coatings did not significantly modify the yields, drip losses, colour and chemical composition of the fish fillets. The yields were higher in the samples protected with heated coatings than in those with ultrasound-treated ones. Transglutaminase addition to heated whey protein coatings delayed lipid oxidation. Ultrasound-treated coatings with or without enzyme addition were equally effective for lipid oxidation reduction after frozen storage of Atlantic salmon than heated-treated transglutaminase-added coatings. (C) 2013 Elsevier Ltd. All rights reserved.