Evaluation of methods for determining the prevalence of blood spots in smoked Atlantic salmon and the effect of exsanguination method on prevalence of blood spots

A major cause of downgrading in the production of smoked salmon is the presence of small haemorrhages or spots of blood in the flesh. We developed a method for determining the prevalence of blood spotting and determined the effects of various exsanguination methods on the prevalence of blood spotting in Atlantic salmon. A methodology based on salting, slicing and direct counting of blood spots was effective for assessing blood spots in salmon. This was superior to examination of fresh or frozen fillets for the detection of commercially important blood spots. Exsanguination reduced blood spots relative to unbled controls, but no clear trends between various methods of exsanguination and blood spots were observed. Although exsanguination affected the number of spots in smoked salmon, it is concluded that other unknown factors play a more important role.