Proteolytic activity and properties of proteins in smoked salmon (Salmo salar)—effects of smoking temperature

The effects of smoking temperature and storage period on different properties related to proteins and enzymes in cold-smoked salmon were investigated. The smoking temperature was important for the solubility properties and the composition of myofibrillar proteins in smoked salmon. Increasing the smoking temperature reduced the extractability of myofibrillar proteins, and their composition was greatly affected. SDS-PAGE analysis revealed that the intensity of the myosin heavy chain band was reduced with increasing smoking temperature and with further storage of smoked samples. The content of free amino acids increased with smoking and further storage, but smoking temperature did not affect the total content or the composition of free amino acids. The smoking temperature did not affect cathepsin B-like activity or the general proteolytic activity. Differences caused by different smoking temperatures were reduced by further storage (+7 days). In conclusion, the effect of the processing parameters was most pronounced early in the productʹs life.