High-pressure processing and water-holding capacity of fresh and cold-smoked salmon (Salmo salar)

The influence of high pressure on the water-holding capacity (WHC) of fresh and cold-smoked salmon (CSS) was investigated up to a pressure level of 200 MPa at room temperature for 10- and 20-min periods. Changes in moisture content and WHC were determined by two methods, namely filter paper and spin–spin relaxation proton nuclear magnetic resonance. Both pressure (p<0.05p<0.05) and process time (p<0.05p<0.05) had significant effects on the moisture content of CSS, but not on fresh Atlantic salmon. Fresh salmon had less WHC than smoked salmon and a pressure of 150 MPa for 10 min caused a 2% increase in WHC of smoked salmon (p<0.001p<0.001). The spin–spin proton relaxation (T2) values were heavily affected by high pressure in both the samples, with substantial effects seen in CSS. At 150 MPa, both fresh and smoked fish behaved differently with respect to T2 values compared with other pressure levels used.