The effect of HPP on the textural properties is not clear. It is likely that toughness decreases when salmon fillets were treated at 400 and 500 MPa for 10, 20, 30 and 60 s, compared to the control sample. When pressure was increased to 700 MPa and up to 900 MPa, the toughness was similar as in the control sample. The probable reason for this is that the measurement of the textural properties was performed on samples, located in different parts of the fillets. reported the difference in toughness on different location in fresh Atlantic salmon fillets. Thestudy of (Jonsson et al. (2001)) showed variation in the value of maximum force, to cut through the samples along the fillet of fresh salmon from 15 N near the head and 42 N near the tail. Studies have shown increased tissue firmness in fresh bluefish at high pressure (200 MPa for 10 min) (Ashie & Simpson, 1996; Simpson,
1998).