Effect of high-pressure pre-treatments on enzymatic activities of Atlantic mackerel (Scomber scombrus) during frozen storage

In this work, we studied the effect of high-pressure processing (HPP) pre-treatments (150, 300 and 450 MPa for 0, 2.5 and 5 min) on key enzyme activities in Atlantic mackerel (Scomber scombrus) during frozen storage (3 months of accelerated storage, -10 degrees C). Except for a minor decrease from treatment at 450 MPa, no substantial effect on acid phosphatase activity was observed. In contrast, cathepsins B and D and lipase were affected by HPP and frozen storage. Increasing the pressure reduced cathepsin B and lipase activities. Generally, increasing the holding time at 150 MPa increased the activity of cathepsin B and lipase (except at month 1), while increasing the holding time at 300 MPa reduced the lipase activity, and no effect was observed at 450 MPa. Overall, cathepsin D activity increased with frozen storage time and for treatments at 300 MPa but decreased at 450 MPa. This work provides novel information of HPP pre-treatments application, lowering enzyme activity during frozen storage of Atlantic mackerel. Industrial relevance: The activity of fish endogenous enzymes has an important role in its deterioration during frozen storage, limiting its commercialisation. This research presents valuable information concerning the employment of high-pressure processing pre-treatments to reduce deteriorative enzymatic activities during the subsequent frozen storage of Atlantic mackerel (Scomber scombrus). High-pressure processing pre-treatments can so be of interest for fish processors to enhance the frozen storage of these fish species and possibly of others. (C) 2014 Elsevier Ltd. All rights reserved.