Effect of high hydrostatic pressure (HHP) treatments on microbiological shelf-life of chilled Chilean jack mackerel (Trachurus murphyi)

摘要

The effect of high hydrostatic pressure (HHP) treatments (450 and 550 MPa for 3 and 4 min at 20 degrees C) on the microbial behaviour and shelf-life extension of Chilean jack mackerel (Trachurus murphyi) during chilled storage at 4 degrees C was studied. Aerobic mesophilic and psychrophilic microorganisms, as well as hydrogen sulphide-producing bacteria (mainly Shewanella putrefaciens) were enumerated immediately after treatment and during subsequent storage at 4 degrees C. Physicochemical parameters such as pH and TMA-N were also recorded. Results showed that HHP treatments were effective in reducing initial microbial counts and delayed microbial growth during refrigerated storage. HHP treatments were also effective in delaying TMA-N production in the fish during storage. As a result, microbiological shelf-life was significantly (p < 0.05) extended from similar to 6 days (control samples) to similar to 29 and similar to 40 days in pressurised samples at 450 MPa/3 min and 550 MPa/4 min, respectively.