Microbial and physicochemical evolution during hyperbaric storage at room temperature of fresh Atlantic salmon (Salmo salar)

Hyperbaric storage (HS; 50-75 MPa) at room temperature (25-37 degrees C) was evaluated using Atlantic salmon (Salmo solar), and compared to refrigeration (4 degrees C, RF). HS at 75 MPa caused a reduction of about 3.5 log units of initial microbial counts, leading to an increase of the microbial shelf-life of at least 25 days, compared to RF (3 days) and HS at 50 MPa, while at 60 MPa a microbial growth slowdown was observed, increasing the microbial shelf-life to at least 6 days. Additionally, at 75 MPa no changes in colour was detected during the 25 days. However, HS/RT enhanced an increase in primary and secondary lipid oxidation products compared to RF, while for atmospheric pressure at room temperature, tertiary lipid oxidation increased. HS may represent an interesting methodology for fresh fish shelf-life extension by microbial growth inhibition and microbial reduction, with additional energy saving when compared to RF. Industrial relevance: Hyperbaric storage at room temperature (HS/RT) has shown a shelf-life extension of fresh fish salmon, as well as possible energy savings, when compared to conventional refrigeration. HS/RT only involves energy consumption during the compression and decompression phases, not requiring additional energy to control the temperature or maintain the product under pressure. However, before industrial implementation, more research is needed to clarify the effect of these storage conditions on mechanisms implied in fish quality degradation.