Inhibitory effects of high pressure processing on microbial growth and histamine formation in spotted mackerel (Scomber australasicus) during refrigerated storage

Effects of high pressure processing (HPP) under 300, 400, 500 and 600 MPa for 5 min on microbiological growth and histamine content of spotted mackerel meats stored at 4 oC were evaluated. It was also found that the L* (lightness), ΔE (color difference), and texture (hardness, cohesiveness and chewiness) of fish meat increased significantly with an increase in pressure, but a* (redness) value decreased. With an increase of pressure, the loads of aerobic plate count (APC), psychrotrophic bacteria count (PBC), H2S-producing bacteria count and coliform in mackerel meat significantly decreased. In addition, HPP significantly delayed the growth of APC and PBC during refrigerated storage for 15 days. Pressure up to 300 MPa significantly inhibited total volatile basic nitrogen (TVBN) and histamine formation, compared to control sample during storage. The results pointed to that the pressurization at least 300 MPa for 5 min on mackerel meat could extend shelf-life during refrigerated storage.