Impacts of high-pressure processing on quality and shelf-life of yellowfin tuna (Thunnus albacares) stored at 4 degrees C and 15 degrees C

The objective of this work was to study the application of high-pressure processing (HPP) on the quality change and extending the shelf-life of yellowfin tuna (Thunnus albacares) stored at low temperature. The effects of HPP treatments (200, 300, 400, 500, and 600 MPa for 5 min) on microbiological and chemical quality, and histamine content of tuna flesh stored at 4 degrees C and 15 degrees C, respectively, were evaluated. With the increased pressure, the levels of aerobic plate count (APC) and coliform in tuna flesh significantly decreased. It was also found that the L* (lightness), b* (yellowness), W (whiteness), Delta E (color difference), and texture (hardness, cohesiveness and chewiness) of fish flesh increased significantly with the increased pressure; however, a* (redness) value decreased. Furthermore, HPP with a pressure of >300 MPa on tuna samples significantly delayed the increase in APC during storage at 4 degrees C or 15 degrees C, respectively, while the samples pressurized more than 200 MPa had significantly lower levels of total volatile basic nitrogen (TVBN) and histamine compared to the control samples during storage. The results indicated that tuna flesh pressurized at least 300 MPa for 5 min could be a technique employed to extend the shelf-life to 1 d at 15 degrees C and 6 d at 4 degrees C, based on the APC limit standard (6.47 log CFU/g). In this study, HPP can be seen as a potential useful technique to preserve tuna flesh due to its ability to reduce bacterial load and retard TVBN and histamine production.