Extension of shelf life of chilled hake (Merluccius capensis) by high pressure

Vacuum packed hake muscle subjected to 400 MPa (three 5-min cycles) at 7 de grees C proved to be more stable at chilled temperatures (2-3 degrees C), a nd sensorially acceptable, until 43 days of storage in comparison with the nine days for the non-pressurized hake. The lot pressurized at 400 MPa had the appearance of cooked muscle. The microbial load was initially reduced b y two log units by pressurization at 400 MPa. Trimethylamine nitrogen (TMA- N) values were also very low. Pressurization had no effect on dimethylamine nitrogen (DMA-N) production. The lot pressurized at 400 MPa showed slower increase in drip loss from day 15 of storage. In the lot subjected to 200 M Pa (three 5-min cycles) at 7 degrees C, which retained the appearance of ra w fish, microorganisms were one log unit lower than in the non-pressurized sample and TMA-N was lower. In conclusion, the chilled shelf life was prolo nged by about one week in the lot pressurized at 200 MPa and about two week s in the lot pressurized at 400 MPa.