Effect of high-pressure pretreatments applied before freezing and frozen storage

23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 The frozen storage of Atlantic mackerel (Scomber scombrus) is limited by lipid damage causing sensory quality losses, an important drawback to its commercialisation. This work deals with changes in functional and sensory properties during freezing and frozen storage of Atlantic mackerel pre-treated by high hydrostatic pressure processing (HPP). Three levels of pressure (150, 300, and 450 MPa), holding time (0.0, 2.5, and 5.0 min) and frozen storage time (0, 1, and 3 months) were tested. Expressible water, CIE colour parameters, mechanical texture parameters and sensory parameters were evaluated. Results showed that HPP at low levels (150 MPa) yielded raw samples with expressible water lower than 40%, improving the quality of frozen muscle. During frozen storage, the flesh colour of the controls (no HPP) tended to yellowness, while low-pressure treatments (150 MPa) yielded samples with lightness similar to fresh muscle. HPP effects on the colour parameters were negligible. Hardness and chewiness values of HPP-treated samples and those for no-HPP controls were similar. Sensory analysis suggested that 150 MPa did not affect the flesh odour. Most importantly, the sensorial acceptability of HPP-treated samples was better than that of frozen fillet controls and similar to that of fresh mackerel.