Effects of freezing and thawing processes on the quality of Atlantic salmon (Salmo salar) fillets

Abstract

High-pressure processing is finding a growing interest in the food industry. Among the advantages of this emerging process is the ability to favorably freeze and thaw food. This study aims at comparing the effect of different freezing and thawing processes on the quality of Atlantic salmon fillets. Atlantic salmon (Salmo salar) samples were frozen by Pressure-Shift Freezing (PSF, 200 MPa, -18 degrees C) and Air-Blast Freezing (ABF, -30 degrees C, 4 m/s). Samples were stored 1 mo at -20 degrees C and then subjected to different thawing treatments: Air-Blast Thawing (ABT, 4 degrees C, 4 m/s), Immersion Thawing (IMT, 20 degrees C), and Pressure-Assisted Thawing (PAT, 200 MPa, 20 degrees C). Changes in texture, color, and drip loss were investigated. The toughness of the PSF samples was higher than that of the ABF sample. The modification of color was more important during high-pressure process than during the conventional process. The PSF process reduced thawing drip compared with ABF. The presence of small ice crystals in the pressure-shift frozen sample is probably the major reason leading to the reduced drip volumes. The freezing process was generally much more influent on quality parameters than the thawing process. These results show the interaction between freezing and thawing processes on selected quality parameters.