Response of Atlantic salmon (Salmo salar) flavor to environmental salinity while culturing between freshwater and seawater

Abstract

Atlantic salmon (Salmo salar) are migratory salmonids and high-end seafood, and are widely cultivated. Its growth and development process needs to experience from freshwater to seawater phases. Salinity, as a key environmental factor, affects metabolism of Atlantic salmon, which in turn greatly affects its volatile organic compound (VOC) content and taste. We used headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and electronic tongue techniques combined with multivariate statistical analysis to detect VOCs and determine changes in the overall taste of Atlantic salmon in five different growth stages (freshwater: 8 months old; seawater: 15, 18, 21, and 24 months old; M1, M2, M3, M4, and M5, respectively). In addition, the content of free amino acids (FAAs) that affect flavor was determined. The fingerprint of Atlantic salmon from HS-GC-IMS identified ten potential markers, including one and three biomarkers in the freshwater and seawater phases, respectively, and showed the potential markers in each growth stage. The electronic tongue effectively distinguished the overall taste of Atlantic salmon in the freshwater and seawater phases. The total FAA content in the freshwater phase was significantly lower than that in the seawater phase, and the umami FAA level in M3 was the highest. Therefore, flavor compounds can be used as potential markers for Atlantic salmon culturing in freshwater and seawater environments and for their different growth stages. Our research will provide reference data for further improving its aquaculture technology and studying the changes of physiological and biochemical indicators during migration of Atlantic salmon from freshwater to seawater.