The effect of depuration salinity on the survival, nutritional composition, biochemical responses and proteome of Pacific oyster (Crassostrea gigas) during anhydrous living-preservation

Control of depuration salinity is crucial to quality maintenance of live Pacific oyster ( Crassostrea gigas ) during anhydrous living-preservation. In present study, the survival, nutritional composition, biochemical responses and proteome changes of C. gigas were investigated during preservation in anhydrous conditions at 4 °C for 7 days after depuration (72 h) at salinity of 26–38 g/L, corresponding to −20%, −10%, 0, +10% and +20% fluctuation away from original production salinity in the spring of 2021. The results showed that the mortality, nutritional components and biochemical responses of C. gigas were sensitive to excessive salinity stress, especially at +20% fluctuation. In-depth proteomic analysis by sequential window acquisition of all theoretical fragment ion mass spectra (SWATH-MS) disclosed that proteome of C. gigas was altered widely and some functional proteins were up and down-regulated significantly. In conclusion, slight fluctuation (±10%) of depuration salinity is helpful in quality-maintaining of C. gigas in subsequent anhydrous living-preservation. • The effect of depuration salinity of C. gigas was evaluated. • Excessive salinity fluctuation would cause the loss of nutrients. • The SWATH-MS-based proteomic method was developed to reveal protein changes. • Laccase-4, GST, and Cathepsin L were potential biomarkers for stress.