Total soluble protein was assayed using Pierce Bicinchoninic Acid (BCA) protein assay (ThermoFisher, USA) to establish the optimal approach for recovering the total amount of soluble protein from the flesh of snakehead fish. Its absorbance was measured at 540 nm in an ELISA plate reader. Bovine serum albumin (BSA) was used as the standard protein. The analysis was performed following the protocol provided by ThermoFisher Scientific. The ratio 1:8 of sample to working reagent was prepared, loaded into a 96-well plate, and incubated at 37 °C for 30 min. The total soluble protein concentration was quantified according to the standard curve obtained from the protein standard.