Chemical composition and functional properties of recovered protein from Japanese anchovy using different extraction methods

Japanese anchovy Engraulis japonicus is a small-sized fish, and it is difficult to obtain its flesh by hand. To enhance the utilization of this fish, this study aims to determine the effect of extraction methods on the amino acid, mineral, and fatty acid profile of recovered protein (RP) from Japanese anchovy, as well as the functional properties of RP. The protein was extracted from minced fish by three methods, including salt water treatment (RP-S) and pH-shifted processes at both acidic (RP-A) and basic (RP-B) solubilization. All RPs had more total essential amino acids than minced fish. Among RP, the highest Na and Fe content was found in RP-S, whereas RP-A showed the highest calcium content. RP-S possessed a lower amount of total polyunsaturated fatty acids than that of RP-A and RP-B. Water- and oil-absorption capacity and foam stability of RP-S and RP-B were on the same level and higher than those of RP-A. The highest emulsion activity index and emulsion stability index was found in RP-B. However, no difference was found in emulsion stability index between RP-S and RP-A. Overall, salt water treatment indicated that this method can be used as an alternative method to recover protein from Japanese anchovy.