Evaluation of the physicochemical and functional properties of isolated proteins extracted from two species of Siberian sturgeon (Acipenser baerii) and Iranian sturgeon (Acipenser persicus)

In the current study, fish-isolated protein (FPI) was extracted by alkaline pH method from the wastes of the head and fins of Siberian sturgeon (Acipenser baerii) and Iranian sturgeon (Acipenser persicus) and its composition, functional and structural characteristics were investigated. The results showed that the extraction efficiency according to the wet weight, the protein recovery of FPI, and the dry matter recovery of FPI from the Siberian sturgeon was higher than that of Iranian sturgeon. The results showed 91-94% protein in FPI of two species. The results did not show any significant differences between the proximate analysis and TVB-N (P> 0.05). The water absorption capacity, foaming capacity, and stability of FPI were shown at 30, 50, and 50%, respectively. The whiteness and transparency index of the FPI extracted was low. The results of particle size and zeta potential (P< 0.05) showed that the size of FPI particles in both samples is about a micron and they have a negative charge, so they can be easily used in colloidal systems. FTIR spectroscopy in both samples showed all the absorption peaks related to the main bonds of the protein structure. In general, considering the large amount of sturgeon waste in processing, and the amount of protein, functional properties, and nutritional value of FPI extracted from two species of sturgeon, there is the possibility of using them in human food and sports supplements.