Introduction: Nowadays, due to the growing world population, lack of water resources and people's need for healthy protein materials, aquaculture is one of the most important issues of human societies. Breeding of sturgeon is one of the sources of income. Apart from caviar, other parts of this fish also have high nutritional value. Therefore, in this project, the percentage of protein and fat in the gizzard, ovary and intestine of the Acipenser gueldenstaedti, Acipenser persicus and Acipenser nudiventris, as well as the percentage of protein and fat in the caviar of Kazakhstan, Russia, and Iran were investigated in comparison with the three parts mentioned in the Acipenser gueldenstaedti.
Materials & Methods: The caught fish were transferred to the breeding and rearing center in hygienic conditions and after separating the caviar, gizzard, ovary and intestine were separated, washed with water, completely crushed with Bosch model device and stored in the freezer for measuring protein by Kjeldahl method and fat by Soxhlet method
Results: The results showed that the highest amount of protein percentage in the intestine of Acipenser nudiventris was 17.07, in the gizzard of Acipenser persicus was 17.21 and in the ovary of Acipenser gueldenstaedti was 29.55. The highest percentage of fat contain, 0.92 was in the intestine of Acipenser persicus, in the gizzard of Acipenser nudiventris was 0.5 and in the ovary of Acipenser persicus was 4.32.
Conclusion: The highest amount of protein in the ovary was reported in the Acipenser gueldenstaedti, while the highest amount of fat was found in the ovary of the Acipenser persicus. Additionally, the highest amount of protein in the intestine was observed in the
beluga (Huso huso), and the highest amount of fat was found in the intestine of the Acipenser persicus. Furthermore, the highest amount of protein in the gizzard was obtained in the Acipenser persicus, and the highest amount of fat was found in the gizzard of the beluga.