Analysis of the physicochemical properties of fresh eggs (raw material for caviar production) of the Salmonidae [sea trout (Salmo trutta L. 1758) and rainbow trout (Oncorhynchus mykiss, Walbaum 1792)] and the acipenseridae [siberian sturgeon (Acipenser baeri Brandt, 1869)], as well as sturgeon hybrids (Acipenser baeri Brandt, 1869 × Acipenser gueldenstaedti Brandt & Ratzeburg, 1833), included determination of basic physicochemical parameters (pH, dry weight, content of protein, fat, fiber and ash), amino acid composition and fatty acid profile. Compared to the Acipenseridae, Salmonidae eggs yielded a 22.5% higher total protein content, a 40.0% higher level of essential amino acids (EAA) and a 57.5% lower crude fat content. The sea trout eggs showed also a completely different fatty acids profile and hence values of lipid indices (lowest PUFA value – 11.72%, highest SFA value – 39.86%). The rainbow trout and sturgeon eggs had a similar fatty acid profile, and were characterized by a high nutritional and dietary value.
