Fatty Acid Composition in Sturgeon Caviar from Different Species: Comparing Wild and Farmed Origins

Abstract

The fatty acid compositions of both lipid classes, triglycerides (TG) and phospholipids (PL), of caviar from 34 specimens of wild caught and 12 farmed specimens were measured. The investigated caviar samples of wild caught sturgeon comprised Huso huso, Acipenser gueldenstaedti, Acipenser stellantus and Polyodon spathula of different origins and those of farmed sturgeon from Acipenser baeri, A. stellatus, and P. spathula, Oleic acid (18 : 1 n - 9) was the dominant fatty acid in TG of all caviar samples. In comparison with the TG, the PL have an elevated content of polyunsaturated fatty acids such as arachidonic (20:4 n-6), eicosapenlaenoic (20 : 5 n-3) and docosahexaenoic acid (22:6 n - 3). In the TG were observed some differences in the fatty acid composition between the caviar samples of the various species, especially in 18 : I n-9 and 20.5 n - 3 hut not in the PL. The proportion of n - 3 to n - b polyunsaturated fatty acids (PUFAs) was independent from the fish species and origins and did not reveal significant differences. The amount of n - 3 PUFAs was in average three times higher compared to n - 6 PUFAs. However, the fatty acid composition of the caviar depends on the origin of the sample, probably caused by differences in the food web. The caviar of farmed sturgeon contained a significant higher amount of linoleic acid (18:2 n - 6) and a lower amount of arachidonic acid, when compared with caviar from wild sturgeon. An explanation could he that sturgeon are not able to convert 18 : 2 n - 6 into 20 : 4 n - 6.