Metal and proximate composition of the edible portion of 11 freshwater fish species

Abstract

Eleven different species of freshwater fish caught from the Evros river (Greece) were tested by atom-absorption spectroscopy for 20 naturally occurring elements and for their proximate composition. Protein content of edible portion averaged between 18 and 23% (wet basis), fat between 0.6 and 7.3%, ash between 0.9 and 1.5%, while moisture content was between 70 and 80%. Mean element levels in the flesh of fish were:P 240 ± 38, K 400 ± 130, Na 19 ± 2.2, Li 1 ± 0.2, Ca 57 ± 8.0, Mg 57 ± 9.2, Zn 0.7 ± 0.17, and Fe 0.7 ± 0.22 mg/100 g. Sr content was below the level of detection. Mean Al, Co, Cr, Cu, Mn, Mo, and Ni concentrations were 140 ± 38, 40 ± 13, 50 ± 26, 90 ± 24, 70 ± 18, 40 ± 13, 30 ± 12 μg/ 100 g, respectively. Cd, Hg, and Pb levels averaged 0.7 ± 0.33, 10 ± 2.2, and 10 ± 1.1 μg/100 g, respectively, and none exceeded legal or suggested limits. Tin content was below the level of detection. It can be concluded that the levels of metals in the flesh of fish assayed meet food products regulations.