THE CHEMICAL COMPOSITION OF TWO COMMERCIAL FISH SPECIES - PIKEPERCH (SANDER LUCIOPERCA) AND RAINBOW TROUT (ONCORHYNCHUS MYKISS) CULTIVATED IN ARTIFICIAL CONDITIONS

Fish is a nutrient rich food and possesses many components that have positive impact on human health. Nowadays, the fish come to the market from wild-capture fisheries and aquaculture. Latter becomes increasingly global for human consumption, thus total finfish aquaculture includes over 300 species farmed in ponds, floating net cages and recirculating aquaculture systems (RAS). It is reasonable to assume that the chemical composition of farmed fish will vary compared to wild-caught ones due to the different rearing conditions and artificial diets used for feeding the fish. This study gives an overview of basic chemical composition of pikeperch (Sander lucioperca) and rainbow trout (Oncorhynchus mykiss). We analysed the muscle flesh composition of fresh and frozen pikeperch obtained from the local commercial tank-based recirculating aquaculture system together with rainbow trout obtained from river-based net cage farming system. We determined that fresh pikeperch contained 78.27 +/- 0.34% moisture, 18.95 +/- 2.45% protein, 1.34 +/- 0.18% fat and 1.62 +/- 0.21% ash, while frozen ones had 78.26 +/- 0.44, 20.91 +/- 0.62, 0.77 +/- 0.15 and 0.99 +/- 0.09% respectively. Statistically significant differences were found for fat and ash content (p<0.05). In both cases, artificially cultivated pikeperch has high nutritional value and fit for human consumption. The chemical composition of trout was the following: 69.61 +/- 1.33% moisture, 17.78 +/- 0.48% protein, 11.41 +/- 2.24% fat and 0.88 +/- 0.01% ash. After reviewing the literature, we found that farmed trout has considerably higher fat content than wild trout. This primarily can be explained by use of lipid-rich diets and lower mobility in cages.