Comparison of Nutritional Composition, Mineral and Heavy Metal Content of Rainbow Trout from Different Aquaculture Systems

Abstract

In this study, proximate compositions, meat yields, mineral matter (Na, Mg, Ca, K), and heavy metal (As, Fe, Zn, Se, Mn, Co, Cu, Pb, Ni) contents of rainbow trout (Oncorhynchus mykiss) obtained from concrete pond systems and dam lake net cage were examined. Mineral and heavy metal contents were measured by ICP-OES instrumental analyser. According to the results of rainbow trout meat yield and nutritional composition analysis varied between; meat yield were 57.43-66.40%, crude protein were 16.99-19.93%, crude fat were 3.07-4.18%, crude ash were 0.98-1.58%, and moisture contents were 75.10-77.65%. Mineral contents of Ca 2.66-30.58 mg.kg-1, Na 19.53-36.04 mg.kg-1, K 252.79-310.05 mg.kg-1, and Mg 120.75-137.44 mg.kg-1 were detected in the presented ranges. Detected heavy metals were As 0.42-0.56 mg.kg-1, Fe 2.16-3.69 mg.kg-1, Zn 2.67-4.69 mg.kg-1, and Se 0.17-0.77 mg.kg-1. On the other hand, Mn, Co, Cu, Pb, and Ni were not detected. As a result of the study, it was found that the proximate composition, meat yield, mineral matter, and heavy metal contents of rainbow trout vary depending on the location and size of the fish (p<0.05). However, the heavy metal levels detected in muscle tissue did not exceed the consumption limits.