Combined effects of metals (Cr6+, Hg2+, Ni2+, Zn2+) and calcium on the serum biochemistry and food quality of the Nile fish (Oreochromis niloticus)


Journal of Food Composition and Analysis, vol.115, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 115
  • Publication Date: 2023
  • Doi Number: 10.1016/j.jfca.2022.104968
  • Journal Name: Journal of Food Composition and Analysis
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Analytical Abstracts, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Food Science & Technology Abstracts, Veterinary Science Database
  • Keywords: Fish, Food quality, Hardness, Metal, Serum, Toxicity
  • Hakkari University Affiliated: Yes


Water hardness affects metal uptake and toxicity in fish. Calcium is the most important ion determining water hardness. Fish are one of the most important food supplies for humans. Thus, Oreochromis niloticus were exposed to Cr6+, Ni2+, Zn2+ and Hg2+ in differing Ca2+ levels (30, 60 and 120 mg Ca2+/L) and subsequently serum biochemical parameters and muscle food quality were investigated. In acute experiments (3 days), fish were exposed to 30 µM of Cr6+, Ni2+ and Zn2+, and 0.3 µM of Hg2+, though they were exposed to 10 µM for Cr6+, Ni2+ and Zn+2 and 0.03 µM for Hg2+ in chronic experiments (30 days). Data showed that there were significant (p < 0.05) alterations in the levels of glucose, alanine transaminase, aspartate transaminase, cholesterol and triglyceride in the serum, most alterations being at the lowest calcium level. Serum ion levels (Na+, K+, Ca2+) also altered significantly, but only in chronic exposures. There were significant variations in the quality of muscle in both durations, as total protein, lipid and raw ash levels altered significantly (p < 0.05), though no significant change occurred in the water content of muscle tissue. This work demonstrated that metals affected the serum biochemistry and muscle food quality of Oreochromis niloticus, emphasizing the stress that fish could face in metal-contaminated waters.