Assessment of essential element accumulation in red swamp crayfish (Procambarus clarkii) and the highly efficient selenium enrichment in freshwater animals

摘要

The red swamp crayfish is an important aquatic food for humans. In this study, the accumulation of trace elements, such as manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and selenium (Se) in the hepatopancreas, abdominal muscle, and exoskeleton of red swamp crayfish from four regions in China were investigated. The mean concentrations of Mn (21.01 mg/kg) and Fe (34.85 mg/kg) in the abdominal muscle were remarkably lower than those in the hepatopancreas (236.07 mg/kg and 2517.94 mg/kg) and exoskeleton (274.67 mg/kg and 111.34 mg/kg). The mean concentrations of Cu (19.62 mg/kg), Zn (73.95 mg/kg), and Se (1.04 mg/kg) in the abdominal muscle were remarkably higher than those (16.52 mg/kg, 21.79 mg/kg, 0.38 mg/kg) in the exoskeleton and lower than those (116.85 mg/kg, 124.74 mg/kg, 2.56 mg/kg) in the hepatopancreas, respectively. The concentrations of Cu (23.56 mg/kg) and Se (1.12 mg/kg) in the abdominal muscle of crayfish from the Ensi region were higher those in the other three regions. There was a highly significant positive correlation between the concentrations of Cu and Se in crayfish and those in the environment (r >= 0.68, P < 0.01). In addition, Se could be specifically enriched in the red swamp crayfish, and a similar situation was found in bighead carp and Chinese mitten crabs. These results highlight the level of intake of essential elements by humans. Importantly, the consumption of the abdominal muscles of crayfish does not result in the overdose of the five essential elements. Therefore, these findings provide new insights into food nutrition and safety control for the consumption of crayfish and other freshwater animals.