Depuration of cadmium from blue mussel (Mytilus edulis) by hydrolysis peptides and chelating metal elements

The present experiment was conducted to investigate the effects of prepared hairtail (Lepidopusc audatus) hydrolysis peptide-metal element (Fe2 +, Zn2 +, Ca2 +, or Mg2 +) complexes (PH-Fe2 +, PH-Zn2 +, PH-Ca2 +, or PH-Mg2 +) on the depuration of cadmium (Cd) from blue mussel (Mytilus edulis) tissues. Cd concentrations in anterior adductor muscle, posterior adductor muscle, gill, mantle, and visceral mass of mussels were 11.391, 15.323, 63.672, 19.509, and 109.621 μg/g, respectively, after 5 days of exposure to 0.32 mg/L Cd. Five groups of these exposed mussels were then exposed to seawater laced with four different concentrations of the peptide complexes listed above (5, 10, 15, and 20 mg/L) for 8 days. After 8 days of depuration, 5 mg/L of PH-Fe2 +, PH-Zn2 +, and PH-Ca2 + showed no significant (P > 0.05) effects on Cd concentrations in mussel tissues. However, significant differences (P < 0.05) were observed in groups exposed to 20 mg/L of PH-Fe2 +, PH-Zn2 +, and PH-Ca2 +. The Cd concentrations in anterior adductor muscle, posterior adductor muscle, gill, mantle, and visceral mass were significantly (P < 0.05) decreased by 29.56-35.83%, 27.51-33.62%, 31.59-40.34%, 25.83-31.28%, and 33.62-33.97%, respectively. Nevertheless, the variables of Cd concentrations in tissues treated with 5-20 mg/L PH-Mg2 + showed no significant (P > 0.05) differences from controls at any point during the experimental period. For these reasons, PH-Fe2 +, PH-Zn2 +, and PH-Ca2 + can be recommended as depuration agents in mussel feed to decrease the Cd concentrations in tissues.