Evaluation of heavy metals, mycotoxins and mineral bioaccessibility through in vitro static digestion models of rainbow trout (Oncorhynchus mykiss) and sole (Dover sole) side stream extracts obtained by pressurized liquid extraction

The recovery of antioxidants and minerals as well as the content of contaminants of rainbow trout and sole side streams (head, skin and viscera) extracts obtained by pressurized liquid extraction (PLE) were evaluated. Then, the effect of the gastrointestinal digestion was tested. No mycotoxins were detected in the extracts, while heavy metals contents (mg/kg) were up to 2.9 (As), 0.054 (Cd), 0.16 (Hg) and 0.073 (Pb), being below maximum legislated limits. A positive effect of PLE was found for the antioxidant capacity recovery, being the oxygen radical capacity of sole head and skin extracts significantly enhanced after digestion (similar to 3.8 times). PLE signifi-cantly increased Mg, Fe, Zn, Se and P (KPLE > 1) contents of rainbow trout side streams, Zn (KPLE5.97) and Fe (KPLE 2.80) of head sole and Mg, Se and P of all samples. Moreover, Mg, Ca and Fe bioaccessibility was lower in all sole extracts compared to rainbow trout.

Automated summary

The recovery of antioxidants and minerals, as well as the content of contaminants, in rainbow trout and sole side streams extracts obtained by pressurized liquid extraction (PLE) were evaluated and the effect of gastrointestinal digestion was tested. No mycotoxins were detected in the extracts, and heavy metals were found to be below maximum legislated limits. PLE significantly increased the antioxidant capacity recovery and the contents of certain minerals in the extracted samples. The bioaccessibility of Mg, Ca, and Fe was lower in sole extracts compared to rainbow trout.