Seasonal variation of Co-enzyme Q10 content in pelagic fish tissues from Eastern Quebec

Seasonal and inter-individual variabilities of Co-enzyme Q10 (CoQ10) concentration were studied in various tissues (flesh, heart) of pelagic fish (mackerel and herring) from Eastern Quebec Fisheries (Canada). A simple and efficient extraction procedure followed by fast reverse-phase HPLC with photodiode array detection (PDA) has been optimized and validated for the determination of CoQ10 levels. Extraction used a first step of homogenization with sodium dodecyl sulphate (SDS) and NaCl, followed by a solvent extraction with ethanol–hexane. No further purification step was required before HPLC analysis. Method validation indicated excellent sensitivity (2.5 ng/injection), reproducibility (CV%=1.5–1.6) and recovery (100.3–105.1%). Good accuracy was also statistically demonstrated since no matrix effect was found. For both fish species, CoQ10 concentrations were the highest in heart (105–148 μg/g fresh tissue). In mackerel, CoQ10 concentrations in red and white flesh were respectively 67 and 15 μg/g fresh tissue. In herring, CoQ10 concentration in flesh was 15–24 μg/g fresh tissue. Slight seasonal variations of CoQ10 concentration were observed in mackerel white flesh and herring flesh. Results indicated that mackerel and herring from Eastern Quebec are good sources of Co-enzyme Q10, whose by-products could be used industrially for the extraction of such a high-value biomolecule.