European plaice (Pleuronectes platessa) in aquaculture – Nutritional, chemical, and physicochemical quality compared to wild stocks

Abstract

European plaice (Pleuronectes platessa) is among Europe's top-consumed fish species, but wild stocks fluctuate and change their habitat due to drastic changes in climate. Their potential in aquaculture is under consideration, and therefore multiple quality aspects have been evaluated in this study. The chemical composition, nutritional profile, and physicochemical properties of European plaice (Pleuronectes platessa) from aquaculture and wild origin (Norwegian west-coast) and differences between female and male farmed individuals were studied. Differences between farmed and wild fish were found for the proximate composition, nutritional profile, and physicochemical attributes. Farmed fish generally had paler color (higher L*; 78.7 ± 4.2) but showed reduced water holding capacity (WHC; 80.3 ± 8.1%), but a firmer fillet texture compared to wild plaice. Farmed fish had significantly higher lipid and lower ash contents than wild individuals. Farmed fish's free amino acid (FAA) content (265.6 ± 59.0 mg/ 100 g) was significantly higher than in wild fish (89.72 ± 43.6 mg/ 100 g), especially the taste contributing FAA glutamate, glycine, alanine, and tyrosine. However, large individual varieties in FAA were observed within farmed and wild specimens. Farmed fish's fatty acid (FA) profile reflects the feed's composition. The overall quality of farmed European plaice was comparable to wild individuals with an excellent nutritional profile. Gender comparisons in farmed fish has shown that females were paler (higher L*) and showed higher hue (h) values, lower color saturation (Chroma, C), and yellowness (a*) compared to males. No apparent difference in texture was found, and no correlations between WHC and pH nor WHC and water content were detected between females and males. Farmed male individuals had higher lipid (2.35 ± 1.5%) and protein (16.97 ± 1.1%) concentrations compared to females (1.72 ± 1.1%; 15.52 ± 1.7%). The overall findings of this study are promising to further investigate this species for cultivation as a sustainable food resource.