Reared perch v. wild perch – first results about organoleptical and technological quality

The Eurasian perch, Perca fluviatilis L., has good potential as a candidate for inland aquaculture diversification in Europe. To aid the development of this new product, we define a quality reference based on attributes of wild perch, and compare the quality of perch reared in three different culture systems: (1) extensive (pond), (2) semi-extensive (tank) and (3) intensive (re-circulation system). In order to define a precise quality reference, it is necessary to characterize the spatial and seasonal variability in quality attributes of wild fish. To do so, wild perch were harvested every three month for a full biological cycle from two different natural systems (Lake Geneva in France and the River Rhine in the Netherlands). Two components of quality were taken into account: organoleptical (colour of skin and fillets (L*C*H° system; 12 variables), seven morphological measurements) and six technological components (viscero, hepato and gonadosomatic index, perivisceral fat index, fillet yield and condition factor K2). Using Principal Component Analysis, we show that within-season variability is high, particularly for Rhine perch. Perch from the Rhine have a compact body and caudal fin, and possess a longer mouth and head than perch from Lake Genva. Reared fish possess wild-like characteristics except for technological variables. Fish from extensive and semi-extensive system show similar attributes, while fish from intensive rearing systems show a higher viscerosomatic and perivisceral fat index.