Fatty acid profiling of European seabass (Dicentrarchus labrax) flesh as a means of authenticating production origin?

Seafood traceability and labelling as imposed by EU Regulation No 2065/2001 (REG in the following) requires that, in addition to commercial designation, both fishery and aquacultured products be qualified as to production method and either catch or farming area. This information is all the more crucial when it comes to widely appreciated species, such as European seabass, which may be available in a wild state or derive from aquaculture, retaining quite a different intrinsic value in the consumers’ opinions and therefore commanding widely different prices. A large study was therefore funded by the Italian Ministry of Agricultural, Food and Forestry Policies to test the usefulness of several analytical methods, taken either alone or in combination, to authenticate European seabass origin, the part reported here exploring the possibility to confirm product label specifications based solely on the fatty acid profile of flesh total lipids. A total of 160 European seabass specimens were collected from November 2009 to December 2010. Aquacultured specimens (n=115) were obtained from 13 farms (Italy 8, Greece 2, Turkey 2, Croatia 1), one of the Italian farms adopting quite a typical extensive production system in brackish lagoons named “vallicoltura”, the others predominantly the floating cage intensive system. Wild specimens (n=45) were obtained from 5 main areas for seabass sourcing in Italy, 4 of which in the Mediterranean sea. Fish were received on ice and promptly filleted, skinned and deboned. Total lipids were extracted (chloroform/methanol 1:1, v/v) from the homogenised flesh of each specimen and fatty acid methyl esters were separated on 30-m DB-23 capillary column. Supervised methods (quadratic discriminant analysis with leave-one-out crossvalidation) were performed on the identified fatty acid data set (22/specimen). As to the “production method” (REG, Article 4), multivariate statistics allowed the correct classification of specimens according to their farmed or wild status, with the only exception of those deriving from Italian “vallicoltura” (n=10). As to the “catch area” (REG, Article 5), about 70% of the wild specimens was allocated to their proper FAO fishing area, whereas around 85% of the Italian product was properly differentiated within the intensive farmed group.