Authenticating Production Origin of Gilthead Sea Bream (Sparus aurata) by Chemical and Isotopic Fingerprinting

Recent EU legislation (EC/2065/2001) requires that fish products, of wild and farmed origin, must provide consumer information that describes geographical origin and production method. The aim of the present study was to establish methods that could reliably differentiate between wild and farmed European gilthead sea bream (Sparus aurata). The methods that were chosen were based on chemical and stable isotopic analysis of the readily accessible lipid fraction. This study examined fatty acid profiles by capillary gas chromatography and the isotopic composition of fish oil (δ13C, δ18O), phospholipid choline nitrogen (δ15N) and compound specific analysis of fatty acids (δ13C) by isotope ratio mass spectroscopy as parameters that could reliably discriminate samples of wild and farmed sea bream. The sample set comprised of 15 farmed and 15 wild gilthead sea bream (Sparus aurata), obtained from Greece and Spain, respectively. Discrimination was achieved using fatty acid compositions, with linoleic acid (18:2n-6), arachidonic acid (20:4n-6), stearic acid (18:0), vaccenic acid (18:1n-7) and docosapentaenoic acid (22:5n-3) providing the highest contributions for discrimination. Principle components analysis of the data set highlighted good discrimination between wild and farmed fish. Factor 1 and 2 accounted for >70% of the variation in the data. The variables contributing to this discrimination were: the fatty acids 14:0, 16:0, 18:0, 18:1n-9, 18:1n-7, 22:1n-11, 18:2n-6 and 22:5n-3; δ13C of the fatty acids 16:0, 18:0, 16:1n-7, 18:1n-9, 20:5n-3 and 22:6n-3; Bulk oil fraction δ13C; glycerol/choline fraction bulk δ13C; δ15N; % N; % lipid.

[1]  G. Ros,et al.  Muscle cellularity and flesh quality of wild and farmed sea bass, Dicentrarchus labrax L. , 2005 .

[2]  P. Sastry,et al.  Lipids of nervous tissue: composition and metabolism. , 1985, Progress in lipid research.

[3]  J. Navarro,et al.  Decreased 20:4n − 620:5n − 3 ratio in sperm from cultured sea bass, Dicentrarchus labrax, broodstock compared with wild fish , 1996 .

[4]  A. Lundebye,et al.  Reducing the levels of dioxins and dioxin-like PCBs in farmed Atlantic salmon by substitution of fish oil with vegetable oil in the feed , 2005 .

[5]  L. Horrocks,et al.  Health benefits of docosahexaenoic acid (DHA) , 1999, Pharmacological research.

[6]  H. Craig.  Isotopic standards for carbon and oxygen and correction factors for mass-spectrometric analysis of carbon dioxide , 1957 .

[7]  J. G. Bell,et al.  Tailoring of Atlantic salmon (Salmo salar L.) flesh lipid composition and sensory quality by replacing fish oil with a vegetable oil blend. , 2005, Journal of agricultural and food chemistry.

[8]  G. Young,et al.  Omega-3 fatty acids and neuropsychiatric disorders. , 2005, Reproduction, nutrition, development.

[9]  P. Calder,et al.  Polyunsaturated fatty acids, inflammation, and immunity , 2001, Lipids.

[10]  K. Fearon,et al.  Fish oil-enriched nutritional supplement attenuates progression of the acute-phase response in weight-losing patients with advanced pancreatic cancer. , 1999, The Journal of nutrition.

[11]  T. Preston,et al.  A streamlined approach to the analysis of volatile fatty acids and its application to the measurement of whole-body flux. , 2004, Rapid communications in mass spectrometry : RCM.

[12]  T. Preston.  The measurement of stable isotope natural abundance variations , 1992 .

[13]  B. Toman,et al.  New Guidelines for δ13C Measurements , 2006 .

[14]  M. Romdhane,et al.  Fatty acids in muscles and liver of Tunisian wild and farmed gilthead sea bream, Sparus aurata , 2007 .

[15]  A. Tacon,et al.  Development of farmed fish: a nutritionally necessary alternative to meat , 1999, Proceedings of the Nutrition Society.

[16]  Steven J. Schwager,et al.  Global Assessment of Organic Contaminants in Farmed Salmon , 2004, Science.

[17]  A. Tacon.  Use of fish meal and fish oil in aquaculture: a global perspective. , 2004 .

[18]  K. Taylor,et al.  Organoleptic and volatile aroma compounds comparison of wild and cultured gilthead sea bream (Sparus aurata): sensory differences and possible chemical basis , 2003 .

[19]  S. Gingras,et al.  Fatty acid composition of wild and farmed Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) , 2005, Lipids.

[20]  Piotr Paneth,et al.  Physical and chemical basis of carbon isotope fractionation in plants , 1992 .

[21]  J. G. Bell,et al.  Dietary lipid composition affects blood leucocyte fatty acid compositions and plasma eicosanoid concentrations in European sea bass (Dicentrarchus labrax) , 1999 .

[22]  D. Houlihan,et al.  Protein growth performance, amino acid utilisation and somatotropic axis responsiveness to fish meal replacement by plant protein sources in gilthead sea bream (Sparus aurata) , 2004 .

[23]  D. McMillan,et al.  Modulation of the liver export protein synthetic response to feeding by an n-3 fatty-acid-enriched nutritional supplement is associated with anabolism in cachectic cancer patients. , 2004, Clinical science.

[24]  D. McMillan,et al.  Metabolic response to feeding in weight-losing pancreatic cancer patients and its modulation by a fish-oil-enriched nutritional supplement. , 2000, Clinical science.

[25]  A. Simopoulos.  Omega-3 fatty acids in health and disease and in growth and development. , 1991, The American journal of clinical nutrition.

[26]  J. G. Bell,et al.  Dioxin and dioxin-like polychlorinated biphenyls (PCBs) in Scottish farmed salmon (Salmo salar): effects of replacement of dietary marine fish oil with vegetable oils , 2005 .

[27]  T. Preston,et al.  Mass spectrometric analysis of stable-isotope-labelled amino acid tracers , 1994, Proceedings of the Nutrition Society.

[28]  K. Fearon,et al.  Reduced total energy expenditure and physical activity in cachectic patients with pancreatic cancer can be modulated by an energy and protein dense oral supplement enriched with n-3 fatty acids , 2004, British Journal of Cancer.