What the Fish: Tracing geographical origin by Stable Isotope, Multielement profile and NIR spectroscopy

Commercialization of seafood industry has led to better accessibility of seafood around the globe and is an important part of global food chain to ensure food requirements worldwide. It forms one of the most complex international food chains and this makes it particularly vulnerable to fraud. In Europe, species substitution and origin mislabelling are the most common frauds faced by the seafood industry. Europe imports over 75% of its seafood with demand for it rising every year, which further increases chances of fraud and make authentication of seafood difficult. Owing to this complex global scenario, traceability of seafood becomes even more important to protect consumer’s rights and ensure safety in food systems. Origin mislabelling includes concealment of geographical origin of illegally harvested fish species whereas species substitution includes replacement of low-value species for a more expensive one for economic gain. Fish growing in different regions have different composition of fatty acids, elemental and isotopic compounds depending on their surroundings. Same differences occur between different species of fish living in the same region due to their varying feeding habits. These traits are used to identify origin mislabelling and species substitution. Several techniques have been employed to identify fish frauds such as DNA based methods, immunological assays, spectroscopic methods, stable isotopes, trace element analysis, fish microbiome analysis, etc. Multielement and stable isotope analyses and NIR spectroscopy are reliable analytical techniques providing useful information and thus accurate chemometric-based traceability models. Multielement profile can also allow to assess the fish nutritional quality and possible presence of contaminants. Stable isotope analysis of elements such as carbon, oxygen, nitrogen and strontium enables to discriminate fish provenance, natural vs feed-based diet, frozen vs fresh fish. NIR is a non-destructive and cost-effective analytical tool. A combined use of these methodologies to identify the fish fraud can strengthen the traceability models, minimising the occurrence of possible prediction errors.

In this context, SUREFISH* PRIMA project aims at deploying innovative solutions to achieve unequivocal traceability of Mediterranean fish products, preventing possible frauds. It gathers 13 partners from Italy, Spain, Tunisia, Egypt, Lebanon and 4 pilot sites fishing/growing and processing the following fish species: anchovy (Engraulis encrasicolus), sardine (Sardina pilchardus), bluefin tuna (Thunnus thynnus), tilapia (Tilapia spp.) and grouper (Epinephelus itajara). In the framework of WP3, we will develop and harmonise multi-element, isotope and NIR based analytical methodologies to trace the provenance of these Mediterranean fish species. Basically, we will analyse fresh or thawed fish meat and additional samples such as fish bones and otoliths, aquaculture feeds and sea or fresh waters. The findings will be gathered in a database useful for comparison with data from literature and other FAO fishing areas.

 

* SUREFISH PRIMA project: Fostering Mediterranean fish ensuring traceability and authenticity, https://surefish.eu/. PRIMA Call 2019 Section 1 - Agro-food Value Chain 2019, Topic 1.3.1.