Prevalence of phylogenetic over environmental drivers on the fatty acid profiles of the adductor muscle of marine bivalves and its relevance for traceability

Abstract

Marine bivalves are among the most traded seafood worldwide. Along with their economic value, they are also an excellent source of proteins, vitamins, minerals, omega-3 and omega-6 fatty acids (FA). The FA profiles of the adductor muscle (AM) of bivalves can be successfully used to trace their geographic origin. This approach is paramount for traceability, as it allows to expose fraudulent practices associated with the capture of bivalves from unsuitable areas for human consumption that may put food safety at risk. However, it is yet to be determined whether phylogenetic or environmental drivers prevail on the shaping of FA signatures when comparing multiple bivalve species originating from the same location or distinct geographic origins. In this study, the FA profiles of the AM of six commercially important bivalve species (Cerastoderme edule, Crassostrea gigas, Mytilus galloprovincialis, Ruditapes philippinarum, Scrobicularia plana and Solen marginatus) from Ria de Aveiro (Northwest Coast of Portugal) were compared. Furthermore, the FA profiles of the AM of C. edule and R. phillipinarum originating from Ria de Aveiro and the Tagus estuary (~250 Km apart) were also compared to identify if phylogenetic drivers prevailed over environmental ones. The FA profiles of the AM of the six bivalve species sampled in Ria de Aveiro differed significantly among themselves, displaying higher levels of similarity between species belonging to the same infraclass. The comparison of species from the same ecosystem and specimens from different ecosystems evidenced that phylogenetic drivers prevail over environmental ones on the shaping of FA profiles of the AM. These findings are important for food safety issues, as they revealed that the FA profile of the AM of a given bivalve species cannot be used as a reliable proxy for another one when aiming to trace geographic origin. The transfer of this technology to bivalve’s production ensures product’s safety, promotion and differentiation, as well as a tool against fraud.