Patrícia Oliveira

The overall quality of frozen hake fillets in the Portuguese market was evaluated. Physical, biochemical, microbiological, and sensory analysis in 20 brands revealed several non-conformities. Hake was identified in 19 brands, although two mislabeled the species. Lower net weight than labeled was evidenced in ca. one-third of brands. TVB-N in ca. one-third of the samples presented high values, although within legal limit. Almost all brands presented excessive amount of ice glaze, low levels of WHC (raw/cooked), low levels of soluble protein, and undue thaw-drip loss, thus reflecting the poor quality of fillets. Added phosphates were below the legal limit in all samples; however, they were used in glaze ice in three brands, and only labeled in one. Overall microbiological quality of frozen fillets was good, though yeasts and molds detected in six samples indicate poor hygienic conditions in some facilities. Labels comply with legal requisites, however, need improvement, namely the ‘best before’ periods. In general, packaging was efficient regarding presence of ice crystals and dehydration signs. Concerning sensory analysis of cooked fillets, 63% of the brands had bad to poor quality and 37% fair quality. Merluccius productus revealed the worst quality, namely regarding thaw drip loss, thaw drip loss protein, M/P ratio, pH and sensory evaluation. Overall results show that a significant part of the hake fillets business operators are still failing in relation with best practices.

Occurrence of tetrodotoxin (TTX), a potent natural neurotoxin, in marine organisms and seafood from the European Union has been of increasing concern due to its relatively recent detection in bivalve mollusks and gastropods. Following a request of the European Food Safety Authority (EFSA) to EU Member States to obtain more data on TTX occurrence, this study collected 117 samples of bivalve mollusks, including mussels (Mytilus galloprovincialis), oysters (Crassostrea gigas) and clams (Ruditapes philippinarum and Donax spp.), from the South and Southwest Portuguese coast between May and October 2018, for TTX determination and microbiological analysis. The analyses carried out by hydrophilic interaction liquid chromatography tandem mass spectrometry (HILIC-MS/MS) did not detect TTX in any sample, and microbiological analysis did not reveal high concentrations of Vibrio spp., which has been linked to the presence of TTX. Although preliminary, results from this study, the first investigating the presence of TTX in bivalve mollusks from the Portuguese coast, suggest that TTX may not represent a risk for human consumption of bivalve mollusks.