Sónia Pedro

The vast biodiversity and chemical richness of the marine environment provide an extensive array of biological benefits

Due to its high prevalence and significant impact on modern society, Alzheimer’s disease (AD) is one of the most important neurodegenerative disorders. It is more common among individuals over the age of 65, and its incidence has increased sharply as a result of rising life expectancy. Several factors have made it challenging to identify an effective treatment for AD. One major difficulty lies in its complexity, as the mechanisms involved in its progression are not yet fully understood. Nevertheless, the role of diet and lipids has been highlighted by numerous studies, underscoring their potential influence on this pathology. Due to the intricacy of its biochemical and metabolic interactions, this subject continues to be of particular interest, highlighting the need for further research. In this sense, this comprehensive and updated review aimed to elucidate these aspects, especially regarding marine-derived lipids, whose bioactive potential may become an irreplaceable tool in the management of AD, whether in terms of its treatment or prevention.

The Portuguese Water Quality Policy, aligned with the Water Framework Directive, requires the monitoring of shellfish production in coastal and brackish water bodies and is based on the EC Shellfish Waters Directive; it preserves the environmental conditions necessary for shellfish growth and contributes to the production of a safe, high-quality sustainable animal food source. Between 2017 and 2021, quarterly measurements of physico-chemical and microbial parameters were conducted at 11 coastal stations and 21 estuarine/coastal lagoons stations along Portugal, to evaluate shellfish water quality and identify the environmental drivers influencing it. Results showed that estuaries and coastal lagoons were more vulnerable to fluctuations in salinity, oxygen and suspended matter and consistently exhibited higher faecal contamination in bivalves than coastal waters. These patterns were shaped by freshwater inputs, climate-driven variability, and local anthropogenic pressures, with contamination often increasing during rainy periods or under stressful environmental conditions. The study highlights the sensitivity of transitional waters to both natural and human-induced changes and underscores the need for targeted management strategies, such as improved wastewater treatment and integrated coastal management, to reduce pollution pressures. Strengthening these measures is essential for the long-term sustainability of Portugal’s shellfish industry and coastal ecosystems.

Bivalves are a high-value product whose production has markedly increased, reaching 9863 tonnes in Portugal in 2021. Bivalves’ habitats—lagoons, estuaries and coastal waters—are exposed to biological and anthropogenic contaminants, which can bioaccumulate in these organisms and pose a significant public health risk. The need to obtain a safe product for human consumption led to the implementation of standardised hygiene regulations for harvesting and marketing bivalve molluscs, resulting in routine monitoring of bivalve production areas for microbial quality, metal contaminants, and marine biotoxins. While excessive levels of biotoxins and metal contamination lead to temporary harvesting bans, high faecal contamination leads to area reclassification and impose post-harvest treatments. In this study, the seasonal and temporal variability of these parameters were analysed using historical data generated by the monitoring programme during the last decade. Moreover, the impact of the monitoring program on bivalve harvesting from 2011 to 2020 was assessed. This program presented a considerable improvement over time, with an increase in the sampling effort and the overall program representativeness. Finally, contamination risk, revising control measures, and defining recommendations for risk mitigation measures are given in the light of ten years’ monitoring.

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.

The main aim of this study was to assess the quality changes and their causes during cod salt-curing for up to 76 days at different temperatures and a relative humidity below 80%. Salt-curing made the fish more yellow (L*a*b* scale), a color change that is more easily detected in sensory analysis against a cream color scale. Intense proteolytic breakdown took place at 12 and 18°C, leading to a greater proteolysis degree and a higher pH. A red surface discoloration of the flesh was apparent after 76 days at 18°C due to the high number of red-halophilic bacteria. These bacteria were also responsible for the highest intensity of “off”-odors and mucus obtained under these conditions. Cod salt-curing should be done below 12°C to reduce the spoilage activity of halophilic bacteria and is best done at chill temperature (close to 6°C) to obtain a good quality product.