Effect of different packaging methods on the free amino acid profiles of the deep-water rose shrimp (Parapenaeus longirostris) during frozen storage.

The composition of free amino acids (FAAs) in seafood products contributes to characterizing their flavor, as well as freshness and quality during storage. Deep-water rose shrimps (Parapenaues longirostris, Lucas, 1846) (DWRS) are being increasingly harvested in the Mediterranean Sea, and the captured specimens are quickly frozen onboard fishing trawlers to preserve freshness and post-harvest quality. Here, we quantified the FAA profiles of DWRS packaged using five methods: (1) 100% N2; (2) vacuum; (3) 50% N2 + 50% CO2; (4) commercial anhydrous sodium sulfite; and (5) air (control). All samples were quickly frozen at -35°C and stored for 12 months at -18°C. Arginine (661 mg/100 g), proline (538 mg/100 g), and glycine (424 mg/100 g) were the most abundant FAAs, whereas the least abundant were tyrosine (67 mg/100 g), histidine (58 mg/100 g), and aspartic acid (34 mg/100 g). FAAs in all samples gradually (and significantly) increased in the first 6 to 8 months of storage, and then significantly decreased. The sodium sulfite treatment (Method 4) kept the initial FAA contents lower than the other treatments, due to the strong antioxidant action of sulfite agents. Interestingly, similar results were obtained for vacuum packaging (Method 2). Thus, combining frozen storage with vacuum packaging represents an alternative approach to chemical additives in shrimp/prawn processing to meet the increasing demand for high-quality seafood products with long shelf-life.

Correction to: Microplastics in seawater: sampling strategies, laboratory methodologies, and identification techniques applied to port environment.

The article Microplastics in seawater: sampling strategies, laboratory methodologies, and identification techniques applied to port environment.

Microplastics in seawater: sampling strategies, laboratory methodologies, and identification techniques applied to port environment.

The European Interreg Italy-France 2014-2020 Maritime Project SPlasH! (Stop to Plastics in H2O!) focused on the study of microplastics (MPs) in the marine port environment to evaluate their presence, abundance, and mechanisms of diffusion to the open sea. In the framework of this project, a worldwide review of 74 studies was carried out, providing an overview of MP investigation techniques, focusing on sampling strategies, laboratory methodologies, and identification of MPs collected in seawater, and specifically evaluating their applicability to the marine port environment. Nets were the most commonly used device for MP surface sampling, but their use can be difficult in narrow spaces within the port basins, and they must be coupled to discrete sampling devices to cover all port basins. In the laboratory, density separation (NaCl, ZnCl2, NaI, sodium lauryl sulfate (SLS)), filtration (polycarbonate, polyamide, glass, cellulose, ANOPORE inorganic membrane filters), sieving, visual sorting, and digestion methods (acidic, enzymatic, alkaline, oxidative) were used to separate MPs from seawater. Digestion becomes essential with water samples with great inorganic and organic loads as deriving from a port. Although many studies are based only on visual MP identification under a microscope, analytical identification techniques unequivocally determine the particle nature and the identity of the plastic polymers and are necessary to validate the visual sorting of MPs. Fourier-transform infrared spectroscopy (FTIR) is the most used analytical identification technique.