Maria Leonor Nunes

Reproductive strategy of the female deep-water shark birdbeak dogfish, Deania calcea : lecithotrophy or matrotrophy?

Little information is available on the maternal–embryonic relationships among sharks. Birdbeak dogfish ( Deania calcea ) has been described as ovoviviparous, but this term comprises a wide range of forms on how the embryos are nourished including lecithotrophy and matrotrophy. To evaluate the maternal–embryonic relationship in birdbeak dogfish we have analysed chemical features (fatty acid composition and mercury (Hg) levels) and biological characteristics (egg and embryo dry weight variation, uterus characterization). Monounsaturated fatty acids were the dominant fatty acids in eggs while polyunsaturated fatty acids (PUFA) were the dominant fatty acids in both pregnant females and embryos. Significant differences were found among eggs, embryos and pregnant females for all fatty acids groups with the exception of saturated fatty acids for embryos and pregnant females. The principal components analysis revealed that embryos are particularly related to n-6 PUFA and pregnant females with n-3 PUFA. A close relationship exists between the Hg level of pregnant females and the Hg level of their embryos which indicates that there is a transfer of mercury from maternal sources. The comparison of the mean dry weight between eggs and embryos showed a gain of 3.8% obtained in the embryos. Histological sections of the uteri of pregnant females showed a high level of both superficial and inner vascularization in the uterine villi as well as the presence of secretor cells. Until now, the importance of this species maternal contribution and interference for the embryos development has never been documented. However, the biological and chemical results observed in the present work show that there is a matrotrophic strategy for the birdbeak dogfish.

Seafood Safety and Human Health Implications

Current projections for the twenty-first century show that global warming will accelerate, with stronger storms, extreme precipitation, dry spells and rising sea levels as the primary symptoms. Such changes will have implications in seafood production, security, and safety, as well as in human health, due to the increase in the frequency of harmful algal blooms, levels and bioaccumulation of several chemical contaminants, prevalence and virulence of common foodborne pathogenic microorganisms. The Mediterranean will be particularly affected by climate change due to water scarcity in the region. Assuring seafood safety in such scenario requires the active involvement of all stakeholders to elaborate and implement adaptation and mitigation plans. In this context, the current chapter aims to provide an overview of the potential effects of climate change in the Mediterranean seafood safety and human health, taking into account chemical and biological contaminants, and to discuss potential adaptation and mitigation measures.

Bay Laurel ( Laurus nobilis ) Oils

Abstract Bay laurel (Laurus nobilis) essential oil (EO) has been recognized to possess many interesting properties (e.g., antiseptic, antidiarrheal, antimycotic, antimicrobial, antiinflammatory, antioxidant, and anticarcinogenic) that have wide potential applications in many fields, including health and food. This chapter aims to revise the information available about the composition and potential food applications of bay laurel EO. So far, the wide application of bay laurel EO in industry is mostly performed in aromatherapy, massage therapy, and cosmetics. Scientific research has assessed its potential application in the food industry as well as several limitations that still need to be overcome.

Effect of seasonal changes on the gelling properties of farmed sea bass (Dicentrarchus labrax)

The effect of seasonal changes (summer versus winter) upon the quality of heat-induced gel products from farmed sea bass (Dicentrarchus labrax) was studied. Moreover, the effect of microbial transglutaminase addition (0.5%, w/w) on the quality was assessed. Fat content of gel products attained from sea bass grown during summer was higher (12.0% versus 7.6%). Textural properties of the gels from the summer fish were higher. Protein of gels from winter fish was less soluble in SDSu2009+u2009DTT (sodium dodecyl sulphate, SDS; dithiothreitol, DTT). Contrary to some literature, higher fat level may have played a protective role during processing. Accordingly, season via fat content variation had a strong effect on the gelling ability of heat-induced gels prepared from sea bass.