Selenium-dependent antioxidant enzymes: Actions and properties of selenoproteins

Unlike other essential trace elements that interact with proteins in the form of cofactors, selenium (Se) becomes co-translationally incorporated into the polypeptide chain as part of 21st naturally occurring amino acid, selenocysteine (Sec), encoded by the UGA codon. Any protein that includes Sec in its polypeptide chain is defined as selenoprotein. Members of the selenoproteins family exert various functions and their synthesis depends on specific cofactors and on dietary Se. The Se intake in productive animals such as chickens affect nutrient utilization, production performances, antioxidative status and responses of the immune system. Although several functions of selenoproteins are unknown, many disorders are related to alterations in selenoprotein expression or activity. Selenium insufficiency and polymorphisms or mutations in selenoproteins’ genes and synthesis cofactors are involved in the pathophysiology of many diseases, including cardiovascular disorders, immune dysfunctions, cancer, muscle and bone disorders, endocrine functions and neurological disorders. Finally, heavy metal poisoning decreases mRNA levels of selenoproteins and increases mRNA levels of inflammatory factors, underlying the antagonistic effect of Se. This review is an update on Se dependent antioxidant enzymes, presenting the current state of the art and is focusing on results obtained mainly in chicken

Methods for Seafood Authenticity Testing in Europe

56 pages, 5 figuresSeafood authenticity is a key parameter for seafood quality, particularly in Europe where regulations provide a strict framework for seafood labeling. A wide variety of methods are commonly used in control laboratories (private or public) to identify seafood species, but emergent approaches for the development of new and fast DNA- and protein-based methods for species differentiation are also considered. To address the challenges in controlling further labeling requirements in the latest European legislation on seafood product traceability and labeling (Regulation (EU) 1379/2013), a review of the development of methods to identify fishing areas and to distinguish between wild and farmed fish, as well as an overview of the advanced methods that could be used for differentiation of fresh and frozen-thawed fish, is given. These methods will become increasingly important in the near future as the risk-based control of food authenticity is prescribed by the new EU control regulation (Regulation (EU) 2017/625)N