Effect of dietary vitamin E supplementation on lipid and colour stability of chicken thigh meat

Lipid and myoglobin oxidation are major causes of meat quality deterioration during storage of fresh chicken meat. Our objective is to determine the effects of dietary -tocopherol supplementation on lipid and colour stability of fresh chicken thigh meat exposed in a supermarket shopwindow or stored in a refrigerator. Chickens were fed with diets containing 25 (control), 100, 200 or 300 mg vitamin E/kg of food for 20 days before slaughtering. Peroxide value (PV) and oxidation products specific extinctions (K232 and K270), chosen as markers for oxidative deterioration of lipids, were lower in chicken meat from animals supplemented with 200 or 300 mg vitamin E than that of the control meat upon storage during 5 days in a shopwindow (p < 0.01) or 9 days in a refrigerator (p < 0.01). Vitamin E dietary supplementation (200 mg vitamin E/kg of food) reduced oxidation products formation in fresh thighs meat but had no significant impact on colour analysed by value redness (a*) measurements

High contribution of Rhizaria (Radiolaria) to vertical export in the California Current Ecosystem revealed by DNA metabarcoding

International audiencePassive sinking of particulate organic matter (POM) is the main mechanism through which the biological pump transports surface primary production to the ocean interior. However, the contribution and variability of different biological sources to vertical export is not fully understood. Here, we use DNA metabarcoding of the 18S rRNA gene and particle interceptor traps (PITs) to characterize the taxonomic composition of particles sinking out of the photic layer in the California Current Ecosystem (CCE), a productive system with high export potential. The PITs included formalin-fixed and ‘live’ traps to investigate eukaryotic communities involved in the export and remineralization of sinking particles. Sequences affiliated with Radiolaria dominated the eukaryotic assemblage in fixed traps (90%), with Dinophyta and Metazoa making minor contributions. The prominence of Radiolaria decreased drastically in live traps, possibly due to selective consumption by copepods, heterotrophic nanoflagellates, and phaeodarians that were heavily enriched in these traps. These patterns were consistent across the water masses surveyed extending from the coast to offshore, despite major differences in productivity and trophic structure of the epipelagic plankton community. Our findings identify Radiolaria as major actors in export fluxes in the CCE