Degradação de α-Tocoferol, retinol e ácido ascórbico durante processamento e armazenamento de rações para camarão α-Tocopherol, retinol and ascorbic acid degradation during the processing and storage of shrimp food

O cultivo de camarão marinho é um setor de grande viabilidade econômica, principalmente na região Nordeste. Entretanto, a alimentação dos camarões é responsável pelo maior custo no cultivo desses crustáceos, a ração deve ser nutricionalmente eficiente, sendo indispensável a presença das vitaminas que são substâncias fundamentais para o funcionamento do organismo animal, e sua falta resulta frequentemente em crescimento e desenvolvimento deficiente. O retinol, -tocoferol e o ácido ascórbico são vitaminas que atuam em diversos processos metabólicos. São indispensáveis em rações animais porque são antioxidantes que auxiliam os animais contra o estresse oxidativo. Objetivou-se, neste trabalho, avaliar as perdas das vitaminas durante o processamento das dietas e no período de armazenagem. Foram formuladas oito dietas isoprotéicas com diferentes níveis de vitamina A, E e C que foram processadas com temperatura de até 80ºC. Após a fabricação e depois de 60 dias de armazenagem foram analisadas e quantificadas as vitaminas a fim de descobrir as perdas durante o processamento e após estocagem. Constatou-se que a vitamina A, que foi adicionada na dieta, foi perdida em até 99,56%. Já a vitamina E perdeu no máximo 93,5% e a vitamina C com 70% de perda, durante o processamento. Durante o período de armazenagem as perdas foram menores. Pode-se concluir que as vitaminas são extremamente sensíveis aos fatores que atuam durante a manufatura das dietas, ocasionando perdas consideráveis de vitaminas.<br>The farming of marine shrimp is a sector of great economic viability, mainly in the Northeast region of Brazil. However, feeding is responsible for the major cost in the farming of these crustaceans, so the food must be nutritiously efficient, since it is essential to the presence of vitamins which are vital substances to the functioning of the animal's organism where its lack frequently results in deficient growth and development. Retinol, -tocopherol, and ascorbic acid are vitamins that act in several metabolic processes, therefore they are indispensable in animal food due to their antioxidant effects that protect these animals against oxidative stress. The objective of this study was to evaluate the vitamin losses during the diet processing and in the storage period. Eight isoproteic diets were formulated with different levels of vitamin A, E and C that were processed with temperatures up to 70º C. After the production and 60 days of storage, the vitamins were analyzed and quantified in order to discover the losses during the processing and post-storage. It was observed that the vitamin A suffered loss of up to 99.56%, vitamin E had its maximum loss value of 93.5% and vitamin C with 70% of loss, during the processing. During the storage period the losses were lower. It can be concluded that the vitamins are extremely sensitive to the factors that occur during the production and food storage, causing considerable vitamin losses

Multi-messenger Observations of a Binary Neutron Star Merger

International audienceOn 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of ${40}_{-8}^{+8}$ Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 $\,{M}_{\odot }$. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at $\sim 40\,{\rm{Mpc}}$) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position $\sim 9$ and $\sim 16$ days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta