Oxidação lipídica em peixes: mecanismo de ação e prevenção.

A aquicultura é uma atividade destinada a produzir alimentos de alto valor nutritivo, porém suas condições ambientais e seu manejo aumentam as reações de estresse nos peixes, prejudicando a qualidade de seus produtos. A oxidação lipídica é uma das principais causas de deterioração do pescado, devido ao alto grau de insaturação dos ácidos graxos dos organismos aquáticos. Esta revisão descreve os principais mecanismos desencadeadores da oxidação lipídica, seus métodos de análise e algumas medidas preventivas, dando enfase à utilização in vivo da vitamina E como substância antioxidante em peixes

Comparison of a retrotransposon-based marker with microsatellite markers for discriminating accessions of Vitis vinifera.

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Restructured products from tilapia industry by products: the effects of tapioca starch and washing cycles.

The tilapia fileting industry generates large amounts of nutritionally significant waste material, and the recovery of this material is important. The manufacture of restructured products from mechanically recovered fish meat (MRFM) obtained from tilapia fileting allows the use of proteins of high biological value that would otherwise be discharged into the environment. The objective of this study was to evaluate the effect of washing cycles (either one cycle or five cycles) and of the addition of tapioca starch (20% vs. a no-starch control) on the characteristics of surimi obtained from MRFM produced by the tilapia industry and destined for use in restructured products. To evaluate the quality attributes of the product, the structure of a surimi protein matrix and its relationship to selected physicochemical parameters and morphological characteristics was assessed. Both the number of washing cycles and the starch addition were found to influence the moisture, protein and lipid content of the MRFM surimi. Higher whiteness was found after five washing cycles. Because the tapioca starch acted as a stabilizer, the fat globules were more stable and well distributed, and an emulsion with better properties resulted. A homogeneous network of fat globules linked to the protein matrix by a layer of tapioca starch was formed. Another advantage of this approach is that tapioca starch is gluten free. This property is important for specific groups in the population, e.g., celiac-intolerant consumers.Autoria na publicação: FABÍOLA HELENA FOGAÇA

Synergism in the antibacterial action of ternary mixtures involving silver nanoparticles, chitosan and antibiotics

The investigations of the antibacterial actions, observed in ternary associations involving silver nanoparticles (AgNPs), chitosan and the antibiotics azithromycin (AZ), levofloxacin (LE) or tetracycline (TE), against Gram-negative and Gram-positive bacterial strains, were performed by in vitro antimicrobial susceptibility testing and checkerboard assays. The pH impact in the culture medium was carefully discarded, but preserving the best conditions for solubilizing chitosan. The synergistic antibacterial effects were observed in the most combinations of AgNPs, chitosan and antibiotic, leading to a reduction from 37 to 97% in the minimum inhibitory concentration of the drugs. The mechanisms for the enhanced antimicrobial effects were proposed based on the investigations of the adsorptions of the drugs on the silver surfaces through surface-enhanced Raman scattering (SERS) spectroscopy.

Determinação de herbicidas usados no cultivo de arroz irrigado na região sul do estado de Santa Catarina através da SPME-GC-ECD

Evaluation of the pollution by the herbicides alachlor, propanil and atrazine in water samples from four rivers in the cities of Turvo and Meleiro, south of Santa Catarina State, was made using the SPME-GC-ECD method. The proposed method was optimized and validated. The correlation coefficients were higher than 0.997 and linear ranges of the analytical curves were 0.1-4; 0.1-2.5 and 0.1-5 µg L-1 for atrazine, alachlor and propanil, respectively. The herbicides were quantified by GC-ECD and identified by GC-MS. Both of the selected rivers presented contamination by at least one of the studied herbicides