1,243 research outputs found

    Understanding olive oil stability using filtration and high hydrostatic pressure

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    Veiled extra virgin olive oil (VEVOO) is very attractive on the global market. A study was performed to highlight the role of different amounts of water and microorganisms on the evolution of VEVOO quality during storage, using the selective effects of the application of individual or combined filtration and high hydrostatic pressure (HHP) treatments. Four oil processing trials were carried out in four replicates, resulting in a full factorial design with two independent fixed factors: filtration and HPP treatments. The turbidity of all the olive oil samples was characterized. Furthermore, all the olive oil samples were analysed for legal parameters, volatile organic compounds and phenolic compounds during the storage tests. The microbial contamination in the presence of a high level of water activity (>0.6 Aw) was related to the formation of volatile aroma compounds, which were responsible for the \u201cfusty\u201d sensory defect. Furthermore, high water activity values were related to an increase in the hydrolytic degradation rate of the phenolic compounds. The oil turbidity has to be planned and controlled, starting from adjustment of the water content and application of good manufacturing practices

    Filtration scheduling: Quality changes in freshly produced virgin olive oil

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    Filtration is the most widespread stabilisation operation for extra virgin olive oil, preventing microbial and enzymatic changes. However, during the harvest, the workload of olive mills is at its peak. This results in two approaches to filtration: (i) delays it until after harvesting, increasing the risk of degraded oil quality, and (ii) filters it immediately, increasing the workload. The aim of our experiment is to assess the risk of delaying filtration and establish a safe delay time. Changes in the sensory profile and volatile compound contents were evaluated during 30 days in filtered and unfiltered samples. Significant differences were related to filtration: both turbidity grade and microbial contamination; no differences for the legal parameters were found. Two, contrasting, results were obtained with respect to oil quality: (i) the fusty defect, appearing in less than five days in unfiltered oils, leading to the downgrade of the oil\u2019s commercial category, and (ii) filtration removing some lipoxygenase volatile compounds. Consequently, a fruity attribute was more pronounced in unfiltered samples until day five of storage; it seems that, from this point, the fusty defect masked a fruity attribute. Hence, filtering within a few days strongly reduced the risk of degraded oil quality compared to a delayed filtration

    A combined crystallographic and computational study on dexketoprofen trometamol dihydrate salt

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    Dexketoprofen trometamol is the tromethamine salt of dexketoprofen [(2S)-2-(3-benzoylphenyl)propanoic acid-2-amino-2-(hydroxymethyl)propane-1,3-diol], a nonsteroidal anti-inflammatory drug (NSAID) used for the treatment of moderate- to strong-intensity acute pain. The crystal structure of the hitherto sole known hydrate phase of dexketoprofen trometamol (DK-T_2H2O), as determined by single-crystal X-ray diffraction, is presented. The water molecules are arranged in dimers included in isolated sites and sandwiched between piles of trometamol cations. The molecular and crystal structures of DK-T_2H2O are analyzed and compared to those of the parent anhydrous crystal form DK-T_A. In both the crystal structures, all the potential H-bond donors and acceptor of the dexketoprofen and trometamol ions are engaged, and both the species crystallize in the P21 space group. However, during the DK-T_A➔DK-T_2H2O hydration process, the unique symmetry axis is not conserved, i.e., the ions are arranged in a different way with respect to the screw axis, even if the two crystal structures maintain structural blocks of DK anions and T cations. Quantum mechanical solid-state calculations provide some hints for the possible intermediate structure during the crystalline–crystalline hydration/dehydration process

    Surto epidêmico da mancha foliar causada por Cylindrocladium spp e sua relação com o crescimento de espécies/procedências de Eucalyptus na região de Tucurui, PA.

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    Plantios experimentais com 15-18 meses de idade de diferentes especies/procedencias de Eucalyptus implantados na regiao de Tucurui,PA, foram atingidos por um surto epidemico de uma mancha foliar associada a varias especies de Cylindrocladium, no periodo chuvoso de 1988. Avaliacao da doenca no campo revelou grande variacao de resistencia entre especies/procedencias testadas. Algumas que apresentaram de moderado a intenso desfolhamento,como E.citriodora Anhembi e E.tereticornis Anhembi, tiveram a sua taxa de crescimento reduzida e um aumento de falhas associado a doenca. Outras especies/procedencias, como E.urophylla Anhembi (Flores) e E.terelliana Anhembi, com pouca ou nenhuma doenca, tiveram,ao contrario, a sua taxa de crescimento mantida ou ate acelerada no periodo de ocorrencia da epidemia. Com a diminuicao das chuvas, as especies/procedencias mais afetadas mostraram, no entanto, recuperacao na sua taxa de crescimento

    Further studies on pyrazolo[1',5':1,6]pyrimido[4,5-d]pyridazin-4(3H)-ones as potent and selective human A1 adenosine receptor antagonists.

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    A new series of pyrazolo[1',5':1,6]pyrimido[4,5-dlpyridazin-4(3H)-ones was synthesized and tested in radioligand binding assays on human A(1), A(2A) and A(3) adenosine receptors. Most of the compounds showed high selectivity of action towards A(1) receptor and high affinity with K-i values in the low nanomolar range. The pharmacological profile of the most active molecules towards A(1) adenosine receptors was evaluated in cAMP functional assay. Compounds demonstrated their ability to completely counteract the effect of the agonist NECA, thus demonstrating their antagonist profile. Moreover, the most interesting compound, tested in the mouse passive avoidance, exhibited an antiamnesic effect at the doses of 10 and 30 mg/kg. (C) 2014 Published by Elsevier Masson SAS
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