55 research outputs found

    Recovery of Natural Antioxidants from Fruit Juice Industry Residuals by Ultrasound-Assisted Extraction and Response Surface Methodology

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    Fruit processing industries produce by-products that are good sources of natural antioxidants. These residuals are non-toxic and available in large quantities. A central composite design (CCD) and response surface methodology (RSM) were used to optimize experimental conditions. The processing variables were solvent type, solvent to solid ratio, ethanol concentration, temperature, and time. The responses were total phenolic content (TPC), scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, and yield. The optimal conditions were 70% ethanol— water mixture as a food grade solvent, temperature of 35 °C and extraction time 60 min for obtaining extracts with maximum of total phenolic content. Predicted values for total phenolic content in pear, apricot, and peach were 24.7, 19.3, and 10.4 mg gallic acid equivalents per 100 g fruit residual, respectively

    Crude oil yield and properties of rice bran oil from different varieties as affected by extraction conditions using soxhterm method

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    The current study was employed to investigate the effect of solvent type, extraction time and bran ratio on the rice bran oil (RBO) properties from three varieties of rice bran namely Bario, lowland and upland rice. RBO was extracted by using soxtherm extraction method using methanol solvent at different extraction time (3, 4 and 5 h) and bran ratio (10, 20 and 30 g). Free fatty acid (FFA), total phenolic content (TPC) and antioxidant properties were assessed. Solvent that has low polarity exhibited the attraction of polar component of oil with the highest yield by ethanol (16.16%), followed by methanol (15.38%). FFA contents occurred higher in lowland types of rice bran in all types of solvents at P<0.05 with ethanol (12.73%), methanol (11.96%) and hexane (11.13%), while the total phenolic content and antioxidant properties were influenced by the types of rice bran and solvents used for extracting components out of the bran. The highest phenolic content in the crude oil was extracted using ethanol in lowland (0.509 mg/ml), and the lowest was extracted by hexane in Bario (0.061 mg/ml). The highest antioxidant activity was observed in RBO extracted using methanol of lowland (73.74%) and RBO extracted using ethanol of upland (73.65%), while the lowest were observed in RBO extracted using hexane. The different types of solvent have the significant impact on the crude oil yield and properties of crude oil extracted

    The influence of solid state information and descriptor selection on statistical models of temperature dependent aqueous solubility.

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    Predicting the equilibrium solubility of organic, crystalline materials at all relevant temperatures is crucial to the digital design of manufacturing unit operations in the chemical industries. The work reported in our current publication builds upon the limited number of recently published quantitative structure-property relationship studies which modelled the temperature dependence of aqueous solubility. One set of models was built to directly predict temperature dependent solubility, including for materials with no solubility data at any temperature. We propose that a modified cross-validation protocol is required to evaluate these models. Another set of models was built to predict the related enthalpy of solution term, which can be used to estimate solubility at one temperature based upon solubility data for the same material at another temperature. We investigated whether various kinds of solid state descriptors improved the models obtained with a variety of molecular descriptor combinations: lattice energies or 3D descriptors calculated from crystal structures or melting point data. We found that none of these greatly improved the best direct predictions of temperature dependent solubility or the related enthalpy of solution endpoint. This finding is surprising because the importance of the solid state contribution to both endpoints is clear. We suggest our findings may, in part, reflect limitations in the descriptors calculated from crystal structures and, more generally, the limited availability of polymorph specific data. We present curated temperature dependent solubility and enthalpy of solution datasets, integrated with molecular and crystal structures, for future investigations

    In vitro and in situ Ruminal Degradability of Oak Leaves (Quercus persica) as Affected by Growth Stage during Spring Season and Polyethylene Glycol Application

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    This study was conducted to identify the nutritive and anti-nutritive composition, in situ rumen degradabil-ity, and the kinetics of in vitro gas production of Persian oak (Quercus persica) leaves harvested at three growth stages during the spring season. A tannin bioassay was also performed using polyethylene glycol (PEG 6000) as a tannin-complexing agent in a gas production test. Leaves were harvested in monthly inter-vals in spring, starting on April when leaves were at the early vegetative stage, and then May and June. As the leaf maturity progressed, crude protein decreased but total phenols, total tannins, and hydrolysable tan-nins increased. Condensed tannin concentration was not affected by maturity stage (Average=13.0 mg leu-cocyanidin equivalent/g dry matter (DM)). As leaf maturity increased, the rapidly degradable A fraction of DM increased. In vitro gas production, metabolizable energy, in vitro DM degradability, ruminal NH3-N, and short-chain fatty acid concentrations were greatest in leaves harvested at the early vegetative stage (April) compared with other months. Application of PEG increased in vitro gas production, metabolizable energy, in vitro DM degradability, and NH3-N and short-chain fatty acid production in the rumen fluid compared with no addition of PEG. Overall, oak leaves harvested at the early vegetative stage appeared to be a good source of forage for ruminants. However, as leaf maturity increased, ruminal fermentability de-creased, which was improved with PEG addition

    Molecular- and organelle-based predictive paradigm underlying recovery by left ventricular assist device support

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    Je suis convaincu que d’une certaine manière tout texte est autobiographique…Jacques Derrida Qu’est-ce qu’une biographie pour un philosophe ? Heidegger a dit d’Aristote : « il naquit, il travailla, il mourut ». Il souligne ainsi que les faits biographiques n’ont pas beaucoup d’importance pour la pensée. Il en est de même dans la littérature. Depuis Proust, une étude biographique à la manière de Lanson est considérée comme plus nuisible qu’utile pour la compréhension d’une œuvre littéraire. Or..
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