152 research outputs found

    Optimization of walnut oil production

    Get PDF
    Walnut is recognized worldwide as a functional health food. In the walnut oil production it is very important to find an appropriate method to recover the oil from seeds. Walnut oil in this study was obtained by pressing the seeds followed by extraction with supercritical CO2. The effects of pressing temperature (70, 85, 100 °C), frequency (20, 30, 40 Hz) and nozzle size (8, 10, 12 mm) in pressing experiments on oil recovery and oil temperature were monitored. The optimal calculated pressing condition within the experimental range of the variables studied was determined. In obtained walnut oil the following parameters were analyzed: peroxide value, free fatty acids, insoluble impurities, moisture content, iodine value, saponification value, p-anisidine value and Totox value. The residual oil from pressed cake obtained at optimal conditions was extracted with CO2 with a goal to extract tocopherols residue from walnut after applied screw press process. Content of tocopherols in walnut oil obtained by pressing and oil extracted by supercritical CO2 were compared

    Optimization of walnut oil production

    Get PDF
    Walnut is recognized worldwide as a functional health food. In the walnut oil production it is very important to find an appropriate method to recover the oil from seeds. Walnut oil in this study was obtained by pressing the seeds followed by extraction with supercritical CO2. The effects of pressing temperature (70, 85, 100 °C), frequency (20, 30, 40 Hz) and nozzle size (8, 10, 12 mm) in pressing experiments on oil recovery and oil temperature were monitored. The optimal calculated pressing condition within the experimental range of the variables studied was determined. In obtained walnut oil the following parameters were analyzed: peroxide value, free fatty acids, insoluble impurities, moisture content, iodine value, saponification value, p-anisidine value and Totox value. The residual oil from pressed cake obtained at optimal conditions was extracted with CO2 with a goal to extract tocopherols residue from walnut after applied screw press process. Content of tocopherols in walnut oil obtained by pressing and oil extracted by supercritical CO2 were compared

    Spin models for orientational ordering of colloidal molecular crystals

    Get PDF
    Two-dimensional colloidal suspensions exposed to periodic external fields exhibit a variety of molecular crystalline phases. There two or more colloids assemble at lattice sites of potential minima to build new structural entities, referred to as molecules. Using the strength of the potential and the filling fraction as control parameter, phase transition to unconventional orientationally ordered states can be induced. We introduce an approach that focuses at the discrete set of orientational states relevant for the phase ordering. The orientationally ordered states are mapped to classical spin systems. We construct effective hamiltonians for dimeric and trimeric molecules on triangular lattices suitable for a statistical mechanics discussion. A mean-field analysis produces a rich phase behavior which is substantiated by Monte Carlo simulations.Comment: 19 pages, 21 figures; misplacement of Fig.3 fixe

    Modelling inactivation of Staphylococcus spp. on sliced Brazilian dry-cured loin with thermosonication and peracetic acid combined treatment

    Get PDF
    peer-reviewedUltrasound (US) has a high capacity to increase food safety. Although high and/or moderate temperature in combination with US has been studied, the knowledge about cooling/low temperatures as well as its combined effect with chemical preservation methods is scarce. Therefore, the aim of this study was to describe the inactivation of Staphylococcus spp. (SA) present in the natural microbiota of sliced Brazilian dry-cured loin (BDL) using US (40 kHz and 5.40 W/g) at 1.6–17.9 kJ/g, temperature (T) between 6.4 and 73.6 °C and peracetic acid (PA) between 5.5 and 274.5 mg/L employing the Central Composite Rotatable Design. The model fully describes how the combination of US, T, and PA affects SA inactivation. In BDL, an increase in US acoustic energy density (kJ/g) allows the reduction of T necessary to inactivate SA because of the occurrence of synergistic effect. However, US applied at low T was inefficient. On the other hand, PA was more efficient at low T, since high T degraded this compound at different rates according to the holding T. Therefore, the data indicates a relation between the technologies used in the combined decontamination of sliced BDL improving dry-cured meat safety

    N-terminal and mid-region tau fragments as fluid biomarkers in neurological diseases

    Get PDF
    Brain-derived tau secreted into CSF and blood consists of different N-terminal and mid-domain fragments, which may have a differential temporal course and thus, biomarker potential across the Alzheimer's disease continuum or in other neurological diseases. While current clinically validated total-tau (t-tau) assays target mid-domain epitopes, comparison of these assays with new biomarkers targeting N-terminal epitopes using the same analytical platform may be important to increase the understanding of tau pathophysiology. We developed three t-tau immunoassays targeting specific N-terminal (NTA and NTB t-tau) or mid-region (MR t-tau) epitopes, using single molecule array technology. After analytical validation, the diagnostic performance of these biomarkers was evaluated in CSF and compared with the Innotest t-tau (and as proof of concept, with N-p-tau181 and N-p-tau217) in three clinical cohorts (n = 342 total). The cohorts included participants across the Alzheimer's disease continuum (n = 276), other dementia (n = 22), Creutzfeldt-Jakob disease (n = 24), acute neurological disorders (n = 18) and progressive supranuclear palsy (n = 22). Furthermore, we evaluated all three new t-tau biomarkers in plasma (n = 44) and replicated promising findings with NTA t-tau in another clinical cohort (n = 50). In CSF, all t-tau biomarkers were increased in Alzheimer's disease compared with controls (P < 0.0001) and correlated with each other (rs = 0.53-0.95). NTA and NTB t-tau, but not other t-tau assays, distinguished amyloid-positive and amyloid-negative mild cognitive impairment with high accuracies (AUCs 84% and 82%, P < 0.001) matching N-p-tau217 (AUC 83%; DeLong test P = 0.93 and 0.88). All t-tau assays were excellent in differentiating Alzheimer's disease from other dementias (P < 0.001, AUCs 89-100%). In Creutzfeldt-Jakob disease and acute neurological disorders, N-terminal t-tau biomarkers had significantly higher fold changes versus controls in CSF (45-133-fold increase) than Innotest or MR t-tau (11-42-fold increase, P < 0.0001 for all). In progressive supranuclear palsy, CSF concentrations of all t-tau biomarkers were similar to those in controls. Plasma NTA t-tau concentrations were increased in Alzheimer's disease compared with controls in two independent cohorts (P = 0.0056 and 0.0033) while Quanterix t-tau performed poorly (P = 0.55 and 0.44). Taken together, N-terminal-directed CSF t-tau biomarkers increase ahead of standard t-tau alternatives in the Alzheimer's disease continuum, increase to higher degrees in Creutzfeldt-Jakob disease and acute neurological diseases and show better potential than Quanterix t-tau as Alzheimer's disease blood biomarkers. For progressive supranuclear palsy, other tau biomarkers should still be investigated

    N-terminal and mid-region tau fragments as fluid biomarkers in neurological diseases

    Get PDF
    Brain-derived tau secreted into CSF and blood consists of different N-terminal and mid-domain fragments, which may have a differential temporal course and thus, biomarker potential across the Alzheimer’s disease continuum or in other neurological diseases. While current clinically validated total tau assays target mid-domain epitopes, comparison of these assays with new biomarkers targeting N-terminal epitopes using the same analytical platform may be important to increase the understanding of tau pathophysiology. We developed three total tau immunoassays targeting specific N-terminal (NTA and NTB total tau) or mid-region (MR total tau) epitopes, using single molecule array technology. After analytical validation, the diagnostic performance of these biomarkers was evaluated in CSF and compared with the Innotest total tau (and as proof of concept, with N-p-tau181 and N-p-tau217) in three clinical cohorts (n = 342 total). The cohorts included participants across the Alzheimer’s disease continuum (n = 276), other dementias (n = 22), Creutzfeldt–Jakob disease (n = 24), acute neurological disorders (n = 18) and progressive supranuclear palsy (n = 22). Furthermore, we evaluated all three new total tau biomarkers in plasma (n = 44) and replicated promising findings with NTA total tau in another clinical cohort (n = 50). In CSF, all total tau biomarkers were increased in Alzheimer’s disease compared with controls (P </p
    corecore