Extraction of wood compounds by use of subcritical fluids

A study of the extraction of oak wood compounds with subcritical water-ethanol mixtures as extractant, with an ethanol content between 0-60%, is reported. Identification and characterisation of the extracted compounds have been made by spectrophotometry and gas chromatography with either flame ionisation or mass detectors. Extraction was performed statically manner by use of a single cycle or repeated cycles. All variables affecting the extraction process were studied and optimised. Extraction time and temperature are 60 min and 200ºC, respectively. Comparison of the extract thus obtained with commercial extracts showed the former to be rich in compounds characteristic of the commercial extracts. The method enables manipulation of the extract composition by changing the temperature and water/ethanol ratio used. It is faster than the traditional procedures for obtaining wood extracts

Two-parameter determination in vinegar by a flow injection-pervaporation system

A flow-injection method (FI) for the sequential determination of ethanol and acetic acid in vinegar is reported. The determination of ethanol is based on the oxidation of the pervaporated ethanol by Cr2O7K2. The acetic acid is determined by an acid-base reaction with Thymol Blue as the indicator. Both reactions are monitored photometrically at 600 nm using a single detector. Optimisation studies and assessment of the sequential FI method are also reported. The linear determination range is between 0-12 % (v/v) for ethanol and 0-10 % (grams of acetic acid in 100 ml) for acetic acid. The sample throughput of the sequential manifold is 7 per hour. The new method has been applied to vinegar samples and the results obtained are in excellent agreement with those from the reference methods used in Spain

Semiautomatic flow-injection method for the determination of volatile acidity in wines

A flow-injection (FI) method based on analytical pervaporation was assessed for its routine use in the determination of volatile acidity in winery laboratories. The new method was compared with both the official method and the Mathieu method, which is most often used in Spanish wineries, by testing 30 different wines, including young and aged, and sweet and dry wines from Montilla-Moriles appellation d´origine. The robustness of the new method was established and then all three methods were studied in terms of range of linearity and regression of the calibration curve, repeatability, reproducibility, sensitivity, detection and quantification limits (LOD and LQ, respectively) and time of analysis. The FI method surpasses the Mathieu method in reproducibility and both the Mathieu and official methods in LOD and LQ and sensitivity; it also requires less personnel involvement and shorter analysis time. The statistical criteria established by the “Office International de la Vigne et du Vin” were applied to the data and the results obtained indicated that the differences between the analytical parameters of the 3 methods are not significant and can be applied indistinctly. The correlation of the methods was studied by taking them 2 by 2, and the corresponding equations, coefficients and deviations confirmed the statistical results. Thus, the new method can be used in winery laboratories with clear advantages over its 2 counterparts (the routine and official methods)

Sequential Spectrophotometric determination of methanol and iron in vinegar by a flow injection-pervaporation method

An easily automatable sequential flow-injection-pervaporation method is proposed for the photometric determination of methanol and iron in vinegar. The method is based on separation of the methanol from the sample matrix by pervaporation followed by its oxidation to formaldehyde with permanganate, decolouration of the latter with S2O5-2 and subsequent reaction of formaldehyde with p-rosaniline to yield a violet reaction product with maximum absorption at 567 nm. Iron is determined by an existing method based on reaction with thiocyanate in acidic medium and monitoring at 508 nm. After optimisation by either the univariate or multivariate approaches, as required, the linear range was established for methanol (4-1000 mg L-1) and iron (0.18-20 mg L-1); The proposed method was then compared with reference methods for methanol and iron in terms of repeatability (2.452 mg L-1 and 0.245 mg L-1, respectively), reproducibility (4.435 mg L-1 and 0.356 mg L-1, respectively), detection limit (LOD=82 and 0.234 mg L-1, respectively) and traceability. The throughput was nine samples per hour

Method for the simultaneous determination of total polyphenol and anthocyan indexes in red wines using a flow injection approach

A simultaneous and fast method for the determination of total polyphenol index (t.p.i.) and total anthocyan index (t.a.i.) has been developed by a flow injection approach and a diode array spectrophotometer for monitoring at 280 nm and 520 nm, respectively. Linear ranges were obtained from 20 to 70 index units and from 20 to 500 mg l-1 for t.p.i. and t.a.i., respectively. The results provided by the proposed method agree with those obtained using the polyphenol index at 280 nm and the Ribereau-Gayon method for the determination of total anthocyans. The sample throughput was 25-30 samples per hour. Analytical features such as repeatability, reproducibility and detection and quantification limits as well as the results of a robustness study based on the Steiner-Younden procedure are also given

Determination of ethanol in beverages by flow injection, pervaporation and density measurements

A fast, clean and easy to automate flow injection-pervaporation method for the determination of ethanol in different beverages using density measurements is proposed. The method is based on separation of the ethanol from the sample using a pervaporation module, thus obtaining in the acceptor chamber of the pervaporator a water-alcohol mixture, the density of which is measured. After optimisation by either the univariate or multivariate approach as required, a linear range between 0-40% was established. Then, the assessment of the method versus a reference one was studied in terms of repeatability (0.12% v/v), reproducibility (0.32% v/v), detection limit (0.11% v/v) and traceability. The sample throughput was 15 samples h-1. The method was in agreement with the reference methods used in the European Union

Superheated liquids for the extraction of solid residues from winemaking processes

Solid residues from winemaking process have been subjected to extraction with superheated water-ethanol mixtures. Identification and characterisation of the extracted compounds have been made by spectrophotometry, gas chromatography with either flame ionisation or mass detectors and high performance liquid chromatography with UV detection. The extraction has been performed in a static manner by single or repetitive cycles. All variables affecting the extraction process have been studied and optimised. The extraction time and temperature are 65 min and 210ºC, respectively. Two phases constitute the extract: an aqueous phase, which is rich in phenol compounds and an oily phase, mainly formed by fatty acids. The method allows manipulation of the extract composition by changing the applied pressure, temperature, water-ethanol ratio and pH. The method is faster than the traditional extraction procedures for obtaining valuable compounds from these residues

CODEA : an agent based multi-objective optimization framework

This work presents CODEA, a COoperative DEcentralized Architecture for Multiobjective Optimization. CODEA is an objectoriented framework that aims at the creation of groups of agents to tackle complex problems by cooperative search. This cooperation is carried out without any individual controlling the cooperation nor the behaviour of the agents. Each agent works on its own to improve itself and collaborates to improve the performance of the group by sharing information

Nature of real-world multi-objective vehicle routing with evolutionary algorithms

The Vehicle Routing Problem with Time Windows VRPTW) is an important logistics problem which in the realworld appears to be multi-objective. Most research in this area has been carried out using classic datasets designed for the single-objective case, like the well-known Solomon's problem instances. Some unrealistic assumptions are usually made when using these datasets in the multi-objective case (e.g. assuming that one unit of travel time corresponds to one unit of travel distance). Additionally, there is no common VRPTW multiobjective oriented framework to compare the performance of algorithms because different implementations in the literature tackle different sets of objectives. In this work, we investigate the conflicting (or not) nature of various objectives in the VRPTW and show that some of the classic test instances are not suitable for conducting a proper multi-objective study. The insights of this study have led us to generate some problem instances using d ata from a real-world distribution company. Experiments in these new dataset using a standard evolutionary algorithm NSGA-II) show stronger evidence of multi-objective features. Our contribution focuses on achieving a better understanding about the multi-objective nature of the VRPTW, in particular the conflicting relationships between 5 objectives: number of vehicles, total travel distance, makespan, total waiting time, and total delay time

Epothilone-d rescues cognition and attenuates alzheimer’s disease-like pathology in APP/PS1 mice

AIMS: Cognitive decline in Alzheimer's disease (AD) patients has been linked to synaptic damage and neuronal loss. Hyperphosphorylation of tau protein destabilizes microtubules leading to the accumulation of autophagy/vesicular material and the generation of dystrophic neurites, thus contributing to axonal/synaptic dysfunction. In this study, we analyzed the effect of a microtubule-stabilizing compound in the progression of the disease in the hippocampus of APP751SL/PS1M146L transgenic model. METHODS: APP/PS1 mice (3 month-old) were treated with a weekly intraperitoneal injection of 2 mg/kg epothilone-D (Epo-D) for 3 months. Vehicle-injected animals were used as controls. Mice were tested on the Morris water maze, Y-maze and object-recognition tasks for memory performance. Abeta, AT8, ubiquitin and synaptic markers levels were analyzed by Western-blots. Hippocampal plaque, synaptic and dystrophic loadings were quantified by image analysis after immunohistochemical stainings. RESULTS: Epo-D treated mice exhibited a significant improvement in the memory tests compared to controls. The rescue of cognitive deficits was associated to a significant reduction in the AD-like hippocampal pathology. Levels of Abeta, APP and ubiquitin were significantly reduced in treated animals. This was paralleled by a decrease in the amyloid burden, and more importantly, in the plaque-associated axonal dystrophy pathology. Finally, synaptic levels were significantly restored in treated animals compared to controls. CONCLUSION: Epo-D treatment promotes synaptic and spatial memory recovery, reduces the accumulation of extracellular Abeta and the associated neuritic pathology in the hippocampus of APP/PS1 model. Therefore, microtubule stabilizing drugs could be considered therapeutical candidates to slow down AD progression. Supported by FIS-PI12/01431 and PI15/00796 (AG),FIS-PI12/01439 and PI15/00957(JV)Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech