La investigación universitaria impulsa la economía rural

La Voz de Galicia, 13 de octubre de 2015

El CIA desarrolló en 5 años 22 proyectos agroambientales y alimentarios.

La investigación universitaria se está convirtiendo en un elemento dinamizador del desarrollo rural sostenible, favoreciendo la revalorización de los recursos del territorio por su contribución a las diferentes actividades de las industrias agroalimentarias.

Esta repercusión socioeconómica en una provincia desangrada demográficamente es una de las consideraciones de la última memoria del Centro de Investigacións Agroambientais e Alimentarias (CIA), una agrupación estratégica de investigación universitaria -la única gallega en un campus periférico- que cuenta con financiación de la Consellería de Cultura, Educación e Ordenación Universitaria.

De las ocho agrupaciones estratégicas de investigación con financiación autonómica, tres versan sobre nuevas tecnologías; dos sobre medicina; una sobre química y otra sobre el mar. La ourensana, dirigida por Jesús Simal, es la única que vincula los ámbitos ambiental, agrario y alimentario en la cadena de producción de alimentos. Es en ese terreno en el que está llamada a ser «unha peza chave para o futuro exitoso do sector agroalimentario» y un apoyo para proyectos económicos de éxito que asienten población en la geografía rural gallega.

Constituido por grupos de investigación del CITI (Centro de Investigación, Transferencia e Innovación, de la Tecnópole), la Facultad de Ciencias de Ourense y la Facultad de Bioloxía de Vigo, el CIA reúne a varias decenas de investigadores. Trabajan en torno a tres ejes: la producción primaria sostenible, el desarrollo de nuevos productos y la calidad y seguridad alimentaria.

Su participación en programas de formación y la investigación cooperativa y multidisciplinar son dos de sus fortalezas. Incrementar la transferencia de los resultados de sus investigaciones al sector público y al privado, y aumentar su presencia en proyectos internacionales, son sus retos.

Colaboración con empresas

La repercusión de sus investigaciones queda patente con los programas de colaboración con 38 empresas alimentarias con interés en productos como aceite, agua, pescado, aves, galletas, bebidas alcohólicas, lácteos, carnes, platos preparados, pan o surimi. Esa colaboración con el sector empresarial ha dado lugar a numerosos proyectos de investigación y ha supuesto una fuente de financiación a mayores, ya que el 34% de los fondos del centro entre 2012 y 2014 procedía de firmas privadas.

Los acuerdos de transferencia y explotación de las investigaciones han dado resultados concretos, como el diseño de procedimientos para obtener aguardiente de castañas y el de un extracto gelificable de proteínas a partir del agua de cocción de pescado, así como la composición para aumentar el contenido proteico en carne de pescado y el procedimiento para su aplicación.

Manufacture of furfural in biphasic media made up of an ionic liquid and a co-solvent

Industrial Crops and Products, 77, 163-166 (2015)

DOI: 10.1016/j.indcrop.2015.08.048

Xylose was converted into furfural operating in a medium containing the acidic ionic liquid (AIL) 1-butyl-3-methylimidazolium hydrogen sulfate, in the presence of toluene as a co-solvent. No catalytic species different from the AIL were needed for furfural production from xylose. Operating at 100-140. °C for 15-480. min in media containing 10. g xylose/100. g AIL and 2-4. g toluene/g (AIL. +. xylose), most furfural generated in the AIL phase was transferred to the co-solvent, limiting the losses caused by undesired side reactions. Operating under optimal conditions (140. °C for 240. min using 4.4. g toluene/g initial AIL phase), xylose was almost completely consumed, and furfural was obtained at 73.8% of the stoichiometric yield.

Agricultural residue valorization using a hydrothermal process for second generation bioethanol and oligosaccharides production

Bioresource Technology, 191, 263-270 (2015)

DOI: 10.1016/j.biortech.2015.05.035

In the present work, the hydrothermal valorization of an abundant agricultural residue has been studied in order to look for high added value applications by means of hydrothermal pretreatment followed by fed-batch simultaneous saccharification and fermentation, to obtain oligomers and sugars from autohydrolysis liquors and bioethanol from the solid phase. Non-isothermal autohydrolysis was applied to barley straw, leading to a solid phase with about a 90% of glucan and lignin and a liquid phase with up to 168gkg-1 raw material valuable hemicellulose-derived compounds. The solid phase showed a high enzymatic susceptibility (up to 95%). It was employed in the optimization study of the fed-batch simultaneous saccharification and fermentation, carried out at high solids loading, led up to 52gethanol/L (6.5% v/v). 

Simple and efficient furfural production from xylose in media containing 1-butyl-3-methylimidazolium hydrogen sulfate

Industrial and Engineering Chemistry Research, 54, 8368-8373 (2015)

DOI: 10.1021/acs.iecr.5b01771

The acidic 1-butyl-3-methylimidazolium hydrogen sulfate ([bmim][HSO4]) ionic liquid was explored as both a reaction medium and a catalyst in the furfural production from xylose. Preliminary experiments were carried out at 100-140 °C for 15-480 min in systems containing just xylose dissolved in [bmim][HSO4] in the absence of externally added catalysts. More than 95% xylose conversion was achieved when operating at 120 or 140 °C for 300 and 90 min, respectively; but just 36.7% of the initial xylose was converted to furfural. Operation in biphasic reaction systems (in the presence of toluene, methyl-isobutyl ketone or dioxane as extraction solvents) at 140 °C under selected conditions resulted in improved furfural production (73.8%, 80.3%, and 82.2% xylose conversion to furfural for the cited extraction solvents, respectively). 

Biomass, sugar, and bioethanol potential of sweet corn

GCB Bioenergy, 7, 153-160 (2015)

DOI: 10.1111/gcbb.12136

Sweet corn is a widely distributed crop that generates agricultural waste without significant commercial value. In this study, we show that sweet corn varieties produce large amounts of residual biomass (10 t ha-1) with high content of soluble sugars (25% of dry matter) in a short growing season (3 months). The potential ethanol production from structural and soluble sugars extracted from sweet corn stover reached up to 4400 l ha-1 in the most productive hybrids, 33% of which (1500 l ha-1) were obtained by direct fermentation of free sugars. We found wide genetic variation for biomass yield and soluble sugars content suggesting that those traits can be included as complementary traits in sweet corn breeding programs. Dual-purpose sweet corn hybrids can have an added value for the farmers contributing to energy generation without affecting food supply or the environment.

Barley straw (Hordeum vulgare) as a supplementary raw material for Eucalyptus camaldulensis and Pinus sylvestris kraft pulp in the paper industry

BioResources, 10 (2) 3682-3693 (2015)

DOI: 10.15376/biores.10.2.3682-3693

The present study shows that barley straw (Hordeum vulgare) can be a supplementary raw material of softwoods and hardwoods such as Pinus sylvestris and Eucalyptus camaldulensis, respectively, for the production of cellulose and paper, reducing an agricultural residue that has no added value. Barley straw has a lower content of cellulose at 36.4% than P. sylvestris and E. camaldulensis, but it contains a lower quantity of lignin, 15.9%. After pulping with soda anthraquinone (AQ), high contents of cellulose (56.5 to 67.5%) and holocellulose (>80%) were attained. Paper sheet properties were able to reach, and even improve upon, those of wood species (Pinus and Eucalyptus) pulped with kraft. Better values of total yield (56.5%), Kappa number (8.9), and ISO brightness (36.4%), were attained for paper sheets from barley straw pulp versus E. camaldulensis and P. sylvestris, respectively, and comparable values for viscosity, tensile, and burst index were obtained.

A new method for determining the sources of airborne particles

Journal of Environmental Management

DOI: 10.1016/j.jenvman.2015.03.037

Air quality is a major issue for humans owing to the fact that the content of particles in the atmosphere has multiple implications for life quality, ecosystem dynamics and environment. Scientists are therefore particularly interested in discovering the origin of airborne particles. A new method has been developed to model the relationship between the emission surface and the total amount of airborne particles at a given distance, employing olive pollen and olive groves as examples. A third-degree polynomial relationship between the air particles at a particular point and the distance from the source was observed, signifying that the nearest area to a point is not that which is most correlated with its air features. This work allows the origin of airborne particles to be discovered and could be implemented in different disciplines related to atmospheric aerosol, thus providing a new approach with which to discover the dynamics of airborne particles.

Voltammetric analysis of mancozeb and its degradation product ethylenethiourea

Journal of Electroanalytical Chemistry

doi:10.1016/j.jelechem.2015.08.030

The purpose of this work was to develop a reliable alternative method for the determination of the dithiocarbamate pesticide mancozeb (MCZ) in formulations. Furthermore, a method for the analysis of MCZ's major degradation product, ethylenethiourea (ETU), was also proposed. Cyclic voltammetry was used to characterize the electrochemical behaviour of MCZ and ETU, and square-wave adsorptive stripping voltammetry (SWAdSV) was employed for MCZ quantification in commercial formulations.

It was found that both MCZ and ETU are irreversibly reduced (−0.6 V and −0.5 V vs Ag/AgCl, respectively) at the surface of a glassy carbon electrode in a mainly diffusion-controlled processes, presenting maximum peak current intensities at pH 7.0 (in phosphate buffered saline electrolyte).

Several parameters of the SWAdSV technique were optimized and linear relationships between concentration and peak current intensity were established between 10–90 μmol L-1 and 10–110 μmol L-1 for MCZ and ETU, respectively. The limits of detection were 7.0 μmol L-1 for MCZ and 7.8 μmol L-1 for ETU. The optimized method for MCZ was successfully applied to the quantification of this pesticide in two commercial formulations. The developed procedures provided accurate and precise results and could be interesting alternatives to the established methods for quality control of the studied products, as well as for analysis of MCZ and ETU in environmental samples.

High-throughput HPLC–MS/MS determination of the persistence of neonicotinoid insecticide residues of regulatory interest in dietary bee pollen

Analytical and Bioanalytical Chemistry

DOI 10.1007/s00216-015-8870-4

The aim of this work is the development of a simple, fast, quantitative, and economic method for the determination of neonicotinoid insecticide residues in dietary bee pollen. Several parameters of the method, such as extraction solvent, extraction time, and solid-phase extraction sorbents for purification [silica, C18, primary–secondary amine (PSA), and Envi-Carb II/PSA], were studied. The final proposed method based on solid–liquid extraction with hexane, cleanup with Supelclean™ Envi-Carb II/PSA cartridges, and subsequent analysis by high-performance liquid chromatography with tandem mass spectrometry was validated and applied to the analysis of commercial bee pollen samples from different geographical zones. Method performance was assessed by the evaluation of several quality parameters of the method, such as recovery values, repeatability, reproducibility, linearity, and limits of detection and quantification. Matrix effects on the chromatographic signal were also studied. The quality parameters of the method were equivalent to or better than those obtained with previously published methods, with recoveries between 81 and 99 % and repeatabilities lower than 8.8 %. The detection and quantification limits were in the ranges 0.2-2.2 μg kg-1 and 0.4-4.3 μg kg-1, respectively.

Thirty-four identifiable airborne fungal spores in Havana, Cuba

Annals of Agricultural and Environmental Medicine

DOI: 10.5604/12321966.1152068

The airborne fungal spore content in Havana, Cuba, collected by means a non-viable volumetric methodology, was studied from November 2010 – October 2011. The study, from a qualitative point of view, allowed the characterization of 29 genera and 5 fungal types, described following the Saccardo´s morphotypes, as well as their morphobiometrical characteristics. In the amerospores morphotype, the conidia of 7 genera (with ascospores, basidiospores and uredospores) and 5 fungal types were included. Among phragmospores morphotype, the ascospores and conidia of 12 different genera were identified. The dictyospores morphotype only included conidial forms from 6 genera. Finally, the less frequent morphotypes were staurospores, didymospores and distosepted spores. In general, the main worldwide spread mitosporic fungi also predominated in the Havana atmosphere, accompanied by some ascospores and basidiospores. Cladosporium cladosporioides type was the most abundant with a total of 148,717 spores, followed by Leptosphaeria, Coprinus and the Aspergillus-Penicillium type spores, all of them with total values ranging from 20,591 – 16,392 spores. The higher monthly concentrations were registered in January (31,663 spores) and the lowest in December (7,314 spores). Generally, the average quantity of spores recorded during the months of the dry season (20,599 spores) was higher compared with that observed during the rainy season (17,460 spores).

Challenges in Relating Concentrations of Aromas and Tastes with Flavour Features of Foods

Critical Reviews in Food Science and Nutrition

DOI: 10.1080/10408398.2015.1048775

Flavour sensations in food are highly influenced by the aroma and taste compounds. Reviewing the extensive literature of recent years in this field has shown that the reconstitution of flavour based on aroma and taste compounds poses numerous problems. These are of different nature and include among others (a) chemical transformations among these compounds, (b) changes in the concentrations of the compounds responsible for the perceived flavour, (c) interactions among the chemical compounds that enhance or reduce a specific flavour sensation, and finally, (d) the complexity of the different food matrices and its influence in the flavour perception. Another difficulty that flavour scientists must face is how to properly model and visualize the complex relationships existing between the chemical composition of foods and the flavour perception. These problems have repercussions on the reconstitution of the flavour signature of food based on the natural concentrations of its key aroma and taste compounds. Therefore, the main aim of this review is to deal with all these issues to propose potential solutions for a robust transformation in a science-based quality approach.

Linear Polyethers as Additives for AOT-Based Microemulsions: Prediction of Percolation Temperature Changes Using Artificial Neural Networks

Tenside Surfactants Detergents: 52 (2015) 264-270.
doi: 10.3139/113.110374

 

Predictive models based on artificial neural networks have been developed for the percolation threshold of AOT based microemulsions with addition of either glymes or polyethylene glycols. Models have been built according to the multilayer perceptron architecture, with five input variables (concentration, molecular mass, log P, number of C and O of the additive). Best model for glymes has a topology of five input neurons, five neurons in a single hidden layer and one output neuron. Polyethylene glycol model's architecture consists in five input neurons, three hidden layers with eight neurons in both first two and five in the last, and a neuron in the last output layer. All of them have a good predictive power according to several quality parameters.

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Higher peroxidase activity, leaf nutrient contents and carbon isotope composition changes in Arabidopsis thaliana are related to rutin stress

Journal of Plant Physiology

DOI: 10.1016/j.jplph.2014.05.009

Rutin, a plant secondary metabolite that is used in cosmetics and food additive and has known medicinal properties, protects plants from UV-B radiation and diseases. Rutin has been suggested to have potential in weed management, but its mode of action at physiological level is unknown. Here, we report the biochemical, physiological and oxidative response of Arabidopsis thaliana to rutin at micromolar concentrations. It was found that fresh weight; leaf mineral contents (nitrogen, sodium, potassium, copper and aluminum) were decreased following 1 week exposure to rutin. Arabidopsis roots generate significant amounts of reactive oxygen species after rutin treatment, consequently increasing membrane lipid peroxidation, decreasing leaf Ca2+, Mg2+, Zn2+, Fe2+ contents and losing root viability. Carbon isotope composition in A. thaliana leaves was less negative after rutin application than the control. Carbon isotope discrimination values were decreased following rutin treatment, with the highest reduction compared to the control at 750μM rutin. Rutin also inhibited the ratio of CO2 from leaf to air (ci/ca) at all concentrations. Total protein contents in A. thaliana leaves were decreased following rutin treatment. It was concluded carbon isotope discrimination coincided with protein degradation, increase lipid peroxidation and a decrease in ci/ca values may be the primary action site of rutin. The present results suggest that rutin possesses allelopathic potential and could be used as a candidate to develop environment friendly natural herbicide.

Modeling the batch bacteriocin production system by lactic acid bacteria by using modified three-dimensional Lotka-Volterra equations

Biochemical Engineering Journal

DOI: 10.1016/j.bej.2014.04.010

Different batch cultures of Lactococcus lactis CECT 539, a nisin-producing strain, were carried out in culture media prepared with whey and mussel processing wastes. From these cultures, a reasonable system of differential equations, similar to the three-dimensional Lotka-Volterra two predators-one prey model, was set up to describe, for the first time, the relationship between the absolute rates of growth, pH drop and nisin production.Thus, the nisin production system was described as a three-species (pH, biomass and nisin) ecosystem. In this case, both nisin and biomass production were considered as two pH-dependent species that compete for the nitrogen source. Excellent agreement (R2 values ≥0.9885) resulted between model predictions and the experimental data, and significant values for all the model parameters were obtained. The developed model was demonstrated (R2 values ≥0.9874) for five batch cultivations of the strains L. lactis CECT 539 in MRS broth and Lactobacillus sakei LB 706 (sakacin A producer), Pediococcus acidilactici LB42-923 (pediocin AcH producer), L. lactis ATCC 11454 (nisin producer) and Leuconostoc carnosum Lm1 (leuconocin Lcm1 producer) in TGE broth. These results suggest that the batch bacteriocin production system in these culture media can be successfully described by using the Lotka-Volterra approach.

Assessment of potential probiotic properties and multiple bacteriocin encoding-genes of the technological performing strain Enterococcus faecium MMRA

Food Control

DOI: 10.1016/j.foodcont.2013.09.044

In the present study, Enterococcus faecium MMRA, a safety and technological performing strain, previously isolated from a well-known fermented dairy product of Tunisia, was evaluated for certain properties relevant to probiotic including acid and bile tolerance, gastrointestinal juice resistance and adhesive properties. Acidic pH (2.0-5.0) and bile salt concentrations of 0.3% were used as stress conditions. The adhesive properties were assessed by determination of bacterial hydrophobicity. The strain MMRA showed interesting features such as high tolerance to gastrointestinal tract transit, an extremely high survival rates under stress caused by acidic pHs or bile salts, and a high adhesive potential linked to the elevated percentage of hydrophobicity. Furthermore, the genome of this strain was examined for the occurrence of known enterocin (enterococcal bacteriocins) genes by means of specific PCR assays and this study revealed the genes coding for enterocins A, B, P and X. Although the joint production of these bacteriocins has not been verified, producers of multiple enterocins could have a great technological potential as protective and/or probiotic cultures in the food industry. The results suggested that E.faecium MMRA should be considered as a potential probiotic which meets the criteria to enhance healthy attributes of fermented dairy product besides both of hygienic and sensory aspects.

Cr(VI) sorption/desorption on pine sawdust and oak wood ash

International Journal of Environmental Research and Public Health

DOI: 10.3390/ijerph120808849

The objective of this work was to study Cr(VI) sorption/desorption on two by-products from the wood industry: pine sawdust and oak wood ash. The retention/release experiments were carried out using standard batch-type trials. In the sorption-phase experiments, pine sawdust showed 23% sorption when a concentration of 100 mg Cr(VI)·L-1 was added, whereas sorption on oak wood ash was 17%. In the desorption-phase, chromium release was clearly higher from pine sawdust than from oak wood ash (98% and 66%, respectively). Sorption curves were well fitted to the Freundlich and Lineal models. In view of the results, both materials can be considered of very limited value to remove Cr from polluted soil and water, which can be of relevance regarding its appropriate use as biosorbents and recycled by-products.

Metalaxyl mobility in acid soils: Evaluation using different methods

International Journal of Environmental Science and Technology 

DOI: 10.1007/s13762-014-0612-1

In the present work, different methods were tested to evaluate the adsorption and desorption of metalaxyl in two acid soils with different organic carbon and clay contents. The three methods (batch, stirred flow chamber and column) that were examined produced similar findings when the two soils were compared: (a) the metalaxyl adsorption capacity was higher in the soil with higher organic matter and clay content, and (b) the soil with the lower organic matter and clay contents provided higher adsorption rate constants. In the two soils tested, the metalaxyl adsorbed in the soil was highly reversible. When only one soil was considered, the different methods yielded different results. The metalaxyl adsorption and its rate were higher with the stirred flow chamber than in the column experiments, and in the column experiments, the total metalaxyl adsorption and the rate of adsorption were higher than in the batch experiments. The percentages of metalaxyl desorbed from the soil were similar in the stirred flow chamber and column experiments, but in the batch experiments, the percentages were significantly lower. In the stirred flow chamber experiments, the desorption processes were faster than the adsorption processes, while in the column experiments, the adsorption and desorption processes exhibited similar rates.

Time evolution of the general characteristics and Cu retention capacity in an acid soil amended with a bentonite winery waste

Journal of Environmental Management

DOI: 10.1016/j.jenvman.2014.12.024

The effect of bentonite waste added to a "poor" soil on its general characteristic and copper adsorption capacity was assessed. The soil was amended with different bentonite waste concentrations (0, 10, 20, 40 and 80Mgha-1) in laboratory pots, and different times of incubation of samples were tested (one day and one, four and eight months). The addition of bentonite waste increased the pH, organic matter content and phosphorus and potassium concentrations in the soil, being stable for P and K, whereas the organic matter decreased with time. Additionally, the copper sorption capacity of the soil and the energy of the Cu bonds increased with bentonite waste additions. However, the use of this type of waste in soil presented important drawbacks for waste dosages higher than 20Mgha-1, such as an excessive increase of the soil pH and an increase of copper in the soil solution.

Heavy metals in pastureland soils situated in A Pastoriza (NW Spain) treated with cattle slurry and NPK fertilizers

Spanish Journal of Soil Science, 5, 154-164 (2015)

DOI: 10.3232/SJSS.2015.V5.N2.05

In Galicia (NW Spain), pasturelands cover a broad extension and are mainly used to feed cattle. Farms are managed in an intensive manner, using cattle slurry and inorganic fertilizers to increase pasture production, but also increasing risks of heavy metal pollution. In this work we studied the influence of fertilization practices on total concentrations and in-depth distribution of heavy metals and related elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) in two forest soils (SN1, SN2) and five pastureland soils (P1-P5) fertilized with cattle slurry and NPK, in a broadly exploded farmland area (A Pastoriza, Lugo). Soils SN2 and P4 were developed over slate, whereas soils SN1, P1, P2, P3 and P5 evolved on Candana quartzite. Forest soils presented acid pH (4.58-4.68), high Al saturation (75-90%), and low available P concentration (4.78-11.96 mg kg-1), whereas those parameters exhibited better scores in the pastureland soils, due to previous amendment and fertilization practices, thus giving pH 5.17-7.02, Al saturation 0.58-59.24%, and available P 5.24-42.07 mg kg-1. Regarding heavy metals, soil depth did not affect significantly to total concentrations, contrary to that happening with parent material, with higher As, Cu, Fe, and Ni concentrations found in soils over slate (possibly due to the presence of pyritic materials). In most cases, heavy metal total concentrations were lower than that considered as reference background levels for soils developed over each of the parent materials, and were always lower than that considered phyto-toxic. In this study, natural soils usually presented heavy metal total contents similar or even higher than that of the fertilized soils (unless Zn in the P4 pastureland), thus indicating that the spread doses of fertilizers did not influence significantly their concentration levels.

Profiling, distribution and levels of carcinogenic polycyclic aromatic hydrocarbons in traditional smoked plant and animal foods

Food Control, 59 (2016) 581–590

doi:10.1016/j.foodcont.2015.06.036

The purpose of this study was to evaluate the concentration of polycyclic aromatic hydrocarbons (PAH8 plus fluoranthene and pyrene) in “Pan de Cea” bread, “Pimentón de La Vera” paprika, “San Simón da Costa”, “Idiazábal” and “Humus” cheeses, and “Chorizo” garlic pork sausage. Results obtained showed that harmless low molecular weight compounds (Fluoranthene and Pyrene) represented the major contribution to the total PAHs. The most important PAHs according to the levels found were those in the 4 PAHs group (the rest of PAHs to add a total of 8 were contributing at very low levels). PAH4 and PAH8 levels showed percentages ranging from 6.0 to 7.0 % in bread, 16–17 % in paprika, 23–28 % in cheese and 20–24 % in meat sausages, respectively. B(a)P did not exceed the imposed limits in the EU. Bread showed the lower PAH concentration (3.4 μg/kg) followed by cheese (88 μg/kg), smoked sausage (1779 μg/kg) and paprika (9937 μg/kg). “Pimentón de la Vera” paprika is a condiment consumed in small quantities. The PAH profile had in common the decrease in PAH content as their molecular weight increased. These results showed that the contamination detected in “Pan de Cea” bread samples was very low, so that the consumption of this product does not pose a health risk. In cheese samples, the PAH contamination was detected meanly in rind, that accounted around the 100% of the total contamination. In meat sausages samples, the 90% of the total PAHs determined were accumulated in the casing. Considering the edible part, the PAH4 and B(a)P mean contents were below the limit established. Although, the highest PAH levels were detected in “Pimentón de la Vera” paprika, it should be pointed out that this product is a condiment consumed in small quantities and not in an everyday basis, it does not represent a risk for consumers. In cheese and meat sausage, according our estimates, the removal of the external part can be considered a good consumer practices to reduce the ingestion of PAHs.

A critical review about human exposure to Polychlorinated Dibenzo-p-Dioxins (PCDDs), Polychlorinated Dibenzofurans (PCDFs) and Polychlorinated Biphenyls (PCBs) through foods

Critical Reviews in Food Science and Nutrition, 55 (11), 2015, 1590-1617

DOI:10.1080/10408398.2012.710279

Dioxins include polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and part of polychlorinated biphenyls (PCBs). Only the compounds that are chlorinated at the 2,3,7, and 8 positions have characteristic dioxin toxicity. PCDDs, PCDFs and PCBs accumulate in the food chain due to their high lipophilicity, high stability, and low vapor pressure. They are not metabolized easily; however their hydroxylated metabolites are detected in feces. They cause a wide range of endocrine disrupting effects in experimental animals, wildlife, and humans. Endocrine related effects of PCDDs, PCDFs and PCBs on thyroid hormones, neurodevelopment and reproductive development were referenced. In addition, some studies of contamination of foods, bioaccumulation, dietary exposure assessment, as well as challenges of scientific research in these compounds were reviewed.

A critical review about the health risk assessment of PAHs and their metabolites in foods

Critical Reviews in food science and nutrition, 55 (10), 2015, 1383-1405

DOI:10.1080/10408398.2012.697497

Polycyclic aromatic hydrocarbons (PAHs) are a family of toxicants that are ubiquitous in the environment. These contaminants generate considerable interest, because some of them are highly carcinogenic in laboratory animals and have been implicated in breast, lung, and colon cancers in humans. Dietary intake of PAHs constitutes a major source of exposure in humans. Factors affecting the accumulation of PAHs in the diet, their absorption following ingestion, and strategies to assess risk from exposure to these hydrocarbons following ingestion have received very little attention. This review, therefore, focuses on concentrations of PAHs in widely consumed dietary ingredients along with gastrointestinal absorption rates in humans. Metabolism and bioavailability of PAHs in animal models and the processes, which influence the disposition of these chemicals, are discussed. Finally, based on intake, disposition, and tumorigenesis data, the exposure risk to PAHs from diet is presented. This information is expected to provide a framework for refinements in risk assessment of PAHs.

Toxicity evaluation of new agricultural fungicides in primary cultured cortical neurons

Environmental Research, 140, 2015, 37-44

doi 10.1016/j.envres.2015.03.013

Fungicides are crucial for food protection as well as for the production of crops of suitable quality and quantity to provide a viable economic return. Like other pesticides, fungicides are widely sprayed on agricultural land, especially in wine-growing areas, from where they can move-off after application. Furthermore, residues of these agrochemicals can remain on crops after harvest and even after some food processing operations, being a major exposure pathway. Although a relatively low toxicity has been claimed for this kind of compounds, information about their neurotoxicity is still scarce.

In the present study, nine fungicides recently approved for agricultural uses in the EU ― ametoctradin, boscalid, cyazofamid, dimethomorph, fenhexamid, kresoxim-methyl, mepanipyrim, metrafenone and pyraclostrobin ― have been evaluated for their toxicity in primary cultured mouse cortical neurons. Exposure to 0.1–100 µM for 7 days in vitro resulted in a dose-dependent toxicity in the MTT cell viability assay. Strobilurin fungicides kresoxim-methyl (KR) and pyraclostrobin (PY) were the most neurotoxic compounds (lethal concentration 50 were in the low micromolar and nanomolar levels, respectively) causing a rapid raise in intracellular calcium [Ca2+]i and strong depolarization of mitochondrial membrane potential. KR- and PY-induced cell death was reversed by the calcium channels blockers MK-801 and verapamil, suggesting that calcium entry through NMDA receptors and voltage-operated calcium channels are involved in KR- and PY-induced neurotoxicity. These results highlight the need for further evaluation of their neurotoxic effects in vivo.

Effects of sugar concentration processes in grapes and wine aging on aroma compounds of sweet wines—a review

Critical Reviews in Food Science and Nutrition, 55(8), 2015, 1053-1073

DOI 10.1080/10408398.2012.680524

Dessert sweet wines from Europe and North America are described in this review from two points of view: both their aroma profile and also their sensorial description. There are growing literature data about the chemical composition and sensory properties of these wines. Wines were grouped according to the production method (concentration of sugars in grapes) and to the aging process of wine (oxidative, biological, or a combination of both and aging in the bottle). It was found that wines natively sweets and wines fortified with liquors differ in their volatile compounds. Sensory properties of these wines include those of dried fruit (raisins), red berries, honey, chocolate and vanilla, which is contributing to their growing sales. However, there is still a need for scientific research on the understanding of the mechanisms for wine flavor enhancement.

Blending Local olive oils with Arbequina or Picual oils produces high quality, distinctive EVOOs

European Journal of Lipid Science and Technology. 2015

doi 10.1002/ejlt.201400357

Arbequina and Picual are the most common olive fruit varieties cultivated in Galicia (NW Spain). However, in recent years, the interest of oil producers in autochthonous Local olive fruits has increased substantially since its oil has differentiated and peculiar characteristics, especially with respect to the aromatic and phenolic composition. The blending of Local oil (in low percentages) with Arbequina or Picual oils is assessed in this study. Quality-related indices, fatty acid composition, as well as minor compounds, such as volatiles and phenolics, were determined for both monovarietal and blending oils. Results obtained showed that the blending has the advantage of producing high quality virgin olive oil with predictable phenolic and aromatic profiles.

Competitive adsorption/desorption of tetracycline, oxytetracycline and chlortetracycline on two acid soils: Stirred flow chamber experiments

Chemosphere, 134 (2015) 361-366

doi 10.1016/j.chemosphere.2015.04.098

The objective of this work was to study the competitive adsorption/desorption of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) on two acid soils. We used the stirred flow chamber technique to obtain experimental data on rapid kinetic processes affecting the retention/release of the antibiotics. Both adsorption and desorption were higher on soil 1 (which showed the highest carbon, clay and Al and Fe oxides content) than on soil 2. Moreover, hysteresis affected the adsorption/desorption processes. Experimental data were fitted to a pseudo-first order equation, resulting qamax (adsorption maximum) values that were higher for soil 1 than for soil 2, and indicating that CTC competed with TC more intensely than OTC in soil 1. Regarding soil 2, the values corresponding to the adsorption kinetics constants (ka) and desorption kinetics constants for fast sites (kd1), followed a trend inverse to qamax and qdmax respectively. In conclusion, competition affected adsorption/desorption kinetics for the three antibiotics assayed, and thus retention/release and subsequent transport processes in soil and water environments.

Cr(VI) sorption/desorption on untreated and mussel-shell-treated soil materials: fractionation and effects of pH and chromium concentration

Solid Earth, 6, 373–382, 2015

doi 10.5194/se-6-373-2015

We used batch-type experiments to study Cr(VI) sorption/desorption on granitic material, forest soil, pyritic material, mussel shell, and on forest soil and granitic material amended with 12 t ha−1 (1.2 kg m−2) shell, considering the effects of varying Cr(VI) concentration and pH. Sequential extractions were carried out to fractionate adsorbed Cr(VI) and to determine the stability of Cr(VI) retention. The pyritic material had the highest Cr(VI) retention capacity, whereas the granitic material showed the lowest retention potential. When high Cr concentrations were added, some saturation of the adsorbent surfaces became apparent, but Cr release remained low. The highest Cr retention was achieved at a very acid pH value, with release progressively increasing as a function of increasing pH. The amendment with 12 t ha−1 mussel shell did not cause marked changes in Cr(VI) re- tention. Sorption data were satisfactory adjusted to the Fre- undlich model. Regarding Cr(VI) fractionation, the soluble fraction (weakly bound) was dominant in mussel shell and in the unamended and amended granitic material, whereas more stable fractions dominated in the pyritic material (resid- ual fraction) and in the forest soil (oxidizable fraction). In conclusion, the pyritic material presented the highest Cr(VI) retention capacity, while the retention was low and weak on the granitic material; mussel shell was not characterized by a marked Cr(VI) retention potential, and it did not cause re- markable increase in Cr(VI) retention when used to amend the granitic material or the forest soil.

A model to forecast the risk periods of Plantago pollen allergy by using the ANN methodology

Aerobiologia (2015) 31:201–211

DOI 10.1007/s10453-014-9357-z

Some biological particles present in the atmosphere, such as pollen grains, give rise to human health problems, allergies, and infections. In view of the recognized special allergenic ability of Plantago pollen grains, a model based on an artificial neural network (ANN) was developed in this work in order to forecast the Plantago airborne pollen concentration. The proposed model uses data from Plantago pollen and the main meteorological variables recorded during 16 years (1993–2008) in the city of Ourense (north- west Spain). Its accuracy was tested during the years 2009 and 2010 with a prediction horizon of 2 days in advance. The model was applied in the atmosphere of the city of Ourense (Spain). Obtained results show that ANN model provides good results against other classical mathematical methodologies, which do not convergence so well. The forecasted pollen concen- trations here are applied to allergology because they allow taking into account preventive measures in risk pollinosis suffers population.

Cleavage of carbofuran and carbofuran-derivatives in micellar aggregates

Progress in Reaction Kinetics and Mechanism, 40 (2015) 105-118

DOI: /10.3184/146867815X14259195615547

In recent years, the stability of carbamate pesticides have been studied by our research group in a wide range of biomimetic microheterogeneous media such as micelles or reverse micelles. These microheterogeneous media included different surfactant species and, hence, different self-assembled structures. In particular, basic hydrolysis of carbofuran and its derivatives have been analysed in the presence of anionic, cationic, non-ionic and reverse micelles. The results obtained from these physicochemical and kinetic studies, as well as a consistent comparison of them, are now summarised.

Evaluation of the effect of fenhexamid and mepanipyrim in the volatile composition of Tempranillo and Graciano wines

Food Research International

Volume 71, May 2015, Pages 108–117

doi:10.1016/j.foodres.2015.02.025

Grapes from Vitis vinifera var. Tempranillo and Graciano of La Rioja (North Central Spain) were vinified after addition of two fungicides (mepanipyrim and fenhexamid) at concentrations corresponding to their MRLs. These fungicides are commonly used in the vine growing to control botrytis disease. The fungicide effect throughout winemaking on the volatile composition and aroma profile of the final wines was evaluated, together with the level of fungicide residues in the final wines that were found to be safe for consumers. Concentrations of C13-norisoprenoids in Graciano wines obtained after the addition of both active substances showed the greatest variations with respect to control wine; whereas the concentration of volatile compounds in Tempranillo wines were seemingly unaffected by the presence of fungicide residues. On the other hand, the aroma profile of monovarietal red wines was evaluated by using odorant series which included volatile compounds with similar odour descriptors. In this sense, supplementation with the antifungals seemed to increase the OAV for the ripe fruit series with respect to the control wines in Graciano wines.

Perspectives on the use of by-products to treat soil and water pollution

Microporous and Mesoporous Materials

Volume 210, 1 July 2015, Pages 199–201

doi:10.1016/j.micromeso.2015.02.001

The use of modified by-products in pollution removal is conceptually very interesting, as shown in a paper by Peng et al. (2015) recently published in Microporous and Mesoporous Materials. However, we would like to stimulate a debate on the convenience of simultaneously continuing to research on the purging potential of raw by-products and waste materials.

Kinetics of tetracycline, oxytetracycline, and chlortetracycline adsorption and desorption on two acid soils

Environmental Science and Pollution Research

January 2015, Volume 22, Issue 1, pp 425-433

DOI 10.1007/s11356-014-3367-9

The purpose of this work was to quantify retention/release of tetracycline, oxytetracycline, and chlortetracycline on two soils, paying attention to sorption kinetics and to implications of the adsorption/desorption processes on transfer of these pollutants to the various environmental compartments. We used the stirred flow chamber (SFC) procedure to achieve this goal. All three antibiotics showed high affinity for both soils, with greater adsorption intensity for soil 1, the one with the highest organic matter and Al and Fe oxides contents. Desorption was always <15 %, exhibiting strong hysteresis in the adsorption/desorption processes. Adsorption was adequately modeled using a pseudo first-order equation with just one type of adsorption sites, whereas desorption was better adjusted considering both fast and slow sorption sites. The adsorption maximum (q max ) followed the sequence tetracycline > oxytetracycline > chlortetracycline in soil 1, with similar values for the three antibiotics and the sequence tetracycline > chlortetracycline > oxytetracycline in soil 2. The desorption sequences were oxytetracycline > tetracycline > chlortetracycline in soil 1 and oxytetracycline > chlortetracycline > tetracycline in soil 2. In conclusion, the SFC technique has yielded new kinetic data regarding tetracycline, oxytetracycline, and chlortetracycline adsorption/desorption on soils, indicating that it can be used to shed further light on the retention and transport processes affecting antibiotics on soils and other media, thus increasing knowledge on the behavior and evolution of these pharmaceutical residues in the environment.

Effect of crushed mussel shell addition on bacterial growth in acid polluted soils

Applied Soil Ecology

Volume 85, January 2015, Pages 65–68

doi:10.1016/j.apsoil.2014.09.010

We applied three different doses of crushed mussel shell (CMS) on two Cu-polluted acid soils to study the effect of these amendments on the growth of the bacterial community during 730 days. Soil pH increased in the short and medium term due to CMS addition. In a first stage, bacterial growth was lower in the CMS-amended than in the un-amended samples. Thereafter, bacterial growth increased slowly. The soil having the highest initial pH value (4.5) showed the first significant increase in bacterial growth 95 days after the CMS amendment. However, in the soil with the lowest initial pH value (3.8) bacterial growth increased significantly only after 730 days from the CMS addition. The highest dose of CMS caused that, at the end of the incubation period, pH value have increased 2 units, whereas bacterial growth was 4–10 times higher. In view of these results, CMS amendment could be considered as an agronomic sound practice for strongly acid soils (pH <4.5).

Adsorption, desorption and fractionation of As (V) on untreated and mussel shell-treated granitic material

Solid Earth, 6 (1) 337-346 (2015)

doi:10.5194/se-6-337-2015

As(V) adsorption and desorption were studied on granitic material, coarse and fine mussel shell and granitic material amended with 12 and 24 t ha−1 fine shell, investigating the effect of different As(V) concentrations and different pH as well as the fractions where the adsorbed As(V) was retained. As(V) adsorption was higher on fine than on coarse shell. Mussel shell amendment increased As(V) adsorption on granitic material. Adsorption data corresponding to the unamended and shell-amended granitic material were satisfactory fitted to the Langmuir and Freundlich models. Desorption was always <19% when the highest As(V) concentration (100 mg L−1) was added. Regarding the effect of pH, the granitic material showed its highest adsorption (66%) at pH <6, and it was lower as pH increased. Fine shell presented notable adsorption in the whole pH range between 6 and 12, with a maximum of 83%. The shell-amended granitic material showed high As(V) adsorption, with a maximum (99%) at pH near 8, but decreased as pH increased. Desorption varying pH was always <26%. In the granitic material, desorption increased progressively when pH increased from 4 to 6, contrary to what happened to mussel shell. Regarding the fractionation of the adsorbed As(V), most of it was in the soluble fraction (weakly bound). The granitic material did not show high As(V) retention capacity, which could facilitate As(V) transfer to water courses and to the food chain in case of As(V) compounds being applied on this material; however, the mussel shell amendment increased As(V) retention, making this practice recommendable.

Liquid chromatography–mass spectrometry method development for monitoring stress-related corticosteroids levels in pig saliva

Journal of Chromatography B

Volume 990, 15 May 2015, Pages 158–163

doi:10.1016/j.jchromb.2015.03.021

Biochemical response stressors results in an increase of adrenocortical activity. Before knowing the corticosteroid levels in saliva in a stressful situation, baselines salivary levels should be established. A method for simultaneous determination of five corticosteroids was developed, validated and applied to pig saliva at farms. The method employs solid-phase extraction (SPE) coupled with clean-up extraction step using silica cartridge in the same step followed by liquid chromatography/tandem mass spectrometry (LC–MS/MS), using electrospray ionization (ESI) in positive mode. The overall method quantification limits range from 0.050 to 0.30 μg/L for the enrichment of 1.0 mL saliva samples and analyte recoveries are between 60 and 90% (RSD < 11%). Some factors studied were: pig sex, breeds, and time at farm. The analytical method clearly shows that CRL and CRS levels of, respectively, 3.0 and 4.0 μg/L in saliva can be indicative of maxima non-stress levels in different pig breeds at farm.

Contenido y distribución de cobre en suelos de viñedo de Betanzos (A Coruña, España)

Spanish Journal of Soil Science, 5 (1) 60-71, 2015

DOI: 10.3232/SJSS.2015.V5.N1.06

El uso sostenido de compuestos de cobre para la producción de uva ha contribuido a la acumulación pronunciada de Cu en sueños de viñedo. Se estudiaron 32 muestras superficiales (0-20 cm) de suelos dedicados al cultivo de la vid en una zona de influencia atlántica en el NW de la Península Ibérica. Los contenidos de cobre total (CuT) fueron, en general, altos y muy variables (entre 63-730 mg kg-1). Los valores son similares a los encontrados en las denominaciones de origen Ribeira Sacra y O Ribeiro, que eran las zonas vitivinícolas cuyos suelos de viñedo presentaban el mayor contenido conocido de CuT del NW peninsular hasta el momento. La distribución del Cu en la fase sólida del suelo indica que la fracción mayoritaria es la unida a la materia orgánica (18-373 mg kg-1), a diferencia de lo que ocurre en otros suelos naturales o con elementos procedentes de fuentes naturales como el Zn, donde la fracción residual es la más importante. La fracción intercambiable de Cu (CuE) fue la que mostró una mayor movilidad geoquímica y su varianza estaba principalmente relacionada con el CuT y, en menor medida, con el Ca intercambiable. Cuando se compara con un elemento predominantemente de origen natural, como es el Zn, la distribución también es muy diferente, ya que la fracción residual es la mayoritaria para el Zn (mientras que era la unida a la materia orgánica en el caso del Cu). Finalmente, las prácticas agrícolas encaminadas a mantener o mejorar la presencia de materia orgánica en los suelos de viñedo son de especial relevancia, puesto que contribuyen a disminuir los posibles efectos tóxicos de los altos contenidos de Cu, tanto en la vid como en la actividad de los microorganismos del suelo.

Un campus aberto á auga... e á sociedade

A seca, o aumento da poboación, a sobreexplotación económica e a mala xestión dos recursos teñen convertido a falta de auga potable nun grave problema planetario. Os expertos prevén que de manterse o ritmo de consumo no 2025 o 60% dos habitantes da Terra vivirá en rexións con escaseza "e nos temos tanta auga que non lle damos valor a ser o lugar de Europa con maior potencial de auga quente, un tesouro termal do que queremos sacar partido e polo que escollemos este ben no noso camiño de especialización". Así llo explicou o reitor da Universidade de Vigo, Salustiano Mato, aos máis de 160 estudantes e docentes que participaron nos actos de conmemoración do Día Mundial da Auga no campus de Ourense, que se celebrou cunha xornada de portas abertas con multitude de actividades para achegar á cidadanía "o que se está a facer no campus", así como o proceso de especialización no que está inmerso co Campus da Auga.

Os rapaces e rapazas do IES 12 de Outubro e dos colexios Salesianos, Santa Teresa de Jesús-Carmelitas e Divina Pastora-Franciscanas achegáronse ás diferentes titulacións que se imparten nos centros e ás liñas de investigación que se están a desenvolver ao abeiro deste campus de especialización en sesións tanto teóricas como prácticas nos laboratorios de Microbioloxía da Facultade de Ciencias e de Arqueoloxía da Facultade de Historia. "Queremos que se nos coñeza co apelido ‘auga’, porque detrás está o futuro ao ser un sector relacionado co termalismo, coa dinamización social e co potencial económico", salientou o reitor, que asegurou que o medio ambiente, a natureza e a alimentación son outras das “marcas” que se agochan tras o campus de Ourense. "Detrás da auga tamén está o noso potencial tecnolóxico e temos que pensar nas nosas capacidades para que este elemento sexa o eixo sobre o que pivotar o noso futuro económico", subliñou durante a inauguración dunhas xornadas que naceron con intención de continuidade.

O vicerreitor, Virxilio Rodríguez, fíxolles aos participantes unha radiografía do campus, con máis de 4000 estudantes e 400 empregados "implicados" no seu crecemento, ademais de explicarlles o proceso de especialización co que Ourense pretende pasar a liderar a investigación e a docencia internacional sobre auga no que están implicados todos os centros do campus. "Espero que sexa unha xornada que serva para orientar o voso futuro académico e para inclinar a balanza cara esta universidade", recalcou. Tras o acto inaugural, presentación das titulacións por parte dos seis decanos e directores dos centros que configuran o campus ourensán, da programación cultural e deportiva e de proxectos de investigación relacionados coa auga, como os desenvolvidos polo grupo EPhysLab ou os que relacionan auga e historia.

Da teoría á práctica

Tras facer varios experimentos en diferentes laboratorios do campus, os participantes volveron a xuntarse no salón de actos Marie Curie do Edificio Politécnico para a entrega de premios do concurso de fotorrelato Auga con Historia, no que os estudantes de Secundaria e Bacharelato debían presentar unha fotografía acompañada dun texto que promovera ou visibilizara o patrimonio artístico, etnográfico, cultural... relacionado coa auga. O xurado decidiu declarar deserto o primeiro e segundo premio e outorgar o terceiro a Iria Ollero, do Colexio Marista Santa María, por Muíños de auga. Luces e sombras. Ademais, entregaron un accésit a Andrea Barja, do Colexio Concepción Arenal, pola obra A auga, a razón pola que estamos aquí. As galardoadas, xunto co diploma e a mención, levaron un lote de libros cedidos pola Deputación de Ourense e dúas tablets, unha dada polo Concello e outra pola empresa tecnolóxica Primux.

Creado polas Nacións Unidas para chamar a atención sobre a importancia da auga doce e a defensa da xestión sostible destes recursos, o Día Mundial da Auga debe servir para resaltar que a sociedade atópase ante "o gran reto do século XXI, xa que aínda hai 1500 millóns de habitantes que sofren dalgunha forma pola falta de auga potable. E ninguén mellor que a Universidade de Vigo para traballar para que a auga sexa un ben sostible", como explicou Rosendo Fernández, vicepresidente da Deputación provincial, durante a clausura, na que tamén estiveron presentes o concelleiro de Termalismo de Ourense, José Ángel Barquero, e un representante de Primux, Manuel Lama.

Fuente: DUVI

Pedro Araújo, premio ao seu traballo coa auga

Un galardón a toda unha traxectoria dedicada a traballar, protexer e estudar as diferentes formas de conservar a pureza e potabilidade da auga. Esta foi unha das razóns pola que o proxecto O Bosque Máxico entregou este martes ao decano da Facultade de Ciencias do campus de Ourense, Pedro Araújo, o seu premio Ouro Azul, co que tamén se lle quixo recoñecer os seus estudos no Campus da Auga. Unha mención "ilusionante" da que se sinte orgulloso e que o anima a seguir traballando en proxectos de investigación con augas termais, tarefa que retomará tras deixar o cargo ao rematar este segundo mandato ao fronte do centro. 

O seu próximo proxecto será determinar as temperaturas de almacén das augas termais, a temperatura máxima que acadan en profundidade antes de subir á superficie, pero tamén ten en mente a procura de zonas termais coa axuda de drones e cámaras termográficas coa Deputación de Ourense.

Fuente: DUVI

Foto: Faro de Vigo

Raquel Rodríguez analiza na súa tese a composición das bebidas tradicionais derivadas da augardente

Son moitas as comidas copiosas que acaban cun chopo dalgún licor de herbas, confiando nunha capacidade dixestiva outorgada normalmente por tradición. Sen embargo, unha investigación da Universidade de Vigo en colaboración co Consello Regulador de Augardentes e Licores de Galicia acaba de demostrar “que o seu consumo moderado pode achegar características beneficiosas para a saúde a través das materias primas das que parte”. Así o asegura Raquel Rodríguez, que na súa tese de doutoramento abordou por primeira vez o proceso de elaboración de bebidas derivadas da augardente dende os seus ingredientes ata o produto final para atopar a combinación de herbas máis axeitada a cada receita.

Grazas a esta investigación, as empresas dedicadas ao eido das augardentes e licores poden facerse unha idea de que características achegar á bebida final que se pretende elaborar “reducindo custes e tempo”. Por iso, a tese inclúe unha serie de fichas coas propiedades sensoriais e medicinais de cada unha das plantas do estudo que poden ser moi útiles para saber que compostos vexetais empregar en función do que se queira achegar ao produto comercial, que especie de carballo ou que grao de tostado sería máis axeitado en función das características que “lle queiramos dar á bebida final sabendo as propiedades de partida da nosa augardente”.

O fiúncho pode ser canceríxeno

Este estudo, levado a cabo ao abeiro do grupo de Biotecnoloxía Alimentaria do campus de Ourense, integrado no CIA, serve para coñecer o que cada unha das plantas utilizadas achega aos licores xa que, aínda que a maioría van acompañadas de propiedades aromáticas e medicinais con efectos positivos como antioxidantes, algunhas levan compostos “pouco beneficiosos para a saúde humana en elevadas concentracións”. É o caso do aceite esencial ou do extracto de folla de eucalipto, que debido ao seu composto químico máis abundante, o eucaliptol, non se debe superar un límite de inxestión diaria, ou de fiúncho, que presentou como principal quimiotipo o estragol, un composto considerado como canceríxeno. 

Nos laboratorios do Centro de Investigación, Transferencia e Innovación (CITI) ourensán, esta química partiu da análise das plantas aromáticas coas que se fabrican os diferentes licores de herbas e augardentes, estudando a composición volátil e fenólica do aceite esencial ou do extracto empregado por medio de diferentes técnicas tradicionais e actuais. O estudo céntrase nas 12 plantas permitidas ata 2012 na elaboración destas bebidas, ano no que se autorizou o uso de calquera especie complementaria, e sabendo que é obrigatorio o uso de polo menos tres plantas para obter o selo do Consello Regulador. 

Rodríguez caracterizou os aceites esenciais e os extractos destas plantas mediante técnicas cromatográficas e espectroscópicas. Desta análise concluíuse que “distintas familias de plantas achegan diferentes características á augardente e ao licor final e que, aínda que dentro da mesma familia a achega de compostos é parecido, a súa proporción cambia segundo sexa o seu quimiotipo principal”, dando pé a distintas propiedades. “Se queremos obter un licor con diferentes características teremos que utilizar compostos vexetais de distintas familias, pero se buscamos un licor con características similares escolleremos plantas da mesma rama”, asegura.

A concentración da planta, o que máis inflúe

Dentro da tese de doutoramento, dirixida por Sandra Cortés e José Manuel Domínguez, a investigadora quixo tamén analizar o proceso de elaboración dos licores e augardentes, avaliando a influencia de parámetros como a concentración do composto vexetal na bebida, a porcentaxe de etanol e mesmo o tempo de maduración. Para a maceración, Rodríguez escolleu as flores da manzanilla, as folla do eucalipto, as semente de coandro e raíz de regalicia para analizar o contido fenólico total, parámetros de cor e quimiotipo. Os resultados demostraron que os parámetros que máis influían de forma xeral eran “en primeiro lugar a concentración da planta seguido da porcentaxe de etanol no augardente empregado, mentres que o tempo de maceración foi unha variable sen apenas influencia”.

Rodríguez levou a cabo o mesmo proceso co envellecemento acelerado da augardente, empregando labras de madeira, que actualmente non están permitidas para este proceso pero que “poden ser de utilidade para avaliar que especia de barrica ou que tostado é o máis axeitado en función das características que se busquen”. E fíxoo con dúas especies de carballo (o Quercus petraea e o Quercus alba) e con distintos graos de tostado (fresco, lixeiro, medio e alto). Os resultados reflicten que, para obter maiores achegas de whiskey lactona e de vainilla como compostos con importancia sensorial procedente da madeira en contacto, de fenoles e de parámetros de cor hai que aumentar a concentración da planta empregada e apostar “por labras da especie petrae e o tostado medio”.

Analizando produtos comerciais

A investigación rematou co estudo do produto final a través da análise de licores e augardentes comerciais e envellecidos en barricas de Quercus alba, Quercus petraea e Quercus robur das rexións de Limousin e Galicia e a mestura de ambas. Como resultado obtívose a potencialidade do carballo galego debido ao maior extracto de compostos fenólicos con características antioxidantes, ademais de recibir a maior puntuación por parte do panel oficial de Oruxo de Galicia na cata levada a cabo en todas as mostras. Ademais, as mostras analizadas presentaban valores dentro intervalo legal marcado polo Consello Regulador de Augardentes e Licores de Galicia, o que corrobora “unha boa elaboración destas bebidas durante todo o proceso”.

Fuente: DUVI

A model to forecast the risk periods of Plantago pollen allergy by using the ANN methodology

Aerobiología (2015)

DOI: 10.1007/s10453-014-9357-z

Some biological particles present in the atmosphere, such as pollen grains, give rise to human health problems, allergies, and infections. In view of the recognized special allergenic ability of Plantago pollen grains, a model based on an artificial neural network (ANN) was developed in this work in order to forecast the Plantago airborne pollen concentration. The proposed model uses data from Plantago pollen and the main meteorological variables recorded during 16 years (1993–2008) in the city of Ourense (northwest Spain). Its accuracy was tested during the years 2009 and 2010 with a prediction horizon of 2 days in advance. The model was applied in the atmosphere of the city of Ourense (Spain). Obtained results show that ANN model provides good results against other classical mathematical methodologies, which do not convergence so well. The forecasted pollen concentrations here are applied to allergology because they allow taking into account preventive measures in risk pollinosis suffers population.

Alkaline hydrolysis of vinclozolin: effect of humic acids aggregates in water

Journal of Molecular Catalysis A: Chemical

DOI: 10.1016/j.molcata.2015.02.017

The influence of natural organic substances as humate colloidal aggregates in water solutions upon the chemical stability of vinclozolin has been investigated in basic media. A large inhibition (9 times-fold) has been observed and it has been rationalized in terms of a micellar pseudophase model. The observed behaviour could increase significantly the half-life of this fungicide. Moreover, these experimental results have been compared with the corresponding ones of other substances in these natural colloidal aggregates.

Sweet, reinforced and fortified wines: grape biochemistry, technology and vinification

Journal of Wine Research (2015) 26, 64-66

DOI:10.1080/09571264.2015.1009252