Uso de las fracciones polares y no polares como fuente de información adicional al estudio de aceites de oliva vírgenes por FTIR

Fourier transform infrared (FTIR) spectroscopy has been proposed to study the degradation of virgin olive oils (VOO) in samples undergoing thermoxidation. The polar and nonpolar fractions of oxidized oils have been analyzed by FTIR to provide further information on the minor spectral changes taking place during thermoxidation. This information assists in the interpretation of the spectra of the samples. For this purpose polar and nonpolar fractions of 47 VOO samples thermoxidized (190 °C) in a fryer were analyzed by FTIR. The time-course change of the band area assigned to single cis double bonds was explained by their correlation with the decrease in oleic acid (adjusted-R2=0.93). The bands assigned to the hydroxyl groups and the first overtone of ester groups was better studied in the spectra collected for the polar and nonpolar fractions, respectively. The bands assigned to peroxide, epoxy, tertiary alcohols and fatty acids were clearly observed in the spectra of the polar fraction while they are not noticeable in the spectra of the oils.La espectroscopía de infrarrojos por transformada de Fourier (FTIR) se ha propuesto para estudiar la degradación de los aceites de oliva vírgenes (AOV) sujetas a termoxidación. Las fracciones polares y no polares de aceites oxidados se analizaron mediante FTIR para obtener más información sobre los cambios espectrales menores que tienen lugar durante la termoxidación. Esa información ayuda en la interpretación de los espectros de las muestras puras. Con este objetivo, fracciones polares y no polares de 47 AOV termoxidados (190 °C) en una freidora se analizaron mediante FTIR. La banda asignada a dobles enlaces cis se explica por su correlación con la disminución de ácido oleico (R2-ajustado=0,93). Las bandas asignadas a los grupos hidroxilos y del primer sobretono de los grupos éster se estudió mejor en los espectros recogidos para la fracción polar y no polar, respectivamente. Grupos asignados a peróxidos, epoxi, alcoholes terciarios y los ácidos grasos se observan claramente en los espectros de la fracción polar.Spanish State Secretary for Research - Ramón y Cajal Program AGL2008-01411Spanish State Secretary for Research - Ramón y Cajal Program AGL2011-30371- C02-0

Tracking Sensory Characteristics of Virgin Olive Oils During Storage: Interpretation of Their Changes from a Multiparametric Perspective

Virgin olive oil is inevitably subject to an oxidation process during storage that can affect its stability and quality due to off-flavors that develop before the oil surpasses its ‘best before’ date. Many parameters are involved in the oxidation process at moderate conditions. Therefore, a multiparametric study is necessary to establish a link between physico-chemical changes and sensory quality degradation in a real storage experiment. In this context, a storage experiment of 27 months was performed for four monovarietal virgin olive oils, bottled in transparent 500-mL PET bottles and subjected to conditions close to a supermarket scenario. Volatile composition, quality parameters and phenolic compounds were determined monthly. Simultaneously, an accredited sensory panel assessed their sensory characteristics. The stability of the fresh samples was also studied with the oxidative stability index (OSI) and mesh cell-FTIR. (E)-2-hexenal, (Z)-3-hexen-1-ol and (E)-2-hexen-1-ol were identified as markers of the fruity attribute. Hexanal and nonanal were also identified as compounds that were associated with the rise of median of defect during storage. Some disagreements were observed between the sensory assessment and the OSI analyzed by Rancimat. However, the increase of concentration of rancid markers agreed with the increase of aldehyde band measured with mesh cell-FTIR.Spanish Research State Agency (research projects AGL2015-69320-R and RTI2018-101546-B-C21

Monitoring Virgin Olive Oil Shelf-Life by Fluorescence Spectroscopy and Sensory Characteristics: A Multidimensional Study Carried Out under Simulated Market Conditions

The control of virgin olive oil (VOO) freshness requires new tools that reflect the diverse chemical changes that take place during the market period. Fluorescence spectroscopy is one of the techniques that has been suggested for controlling virgin olive oil (VOO) freshness during its shelf-life. However, a complete interpretation of fluorescence spectra requires analyzing multiple parameters (chemical, physical–chemical, and sensory) to evaluate the pace of fluorescence spectral changes under moderate conditions with respect to other changes impacting on VOO quality. In this work, four VOOs were analyzed every month with excitation–emission fluorescence spectra. The same samples were characterized with the concentration of fluorophores (phenols, tocopherols, chlorophyll pigments), physical–chemical parameters (peroxide value, K232, K270, free acidity), and sensory attributes (medians of defects and of the fruity attribute). From the six components extracted with parallel factor analysis (PARAFAC), two components were assigned to chlorophyll pigments and those assigned to tocopherols, phenols, and oxidation products were selected for their ability to discriminate between fresh and aged oils. Thus, the component assigned to oxidation products correlated with K270 in the range 0.80–0.93, while the component assigned to tocopherols–phenols correlated with the fruity attribute in the range 0.52–0.90. The sensory analysis of the samples revealed that the changes of these PARAFAC components occurred at the same time as, or even before, the changes of the sensory characteristics.Agencia Estatal de Investigación de España-AGL2015-69320-R y RTI2018-101546-B-C2

Multianalyte analysis of volatile compounds in virgin olive oils using SPME-GC with FID or MS detection: results of an international interlaboratory validation

The organoleptic assessment (Panel test) is the only procedure within the official methods for determining the quality of virgin olive oils that involves an expert panel. There is an urgent need for analytical methodology that can reliably measure volatile compounds in virgin olive oils that is capable of supporting and anticipating the official Panel test. For this reason, a new method based on solid-phase microextraction–gas chromatography with the choice of two possible detectors (FID or MS) was subjected to a large international interlaboratory validation study. The study involved a two-stage process: first, a pretrial phase in which 7 participants were exposed to the method for the first time to identify any initial problems with the methodology; then, a formal validation stage (trial proper), which involved 20 laboratories from Europe, USA, Japan and China. The performance of the different detectors was investigated. While both methods have advantages, the method using FID provided better results for 11 compounds, in terms of reproducibility, compared to MS. This information will allow to implement the method with accurate information of the method performance depending on the detector used. Practical applications: This study provides information from an interlaboratory validation of a method for measuring volatile compounds in virgin olive oils conducted with laboratories (from industry and academia) working in the olive oil sector. The information on the expected analytical errors in the determination of each volatile compound is necessary to apply this method for supporting the official Panel test (sensory analysis). The SPME-GC-MS/FID methods proposed in this work can be used for the internal quality control of a company/distributor/quality control laboratory and could also be used in cases of difficult/contradictory organoleptic assessment, or to confirm results from sensory panels in cases of disputes/disagreement (Reg. EU 2022/2105).European Commission 63569

Peer inter-laboratory validation study of a harmonized SPME-GC-FID method for the analysis of selected volatile compounds in virgin olive oils

In the context of supporting the panel test in the classification of virgin olive oils, the qualitative and quantitative analysis of a number of volatile compounds responsible for their aroma is of great importance. Herein, the data obtained from three laboratories that analyzed the same samples are presented with the view to develop an inter-laboratory validation study of a harmonized solid-phase micro-extraction coupled with gas-chromatography with flame ionized detector (SPME-GC-FID) method for determination of selected volatile compounds. In particular, quantification of the minimum number of key markers responsible for positive attributes (e.g. fruity) and sensory defects was investigated. Three quantification strategies were considered since they can have a notable impact on the effectiveness of the use of markers as well as on the robustness and simplicity of the method that is designed for control laboratories. A peer-validation study indicated repeatability with a mean relative standard deviation (RSD%) lower than 14% except for ethyl propanoate, 3-methyl-1-butanol, 1-octen-3-ol, and (E)-2-decenal. Linearity was satisfactory (R2 > 0.90) for all compounds when the calibration curves were corrected by the internal standard. Several critical issues were identified, such as high RSD% (>50%) in terms of reproducibility for ethyl propanoate, (E)-2-decenal, and possible improvements of the limits of detection (LODs) and quantitation (LOQs) of (E)-2-heptenal, (E,E)-2,4-hexadienal, and (E)-2-decenal. In particular, some compounds (ethyl propanoate, (E)-2-heptenal, 1-octen-3-ol, (E,E)-2,4-hexadienal, (E)-2-decenal and pentanoic acid) showed LOQs that were higher than the concentrations found in some samples. The discussion permitted improvement of the protocol towards the final version for an upcoming full validation process

Highly Anisotropic Organometal Halide Perovskite Nanowalls Grown by Glancing-Angle Deposition

Polarizers are ubiquitous components in current optoelectronic devices as displays or photographic cameras. Yet, control over light polarization is an unsolved challenge, since the main drawback of the existing display technologies is the significant optical losses. In such a context, organometal halide perovskites (OMHP) can play a decisive role given their flexible synthesis with tunable optical properties such as bandgap and photoluminescence, and excellent light emission with a low non-radiative recombination rate. Therefore, along with their outstanding electrical properties have elevated hybrid perovskites as the material of choice in photovoltaics and optoelectronics. Among the different OMHP nanostructures, nanowires and nanorods have lately arisen as key players in the control of light polarization for lighting or detector applications. Herein, the fabrication of highly aligned and anisotropic methylammonium lead iodide perovskite nanowalls by glancing-angle deposition, which is compatible with most substrates, is presented. Their high alignment degree provides the samples with anisotropic optical properties such as light absorption and photoluminescence. Furthermore, their implementation in photovoltaic devices provides them with a polarization-sensitive response. This facile vacuum-based approach embodies a milestone in the development of last-generation polarization-sensitive perovskite-based optoelectronic devices such as lighting appliances or self-powered photodetectors

Maximizing resource recovery from urban wastewater through an innovative facility layout

[EN] This research work proposes an innovative layout for urban wastewater treatment based on anaerobic technology, microalgal cultivation and membrane technology. The proposed Water Resource Recovery Facility (WRRF) system can treat urban wastewater efficiently, complying with legal discharge limits and allowing for resource recovery, i.e. energy, nutrients and reclaimed water. In addition, the proposed layout produces less solid wastes than a conventional wastewater treatment plant (WWTP) and it is possible to recover energy as biogas, not only from the original wastewater sources but also from the biomass generated in the WRRF system

Resource recovery from sulphate-rich sewage through an innovative anaerobic-based water resource recovery facility (WRRF)

[EN] This research work proposes an innovative water resource recovery facility (WRRF) for the recovery of energy, nutrients and reclaimed water from sewage, which represents a promising approach towards enhanced circular economy scenarios. To this aim, anaerobic technology, microalgae cultivation, and membrane technology were combined in a dedicated platform. The proposed platform produces a high-quality solid- and coliform-free effluent that can be directly discharged to receiving water bodies identified as sensitive areas. Specifically, the content of organic matter, nitrogen and phosphorus in the effluent was 45 mg COD.L-1 , 14.9 mg N.L-1 and 0.5 mg P.L-1 , respectively. Harvested solar energy and carbon dioxide biofixation in the form of microalgae biomass allowed remarkable methane yields (399 STP L CH 4.kg(-1) CODinf ) to be achieved, equivalent to theoretical electricity productions of around 0.52 kWh per m 3 of wastewater entering the WRRF. Furthermore, 26.6% of total nitrogen influent load was recovered as ammonium sulphate, while nitrogen and phosphorus were recovered in the biosolids produced (650 +/- 77 mg N.L-1 and 121.0 +/- 7.2 mg P.L-1).This research was supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTM2014-54980-C2-1-R and CTM2014-54980-C2-2-R) jointly with the European Regional Development Fund (ERDF), which are gratefully acknowledged. This research was also supported by the Spanish Ministry of Education, Culture and Sport via two pre-doctoral FPU fellowships (FPU14/05082 and FPU15/02595) and by the Spanish Ministry of Economy and Competitiveness via two pre-doctoral FPI fellowships (BES-2015-071884, BES-2015-073403) and one Juan de la Cierva contract (FJCI-2014-21616). The authors would also like to acknowledge the support received from Generalitat Valenciana via two VALithornd post-doctoral grants (APOSTD/2014/049 and APOSTD/2016/104) and via the fellowships APOTI/2016/059 and CPI-16-155, as well as the financial aid received from the European Climate KIC association for the 'MAB 2.0' Project (APIN0057_ 2015-3.6-230_ P066-05) and Universitat Politecnica de Valencia via a pre-doctoral FPI fellowship to the seventh author.Seco Torrecillas, A.; Aparicio Antón, SE.; Gonzalez-Camejo, J.; Jiménez Benítez, AL.; Mateo-Llosa, O.; Mora-Sánchez, JF.; Noriega-Hevia, G.... (2018). Resource recovery from sulphate-rich sewage through an innovative anaerobic-based water resource recovery facility (WRRF). Water Science & Technology. 78(9):1925-1936. https://doi.org/10.2166/wst.2018.492S19251936789Bair, R. A., Ozcan, O. O., Calabria, J. L., Dick, G. H., & Yeh, D. H. (2015). Feasibility of anaerobic membrane bioreactors (AnMBR) for onsite sanitation and resource recovery (nutrients, energy and water) in urban slums. Water Science and Technology, 72(9), 1543-1551. doi:10.2166/wst.2015.349Barat, R., Serralta, J., Ruano, M. V., Jiménez, E., Ribes, J., Seco, A., & Ferrer, J. (2013). Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants. Water Science and Technology, 67(7), 1481-1489. doi:10.2166/wst.2013.004Batstone, D. J., Hülsen, T., Mehta, C. M., & Keller, J. (2015). Platforms for energy and nutrient recovery from domestic wastewater: A review. Chemosphere, 140, 2-11. doi:10.1016/j.chemosphere.2014.10.021Bilad, M. R., Arafat, H. A., & Vankelecom, I. F. J. (2014). Membrane technology in microalgae cultivation and harvesting: A review. Biotechnology Advances, 32(7), 1283-1300. doi:10.1016/j.biotechadv.2014.07.008Carrington E.-G. 2001 Evaluation of Sludge Treatments for Pathogen Reduction. http://europa.eu.int/comm/environment/pubs/home.htm.Cookney, J., Mcleod, A., Mathioudakis, V., Ncube, P., Soares, A., Jefferson, B., & McAdam, E. J. (2016). Dissolved methane recovery from anaerobic effluents using hollow fibre membrane contactors. Journal of Membrane Science, 502, 141-150. doi:10.1016/j.memsci.2015.12.037De Morais, M. G., & Costa, J. A. V. (2007). Biofixation of carbon dioxide by Spirulina sp. and Scenedesmus obliquus cultivated in a three-stage serial tubular photobioreactor. Journal of Biotechnology, 129(3), 439-445. doi:10.1016/j.jbiotec.2007.01.009Giménez, J. B., Robles, A., Carretero, L., Durán, F., Ruano, M. V., Gatti, M. N., … Seco, A. (2011). Experimental study of the anaerobic urban wastewater treatment in a submerged hollow-fibre membrane bioreactor at pilot scale. Bioresource Technology, 102(19), 8799-8806. doi:10.1016/j.biortech.2011.07.014Giménez, J. B., Martí, N., Ferrer, J., & Seco, A. (2012). Methane recovery efficiency in a submerged anaerobic membrane bioreactor (SAnMBR) treating sulphate-rich urban wastewater: Evaluation of methane losses with the effluent. Bioresource Technology, 118, 67-72. doi:10.1016/j.biortech.2012.05.019Giménez, J. B., Bouzas, A., Carrere, H., Steyer, J.-P., Ferrer, J., & Seco, A. (2018). Assessment of cross-flow filtration as microalgae harvesting technique prior to anaerobic digestion: Evaluation of biomass integrity and energy demand. Bioresource Technology, 269, 188-194. doi:10.1016/j.biortech.2018.08.052González-Camejo, J., Serna-García, R., Viruela, A., Pachés, M., Durán, F., Robles, A., … Seco, A. (2017). Short and long-term experiments on the effect of sulphide on microalgae cultivation in tertiary sewage treatment. 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A Large Multicenter Prospective Study of Community-Onset Healthcare Associated Bacteremic Urinary Tract Infections in the Era of Multidrug Resistance: Even Worse than Hospital Acquired Infections?

Introduction: Healthcare-associated (HCA) infections represent a growing public health problem. The aim of this study was to compare community-onset healthcare associated (CO-HCA) bacteremic urinary tract infections (BUTI) and hospital-acquired (HA)-BUTI with special focus on multidrug resistances (MDR) and outcomes. Methods: ITUBRAS-project is a prospective multicenter cohort study of patients with HCA-BUTI. All consecutive hospitalized adult patients with CO-HCA-BUTI or HA-BUTI episode were included in the study. Exclusion criteria were: patients < 18 years old, non-hospitalized patients, bacteremia from another source or primary bacteremia, non-healthcare-related infections and infections caused by unusual pathogens of the urinary tract. The main outcome variable was 30-day all-cause mortality with day 1 as the first day of positive blood culture. Logistic regression was used to analyze factors associated with clinical cure at hospital discharge and with receiving inappropriate initial antibiotic treatment. Cox regression was used to evaluate 30-day all-cause mortality. Results: Four hundred forty-three episodes were included, 223 CO-HCA-BUTI. Patients with CO-HCA-BUTI were older (p < 0.001) and had more underlying diseases (p = 0.029) than those with HA-BUTI. The severity of the acute illness (Pitt score) was also higher in CO-HCA-BUTI (p = 0.026). Overall, a very high rate of MDR profiles (271/443, 61.2%) was observed, with no statistical differences between groups. In multivariable analysis, inadequate empirical treatment was associated with MDR profile (aOR 3.35; 95% CI 1.77–6.35), Pseudomonas aeruginosa (aOR 2.86; 95% CI 1.27–6.44) and Charlson index (aOR 1.11; 95% CI 1.01–1.23). Mortality was not associated with the site of acquisition of the infection or the presence of MDR profile. However, in the logistic regression analyses patients with CO-HCA-BUTI (aOR 0.61; 95% CI 0.40–0.93) were less likely to present clinical cure. Conclusion: The rate of MDR infections was worryingly high in our study. No differences in MDR rates were found between CO-HCA-BUTI and HA-BUTI, in the probability of receiving inappropriate empirical treatment or in 30-day mortality. However, CO-HCA-BUTIs were associated with worse clinical cure. © 2021, The Author(s)