Desarrollo de nuevos métodos de extracción para el análisis de compuestos de interés enológico

El sector vitinícola en España está desarrollando una intensa modificación en sus condiciones y sistemas de producción. Todo esto lleva al personal técnico de la bodega a enfrentarse con nuevas problemáticas que tiene que resolver, a veces, con una información limitada sobre diversos pa'rmetros de interés. En esta tesis doctoral se ha pretendido dotar de nuevos sistemas para generar información de interés para el sector vitinícola, tanto en la maduración de la uva, como en la posterior etapa de vinificación. Estos nuevos sistemas son métodos de análisis, basados en unos casos en tecnologías desarrolladas recientemente y, en otros, en nuevas aplicaciones a soluciones tecnológicas ya empleadas anteriormente, cuyos parámetros han sido compuestos con una relación con las propiedades organolépticas y de estabilidad de los vinos; como son los compuestos fenólicos, y los compuestos aromáticos y sus precusores. En concreto, los objetivos específicos desarrollados han sido: 1.- Evaluación de la posibilidad del uso de la extracción con fluidos presurizados en la determinación de la composición fenólica de uvas y de residuos de vinificación. 2.- Desarrollo métodos rápidos para la determinación de polifenoles de interés, concretamente ésteres, catequinas y reveratrol, en uvas y residuos de vinificación. 3.-Incremento de la selectividad de los métodos desarrollados mediante acoplamiento directo entre técnicas de extracción. 4.- Evaluación de las diferentes fases sólidas disponibles comercialmente para el desarrollo de un método de determinación de compuestos terpénicos en vinos. 5.- Evaluación de la utilización del método de la glucosa glucosídica total en la determinación de precursores aromáticos en uvas cultivadas en climas cálidos y estudiar la posible correlación con los parámetros habitualmente controlados durante la maduración de esas uvas

Effects from the Freezing of Either Whole or Crushed Grapes on the Volatile Compounds Contents in Muscat Wines

The transfer of aromatic compounds from the grape skins to the musts has been studied using a process involving freezing whole bunches or crushed grapes for winemaking the Muscat of Alexandria variety (white wine). Subsequently, a prefermentative maceration has been applied to some of the samples. The aromatic profiles of the final wines have been determined using gas chromatography coupled to mass spectrophotometry (GC-MS). The results revealed that, in the trials in which whole grapes were frozen, the final wines had a higher aromatic concentration compared to that of wines obtained by either freezing crushed grapes or obtained with traditional winemaking techniques. Thus, the wines produced from frozen whole grapes were found to exhibit different characteristics from the rest of the wines. The compounds affected by the freezing either of the whole bunches or the crushed grapes were terpenes, acids, and esters. Lower differences were found for wines produced applying prefermentative maceration after the freezing process

Reusable Fe₃O₄/SBA15 nanocomposite as an efficient photo-Fenton catalyst for the removal of sulfamethoxazole and Orange II

Today, the presence of recalcitrant pollutants in wastewater, such as pharmaceuticals or other organic compounds, is one of the main obstacles to the widespread implementation of water reuse. In this context, the development of innovative processes for their removal becomes necessary to guarantee effluent quality. This work presents the potentiality of magnetic nanoparticles immobilized on SBA-15 mesoporous silica as Fenton and photo-Fenton catalysts under visible light irradiation. The influence of the characteristics of the compounds and nanoparticles on the removal yield was investigated. Once the key aspects of the reaction mechanism were analyzed, to evaluate the feasibility of this process, an azo dye (Orange II) and an antibiotic (sulfamethoxazole) were selected as main target compounds. The concentration of Orange II decreased below the detection limit after two hours of reaction, with mineralization values of 60%. In addition, repeated sequential experiments revealed the recoverability and stability of the nanoparticles in a small-scale reactor. The benchmarking of the obtained results showed a significant improvement of the process using visible light in terms of kinetic performance, comparing the results to the Fenton process conducted at dark. Reusability, yield and easy separation of the catalyst are its main advantages for the industrial application of this processThis research was supported by two projects granted by Spanish Ministry of Science, Innovation and Universities: HP-NANOBIO Project, grant number PID2019-111163RB-I00; CLUSTERCAT Project, grant number MAT2015-67458-P; and Fundación Ramón Areces (Spain), grant number CIVP18A3940.S

Novel synthetic routes of large-pore magnetic mesoporous nanocomposites (SBA-15/Fe3O4) as potential multifunctional theranostic nanodevices

In this paper, novel magnetic silica nanocomposites were prepared by anchoring magnetite nanoparticles onto the outer surface of mesoporous SBA-15 silica; the magnetic nanoparticles were prepared by microemulsion and solvothermal methods, varying the synthesis conditions in order to control the final physicochemical, textural and magnetic properties. The morphology and mesostructure of the materials were characterized by X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), N2 adsorption–desorption, and Transmission and Scanning Electron Microscopy (TEM and SEM). Magnetic silica nanocomposites feature a two-dimensional hexagonal arrangement constituted by a homogeneous pore channel system with diameters between 13 and 18 nm and a Brunauer–Emmett–Teller (BET) surface area higher than 260 m2 g−1. The different morphologies of the samples are given by the presence of diverse magnetic nanoparticle arrangements covalently linked onto the outer surface of the mesoporous silica rods. This confers on them a superparamagnetic behaviour with a magnetic response between 50–80 emu g−1, even though the weight percent of magnetite present in the samples does not exceed 21.7%. In addition, the magnetic nanocomposites exhibit magnetic hyperthermia with moderate Specific Absorption Rate (SAR) valuesThis work was supported in part by MINECO (Spain) and FEDER Funds (projects MAT 2015-67458-P and CTQ2016-79461-R); and the European Commission (PANA project, Call H2020-NMP-2015-two-stage, Grant 686009; and the MADIA project, Call H2020-ICT-2016-1, Grant 732678)S

LED-driven photo-Fenton process for micropollutant removal by nanostructured magnetite anchored in mesoporous silica

The presence of organic micropollutants in water bodies represents a threat to living organisms and ecosystems due to their toxicological effects and recalcitrance in conventional wastewater treatments. In this context, the application of heterogeneous photo-Fenton based on magnetite nanoparticles supported on mesoporous silica (SBA15) is proposed to carry out the non-specific degradation of the model compounds ibuprofen, carbamazepine, hormones, bisphenol A and the dye ProcionRed®. The operating conditions (i.e., pH, catalyst load and hydrogen peroxide concentration) were optimized by Response Surface Methodology (RSM). The paramagnetic properties of the nanocatalysts allowed their repeated use in sequential batch operations with catalyst losses below 1%. The feasibility of the process was demonstrated as removal rates above 90% after twelve accomplished after twelve consecutive cycles. In addition, the contributions of different reactive oxygen species, mainly •OH, were analyzed together with the formation of by-products, achieving total mineralization values of 15% on averageThis research was supported by HP-NANOBIO [PID2019-111163RB-I00] and MAGDEMON [PID2020-112626RB] projects, funded by MCIN/AEI/10.13039/501100011033 and SPOTLIGHT [PDC2021-121540-I00] project, funded by MCIN/AEI/10.13039/501100011033 and European Union NextGenerationEU/PRTR. J.G.-R. thanks MCIN/AEI/10.13039/501100011033 for their FPU predoctoral fellowship [FPU19/00461] and J.J.C. thanks Xunta de Galicia for his postdoctoral fellowship [ED481B-2021/015]. The authors belong to the Galician Competitive Research Groups (GRC) ED431C-2021/16 and ED432C-2021/37, co-funded by FEDER (EU)S

Exploiting the potential of supported magnetic nanomaterials as Fenton-Like catalysts for environmental applications

In recent years, the application of magnetic nanoparticles as alternative catalysts to conventional Fenton processes has been investigated for the removal of emerging pollutants in wastewater. While this type of catalyst reduces the release of iron hydroxides with the treated effluent, it also presents certain disadvantages, such as slower reaction kinetics associated with the availability of iron and mass transfer limitations. To overcome these drawbacks, the functionalization of the nanocatalyst surface through the addition of coatings such as polyacrylic acid (PAA) and their immobilization on a mesoporous silica matrix (SBA15) can be factors that improve the dispersion and stability of the nanoparticles. Under these premises, the performance of the nanoparticle coating and nanoparticle-mesoporous matrix binomials in the degradation of dyes as examples of recalcitrant compounds were evaluated. Based on the outcomes of dye degradation by the different functionalized nanocatalysts and nanocomposites, the nanoparticles embedded in a mesoporous matrix were applied for the removal of estrogens (E1, E2, EE2), accomplishing high removal percentages (above 90%) after the optimization of the operational variables. With the feasibility of their recovery in mind, the nanostructured materials represented a significant advantage as their magnetic character allows their separation for reuse in different successive sequential batch cyclesThis research was funded by HP-NANOBIO Project (PID2019-111163RB-I00) and MAGDEMON Project (PID2020-112626RB) granted by Spanish Ministry of Science and InnovationS

Valorization of grape stems

The wine industry produces large amounts of grape stem byproducts, which have been described as a natural source of polyphenols. In the present study, an extract from grape stems was evaluated for its antioxidant and antimicrobial activities in model wine to determine its potential capacity to replace and/or reduce SO2 in winemaking. Additionally, its possible effects on aroma were studied. Grape stem extract (STE) showed high antioxidant activity and it can be proposed as an energetic antioxidant. Its antimicrobial activity was compared to that of SO2. STE showed a lower inhibitory effect than SO2 for Saccharomyces cerevisiae, Hanseniaspora uvarum, Dekkera bruxellensis and Pediococcus damnosus whereas STE seems to be more efficient against Candida stellata and Botryotinia fuckeliana. GC–olfactometry analysis of STE showed that its most important odorants are naturally present in wines, and thus olfactometric profile modifications in wine, after STE addition, could appear quantitatively but not qualitatively. It can be concluded that grape stems are compounds with a low sourcing cost, high antioxidant activity and good antimicrobial properties.Ciencias de la AlimentaciónFarmaciaMedicin

Efficacy of olive oil mill extract in replacing sulfur dioxide in wine model

Olive oil industry produces high amounts of olive mill solid waste. These have been described as natural source of hydroxytyrosol, which shows high antioxidant and antimicrobial properties joint to healthpromoting effects. In the present work, an olive mill solid waste extract dissolved in model wine was evaluated to determine its potential capacity to replace and/or reduce sulfur dioxide in winemaking. Olive oil mill extract is a potent antioxidant of biological origin. The extract resulted in 4 and 40 mmol/L Trolox/mg extract by DPPH and ORAC respectively. Its antimicrobial activity was approaching to that of SO2 for Hanseniaspora uvarum, Candida stellata, Lactobacillus plantarum, Pediococcus damnosus and Acetobacter aceti, higher for Oenococcus oeni and lower for Dekkera bruxellensis and Botryotinia fuckeliana. Additionally, GC-olfactometry analysis showed that the most important odorants from the extract are naturally present in wines. However, some odorant zones might be significantly increased in wine after extract addition. It can be concluded that olive mill solid waste extracts is a source of bioactive compounds of low cost, with high antioxidant activity and good antimicrobial properties.Ciencias de la Alimentació

Ultrasounds Application on Red Winemaking

The aim of this publication is to transfer the sector an overview of ultrasound assays in red developed Rancho winemaking for red&nbsp; grape varieties with color instability in warm climates, such us Centro de la Merced and their application in Oenology field. This is intended to inform aboutultrasound aplication on enhacement of Tempranillo.&nbsp;El objetivo de este documento es la transferencia al sector de una visi&oacute;n general de los distintos ensayos con ultrasonidos que se realizan en el Centro Rancho de la Merced y su aplicaci&oacute;n en la Enolog&iacute;a. De esta manera se pretende informar sobre su aplicaci&oacute;n para la mejora de la vinificaci&oacute;n en tinto en variedades tintas con inestabilidad en el color en climas c&aacute;lidos, como la Tempranillo.</p

Ultrasound-Assisted Extraction of Stilbenes from Grape Canes

An analytical ultrasound-assisted extraction (UAE) method has been optimized and validated for the rapid extraction of stilbenes from grape canes. The influence of sample pre-treatment (oven or freeze-drying) and several extraction variables (solvent, sample-solvent ratio and extraction time between others) on the extraction process were analyzed. The new method allowed the main stilbenes in grape canes to be extracted in just 10 min, with an extraction temperature of 75 °C and 60% ethanol in water as the extraction solvent. Validation of the extraction method was based on analytical properties. The resulting RSDs (n = 5) for interday/intraday precision were less than 10%. Furthermore, the method was successfully applied in the analysis of 20 different grape cane samples. The result showed that grape cane byproducts are potentially sources of bioactive compounds of interest for pharmaceutical and food industries