Sensor arrays for Enology applications: Using nanoscience for grape analysis

Esta tesis presenta el desarrollo de nuevo sensores basados en diferentes materiales electroactivos mediante el uso de diferentes técnicas. Se han llevado a cabo diferentes estrategias para mejorar el comportamiento y la selectividad de los sensores incluyendo enzimas y nuevos materiales electroactivos como ftalocianinas, nanopartículas y materiales derivados del carbono (microesferas, nanotubos…). Los electrodos modificados mostraron un aumento en la sensibilidad y selectividad frente ácidos orgánicos, compuestos fenólicos y azúcares comparados con los electrodos clásicos. El uso de la técnica de Langmuir-Blodgett permitió preparar sensores con una superficie nanoestructurada que fue la responsable de la mejora en las respuestas electroquímicas frente al análisis de compuestos de interés en la industria enológica. Estos nuevos sensores se han combinado para desarrollar lenguas (bio)electrónicas empleadas en la discriminación de mostos de uvas con diferentes características organolépticas. Además se ha llevado a cabo con éxito el control la maduración de la uva.Departamento de Química, Física y Química Inorgánic

Impact of Temperature, Ethanol and Cell Wall Material Composition on Cell Wall-Anthocyanin Interactions.

The effects of temperature and ethanol concentration on the kinetics of anthocyanin adsorption and desorption interactions with five cell wall materials (CWM) of different composition were investigated. Using temperatures of 15 °C and 30 °C and model wine with ethanol concentrations of 0% and 15% (v/v) over 120 min, the adsorption and desorption rates of five anthocyanin-glucosides were recorded in triplicate. Small-scale experiments were conducted using a benchtop incubator to mimic a single berry fermentation. Results indicate that more than 90% of the adsorption occurs within the first 60 min of the addition of anthocyanins to CWM. However, desorption appears to occur much faster, with maximum desorption being reached after 30 min. The extent of both adsorption and desorption was clearly dependent not only on temperature and ethanol concentration but also on the CWM composition

Bioelectronic tongue based on lipidic nanostructured layers containing phenol oxidases and lutetium bisphthalocyanine for the analysis of grapes

Producción CientíficaIn this work, a multisensor system formed by nanostructured voltammetric biosensors based on phenol oxidases (tyrosinase and laccase) has been developed. The enzymes have been incorporated into a biomimetic environment provided by a Langmuir-Blodgett (LB) film of arachidic acid (AA). Lutetium bisphthalocyanine (LuPc2) has also been introduced in the films to act as electron mediator. The incorporation of the enzymes to the floating layers to form Tyr/AA/LuPc2 and Lac/AA/LuPc2 films has been confirmed by the expansion in the surface pressure isotherms and by the AFM images. The voltammetric response towards six phenolic compounds demonstrates the enhanced performance of the biosensors that resulted from a preserved activity of the tyrosinase and laccase combined with the electron transfer activity of LuPc2. Biosensors show improved detection limits in the range of 10-7-10-8molL-1. An array formed by three sensors AA/LuPc2, Tyr/AA/LuPc2 and Lac/AA/LuPc2 has been employed to discriminate phenolic antioxidants of interest in the food industry. The Principal Component Analysis scores plot has demonstrated that the multisensor system is able to discriminate phenols according to the number of phenolic groups attached to the structure. The system has also been able to discriminate grapes of different varieties according to their phenolic content. This good performance is due to the combination of four factors: the high functionality of the enzyme obtained using a biomimetic immobilization, the signal enhancement caused by the LuPc2 mediator, the improvement in the selectivity induced by the enzymes and the complementary activity of the enzymatic sensors demonstrated in the loading plots.Ministerio de Economía, Industria y Competitividad – FEDER (Grant CICYT AGL2012-33535)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA-032U13

Interspecies somatic cell nuclear transfer in wild felids: A systematic review and meta-analysis

El objetivo de este trabajo fue realizar una revisión sistemática sobre la transferencia nuclear de células so-máticas de félidos salvajes utilizando ovocitos maduros de gato doméstico (Felis catus). Además, se realizaron dos metaanálisis con el programa Comprehensive Meta-Analysis V4 para evaluar el efecto de la transferencia nuclear de células somáticas interespecie (TNCSi) en la división embrionaria y formación de blastocisto en comparación con la técnica intraespecie con células somáticas y ovocitos de gato (TNCSg-g). El metaanálisis se realizó con un modelo aleatorio y el tamaño del efecto se determinó mediante el riesgo relativo (RR). En la revisión sistemática se seleccionaron 16 artículos científicos de un total de 248 y 3230 referencias inicia-les en PubMed y ScienceDirect, respectivamente. Los artículos publicaban tasas de división embrionaria del 27.5% al 96.7% y una tasa máxima de formación de blastocisto del 41.5%. Solo 2 de los 8 artículos obtuvieron descendencia viva, con una eficiencia del 1% aproximadamente sobre el total de embriones transferidos. El riesgo de sesgo de los 10 artículos seleccionados para el metaanálisis fue bajo. No se encontraron diferencias significativas (p>0.05) en la división embrionaria entre la TNCSi y la TNCSg-g. Sin embargo, se observó una menor (p=0.016; RR=0.4) probabilidad de formación de blastocistos en el grupo experimental de TNCSi en comparación con la TNCSg-g. En conclusión, la bibliografía sobre TNCSi en félidos salvajes es escasa y es-tudia especies muy distintas, lo que dificulta los metaanálisis. Aunque la división embrionaria hasta el estadio de 2-4 células es similar en la TNCSi y la TNCSg-g, la formación de blastocisto es menor cuando la célula somática es de una especie de félido distinta al gatoThe aim of this work was to systematically review scientific articles on interspecies somatic cell nuclear transfer (iSCNT) in wild cats using domestic cat oocytes. In addition, two meta-analyses were performed us-ing the Comprehensive Meta-Analysis V4 program to evaluate the effect of iSCNT on embryonic division and blastocyst formation compared to the intraspecies technique with somatic cells and oocytes from domestic cat (SCNTc-c). The meta-analysis was performed using a randomized model and the effect size was determined us-ing the relative risk (RR). Sixteen scientific articles were selected from a total of 248 and 3230 initial references in PubMed and ScienceDirect, respectively. The articles report embryonic cleavage rates of 27.5% to 96.7% and a maximum blastocyst formation rate of 41.5%. Only 2 of the 8 articles obtained live offspring, with an efficiency of approximately 1% of the total number of embryos transferred. The risk of bias of the 10 articles se-lected for the meta-analysis was low. No significant differences (p>0.05) were found in the embryonic division between the iSCNT and the SCNTc-c. However, a lower (p=0.016; RR=0.4) probability of blastocyst formation was observed in the experimental group of iSCNT compared to SCNTc-c. In conclusion, the bibliography on iSCNT in wild cats is scarce and studies very different species, which makes meta-analyses difficult. Although embryonic division up to the 2-4 cell stage is similar in iSCNT and SCNTc-c, blastocyst formation is less when the somatic cell is from a felid species other than the cat

TRANSFERENCIA NUCLEAR DE CÉLULAS SOMÁTICAS INTERESPECIE EN FÉLIDOS SALVAJES: UNA REVISIÓN SISTEMÁTICA Y METAANÁLISIS

The aim of this work was to systematically review scientific articles on interspecies somatic cell nuclear transfer (iSCNT) in wild cats using domestic cat oocytes. In addition, two meta-analyses were performed using the Comprehensive Meta-Analysis V4 program to evaluate the effect of iSCNT on embryonic division and blastocyst formation compared to the intraspecies technique with somatic cells and oocytes from domestic cat (SCNTc-c). The meta-analysis was performed using a randomized model and the effect size was determined using the relative risk (RR). Sixteen scientific articles were selected from a total of 248 and 3230 initial references in PubMed and ScienceDirect, respectively. The articles report embryonic cleavage rates of 27.5% to 96.7% and a maximum blastocyst formation rate of 41.5%. Only 2 of the 8 articles obtained live offspring, with an efficiency of approximately 1% of the total number of embryos transferred. The risk of bias of the 10 articles selected for the meta-analysis was low. No significant differences (p>0.05) were found in the embryonic division between the iSCNT and the SCNTc-c. However, a lower (p=0.016; RR=0.4) probability of blastocyst formation was observed in the experimental group of iSCNT compared to SCNTc-c. In conclusion, the bibliography on iSCNT in wild cats is scarce and studies very different species, which makes meta-analyses difficult. Although embryonic division up to the 2-4 cell stage is similar in iSCNT and SCNTc-c, blastocyst formation is less when the somatic cell is from a felid species other than the cat. El objetivo de este trabajo fue realizar una revisión sistemática sobre la transferencia nuclear de células somáticas de félidos salvajes utilizando ovocitos maduros de gato doméstico (Felis catus). Además, se realizaron dos metaanálisis con el programa Comprehensive Meta-Analysis V4 para evaluar el efecto de la transferencia nuclear de células somáticas interespecie (TNCSi) en la división embrionaria y formación de blastocisto en comparación con la técnica intraespecie con células somáticas y ovocitos de gato (TNCSg-g). El metaanálisis se realizó con un modelo aleatorio y el tamaño del efecto se determinó mediante el riesgo relativo (RR). En la revisión sistemática se seleccionaron 16 artículos científicos de un total de 248 y 3230 referencias iniciales en PubMed y ScienceDirect, respectivamente. Los artículos publicaban tasas de división embrionaria del 27.5% al 96.7% y una tasa máxima de formación de blastocisto del 41.5%. Solo 2 de los 8 artículos obtuvieron descendencia viva, con una eficiencia del 1% aproximadamente sobre el total de embriones transferidos. El riesgo de sesgo de los 10 artículos seleccionados para el metaanálisis fue bajo. No se encontraron diferencias significativas (p>0.05) en la división embrionaria entre la TNCSi y la TNCSg-g. Sin embargo, se observó una menor (p=0.016; RR=0.4) probabilidad de formación de blastocistos en el grupo experimental de TNCSi en comparación con la TNCSg-g. En conclusión, la bibliografía sobre TNCSi en félidos salvajes es escasa y estudia especies muy distintas, lo que dificulta los metaanálisis. Aunque la división embrionaria hasta el estadio de 2-4 células es similar en la TNCSi y la TNCSg-g, la formación de blastocisto es menor cuando la célula somática es de una especie de félido distinta al gato.

Monitoring the phenolic ripening of red grapes using a multisensor system based on metal-oxide nanoparticles

Producción CientíficaThe maturity of grapes is usually monitored by means of the sugar concentration. However, the assessment of other parameters such as the phenolic content is also important because the phenolic maturity has an important impact on the organoleptic characteristics of wines. In this work, voltammetric sensors able to detect phenols in red grapes have been developed. They are based on metal oxide nanoparticles (CeO2, NiO, and TiO2,) whose excellent electrocatalytic properties toward phenols allows obtaining sensors with detection limits in the range of 10−8 M and coefficients of variation lower than 7%. An electronic tongue constructed using a combination of the nanoparticle-based sensors is capable to monitor the phenolic maturity of red grapes from véraison to maturity. Principal Component Analysis (PCA) can be successfully used to discriminate samples according to the ripeness. Regression models performed using Partial Least Squares (PLS-1) have established good correlations between voltammetric data obtained with the electrochemical sensors and the Total Polyphenolic Index, the Brix degree and the Total Acidity, with correlation coefficients close to 1 and low number of latent variables. An advantage of this system is that the electronic tongue can be used for the simultaneous assessment of these three parameters which are the main factors used to monitor the maturity of grapes. Thus the electronic tongue based on metal oxide nanoparticles can be a valuable tool to monitor ripeness. These results demonstrate the exciting possible applications of metal oxide nanoparticles in the field of electronic tongues.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-67482- R)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA011U16)Junta de Castilla y León (grant BOCYL-D-24112015-9

Electronic Noses and Tongues in Wine Industry

Producción CientíficaThe quality of wines is usually evaluated by a sensory panel formed of trained experts or traditional chemical analysis. Over the last few decades, electronic noses (e-noses) and electronic tongues have been developed to determine the quality of foods and beverages. They consist of arrays of sensors with cross-sensitivity, combined with pattern recognition software, which provide a fingerprint of the samples that can be used to discriminate or classify the samples. This holistic approach is inspired by the method used in mammals to recognize food through their senses. They have been widely applied to the analysis of wines, including quality control, aging control, or the detection of fraudulence, among others. In this paper, the current status of research and development in the field of e-noses and tongues applied to the analysis of wines is reviewed. Their potential applications in the wine industry are described. The review ends with a final comment about expected future developments.CM-P agradece a la Universidad de Valladolid por su beca PIF-UVa y CG-H por su contrato pre-doctoral JCYL (BOCYL-D-24112015-9).Ministerio de Economía, Industria y Competitividad – FEDER (Grant AGL2015-67482-R)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA-032U13

An Electrochemical Quartz Crystal Microbalance Multisensor System Based on Phthalocyanine Nanostructured Films: Discrimination of Musts

Producción CientíficaAn array of electrochemical quartz crystal electrodes (EQCM) modified with nanostructured films based on phthalocyanines was developed and used to discriminate musts prepared from different varieties of grapes. Nanostructured films of iron, nickel and copper phthalocyanines were deposited on Pt/quartz crystals through the Layer by Layer technique by alternating layers of the corresponding phthalocyanine and poly-allylamine hydrochloride. Simultaneous electrochemical and mass measurements were used to study the mass changes accompanying the oxidation of electroactive species present in must samples obtained from six Spanish varieties of grapes (Juan García, Prieto Picudo, Mencía Regadío, Cabernet Sauvignon, Garnacha and Tempranillo). The mass and voltammetric outputs were processed using three-way models. Parallel Factor Analysis (PARAFAC) was successfully used to discriminate the must samples according to their variety. Multi-way partial least squares (N-PLS) evidenced the correlations existing between the voltammetric data and the polyphenolic content measured by chemical methods. Similarly, N-PLS showed a correlation between mass outputs and parameters related to the sugar content. These results demonstrated that electronic tongues based on arrays of EQCM sensors can offer advantages over arrays of mass or voltammetric sensors used separately.Ministerio de Economía, Industria y Competitividad – FEDER (Grant CICYT AGL2012-33535)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA-032U13)University of Valladolid (PIF-UVa

Improvement of electrocatalytic effect in voltammetric sensors based on phthalocyanines

Producción CientíficaVoltammetric sensors based on phthalocyanines have been used to detect a variety of compounds. In this paper, the state of the art of sensors prepared using classical techniques will be revised. Then, new strategies to improve the performance of the sensors will be described using as example sensors chemically modified with lutetium bisphthalocyanine (LuPc2) dedicated to the detection of phenols of interest in the food industry. Classical LuPc2 carbon paste electrodes can detect phenols such as catechol, caffeic acid or pyrogallol with limits of detection in the range of 10-4–10-5 M. The performance can be improved by using nanostructured Langmuir–Blodgett (LB) or Layer by Layer (LbL) films. The enhanced surface to volume ratio produce an increase in the sensitivity of the sensors. Limits of detection of 10-5–10-7 M are attained, which are one order of magnitude lower than those obtained using conventional carbon paste electrodes. Moreover, these techniques can be used to coimmobilize two electrocatalytic materials in the same device. The limits of detection obtained in LB sensors combining LuPc2/AuNPs or LuPc2/CNT are further improved. Finally, the LB technique has been used to prepare biosensors where a phenol oxydase (such as tyrosinase or lacasse) is immobilized in a biomimetic environment that preserves the enzymatic activity. Moreover, LuPc2 can be co-immobilized with the enzyme in a lipidc film formed by arachidic acid (AA). LuPc2 can act as an electron mediator facilitating the electron transfer. These biomimetic sensors formed by LuPc2/AA/enzyme show Limits of detection of 10-8 M and an enhanced selectivity.CM-P agradece a la Universidad de Valladolid por su beca PIF-UVa y CG-H por su contrato pre-doctoral JCYL (BOCYL-D-24112015-9).Ministerio de Economía, Industria y Competitividad – FEDER (Grant CICYT AGL2012-33535)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA-032U13

Overhead photoselective shade films mitigate effects of climate change by arresting flavonoid and aroma composition degradation in wine

IntroductionOverhead photoselective shade films installed in vineyards improve berry composition in hot grape-growing regions. The aim of the study was to evaluate the flavonoid and aroma profiles and composition of wines from Cabernet Sauvignon grapes (Vitis vinifera L.) treated with partial solar radiation exclusion.MethodsExperimental design consisted in a randomized experiment with four shade films (D1, D3, D4, D5) with differing solar radiation spectra transmittance and compared to an uncovered control (C0) performed over two seasons (2021 and 2022) in Oakville (CA, USA). Berries were collected by hand at harvest and individual vinifications for each treatment and season were conducted in triplicates. Then, wine chemical composition, flavonoid and aromatic profiles were analyzed.ResultsThe wines from D4 treatment had greater color intensity and total phenolic index due to co-pigmentation with anthocyanins. Shade film wines D5 and D1 from the 2020 vintage demonstrated increased total anthocyanins in the hotter of the two experimental years. In 2021, reduced cluster temperatures optimized total anthocyanins in D4 wines. Reduced cluster temperatures modulated anthocyanin acylation, methylation and hydroxylation in shade film wines. Volatile aroma composition was analyzed using gas chromatography mass spectroscopy (GCMS) and D4 wines exhibited a more fruity and pleasant aroma profile than C0 wines.DiscussionResults provided evidence that partial solar radiation exclusion in the vineyard using overhead shade films directly improved flavonoid and aroma profiles of resultant wines under hot vintage conditions, providing a tool for combatting air temperatures and warmer growing conditions associated with climate change