Aplicación de tecnologías no térmicas (ultrasonidos y microondas) en enología

En la última década, la industria enológica ha experimentado avances significativos en el uso de tecnologías no térmicas, como los ultrasonidos de alta potencia (US), gracias a la aprobación de su uso por parte de la Organización Internacional de la Vid y el Vino, si bien otras tecnologías como las microondas continúan siendo objeto de estudio. El objetivo principal de estas tecnologías es acelerar la extracción de compuestos de interés durante la maceración en vinos tintos, al romper las paredes celulares que actúan como barreras de difusión, respondiendo a las necesidades logísticas de las bodegas y al desafío del cambio climático. A pesar de los avances, la mayoría de los ensayos realizados hasta ahora se han limitado a escala de laboratorio, por lo que es esencial estudiar estas tecnologías a escala semiindustrial e industrial, extrapolable a bodega. La presente Tesis Doctoral se centra en investigar la capacidad de los ultrasonidos de alta potencia para acelerar la extracción de compuestos de interés, especialmente fenólicos, durante la maceración de vinos tintos mediante la ruptura de las paredes celulares de la uva, y analiza, a su vez, el efecto extractivo de las microondas, tecnología emergente en enología, empleando equipos de ultrasonidos de escala semiindustrial así como un sistema de microondas a escala de laboratorio. Los resultados obtenidos muestran que la aplicación de US sobre uva estrujada provoca la alteración de las paredes celulares, afectando a su morfología, generando roturas y facilitando la liberación del contenido intracelular. Este efecto varía según las condiciones de tratamiento, siendo mejor el uso de bajas frecuencias para conseguir mayor extracción de compuestos fenólicos. Además, se observó que el uso de US aumenta la intensidad del color y la concentración de compuestos fenólicos en los vinos tintos con el mismo tiempo de maceración (7 días) y permite, también, obtener vinos con características cromáticas similares a los métodos tradicionales de maceración, pero en un tiempo más corto (3 días). Ensayos desarrollados sobre uva en estado no óptimo (con bajo contenido en azúcar y fenólicamente inmadura o bien parcialmente botritizada), mostraron que el uso de US lleva a la obtención de vinos de alta calidad organoléptica con un menor contenido alcohólico, sin que se observen características sensoriales indeseables. Además, se realizaron comparaciones con enzimas pectolíticas, empleadas tradicionalmente en la elaboración de vino con el mismo propósito. Los resultados indicaron que el uso de US permite una mayor extracción de compuestos en comparación con las enzimas. Sin embargo, la combinación de la aplicación de US y la adición posterior de enzimas mostró un efecto sinérgico, dando lugar a vinos de mayor calidad fenólica frente al uso de las técnicas por separado. Es importante destacar que el efecto de los US varía según la variedad de uva, ya que las diferencias estructurales y de composición de las paredes celulares dieron lugar a diferencias en la extracción de compuestos fenólicos, dependiendo especialmente de la cantidad de pared celular de la misma. En cuanto al uso de microondas sobre uva estrujada, se observó un aumento en la extracción de compuestos fenólicos, como antocianos, flavonoles, ácidos fenólicos y taninos, con un tiempo corto de maceración. Esto permitió reducir el tiempo de elaboración y mejorar la estabilidad del color de los vinos. Por tanto, esta Tesis Doctoral demuestra los beneficios del uso de ultrasonidos de alta potencia y el potencial de las microondas como herramientas para potenciar la extracción de compuestos de interés en la producción de vinos, no solo reduciendo los tiempos de procesamiento y aumentando, por tanto, la productividad de las bodegas, sino también mejorando la calidad de los vinosIn the last decade, the winemaking industry has experienced significant advances in the use of non-thermal technologies, such as high-power ultrasound (US), thanks to the approval of its use by the International Organisation of Vine and Wine, although other technologies such as microwaves continue to be studied. The main objective of these technologies is to accelerate the extraction of compounds of interest during maceration in red wines by breaking down the cell walls that act as diffusion barriers, responding to the logistical needs of wineries and the challenge of climate change. Despite the advances, most of the tests carried out so far have been limited to the laboratory scale, so it is essential to study these technologies on a semi-industrial and industrial scale, which can be extrapolated to the winery. This Doctoral Thesis focuses on investigating the capacity of high-power ultrasound to accelerate the extraction of compounds, especially phenolics, during the maceration of red wines by breaking the cell walls, and also analyses the extractive effect of microwaves, an emerging technology in oenology, using semi-industrial-scale ultrasound device, as well as a laboratory scale microwave system. The results obtained show that the application of US on crushed grapes causes alteration of the cell walls, affecting their morphology, generating ruptures and facilitating the release of intracellular content. This effect varies according to the treatment conditions, with the use of low frequencies being better in the case of seeking a greater extraction of phenolic compounds. Furthermore, it was observed that the use of US increases the colour intensity and the concentration of phenolic compounds in red wines with the same maceration time (7 days) and also allows obtaining wines with chromatic characteristics similar to traditional maceration methods, but in a shorter time (3 days). Tests carried out on less-than-optimal grapes (with low sugar content and phenolically immature or partially botrytised) showed that the use of US leads to wines of high organoleptic quality with a lower alcohol content, without any undesirable sensory characteristics. In addition, comparisons were made with pectolytic enzymes, traditionally used in winemaking for the same purpose. The results indicated that the use of US allows a higher extraction of compounds compared to enzymes. However, the combination of the application of US and the subsequent addition of enzymes showed a synergistic effect, resulting in wines of higher phenolic quality compared to the use of the techniques separately. It is important to note that the effect of the US varies according to the grape variety, as the structural and compositional differences in the cell walls resulted in differences in the extraction of phenolic compounds, depending especially on the amount of cell wall in the grape. As for the use of microwaves on crushed grapes, an increase in the extraction of phenolic compounds, such as anthocyanins, flavonols, phenolic acids and tannins, was observed with a shorter maceration time. This allowed for a reduction in winemaking time and improved colour stability of the wines. In summary, this PhD Thesis demonstrates the benefits of using high power ultrasound and the potential of microwaves as tools to enhance the extraction of compounds of interest in wine production, not only reducing processing times, and, therefore, increasing winery productivity, but also improving wine quality

Key-Value vs Graph-based data lakes for realizing Digital Twin systems

Digital twins constitute virtual representations of physically existing systems, synchronized at a specified frequency and fidelity. One way to connect physical and digital twins is through data lakes, which are efficient storage and query processing systems to manage the data exchanged between the twins. Existing digital twin systems make use of NoSQL or time databases for realizing their data lakes. Although very efficient, these proposals present some limitations for implementing non-trivial queries over highly connected data. In this paper we explore the use of graph databases for implementing data lakes, compare them with similar NoSQL proposals, and discuss the situations where one solution outperforms the other.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Project-Based Learning Applied to Unmanned Aerial Systems and Remote Sensing

The development of unmanned aerial vehicle (UAV) technology and the miniaturization of sensors have changed the way remote sensing (RS) is used, popularizing this geoscientific discipline in other fields, such as precision agriculture. This makes it necessary to implement the use of these technologies in teaching RS alongside the classical platforms (satellite and manned aircraft). This manuscript describes how The Higher Technical School of Agricultural Engineering at the University of Córdoba (Spain) has introduced UAV RS into the academic program by way of project-based learning (PBL). It also presents the basic characteristics of PBL, the design of the subject, the description of the teacher-guided and self-directed activities, as well as the degree of student satisfaction. The teaching and learning objectives of the subject are to learn how to determine the vigor, temperature, and water stress of a crop through the use of RGB, multispectral, and thermographic sensors onboard a UAV platform. From the onset, students are motivated, actively participate in the tasks related to the realization of UAV flights, and subsequent processing and analysis of the registered images. Students report that PBL is more engaging and allows them to develop a better understanding of RS

Effect of Lockdown Measures on Atmospheric Nitrogen Dioxide during SARS-CoV-2 in Spain

The disease caused by SARS-CoV-2 has affected many countries and regions. In order to contain the spread of infection, many countries have adopted lockdown measures. As a result, SARS-CoV-2 has negatively influenced economies on a global scale and has caused a significant impact on the environment. In this study, changes in the concentration of the pollutant Nitrogen Dioxide (NO2) within the lockdown period were examined as well as how these changes relate to the Spanish population. NO2 is one of the reactive nitrogen oxides gases resulting from both anthropogenic and natural processes. One major source in urban areas is the combustion of fossil fuels from vehicles and industrial plants, both of which significantly contribute to air pollution. The long-term exposure to NO2 can also cause severe health problems. Remote sensing is a useful tool to analyze spatial variability of air quality. For this purpose, Sentinel-5P images registered from January to April of 2019 and 2020 were used to analyze spatial distribution of NO2 and its evolution under the lockdown measures in Spain. The results indicate a significant correlation between the population’s activity level and the reduction of NO2 values

Machine Learning Methods and Synthetic Data Generation to Predict Large Wildfires

Wildfires are becoming more frequent in different parts of the globe, and the ability to predict when and where they will occur is a complex process. Identifying wildfire events with high probability of becoming a large wildfire is an important task for supporting initial attack planning. Different methods, including those that are physics-based, statistical, and based on machine learning (ML) are used in wildfire analysis. Among the whole, those based on machine learning are relatively novel. In addition, because the number of wildfires is much greater than the number of large wildfires, the dataset to be used in a ML model is imbalanced, resulting in overfitting or underfitting the results. In this manuscript, we propose to generate synthetic data from variables of interest together with ML models for the prediction of large wildfires. Specifically, five synthetic data generation methods have been evaluated, and their results are analyzed with four ML methods. The results yield an improvement in the prediction power when synthetic data are used, offering a new method to be taken into account in Decision Support Systems (DSS) when managing wildfires

Ultrasound treatment of crushed grapes: Effect on the must and red wine polysaccharide composition

This paper studied the effect on the molecular weight and polysaccharide composition of musts and wines of the application of high-power ultrasound (US) at 20 and 28 kHz on crushed grapes. Two different pomace maceration times (short and mid) were tested for sonicated and control vinifications. A long pomace maceration time was also tested for non-treated wines. In must samples, US significantly increased the content of monosaccharides and polysaccharides rich in arabinose and galactose (PRAG), and the average molecular weight of smaller PRAG, mannoproteins (MP) or mannans. The 28 kHz had a major effect on most wine monosaccharides and grape polysaccharides. The wine obtained from sonicated grapes at 28 kHz and with mid maceration had higher rhamnogalacturonans type II and PRAG content than its control, and closer polysaccharide and monosaccharide content to long maceration control wines. No significant differences were obtained in the MP content between sonicated and control wines.This research was funded by the Ministerio de Ciencia, Innovación y Universidades from the Spanish Government and Feder Funds, grant number RTI2018-093869-B-C21

Effect of Pre-fermentative Treatments on Polysaccharide Composition of White and Rosé Musts and Wines

This paper studied the effect of conventional pre-fermentative techniques (direct pressing "CP" and cold maceration "CM") and an innovate technique (high power ultrasounds "S"), applied to Viogner and Monastrell grapes on the polysaccharide content of the musts, white and rosé wines, and after six months of bottle aging. The results showed that the longer pre-fermentation maceration time applied with the CM technique compared to the short ultrasonic maceration was key in the extraction of polysaccharides from the grape to the must. CP treatment produced wines with the lowest content of total soluble polysaccharide families since it was the least intense pretreatment for the disruption of the grape berry cell wall polysaccharides. Ultrasonic pretreatment could be used as a new tool to increase the solubilization of polysaccharides in wines, positively affecting the wine colloidal properties. During bottle aging, there wasn't a clear effect of pretreatments on the evolution of polysaccharides.This research was funded by the Ministerio de Ciencia, Innovación y Universidades from the Spanish Government and Feder Funds, grant number RTI2018–093869–B-C21.Peer reviewe

Effect of marine heat waves on carbon metabolism, optical characterization, and bioavailability of dissolved organic carbon in coastal vegetated communities

Dissolved organic carbon (DOC) plays an essential role in the global marine carbon cycle, with coastal vegetated communities as important DOC producers. However, the ultimate fate of this DOC remains still largely unknown due to the lack of knowledge about its chemical composition and lability. Furthermore, global change could alter both DOC fluxes and its bioavailability, affecting the carbon sequestration capacity of coastal vegetated communities. This study explores, in two contrasting seasons (winter and summer), the effects of an in situ simulated marine heatwave on carbon metabolism and DOC fluxes produced by seagrass (Cymodocea nodosa) and macroalgae (Caulerpa prolifera) communities. In addition, the fluorescent characteristics and biodegradability of the dissolved organic matter released directly by the communities under such conditions are evaluated. Under marine heatwave conditions, a significant increase in net community production (NCP) in C. nodosa and a shift to negative DOC fluxes in C. prolifera were observed. In control treatments, the seagrass-dominated community produced a substantial amount of labile (between 44% and 58%) and recalcitrant DOC (between 42% and 56%), while C. prolifera community produced mainly recalcitrant DOC (between 64% and 87%). Therefore, this research revealed that temperature is an important factor determining the NCP in benthic communities and the chemical structure and bioavailability of DOC produced by these communities, since both communities tended to produce more humic-like and less bioavailable DOC with increasing temperature. © 2022 The Authors. Limnology and Oceanography published by Wiley Periodicals LLC on behalf of Association for the Sciences of Limnology and Oceanography

Using Unmanned Aerial Vehicles (UAV) for forest damage monitoring in south-western Europe

P. 1-8Prescribed burns are being considered as a management tool for the prevention of forest fires in many countries that have important firefighting problems. Knowledge of fire intensity and eliminated vegetation fuel are of great interest to evaluate their effectiveness. Both parameters are directly related to burn severity, so their evaluation is fundamental to predict the post-fire evolution of burned area. In this study we evaluated two prescribed burnings carried out in North of Spain during October 2017 by using multispectral data from an Unmanned Aerial Vehicle (UAV). In particular, four surface reflectance images were obtained in green (550 nm), red (660 nm), red-edge (735 nm) and near infrared (790 nm) at very high spatial resolution (GSD 20 cm) from which different spectral indexes were computed. Additionally, vegetation and soil burn severity was measured in 153 field plots and an analysis of variance (ANOVA) between each spectral index and burn severity (both in vegetation and soil) was performed. A Fisher’s least significant difference test determined that three vegetation burn severity levels and two soil burn severity levels could be statistically distinguished. The identification of such burn severity levels is sufficient and useful to forest managers. We conclude that multispectral data from UAVs may be considered as a valuable indicator of burn severity for prescribed burnings.S