Application of an E-Tongue to the Analysis of Monovarietal and Blends of White Wines

This work presents a multiparametric system capable of characterizing and classifying white wines according to the grape variety and geographical origin. Besides, it quantifies specific parameters of interest for quality control in wine. The system, known as a hybrid electronic tongue, consists of an array of electrochemical microsensors-six ISFET based sensors, a conductivity sensor, a redox potential sensor and two amperometric electrodes, a gold microelectrode and a microelectrode for sensing electrochemical oxygen demand-and a miniaturized optofluidic system. The test sample set comprised eighteen Catalan monovarietal white wines from four different grape varieties, two Croatian monovarietal white wines and seven bi- and trivarietal mixtures prepared from the Catalan varieties. Different chemometric tools were used to characterize (i.e., Principal Component Analysis), classify (i.e., Soft Independent Modeling Class Analogy) and quantify (i.e., Partial-Least Squares) some parameters of interest. The results demonstrate the usefulness of the multisensor system for analysis of wine

Bioinspired Sensor Systems

This editorial summarizes and classifies the contributions presented by different authors to the special issue of the journal Sensors dedicated to Bioinspired Sensor Systems. From the coupling of sensor arrays or networks, plus computer processing abilities, new applications to mimic or to complement human senses are arising in the context of ambient intelligence. Principles used, and illustrative study cases have been presented permitting readers to grasp the current status of the field

Hybrid Electronic Tongues Applied to the Quality Control of Wines

The legislation of food industry is becoming increasingly strict with regard to the quality of food products. Therefore, the market is demanding for automatic systems of analysis that allow fast and accurate monitoring of the evolution of quality parameters in agrofood products or permit obtaining information to optimize production processes. In this context, sensors and more specifically microsensors play an important role since they allow fast and reproducible measurement of a large number of quality parameters with good reliability and can be implemented in portable systems. This paper presents a review of the results obtained with an electronic tongue based on different kinds of microsensors applied to wine analysis by the team of IMB-CNM. This multisensor system allows on one hand classifying the wine according to its features like grape variety, geographic origin, year, and organoleptic characteristics and on the other hand quantifying some parameters of interest in quality control, such as alcoholic degree, pH, ions, total acidity, glycerol, and color

Application of an E-Tongue to the Analysis of Monovarietal and Blends of White Wines

This work presents a multiparametric system capable of characterizing and classifying white wines according to the grape variety and geographical origin. Besides, it quantifies specific parameters of interest for quality control in wine. The system, known as a hybrid electronic tongue, consists of an array of electrochemical microsensors—six ISFET based sensors, a conductivity sensor, a redox potential sensor and two amperometric electrodes, a gold microelectrode and a microelectrode for sensing electrochemical oxygen demand—and a miniaturized optofluidic system. The test sample set comprised eighteen Catalan monovarietal white wines from four different grape varieties, two Croatian monovarietal white wines and seven bi- and trivarietal mixtures prepared from the Catalan varieties. Different chemometric tools were used to characterize (i.e., Principal Component Analysis), classify (i.e., Soft Independent Modeling Class Analogy) and quantify (i.e., Partial-Least Squares) some parameters of interest. The results demonstrate the usefulness of the multisensor system for analysis of wine.We acknowledge funding from the Spanish R & D National Program (MICINN Project TEC2007-68012-C03-01/03), the CIDEM network GTQ-Tecnio and the Juan de la Cierva scholarship (Manuel Gutiérrez

Application of an E-Tongue to the Analysis of Monovarietal and Blends of White Wines

This work presents a multiparametric system capable of characterizing and classifying white wines according to the grape variety and geographical origin. Besides, it quantifies specific parameters of interest for quality control in wine. The system, known as a hybrid electronic tongue, consists of an array of electrochemical microsensors-six ISFET based sensors, a conductivity sensor, a redox potential sensor and two amperometric electrodes, a gold microelectrode and a microelectrode for sensing electrochemical oxygen demand-and a miniaturized optofluidic system. The test sample set comprised eighteen Catalan monovarietal white wines from four different grape varieties, two Croatian monovarietal white wines and seven bi- and trivarietal mixtures prepared from the Catalan varieties. Different chemometric tools were used to characterize (i.e., Principal Component Analysis), classify (i.e., Soft Independent Modeling Class Analogy) and quantify (i.e., Partial-Least Squares) some parameters of interest. The results demonstrate the usefulness of the multisensor system for analysis of wine

Développement de langue électronique : étude de mélanges complexes et de bactéries

The objective of this PhD thesis is to explore the potential applications of the electronic tongue, based on combinatorial cross-reactive receptors and surface plasmon resonance imaging, for analysis and discrimination of different complex mixtures and bacteria. In this work, various complex mixtures of different nature such as wine, beer, and milk (either animal-based or plant-based) are used. It has been demonstrated that the electronic tongue is capable of responding differently to theses samples with good selectivity. For each of them, it can generate characteristic continuous 2D profile and 3D image, based on which the differentiation and classification of the complex mixtures have been carried out. Furthermore, it has been illustrated that the electronic tongue is efficient for monitoring the deterioration of milk. In the second part of this thesis, the electronic tongue has been applied for detection and analysis of bacteria. At first, some fluidic parameters have been optimized due to the variable morphology of these complexes and large biological objects. Under optimized experimental conditions, the electronic tongue is effective for analysis of bacteria with the possibility for quantification. Thereafter, the electronic tongue has allowed for the discrimination of different bacteria according to their genus, species and strains based on continuous 2D profiles and 3D images.L'objectif de cette thèse est d'explorer les applications potentielles d'un système de langue électronique basée sur des récepteurs combinatoires à réactivités croisées et l'imagerie par résonance de plasmons de surface, pour l'analyse et la discrimination de différents milieux complexes et de bactéries. L'étude de milieux complexes a été réalisée sur des échantillons de différentes natures comme le vin, la bière et le lait d'origines végétale et animale. Les expériences ont démontré que notre système de langue électronique est capable de répondre avec une bonne sélectivité à ces milieux complexes et qu'il génère ainsi des profils continus 2D et des images 3D, propres à chaque échantillon. La différentiation et la classification de ces divers types de boissons ont été réalisées grâce à ces signatures 2D et 3D. Le dispositif a également prouvé son efficacité pour le suivi du vieillissement du lait. Une seconde étude a été dédiée à l'application du système pour la détection de bactéries. Dans un premier temps, des paramètres fluidiques ont été optimisés comme la forme et la profondeur de la cuve ou le débit fluidique, en raison de la morphologie variable des bactéries, considérées ici comme des objets biologiques complexes et volumineux. Dans un second temps, le système s'est révélé performant pour l'analyse de bactéries et a montré la possibilité de quantifier ces analyses. En effet, la langue électronique a permis la discrimination de différentes bactéries selon leur genre, leur espèce et en fonction des souches grâce aux profils continus 2D et aux images 3D

Disposable Lab-on-Chip Systems for Biotechnological Screening

The main goal of this work was to develop different disposable Lab-on-Chip (LoC) systems for the application of biotechnological screening e.g. for bioprocess development through microorganisms or drug testing with human cell lines. Nowadays, microfluidics represents a highly promising field for the fabrication of microtools, as the increasing demand for screening data are difficult to meet with current platforms. This is mainly due to time and cost aspects as well as a limited amount of newly developed drugs. The ideal microfluidic platform for biotechnological screening should include three different groups of elements: (i) microbioreactors (MBR) in which cultivation takes place; (ii) auxiliary microfluidic systems (for transportation, filtration or mixing), and (iii) enzymatic biosensors for onchip analysis of substrate concentrations which are difficult to measure offline due to small available sample volumes. Within the scope of this work, various horizontally and vertically positioned MBR designs (resembling plug flow reactors, micro stir tanks or bubble columns) were developed, fabricated and successfully applied to the screening of different biological expression systems, such as yeast cells (S. cerevisiae), fungal spores (A. ochraceus) and primary human endothelial cells. Different integrated functional structures based on geometrical, optical or electrical elements allowed for online monitoring of various physical, chemical and biological process parameters during cultivation. In terms of the second group, passive and active microvalves, PZTand pneumatically actuated micropumps, passive filtration and mixing elements were produced. The third group comprised different types of enzymatic biosensors based on a hybrid detection principle (electrochemical-optical) and on different types of enzymatic responses. In general, the unique LoC setup (patterned element made of poly(dimethylsiloxane) and bonded to a glass substrate) allows an easy integration of systems into one monolithic LoC platform which are usually better suited for technically mature systems. Modular systems are advantageous for prototyping of new microfluidic applications. Therfore, an LoC construction kit was developed that offers a user friendly, standardized modular platform.Im Rahmen der Dissertation wurden verschiedene Einweg-Lab-on-Chip Systeme entwickelt, die beispielsweise bei biotechnologischen Parameterstudien von Mikroorganismen zur Bioprozesssteigerung oder von humanen Zelllinien zum Wirkstoffscreening Anwendung finden. Die Mikrofluidik ist ein vielversprechendes Forschungsgebiet für die Herstellung von kostengünstigen Mikrochips, womit der steigende Bedarf für Screening-Daten aufgrund von Vorteilen wie Zeit- und Kostenreduzierung erfüllt werden kann. Eine ideale mikrofluidische Plattform zum biotechnologischen Screenen sollte aus folgenden Gruppen bestehen: (i) dem Mikrobioreaktor zur Kultivierung, (ii) mikrofluidische Komponenten zum Transportieren, Filtrieren und Mischen von Suspensionen, und (iii) einem enzymatischen Biosensor für die on-Chip Analyse von Substratkonzentrationen. Innerhalb der Arbeit wurden diverse horizontal und vertikal positionierte Mikrobioreaktoren entwickelt, hergestellt und erfolgreich zum Screenen von unterschiedlichen biologischen Expressionssystemen (wie S. cerevisiae, A. ochraceus und humane Endothelzellen) angewendet. Die Integration von geometrischen, optischen und elektrischen Funktionselementen erlaubte eine online Überwachung von verschiedenen physikalischen, chemischen und biologischen Prozessparametern während der Kultivierung. Im Bereich der Gruppe (ii) wurden passive und aktive Mikoventile, PZT- und pneumatisch aktuierte Mikropumpen, Filtrations- und Mischkomponenten hergestellt und charakterisiert. Gruppe (iii) umfasste die Entwicklung eines enzymatischen Biosensors mit hybridem (elektrochemisch-optisch) Messumformer. Der einheitliche Chipaufbau aller Lab-on-Chip Systeme – bestehend aus einer Kombination von strukturiertem Polydimethylsiloxan und Glas – erlaubt das monolithische und modulare Zusammenschalten der Einzelsysteme zu der gewünschten Plattform. Da für erste Prototypen eine modulare Verschaltung zu bevorzugen ist, wurde ein Baukastensystem entwickelt, welches eine standardisierte und benutzerfreundliche Plattform für flexible Versuchsaufbauten bietet

Desarrollo de una herramienta instrumental de gusto artificial aplicable a bebidas alcohólicas a base de miel de abejas

Se llevó a cabo el monitoreo a lo largo del tiempo de la fermentación de hidromiel a 25°C, usando Saccharomyces cerevisiae subsp. bayanus como agente fermentador, miel diluida, polen, frutos rojos, diferentes hierbas aromáticas y especias, partiendo de mostos con 24°Brix, los cuales se pasteurizaron previamente. Se desarrolló una herramienta de gusto artificial con un potenciostato de cuatro canales, combinación de sensores de platino y grafito modificados con sulfato de cobre, aplicación de voltametría cíclica y onda cuadrada. Las señales obtenidas se correlacionaron con otras variables obtenidas: pH, acidez total, contenido de azúcares, productividad, conversión, contenido de etanol, actividad antioxidante, perfil de compuestos volátiles, espectro FTIR-ATR, nariz electrónica, lengua electrónica comercial y panel sensorial entrenado. Mediante análisis de componentes principales y correlaciones lineales por mínimos cuadrados se pudo establecer que la herramienta permite el monitoreo del proceso fermentativo, así como también la clasificación de diferentes hidromieles.Abstract. A mead fermentation monitoring was done at 25°C by using Saccharomyces cerevisiae subsp. bayanus, diluted honey, pollen, red fruits, various herbs and spices, starting from pasteurized musts with 24 °Brix. An artificial taste system was developed with a four channel potentiostat, platinum and modified with copper sulfate graphite sensors, and the application of cyclic and square wave voltammetry. The signals obtained were correlated with other variables obtained: pH, total acidity, sugar content, productivity, conversion, ethanol content, antioxidant activity, profile of volatile compounds, FTIR-ATR spectrum, electronic nose and electronic tongue and a trained sensory panel. By using principal component analysis and least squares linear correlations it was established that the tool allows monitoring the fermentation process as well as the classification of different meads.Doctorad