Electronic tongue technology applied to the analysis of grapes and wines

Abstract

The Doctoral Thesis entitled “Electronic tongue technology applied to the analysis of grapes and wines” has been developed in the group of sensors UVaSens under the supervision of Prof. PhD. Maria Luz Rodriguez Mendez, from the Inorganic Chemistry and Physical Chemistry Department at the Engineers School, and Prof. PhD. Ana Cristina Garcia Cabezon, from the Materials Science and Metallurgical Engineering Department at the Engineers School, both from the University of Valladolid (Spain). The author of this Thesis has carried out a research stay at the Missouri State University (Springfield, EE.UU.) under the supervision of Prof. PhD. Adam Wanekaya for 4 months to be able to obtain an international Ph.D. mention. Therefore, this dissertation together with the research stay certification will lead to obtain that purpose. This dissertation contains research that studies the use of sensors and biosensors implemented as arrays of electrodes in electronic and bioelectronic tongues to analyze quality characteristics of wines and grapes of interest in the agrofood industry such as sugar and/or polyphenolic content. To construct the arrays of sensors and biosensors it has been used and combined different and novelty electrocatalytic materials. The samples of wine and grape used in this study have been provided by the wineries “Cooperativa de Cigales” and “Instituto Tecnologico Agrario de Castilla y Leon (ITACyL)”, both located in Castilla y Leon region (Valladolid, Spain), and by the “Oenological Center of Haro” located in La Rioja (Haro, Spain). The chemical parameters of the samples were analyzed in UVaSens laboratory and also by the ITACyL, following international regulations (OIV, The International Organisation of Vine and Wine). The following sentences provide an overview of the structure of this dissertation. Chapter 1 provides an introduction and background of this research. A literature review containing a state of the art, the applications of these devices in the food industry, the type of sensors used to develop electronic tongues, the electrochemical techniques applied, the electrocatalytic materials that help to improve the responses of the electronic tongues, the techniques used to fabricate nanostructured films to modify sensors as well as the most common statistics tools implemented to analyze data obtained from electronic tongues is presented in Chapter 2. Chapter 3 compiles 9 research papers with results obtained from the studies carried out and published in international journals with impact factor. An overview of conclusions from the entire dissertation is presented in Chapter 4. Finally, Annexes A, B and C contain a summary written in Spanish in accordance with the regulations of the University of Valladolid, the co-authored list of papers published during the Doctoral studies and the attestation letter of the international research stay carried out in the Chemistry Department of the Missouri State University (Springfield, USA) signed by the supervisor Prof. Wanekaya.