Electronic Tongues for the Organoleptic Characterization of Wines

Abstract

Electronic noses and tongues are the products of advanced chemical and physical sciences combined with intuitive integration of sensors, microprocessors, advanced informatics and statistics. They include for example resistive, optical, electrochemical or piezoelectric platforms where a variety of sensing materials (including among many others, metal oxide semiconductors, conducting polymers, nanoparticles, phthalocyanines or enzymes) have been immobilized using a variety of techniques. Some of these devices are available commercially, whereas others are home-grown devices that require commercialisation. Electronic noses and tongues have been used to characterize components that contribute to sensory or compositional profiles, from ripening to harvesting and from storage of raw materials to packaging and consumption. Electronic noses and tongues are thus suitable for high-throughput analysis, quality control or to determine the nature and extent of spoilage and adulteration. These devices have also been used to ascertain the geographical origins of food and mixtures. Devices used to analyse one particular food item can theoretically be adapted for other food items or components. This does not just mean the re-deploying the sensing devices but also the mode of statistical analysis. This includes supervised and no supervised tools such as principal component analysis (PCA), linear discriminant analysis (LDA), partial least squares (PLS), artificial neural networks (ANN), etc. In other words, there is cross transference of chemistry, physics, concepts, techniques, findings and approaches from one food to another. However, finding all this information in a coherent and comprehensive text has been problematical as hitherto no publication has attempted to marshal together all the relevant information on these important devices in relation to food science. This is addressed in “Electronic Noses and Tongues in Food Science”. Its unique feature is the three parts dedicated to the electronic nose, the electronic tongue and combined systems of electronic nose and tongue. Part I covers a description of electronic nose systems and their applications to the analysis of the volatile composition of different foods and beverages. Part II focuses on the electronic tongue, which has become increasingly important over recent years because it can analyse complex liquids such as wines or milks by direct immersion in the samples and not restricted to the headspace. Part III covers newer developments combining electronic nose and electronic tongue. Each part presents the main applications in the food industry. Classical applications in the field of meat, wines, dairy products or beers have been presented but also other less known applications such as the detection of gliadins or the assessment of the phenolic content in foods. The book is designed for food scientists, technologist, food-industry workers, as well as research scientists. Contributions are from leading national and international experts, including those from world renowned institutions. Readers can dip into the book for reference purposes, read any chapter as a standalone treatise, read it from cover to cover if food analysis is an integral part of their day-to-day job. I must finish by thanking all of the contributors to the book, each a recognised expert in their field. I also thank Elsevier Publishing for all the guidance on pulling together such an eclectic book. Finally, many thanks to my colleagues and PhD students for their help and support!