Dielectric properties measurement in food. Applications in products and processes quality control

Currently, industries demand non-destructive, in-line control systems of the internal and external quality. These systems must be fast, precise and cheap. Occasionally, they permit the production line feedback with the information obtained of the measured quality parameters.;The dielectric properties measurement in microwaves band, can become a very important tool for the food industry. These properties can be measured in real time with a relatively cheap equipment and are related with some structural and physical-chemical properties of foods.;The general objective of this thesis is to set in motion a calibrated and regulated method for dielectric properties measurement in foods, as a first step for its application at the in-line quality control of products and processes.;At the first place, the art state has been determined and theoretical concepts and applications have been clarified and unified. Later the experimental set up necessary to carry out the dielectric properties measurement in the laboratory, has been selected, mounted, calibrated and placed ready. It was verified that the measures carried out with that apparatus were coherent between itself and with the results obtained by other investigators.;The dielectric spectra of some dissolutions have been measured and modelled. Since, these dissolutions would be able to simplify the liquid phase of foods. From there, the level of complication of the measurements has increased progressively. Starting from simple systems composed of air, solid matrix and liquid phase.;In this thesis, they have been included two industrial applications, financed both by interdisciplinary projects of the UPV. One of them referring to in-line control, for that, it was verified if there were significant differences among skin, pulp, juice and seeds of citric fruits as a first step in its future application at the in-line detection of seeds. And the other was applied to processes monitoring, for it, it has been chosen to measure cod samples in different stages of the desalting process, for its future application at the in-line control of its optimum desalting point.;This thesis has generated 2 book chapters, 3 final career works, 1 international article and numerous Congress presentations.