Complex Permittivity Measurement of High Loss Liquids and its Application to Wine Analysis

The microwave dielectrometry of high loss liquids is discussed in the present work. For such liquids the ratio of the imaginary to the real complex permittivity parts is of the order of one or more. High loss liquids are water and water solutions of organic and non-organic substances. Water is the most investigated liquid during long time. The reason for the impressive interest to water is due to its ubiquity in our environment. Usually water is used as the reference liquid for differential measurement of water-containing liquids under test, for instance, grape wines and musts. The present paper is directed to the control of naturalness (authenticity) of grape wines and musts by their complex permittivity determination. This complex permittivity determination will be performed in the millimeter wave band where the frequency dispersion of complex permittivity of water has a maximum. It is necessary to underline that the wine trade is a multi-million-income industry in which frauds can have enormous financial repercussions and the quality of products directly impacts on human health. A universal wine and must authenticity identification method does not exist. Each of known methods (the methods of analytical chemistry, wine sampling, physical-chemical methods) have own advantages and disadvantages and assume a definite area of usage [《rganisation internationale de la Vigne et du Vin, 2009]. Thus, the development of alternative methods of wine product quality determination remains actual. One feature of the wine trade in Ukraine and other former Soviet Union countries is the increase of fraud. The main types of fraud are unregulated sugar use, substitution of the sort of vine, not keeping the ripening terms for the wines, water addition, blending of cheap wines instead the best wines, addition of artificial sweeteners, dyes, aromatizers, and fake wine production without vine processing. In Europe and USA there is fraud growth by bottling inferior wine under a quality label – with the wine originating from a different region or even country than that it is stated. Despite the rigor of wine quality demands fake wine production did not decrease due to lack of reliable methods for identification and suitable reference data [Ezhov et al., 1999].