Detection of alcohols in beverages: An application of porphyrin-based Electronic tongue

According to the World Drink Trends data monitor, a stable growth of alcohol consumption across most of the countries has been registered in the last years. Quality evaluation of alcoholic beverages becomes, hence an important industrial task and fast and inexpensive analyzers are the targets of interest. In a present study we aimed to develop an analytical instrument which may permit a rapid, online control of ethanol content in beverages of various sources in a wide range of concentrations. Potentiometric responses of porphyrin-based solvent polymeric membranes towards several aliphatic monatomic alcohols in single-, two- and four-component solutions were evaluated. Sensitivity of membranes in single-component alcohol solutions decreased in the following order: ethanol > methanol > isobutyl alcohol. A performance of potentiometric porphyrin-based Electronic tongue (ET) for analysis of alcoholic beverages is described. The utility of ET system for an identification of beverages made of two different source materials: grape and barley has been shown. Simultaneously a scale of beverages' 'alcoholic degree' in ethanol concentration units was evolved. The alcoholic strength of several commercial sorts of wine, beers, grappa and whiskey was successfully evaluated according to the evolved scale. (c) 2006 Elsevier B.V. All rights reserved