Discrimination of grape juice and fermented wine using a tin oxide multisensor

A multisensor was applied to discriminate between grape juice and fermented Albillo white wine variety. The multisensor consists of 15 sensing element s formed by tin oxide thin layers deposited by r.f. reactive sputtering. So me components were doped with platinum and chromium, aiming to improve thei r sensitivity and selectivity to the wine varieties tested. Each sensor was characterised by resistance measurements from 200 to 350 degrees C, in ord er to find the optimum detection temperature. The detection of the volatile compounds present in wine was useful to distinguish between the different wine phases. The response to the fermented wine was always better than the corresponding one to the grape juice. All the sensors had a high sensitivit y and the best responses were obtained in doped sensors at 350 degrees C. A t this temperature, the different wine phases (grape juice, fermented wine and wine) were detected. The presence of volatile organic compounds in the different phases of wine elaboration is also discussed. (C) 1999 Elsevier S cience S.A. All rights reserved.