PRODUCTION OF REPRESENTATIVE WINE EXTRACTS FOR CHEMICAL AND OLFACTORYANALYSIS

The similarity of the odour of aqueous wine distillates, obtained by v acuum distillation at low pressure, and of different types of organic extracts of wine to the odour of the original wine was assessed. The s ensory characteristics of the wine distillates were found to be very s imilar to the wines from which they were obtained. The distillate subm itted to an aroma extract dilution analysis by gas chromatography gave an aromagram with 13 peaks. Aromagrams were also obtained by direct i njection of wine but the aroma profile was characterized by large odor active regions, described as toasted, burnt, roasted or burnt sugar, due to heat degradation of non-volatile components of wine in the inje ctor. Different extracts from the same wine obtained with a new extrac tion method, consisting of a single extraction lasting 3h with a small volume of dichloromethane at low temperatures in an oxygen free envir onment, and with classic solvent extraction, involving concentration b y distillation of the solvent, were compared by sniffing analysis. The results show that the extracts prepared according to classic solvent extraction lack several characteristic wine odors and have additional unpleasant and nauseous odors absent in the original wine. On the cont rary, the extracts obtained with the proposed method exhibited most of the characteristic odors of the original wine but not the odors which appeared to be artifacts arising during distillation of the solvent a t atmospheric pressure, These extracts submitted to HRGC/O analysis al lowed the location of more than 25 odors; therefore the method propose d may be an alternative for the preparation of wine samples for aroma analysis.