A. Carnacini

Sensory characterisation of wine vinegars

Abstract Ninety-six samples of vinegars of different sources were subjected to sensory analysis. For white vinegars, Linear Discriminant Analysis showed that sensory analysis could be used to distinguish between the different sources of vinegar, and especially to discriminate between alcohol and apple vinegars from wine vinegars on the basis of only seven sensory parameters. Principal Component Regression showed that the quality level of vinegars could be determined by taste, smell and clarity. Only ‘quality’ red vinegars were appreciated for their vinous character.

Polyalcohols in vinegar as an origin discriminator

Polyalcohol content in vinegars of different botanical and geographical origin was studied by means of capillary gas chromatography. The data were statistically evaluated in order to discriminate the different vinegar types. Wine vinegars did not show a characteristic polyalcohol pattern, while apple vinegars and alcohol vinegars were well recognizable. The former had high sorbitol content and the latter showed the lowest amount of polyalcohols. Statistical analysis showed that polyalcohol determination is a possible tool to discriminate vinegar raw material at least for white products.

Influence of yeast strain on the composition of wines for the production of brandy

FifteenSaccharomyces strains used in the production of Trebbiano wine for brandy were examined. The chemical analysis of the wine showed significant differences depending on the yeast strain used. In particular,Sacch. bayanus strains produced many compounds desirable for flavour effects (i.e. 2‐phenethyl alcohol) and few undesirable compounds, such as acetic acid and sulphur anhydride.

Volatile Composition of Vernaccia di Oristano Sherry-Like Wine as Affected by Biological Ageing

Forty compounds were identified by gas chromatography and gas chromatography/mass spectrometry in the volatile fraction of Vernaccia di Oristano, an Italian sherry-like wine produced in Sardinia since the 11th century. The individual aromatic compounds were identified and quantified in the original wine, both after biological ageing by inoculation of the original wine with Saccharomyces cerevisiaevarbayanusandS cerevisiaevarprostoserdovii, and after ageing under sterile conditions. The effects of flor yeasts in terms of production or subtraction of flavour components are discussed.

Characterisation of white vinegars of different sources with artificial neural networks

Wine and cider vinegars currently attract growing interest from consumers, giving rise to a consequent increase in supply. A full appreciation of their quality is only possible, however, through recognition of their superior quality when compared with vinegars produced from raw materials of inferior quality. Therefore, it is necessary to pinpoint the parameters that define the quality of these products. Chemico-physical and sensory analysis has been used to draw up artificial neural networks (ANNs), on the basis of a vast sampling of vinegars from various countries, produced from a variety of raw materials, that was already subjected to multivariate statistical analysis. Among the chemical parameters, polyalcohols and other elements such as pH, tartaric acid and proline proved to be highly reliable, whereas other volatile substances and the results of sensory analysis were not very discriminating and could not be used to re-classify samples of unknown origin. The positive results obtained indicate that ANNs are a powerful mathematical tool, since they can be used to construct models that predict the botanical origin of the product and to re-classify samples of unknown origin, without any initial restrictive hypothesis.