Characterisation and differentiation of grape brandies by multiple discriminant analysis

Gas chromatography has shown that clear, quantitative differences exist between the various flavour constituents of German and French grape brandies as well as French cognacs. The amounts of some selected flavour compounds from 24 grape brandies have been submitted to multiple discriminant analysis. Discriminant analysis was carried out in three parts corresponding to the column chromatographic pre‐separation of volatile compounds into three fractions (I: non‐polar compounds; II: oxo compounds; III: hydrophilic substances). Using the components of fraction I a statistically highly significant differentiation between French cognacs and the remaining groups of grape brandies was obtained. With the components of fractions II and III some misclassifications occurred. Only after employing all the constituents of fractions I‐III was a statistically highly significant separation between French and German grape brandies as well as the group of cognacs achieved. Among the esters predominantly the ethyl esters of octanoic, butanoic, 2‐furanoic and 2‐hydroxy‐isocaproic acid contributed towards the separation and classification of individual groups. The best differentiation was given by the contents of 1‐octanol and damascenone.