Abstract

Freshly-distilled French wine brandies were evaluated by gas chromatography-olfactometry (GC-O). Six brandy samples were studied, coming from two growth areas, both belonging to the same limited geographic zone, which is a homogeneous vineyard area. The GC-O methodology, using detection frequency analysis, revealed 88 olfactive areas (OAs) for which the detection frequency was ≥ 25%. OAs were then identified using gas chromatography-mass spectrometry in electron and chemical ionization modes and semi-quantified by internal normalization using gas-chromatography with flame ionization detection. Co-eluting species were separated by multidimensional gas chromatography-mass spectrometry/olfactometry (MDGC-MS/O). Eleven new molecules were tentatively identified for the first time in brandy, as impact odorant compounds: ethyl prop-2-enoate, 2-furfuryl formate, 1,2,4,5-tetramethylbenzene, (Z)-ocimenol, 1,4,6-trimethyl-1,2-dihydronaphthalene, 2-ethoxybenzyl alcohol, 2-ethylhexanoic acid, 2-phenoxyethanol, 4-hydroxy-3-methylacetophenone, 4-(2,3,6-trimethylphenyl)butan-2-one and 2,3-dihydrofarnesol. Composition and perception differences between samples according to their origin were investigated. Statistical analyses on OA detection frequencies and semi-quantitative data were used to distinguish the samples. A lot of variables appeared to be common to all spirits, and may represent an aromatic background for the brandies, characteristic of the geographic zone. Although a few particular OAs were found more relevant in particular samples, no growth area-specific compound was identified. Therefore, differences between spirits are more likely due to an aromatic balance between concentrations of a set of common molecules, among which ethyl esters and alcohols played a prominent role, rather than the presence of specific compounds with unique aromas.

 

source:  onlinelibrary.wiley.com/doi/10.1002/ffj.3325/full