Identification of some volatile descriptors of the rock-rose-like aroma of fortified red wines from douro demarcated region.

2,2,6-Trimethylcyclohexanone and ethyl dihydrocinnamate, known sensorial descriptors of rock-rose (Cistus ladaniferus) aroma, are reported as minor constituents of young fortified wines from the Douro Demarcated region (vintage 1997) for the first time. These compounds were respectively identified by GC-MS in two different fractions (A and B) obtained by preparative GC. Quantitative analysis by GC-MS was performed on 14 fortified wines originating from the different Douro subregions. Ethyl dihydrocinnamate was found to be present at concentrations between 2.3 and 6.7 microgram/L, while 2,2,6-trimethylcyclohexanone ranged from 0.05 to 0.4 microgram/L.