Abstract:
Pinotage wine from several South African wine cellars has been
produced with a novel coffee flavour. We have investigated this innovative
coffee effect using in house developed solventless sampling and fractionating
olfactometric techniques, which are unique in their ability to study synergistic
aroma effects as opposed to traditional gas chromatography olfactometry (GCO)
which is designed to, ideally, evaluate single eluting compounds in a
chromatographic sequence. Sections of the chromatogram, multiple or single
peaks, were recaptured on multichannel open tubular silicone rubber
(polydimethylsiloxane (PDMS)) traps at the end of a GC column. The
recaptured fractions were released in a controlled manner for offline olfactory
evaluation, and for qualitative analysis using comprehensive gas
chromatography coupled to time of flight mass spectrometry (GCxGC-TOFMS)
for compound separation and identification, thus permitting correlation of odour
with specific compounds. A combination of furfural and 2-furanmethanol was
responsible for a roast coffee bean-like odour in coffee style Pinotage wines.This coffee perception is the result of a synergistic effect in which no individual
compound was responsible for the characteristic aroma.
