posted on 2020-03-24, 14:05authored byG. Bergler, V. Nolleau, C. Picou, M. Perez, A. Ortiz-Julien, M. Brulfert, C. Camarasa, A. Bloem
To
study the contribution of yeasts to the formation of terpene
derivatives during winemaking, a dispersive liquid–liquid microextraction
gas chromatography mass spectrometry method was developed for the
quantitation of terpenes in white wines, synthetic wine, and a fermented
synthetic medium. A mixture of acetone (disperser solvent) and dichloromethane
(extraction solvent) was added to 5 mL of sample. The proposed method
showed no matrix effect, good linearity in the enological range (from
10 to 200 μg/L), good recovery, and satisfactory inter- and
intraday reproducibilities (below 20 and 15% of the relative standard
deviation). This sample preparation technique is very interesting
for high-throughput studies and economic and environmental reasons
because it is fast and easy to operate with high enrichment and consumes
a low volume of organic solvents. This method was applied to explore
the capacities of 40 yeast strains to produce terpene compounds during
fermentation of Chardonnay and Ugni Blanc musts as well as in a synthetic
medium. Interestingly, most of the studied compounds were detected
and quantified in the resulting wines. This study shows that yeast
strains can intrinsically produce terpene derivatives under enological
conditions and also highlights the differences between the de novo biosynthesis of terpenes and their precursor-linked
production.