Description
Use of commercial starters for malolactic fermentation (MLF) is a
common practice, and outcomes of this procedure are very relevant for wine
producers because aroma attributes might change according to the strain
used.
MLF was carried out in the Trincadeira wine variety in three batches:
spontaneously and with inoculation of two different commercial starters. Wine
extracts before and after MLF were obtained through liquid–liquid extraction.
Gas chromatography/ion trap mass spectrometry analysis allowed the detection
of 21 compounds, some of them tentatively identified through electron
impact spectra comparison with a database, through interpretation of multistage
mass spectrometry and chemical ionization mass spectrometry spectra
and confirmation by comprehensive multidimensional gas chromatography/
time of flight-mass spectrometry (GC ¥ GC/ToF-MS).
After MLF, an increase in ethyl lactate, g-butyrolactone and diethyl
succinate and a drop in isoamyl acetate, ethyl octanoate, ethyl decanoate,
2,3-dimethyl-hexan-3-ol, propanol, isobutanol and 2,3-butanediol was
observed. The concentrations of the 10 compounds are statistically different in
wines before and after MLF, and wines after MLF show significant differences
for the nine compounds.
; Cabrita, M.J. 
