The need to reuse grapevine (
Vitis vinifera
L.) by-products
avoiding negative environmental impact
demands the search for new valorization methods like
thermomaceration. The combination of grapevine by-products
and grape must may be an alternative to get
hold of additional aroma. The objective of this study
was to assess the aroma potential of grape pomace,
grapevine leaves and canes for País (PA) and Lachryma
Christi (LC) cultivars to enrich grape must. Fifty aroma
compounds were identified in the samples using stir bar
sorptive extraction followed by thermal desorption, gas
chromatography and mass spectrometry. ‘País’ must
showed high contents of esters with a characteristic
fruity odor, while benzenoids prevail in LC must giving
a phenolic, balsamic odor. Thermomaceration increased
contents of 13 free and bound volatile compounds, as
well as new compounds (isoeugenol, phenol, vanillin
and 2-ethyl hexanol) appeared in enriched juice (EJ).
Cluster analysis showed differences among PA, LC and EJ
samples. Principal component analysis was successfully
applied to discriminate grape juice samples (p < 0.05)
being D-limonene, 5-hydroxymethyl-2-furfural and
hexadecanoic acid the compounds that contributed most
to the differentiation and increase of free and hydrolyzed
aroma compounds after thermomaceration. Both grape-grapevine
by-products and juice processing conditions
affected the generation and increase of free and bound
aroma compounds after thermomaceration of grape must.
