Shedding Light on Port Wine Aroma Production Complexity: Terroir versus Yeast Impacts
Carina Costa, Denisa Mateus, Susana Sousa, Cláudia Coimbra,
Frank Rogerson, João Simões, and Silvia
Rocha*
*University of Aveiro, Department of Chemistry & QOPNA ,
University of Aveiro, 3810-193, Aveiro, Portugal (smrocha@ua.pt)
Port wine is a fortified wine produced in the Douro Appellation
(Portugal) under very specific conditions resulting from natural
and human factors. Its intrinsic aroma characteristics are
modulated by a network of factors: terroir particularities, grape
varieties and winemaking procedures, particularly the yeast
strains. Over the past three decades, targeted consistency in
winemaking has led to the almost ubiquitous application of
commercial Saccharomyces strains. Although the recent
introduction of commercial non-Saccharomyces strains has resulted
in improved complexity, the potential impact and diversity of
native Douro yeast strains responsible for Port production have
yet to be studied; hence, the present investigation of their
impact on grapes from different terroirs. An in-depth study was
conducted on the impact of the binomial “yeast strain versus
terroir” on potential aroma characteristics of Port wine produced
from the Touriga Nacional variety. The strategy included the
analysis of wine volatile composition, sensory properties, and
yeast population profiling through fermentation, permitting a
comprehensive understanding of the impact of “terroir versus
yeasts”. The wines were analyzed using an advanced
multidimensional gas chromatography methodology (HS-SPME/GC ×
GC-ToFMS) in tandem with ANOVA-simultaneous component analysis
and hierarchical clustering analysis. Attention was principally
focused on volatiles reported as exhibiting high level odor
activity values in Port wines [1]. Several volatile components
were determined distributed over the chemical families of acids,
alcohols, aldehydes, terpenic compounds, esters, norisoprenoids,
and volatile phenols. This research reveals that native strains
were detected under all conditions analyzed, including those
inoculated with commercial strains. Despite the significant
contribution made by yeast strains, terroir had the greatest
effect on Port wine aroma.
[1] Rogerson, F. S. S.; De Freitas, V. A. Journal of Food
Science, 2002, 67(4), 1564-1569.
Funding Support: This study was financially supported by EU in the frame of the Portugal 2020-(SI I&DT) programme. POCI-01-0247-FEDER-017736
