Abstract
The purpose of this study was to analyze the matrix fingerprints of the polyphenol and volatile compounds in international monovarietal Chardonnay and Sauvignon Blanc wines, and their impact on the sensory profile in order to build comprehensive maps of those profiles; this had the aim of providing valuable information to both provider companies and the consumers.
The sensory profiles were generated through modified Rate-All-That-Apply (MRATA) sensory analysis, with a semi-trained panel; the volatile and phenolic compounds were analyzed with bidimensional gas-chromatography (HS-SPME-GCxGC-ToF/MS) and LC-QqQ-MS respectively.
An explorative Multiple Factor Analysis model (MFA) was built to study the correlations between the chemical and the sensory profiles, for both Chardonnay and Sauvignon Blanc wines. Furthermore, the sensory profiles were modeled by multivariate partial least square regressions on the volatile compounds in order to find those combinations of compounds most affecting the sensory descriptors. Similarly, the overall quality judgment (OQJ - an objective quality score assigned by the panelists) was modeled by PLS on the sensory descriptors, to explain which combinations of the sensory descriptors had more impact on the OQJ.
MFA showed interesting correlations between the volatile profiles and the sensory descriptors: for example, b-damascenone in Sauvignon Blanc wines correlated well with the fruity descriptors and correlated inversely with the vegetative descriptors.
The PLS model showed that the most important variables in projection (VIP) in Sauvignon Blanc for explaining the OQJ were passion fruit (positive effect) woody and warmness (negative effects). Instead, OQJ for Chardonnay showed a correlation with flower, citrus, vegetables (aroma descriptors), and the color green (sight descriptor) with MFA. The same results were obtained from PLS in which the most important VIP were flowers and citrus aroma, color green, and warmness. Further statistical analysis and a more extensive sampling will aid the understanding of the effect of polyphenol compounds.