MULTIVARIATE STATISTICAL TECHNIQUES FOR THE ANALYSIS OF INSTRUMENTAL AND SENSORIAL DATASETS: THE CASE OF AROMAS AND THEIR PERCEPTION IN WINES

Abstract

The purpose of this work is to look for changes in the aroma profile of wines obtained under Critical Agricultural Practices (CAP), in comparison with wines treated under Good Agricultural Practices (GAP). Four new fungicides (mandipropamid, valifenalate, cyazofamid and famoxadone) to control downy mildew (Plasmopara viticola) were applied under CAP in an experimental vineyard producing white grapes Vitis vinifera cv. Godello. Several fatty acids, their esters and acetates were formed during the winemaking process in higher levels under GAP and could be expected to strongly influence the aroma of the wines by introducing floral, fruity and spicy nuances. The concentrations of six compounds (2-phenylethyl acetate, ethyl butanoate, ethyl octanoate, 4-vinylguaiacol, 3- methylbutanoic acid and methionol) were found to suffice with a view to discriminating between wines from grapes treated with fungicides under CAP and under GAP. The critically treated wine was moved to a sweeter balance with a ripe fruit taste, which are associated to higher viscosity and also a higher cloudy colour. We conducted exploratory research with a view to correle the results of instrumental analyses of the aroma compounds in Godello wine and their sensory perception, using Principal Component Analysis (PCA) and Partial Least Squares Regression (PLS) for comparisons. PCA revealed the distribution of volatile compounds with near-unity or higher Odour Activity Values (OAVs) in relation to sensory characteristics, and PLS exposed relationships between sensory descriptors and volatile compounds in the wines.