Varietal Discrimination of Trebbiano d'Abruzzo, Pecorino and Passerina White Wines Produced in Abruzzo (Italy) by Sensory Analysis and Multi-Block Classification Based on Volatiles, Organic Acids, Polyphenols, and Major Elements

Reliable analytical methods able to establish wine authenticity and compliance with the origin/variety denomination are essential tools for the safeguarding of consumers from fraud. In this work, we attempted the discrimination of certified monovarietal white wines produced in the Abruzzo region (Central Italy) in 2015 with Trebbiano d'Abruzzo, Pecorino or Passerina grapes, all belonging to the Trebbiano variety. A preliminary sensory analysis revealed a high similarity among the three wines. The aroma profile and polyphenol and organic acid profiles were collected by gas chromatography and ultra-high-performance liquid chromatography, respectively, on 46 samples representing the three wine varieties. Eventually, the concentration of 14 elements in the same samples, determined by inductively coupled plasma optical emission spectrometry, was considered. Partial Least Squares Discriminant Analysis pursued on the individual analytical responses gave unsatisfactory results in terms of varietal discrimination. A data fusion approach, Sequential and Orthogonalized Partial Least Squares Linear Discriminant Analysis, on the other hand, provided better results as it misclassified only three (out of eighteen) external samples. Tartaric acid, malic acid, Cu, Na, Ni, Sr, Ca, Fe, 3-methyl-1-butanol, 2-methyl-1-butanol, ethyl hexanoate, and 2-phenylethyl acetate were found to be the variables relevant in the discrimination of the three monovarietal wines.