# Chemosensory Profile of South Tyrolean Pinot Blanc Wines: A Multivariate Regression Approach
## 1 Introduction  
Pinot Blanc is a versatile, non-aromatic grape variety widely cultivated across the world. Characterized by high tittatable acidity, Pinot Blanc can be used for the production of both still and sparkling wines. In Italy, Pinot Blanc is suitably cultivated in areas such as Trentino-South Tyrol, Veneto, Piemonte, Friuli-Venezia Giulia, and Puglia [1], although it is also admitted for DOP and IGP productions throughout the country. In particular, the cultivated area of Pinot Blanc in South Tyrol corresponds to about 600 ha, which represents about 10% of the total viticulture surface area of the province [2]. The aromatic profile of wines can derive from grapes (varietal or primary aromas), production operations such as crushing, pressing, or maceration (secondary aromas), alcoholic and malolactic fermentations (fermentation aromas), and aging processes (maturation aromas) [3; 4; 5]. In addition to the chemical complexity deriving from the release of the compounds most readily extracted from grapes during crushing, maceration processes can induce the further release of aroma-impacting compounds. The maceration process aims at obtaining the maximum intensity of varietal aroma [6] through the extraction of terpenes, esters, aldehydes and alcohols. Besides, the maceration can increase the extraction of other molecules, such as phenolic compounds [7; 8; 9; 10]. Despite its widespread national and international production, only a few recent studies on the volatile and sensory profiles of Pinot Blanc wines are available in the literature. The aroma of Austrian Pinot Blanc wines was studied to characterize their typical sensory traits [11]. The authors associated the \"pear\"aroma to the particular typicity of Austrian Pinot Blanc wines; this aroma was associated with short- and long-chain esters, such as ethyl (E, Z)-2,4-decadienoate and methyl (_E_)-geranoate [12]. These volatile compounds were mainly associated with notes of apple, banana, apricot, citrus, caramel, and green notes, occasionally with quince and exotic fruits, and in some cases with spicy and nutty notes. When Pinot Blanc wines have matured, they show fresh bread notes, which gain in structure during the aging in-bottle [12]. Recently, [PERSON] et al. compared Pinot Blanc wines obtained with an experimental vniification versus a control vniification, in order to highlight the most notable differences in terms of their quality and evolution in-bottle [13]. These authors showed that the Pinot Blanc control wines evolved faster than the experimental wines (differing from the control wines as the experimental winemaking also involved a pre-fermentative cold maceration, addition of pectolytic enzymes, addition of yeast autolyastate and a bentonite clarification step) when monitoring the profile of phenolic and volatile compounds as well as the sensory properties. Many studies have demonstrated the existence of interactions between the evolution of sensory characteristics and the chemical compounds [14]. Explaining the perceptions in terms of cross-modal interactions occurring between aroma and taste is still a challenge [15]. Therefore, to explore these interactions, the best approach would be to move away from a univariate description evaluating the strongest correlations between sensory attributes and chemical compounds taken one-at-a-time, and to study a multivariate approach (where sensory and volatile/non-volatile analyses are combined to calculate models, including interactions), instead. This would result in considering the chemical profile as a whole in its effect on the sensory descriptors. The present study aims at correlating sensory descriptors and chemical compounds (volatile and phenolic) of two Pinot Blanc wines, by applying two alternative multivariate approaches, namely Partial Least Square Regression (PLS) and Principal Component Regression (PCR).