Stepwise linear discriminant analysis to differentiate Spanish red wines by their Protected Designation of Origin or category using physico-chemical parameters

Abstract

a b s t r a c tAim: The aim of this work was to determine the physico-chemical variables that differentiating red wines from the "Castilla y León" Spanish region by their Protected Designation of Origin (PDO) and wine category ("young", "oak", "crianza", or "reserve"). Methods and results: A total of 135 commercial red wines from four Spanish PDOs in the region of Castilla and León were analysed. Forty physico-chemical parameters, related to classical enological parameters, phenolic and polysacharidic composition, and content of higher alcohols were evaluated. Differences in physico-chemical composition were found in red wines from different PDOs and different categories. Stepwise linear discriminant analysis (SLDA) was applied to find a linear combination of the physico-chemical variables that separate and classify the red wines according to the PDO or category. One SLDA model selected 15 physico-chemical variables that allowed for good discrimination and classification of the wines from different PDOs. The SLDA model selected seven variables for wine category differentiation, but only allowed for good discrimination between young wines and aged wines ("crianza" and "reserve"). Conclusions:The variables that contributed most to the separation of Tempranillo red wines were total polyphenols, total tannins, and absorbance values at 230 nm and 280 nm. The polysaccharides with an average molecular weight of 10 kDa, flavanols, stilbenes and 2-methyl-1-butanol were those most associated with the differentiation of the wines elaborated with the Mencía grape variety. The percentage of polymeric anthocyanins and absorbance at 230 nm could be proposed as good indicators for aged wines, and total tannins for young wines. Significance and impact of the study: This study provides improved knowledge of the physico-chemical variables that could be used as markers of the origin of wines and/or the grape variety (Tempranillo and Mencía) and that allow differentiating young wines from those aged for a long time. k e y w o r d s higher alcohols, organic acids, phenolic compounds, polysaccharides, Protected Designation of Origin, red wine categories, stepwise linear discriminant analysis

Volatile and Non-Volatile Characterization of White and Rosé Wines from Different Spanish Protected Designations of Origin

“…As mentioned previously, a higher content of polysaccharides from grapes and yeast could have an important effect on the technological and sensory properties of wines [5][6][7]42]. These results were in accordance with those obtained in another study carried out on red wines from different PDOs [15] which also observed that the content of LMW polysaccharides in the wines from BI (elaborated with the Mencía grape variety) was significantly higher than in the wines from other PDOs (elaborated with the Tempranillo grape variety).…”

“…Total organic acids (tartaric, malic and lactic acid) and glycerol (both expressed in g L −1 ) were analyzed according to the methodology described in [26], with some modifications [15], and using a high-performance liquid chromatography (HPLC) column coupled to a diode array detector (DAD) and a refractive index detector (RID).…”

“…Soluble polysaccharides were determined and quantified (expressed in mg L −1 of dextrans) using high-performance size exclusion chromatography coupled to a refractive index detector (HPSEC-RID) and following the methodology described in [8], with some modifications specified in [15]. Different polysaccharide fractions according to their molecular weight were obtained: high-molecular-weight (HMW) (range: 50-730 kDa), medium-molecular-weight (MMW) (range: 15-50 kDa), low-molecular-weight (LMW) (range: 9-15 kDa) and very low-molecular-weight (VLMW) (range: 5-9 kDa).…”

“…All these compounds can vary largely in wines due to several factors such as environmental characteristics of the geographical region, grape varieties used in the winemaking, vineyard location, the fermentation yeast strain used as well as local know-how applied in the winemaking [14][15][16][17]. Thus, wines labeled with Protected Designation of Origin (PDO) are characterized by particular physicochemical and sensory properties which may allow differentiating these wines from those elaborated in other geographical areas.…”

“…Several studies carried out in different regions of several countries have shown that the composition of wines (volatile and nonvolatile compounds) can be very different depending on the aspects mentioned above [14,15,[20][21][22][23][24]. Spain is one of the main wineproducing countries in the world with seventy-five recognized PDOs.…”