Relationship between polyphenolic composition and some sensory properties in red wines using multiway analyses

Polyphenolic compounds are responsible for important sensory properties of red wines (especially colour, astringency and, to a lesser extent, bitterness). Various model solution studies have investigated the relationships between specific phenolic compounds and sensory perception. The purpose of the present study was to relate polyphenolic composition to sensory data for a very large number of different commercial wines, using multiway analyses. Two homogeneous populations of commercial red wines (61 French and 60 German wines) were analyzed. Thirty simple polyphenolic compounds (anthocyanins, flavonols and phenolic acids) and some red pigment derivatives have been quantified using direct injection by liquid chromatography (LC) coupled to diode array detection and mass spectrometry. Condensed tannins were analyzed using LC after thiolysis. Sensory perception was assessed using descriptive analysis by four trained panels (2 countries × 2 years). We first checked the consistency of the sensory data both through the 2 assessment years, and through the two countries. Although reproducibility was high, especially through countries, slight scale factor differences and scale shifts were detected. A chemical consensus was then built using common components and specific weights analysis for both wine subsets, where the sensory variables of each panel were projected separately. Although data structure was very different between the two wine subsets, common main chemical-sensory relationships were confirmed. The hypothesis of a relationship between flavonol aglycones and bitterness was raised. A partial least squares regression was performed and predicted linearly astringency with a R2 value of 0.80, but not colour intensity and hue, due to non-linear relationship and saturation of visual perception.