engleski

Targeted metabolomics study for varietal discrimination of wines according to phenol composition and tentative elucidation of particular variety-typical sensory features

Information on the content and composition of phenols in monovarietal wines is of fundamental importance for adequate wine quality management and control, it is useful for predicting wine sensory properties and oxidative stability, and may indicate wine age and production technology. It may also be used for authentication of varietal origin, as well as a strong point in marketing. To investigate the possibility of wine varietal differentiation based on phenol composition despite the existing heterogeneity, almost 200 samples produced from grapes of various red and white varieties grown in various terroirs in three Croatian regions were subjected to targeted profiling of phenols by ultra-performance liquid chromatography-triple quadrupole mass spectrometry. Descriptive sensory analysis was performed, including evaluation of varietal typicity, to investigate if there is a relation between variety-typical sensory profiles and certain phenols. Many of identified phenols were attributed as discriminators between wines. Plavac mali was characterized by the most distinguished anthocyanin profile, with generally the lowest concentrations among the investigated red wines. On the other hand, the wines from this variety were generally the most abundant in non- anthocyanin phenols. Cabernet Sauvignon wine stood out with the highest values of acetylated to p-coumaroylated anthocyanins ratio and the percentage of the sum of the acylated anthocyanins. Teran wine was characterised by the highest concentration of anthocyanins in general, while Merlot exhibited the least distinguished profile. As for white wines, those from the region of Dalmatia made from Pošip and Maraština varieties were generally more abundant in phenols than others. Malvazija istarska wines contained the lowest concentration of the majority of flavonols and hydroxycinammates, while Graševina was distinguished by the lowest amounts of flavan-3-ols. The highest concentrations of hydroxycinammates were found in Muscat blanc wines. Linear discriminant analysis resulted in successful differentiation, with peonidin 3-(6”- acetyl)-glucoside and taxifolin as the most potent differentiators among red, and cis-piceid among white wines. Particular varietal typicity concepts were partially confirmed by tentatively relating the concentrations of certain phenols and their possible sensory effects. This work has been supported by the UIP-2014-09- 1194 (Croatian Science Foundation) and ADP 2017 (Trento, Italy) projects.

UPLC-QqQ-MS/MS ; Wine ; Phenols ; Variety

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