Chemical and sensory characterization of Xinomavro PDO red wine

Abstract

Aroma is considered one of the most important factors in determining the quality and character of wine. The relationship between wine character and its volatile composition is recognized by several researchers worldwide. Since these compounds influence the sensory perceptions of consumers, both volatile composition and sensory properties are essential in determining wine aroma characteristics.

In this study, the volatile composition with its corresponding aroma descriptors was used to identify the main aroma compounds of the variety Xinomavro. Xinomavro (Vitis Vinifera L.) is one of the noble red grape varieties of Northern Greece and is present in many PDO red wines. In the experimental winery of our laboratory, a total of 6 different red wines were produced according to the same vinification protocol.

Aroma compounds of wine samples were extracted by Liquid-Liquid extraction, concentrated with SAFE method and analysed by Gas Chromatography-Mass Spectrometry (GC-MS) /Olfactometry to identify the key odorants of the variety. Olfactory analysis identified 30 aroma-active compounds, of which, ethyl hexanoate had the highest modified detection frequency (MF%).

25 of the key-volatile compounds were quantified using GC-MS, SIM mode, followed by the determination of Odor Activity Values (OAVs). A trained panel evaluated the wines using sensory descriptive analysis, based on a total of 11 aroma attributes. According to the data obtained, a complex aroma profile rich in alcohols, ethyl esters, acetate esters and fatty acids, with a contribution of terpenes and volatile phenols was recorded. Ethyl octanoate, ethyl hexanoate, isoamyl acetate, β-damascenone and eugenol were the aroma compounds with OAVs > 10. All these compounds are associated with fruity and  spicy aromas. Following this pattern, the aroma of the six wines was mainly characterized by three typical sensory terms, red fruits, which include berry fruits, strawberry and cherry, spices, which include pepper and clover and tomato paste.

This study provides a useful approach on the chemo-sensory fingerprint of Xinomavro PDO wines. It may be further used to determine the aroma “key” compounds responsible for Xinomavro aroma characters, as they derived from the sensory evaluation. This final result will be a great tool to improve the Xinomavro wines using winemaking methods to enhance the distinctive aromatic profile of this specific variety.