Assessment of the volatile and non-volatile profile of Savatiano PGI wines as affected by various terroirs in Attica, Greece.

Establishing the concept of terroir in wines, combined with the exploitation of native grape varieties, is considered a viable alternative to produce quality wines for increasing interest in the wine market. The aim of this study is the characterization of Protected Geographical Indication (PGI) Savatiano white wines from different regions of Attica (Greece), through the chemical and sensory description of the aroma of wines and the determination of their phenolic profiles. The wines produced with the same vinification protocol were evaluated using the descriptive sensory analysis method while they underwent profiling of volatile and phenolic compounds by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) respectively. The presence of regional differences within the wines was also explored, elaborated with variables that contribute to their differentiation, such as soil type, monthly average temperature, and rainfall. Volatile and sensory profiles of the wines separated the regions and confirmed that sub-regional differences attributed mainly to soil characteristics affect wine aroma. The wines from the east part of Attica were higher in esters, terpenes and higher alcohols with high scores in fruity and blossoms attributes while wines from the north part of Attica presented higher intensity of mineral, nutty and herbaceous attributes. The separations based solely on the phenolic compounds concentration were less clear but a relationship was found between the content of phenolic acids and flavonoids and the studied regions. To our knowledge this is the first characterization of Savatiano PGI wines of Attica generating a fingerprint including chemical composition and sensory aroma characteristics to differentiate wines, combining this pattern with particular sub-regions.

Chemical and Sensory Characterization of Xinomavro Red Wine Using Grapes from Protected Designations of Northern Greece.

Despite Xinomavro (Vitis vinifera L.) being a well-known noble red grape variety of northern Greece, little is known about its ''bouquet'' typicity. Volatile compounds of Xinomavro wines produced using a common vinification protocol were analyzed by gas chromatography-mass spectrometry and sensory descriptive analysis was carried out with a trained panel. Wines were characterized by the presence of fatty acids, ethyl and acetate esters, and alcohols, with contributions from terpenes and a volatile phenol. The most active aroma compounds were determined to be 3-methylbutyl acetate, ß-damascenone, ethyl esters of octanoic and hexanoic acids, and eugenol. Those compounds positively correlated with fruity and spicy odor descriptors, with the wines being mostly characterized by five typical aroma terms: strawberry, berry fruit, spices, tomato, and green bell pepper. Partial least squares regression (PLSR) analysis was used to visualize relationship between the orthonasal sensory attributes and the volatile aroma compounds with calculated OAVs > 1. Key aroma-active volatiles in the wines were identified using GC-MS/olfactometry, providing a list of 40 compounds, among which 13 presented a modified detection frequency > 70%. This study is the first of its kind and provided strong indications regarding the aroma compounds defining the sensory characteristics of Xinomavro wines.

Impact of Assimilable Nitrogen Supplementation on Saccharomyces cerevisiae Metabolic Response and Aromatic Profile of Moschofilero Wine.

The concentration of nitrogen in must is critical to yeast fermentation efficiency and wine aroma profile. The present work determined the effect of the amount of yeast assimilable nitrogen (YAN) on fermentation kinetics, aroma production, and gene expression patterns of the wine yeast Saccharomyces cerevisiae. Fermentations were performed under two different YAN concentrations of must. Acetate esters, linalool, and nerol appeared to be clearly affected by the different YAN levels. Real-time-PCR results revealed that the genes involved in ethyl and acetate esters production recorded, in general, higher transcript levels under high nitrogen supplementation. In addition, an up-regulation of the BGL2 and EXG1 genes, which are related to terpenes production, was observed in the case of high nitrogen content and it is well corresponded to the terpenol concentration found. Our study revealed the impact of nitrogen supplementation on yeast metabolism and its importance to adjust wine's aromatic composition and sensory profile.