Effect of different winemaking techniques and grape variety on chemo-sensory parameters of white wines

Abstract

AIM: Study the chemical and sensory parameters of fifty commercial white wines elaborated with different techniques (fermented in oak barrel and aged on lees (FB+AL); aged on lees (AL); and without aging (WA)) and different grape varieties (Verdejo, Sauvignon blanc and Godello).

METHODS: Classical enological parameters (1), phenolic families (2), polysaccharides (3), volatile groups (4) and sensory attributes were analysed.

RESULTS: In general, the FB+AL wines had the highest content of the different phenolic families studied and the AL wines the lowest. In the FB+AL wines also highlighted the highest total polysaccharide content and acidity and WA ones the lowest. Respect to the volatile groups, the FB+AL wines showed the highest concentration of higher alcohols and those volatiles which come from the oak wood, such as whiskey lactones, vanillic and furanic derivatives, and positive volatile phenols. On the contrary, the AL and WA wines were characterized by their higher content of ethyl esters and alcohol acetates than FB+AL wines. Sensory differences were found between the wines elaborated with different techniques, The FB+AL wines showed the highest values of the olfactory intensity, followed by the WA and AL ones. This result was mainly due to the difference found in the white and tropical fruits and spice and toasted aromas. The FB+AL wines were better valuated in body and persistence attributes than the WA ones. Godello wines presented the highest ethanol content and Verdejo wines the lowest. Sauvignon blanc wines had the highest tartaric esters and flavonols, ethyl esters, ethyl esters, alcohol acetates and C6 alcohols, and the lowest total polysaccharides and aldehydes. Godello wines also had higher content of higher alcohols than Verdejo and Sauvignon blanc wines, and higher content of terpenes than Verdejo wines. Sauvignon blanc wines were characterized by having the highest vegetal aromas, Verdejo wines by tropical fruit aromas and Godello ones by white fruit aromas.

CONCLUSIONS

Differences in chemo-sensory parameters were found in the wines elaborated with different techniques. The FB+AL technique had more influence on these parameters due to the release of several compounds from oak and lees. The grape variety influence was different depending on the parameter analysed, highlighting the differences found in the aromatic attributes of each varietal wine.