Some clues about the changes in wine aroma composition associated to the maturation of "neutral" grapes

Abstract

This paper presents a study of the influence of the harvesting date on concentrations of odorants in Moristel wines of two vintages. The wine made from grapes harvested early facilitated the accumulation of acetaldehyde (associated with low polyphenols concentrations) and higher concentrations of branched acids. A reason for these greater levels could be the lack of reduction factors (NADH or NADPH). Other changes with potential sensory consequences are the decrease of the branched acid/branched alcohol, branched ester/branched acid and branched ester/branched alcohol ratios that occurs as the grapes ripen. Besides, the variations of varietal or typical maturation markers did not have sensory importance. These results suggest that the characteristics of wines associated to the degree of maturity of grapes are mostly related to the changes in the profiles of fermentative compounds (especially acetaldehyde) induced by changes in the polyphenolic content and in the medium in which the yeast develops.

Keywords: Acetaldehyde; Acetaldehyde (PubChem CID177); C-3-hexenol (PubChem CID5281167); Grape maturity; Maturity markers; Moristel; Reduction factors; Wine aroma; Wine aromatic buffer; ethyl isobutyrate (PubChem CID7342); ethyl isovalerate (PubChem CID7945); ethyl vanilllate (PubChem CID12038); isoamyl alcohol (PubChem CID31260); isobutanol (PubChem CID6560); isobutyric acid (PubChem CID6590); isovaleric acid (PubChem CID10430); γ-nonalactone (PubChem CID7710).