Esters in wines : new insight through the establishment of a database of french wines
Résumé
This work aimed to establish a database of wine esters from French wines to update the knowledge of wine aroma composition. Thirty odorant esters were quantified by HS–SPME–GC-MS in 183 commercial French wines from 1 to 29 years old and included red, dry white, sweet white, and rosé wines and red wines from carbonic maceration (Beaujolais nouveau; BN). Higher concentrations of ethyl esters of fatty acids (EEFAs) were found in wines made at low temperature (white and rosé). However, the relative composition of EEFAs was similar in all types of wines and mainly depended on the length of the carbon chain. Higher alcohol acetate (HAA) levels were favored in wines made under strict anaerobiosis (BN, white), but the relative composition of HAAs depended on the type of wine. Such variability in the relative compositions of HAAs among wines might originate from differences in lipids, oxygen, and nitrogen status of fermented media. Conversely, concentrations of ethyl esters of branched acids (EEBAs) were higher in wines made with grape skin contact (BN, red). The relative concentrations of EEBAs were similar regardless of the type of wine, with ethyl isobutyrate the most abundant. We hypothesized that this specific EEBAs profile in wines might originate from the redox balance regulation of yeast metabolism. Moreover, concentrations of EEBA increased with wine age at similar rates in white and red wines. On the other hand, chemical hydrolysis during wine aging was observed only in the analytical data for higher alcohol acetates in white wines and for ethyl decanoate and dodecanoate in red and white wines. The results help in understanding the aromatic contribution of esters in aged wine.