Decrease of Wine Volatile Aroma Esters by Oxidation

The effect of oxidation on the levels of wine volatile aroma esters was studied. Chardonnay wine wasbottled either in the presence of nitrogen or air in the headspace. Moreover, Fe II was added to the wineand the bottles were closed in the presence of air. Absorbance values were recorded at 420 nm (browningindex), while volatile esters were evaluated during storage using SPME/GC-MS. During wine storage ofup to nine months, wines bottled in the presence of air exhibited higher browning indexes and lowerlevels of several esters, such ethyl acetate, isoamyl acetate, ethyl hexanoate, ethyl octanoate and ethyldecanoate, in comparison to wines bottled under nitrogen. Addition of Fe II led to higher browning indexesand lower levels of several esters during wine storage. In addition, Fe II was added along with H2O2 toChardonnay wine and the bottles were closed in the presence of air. These additions led to wines withhigher browning indexes and lower levels of several esters during wine storage up to 40 days. The presentresults demonstrate that wine volatile aroma esters can be decreased by oxidation under semi-oxidativeand forced oxidative conditions. As a result, oxidation should be taken into account in the decrease ofaroma esters during wine storage.