Effect of Simulated Alcoholic Fermentation on Aroma Components of Grape Berries During Anaerobic Metabolism

¹ Institut National de la Recherche Agronomique, I.P.V. Laboratoire de Biochimie Métabolique et Technologie, 2, Place Viala, 34060 Montpellier, France
² Institut National de la Recherche Agronomique, I.P.V. Laboratoire des Aromes et des Substances Naturelles, 2, Place Viala, 34060 Montpellier, France.

The effect of the simulation of alcoholic fermentation on the volatile components present in grape berries during their anaerobic metabolism has been investigated. Volatile compounds were analyzed by gas chromatography and identified by coupling with an ion trap detector. The results were examined by two-way analysis of variance to evaluate, in this experiment, the effect of time of anaerobiosis and of simulation of alcoholic fermentation. This study confirms the evolution of volatile compounds during anaerobic metabolism and identifies them, e.g. the low concentrations of C6 compounds, the increase of alcohols, of esters (especially diethyl succinate and ethyl cinnimate), acetoin, and benzaldehyde. Total alcohols increase to the same extent with or without alcoholic fermentation, but the respective percentage of each alcohol component varies in the two series of experiments. The presence of ethanol leads to a greater increase of diethyl succinate and ethyl cinnimate concentrations in treated berries as compared to control samples. Total esters and ethyl cinnimate alone are correlated to the concentration of ethanol within the berries. Ethyl lactate was found only in the ethanol-supplied samples.

Key words: anaerobic metabolism, aroma components, alcoholic fermentation, carbonic maceration, grapes

Submitted on September 30, 1988