Study of methods for the extraction of volatile compounds from fermented grape must

The main objective of the present study was to analyze the volatile compounds extracted from fermented grape musts by two extraction methods in order to characterize the samples. The purge and trap system provided the necessary sensitivity for the analysis of low-boiling point compounds, such as acetaldehyde and ethyl acetate, and the liquid–liquid extraction method allowed for the analysis of a great number of medium to high boiling point volatile compounds, such as phenylethyl alcohol, hexanoic and octanoic acids, ethyl hexanoate and ethyl octanoate. Ethyl propionate and propyl acetate, extracted by the liquid–liquid method, characterized the sample of grape must fermented by Kloeckera apiculata. The sample of grape must fermented by Pichia membranaefaciens was characterized by 2-propanol and 2-hexanone, extracted by the purge and trap system and liquid–liquid method, respectively. These results show that the purge and trap/dynamic headspace system and liquid–liquid extraction method are complementary in the determination of the aroma profiles of fermented grape musts and characterization of the samples.