Variations in Main Flavor Compounds of Freshly Distilled Brandy during the Second Distillation

The present study investigated the variations in main flavor compounds of a Chinese brandy during the second distillation process using headspace–solid-phase microextraction coupled with gas chromatography-mass spectrometry. A total of 97 volatile compounds involving esters, alcohols, aldehydes, ketones, furans, benzene derivatives and terpenes were quantified, and 28 components were identified as key ingredients. By monitoring the second distillation process, it was found that most ethyl esters (ethyl hexanoate, ethyl octanoate, etc.), alcohols (3-methylbutanol, etc.), terpenes (linalool, etc.), acetaldehyde and ionone all had higher values at the beginning of the distillation, but declined gradually or sharply along with the distillation process. However, two esters (ethyl lactate and diethyl succinate), acids (acetic acid, hexanoic acid), benzene derivatives (2-phenylethanol, etc.) and furan (furfural) showed lower levels when the distillation was just started, and gradually increased, accumulating as a large quantity at the end of the distillation.