Assessment of key aroma compounds in fresh jujube brandy by GC‐O‐MS and odor activity value

Abstract

Fresh jujube brandy (FJB, 50% v/v ethanol) was produced by the distillation of the fermented broth obtained by continuous jujube fermentation with Saccharomyces cerevisiae. Fifty-five aroma-active compounds of jujube brandy (JB) were found by GC-O-MS. Through the calculation of odor activity value, 27 compounds that make a contribution to the JB aroma were identified and 16 key flavor compounds of JB were determined, including ethyl octanoate, ethyl caproate, ethyl isovalerate, ethyl laurate, 2-undecanone, ethyl valerate, etc., followed by aroma reconstruction experiments for confirmation. Great similarity and differences were found in different brandies on the characteristic aroma compounds by principal component analysis. Furthermore, four components (ethyl butyrate, ethyl valerate, ethyl octanate, and benzaldehyde) were partly originated from jujube. During fermentation, eight methyl esters converted to ethyl esters, and nine new compounds (ethyl 2-methyl-butyrate, ethyl iso-valerate, etc.) were formed. Practical applications FJB (50% v/v ethanol), produced by the distillation of the fermented broth obtained by continuous jujube fermentation with Saccharomyces cerevisiae, is a famous alcoholic beverage in Taihang Mountain districts in Hebei with Chinese characteristics. But the development of FJB was restricted because its flavor and quality were very unstable. Understanding the key aroma compounds of JB and its formation mechanism could provide a guide of process optimization and flavor regulation, making it become a unique brandy with Chinese characteristics, recognized and accepting by the world.