Qualitative and quantitative research of propyl lactate in brewed alcoholic beverages

Recently, propyl lactate has been firstly detected in Chinese Baijiu (Chinese liquor) as one of the odor-active components. In this study, the contents of propyl lactate in other different brewed alcoholic beverages were investigated, including wine, soju, sake, vodka, rum, tequila, whisky and beer, and analyzed by solid-phase microextraction and liquid-liquid extraction coupled with gas chromatography-mass spectrometry, determined by internal standard method followed by GC-MS with selective ion monitoring. The analyses indicated that propyl lactate was present in beer and tequila samples, while not detected in other brewed alcoholic beverages. The results showed that among the 40 beer samples from 11 different countries, 36 of them contained propyl lactate at concentrations in the range of 0.23-51.71 mu gL(-1). In addition, all of six tequila samples contained propyl lactate at concentrations in the range of 0.77-12.14mgL(-1), and the odor activity values (OAVs) of propyl lactate were greater than 1 in all of the tequila samples. These findings indicated that propyl lactate was widely distributed in beer and tequila; it was also an odor-active component of tequila according to OAVs.