J. Zheng (1), F. Yuan (2), M. C. QIAN (2);
(1) Sichuan University and Oregon State University, Chengdu China and Corvallis, OR, U.S.A.; (2) Oregon State University, Corvallis, OR, U.S.A.
Furaneol and sotolon have been identified in beer, wines, and other alcoholic beverages as very important aroma compounds. However, it is difficult to reliably analyze these compounds due to their high polarity and thermal instability. In this study, a reliable and robust method was developed to analyze furaneol and sotolon based on N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) silyation coupled with GC-MS. Various derivative parameters were evaluated, and the results demonstrated that the ratio of sample, BSTFA (5% trimethyl chlorosilane, TMCS), and dichloromethane of 1:1:1, derivatization temperature of 50°C, and reaction time of 30 min were the best for the reaction. Recovery of furaneol and sotolon was 92.5 and 85.2%, respectively. Limit of detection (LOD) and limit of quantification (LOQ) were 7.3 and 9.1 µg/L for furaneol and 24.3 to 30.4 µg/L for sotolon, respectively. The optimal method resulted in good repeatability and reproducibility with inter- and intra-day relative standard deviations less than 11%. The developed method was applied to wines, beer, and iced tea; the results showed that the beer samples had the highest furaneol and sotolon concentrations, ranging from 101 µg/L to 487 µg/L, which was 200–400 times higher than in Pinot Noir wine and 20–40 times higher than the iced tea.
Michael C. Qian is a professor of flavor chemistry at Oregon State University and chair of the Food and Agricultural Food Chemistry Division of the American Chemical Society (2014). He received his Ph.D. degree from the University of Minnesota under the guidance of Gary Reineccius. Michael’s research interests at Oregon State University cover aroma/flavor chemical/biochemical generation in dairy products, small fruits (blackberries, raspberry, and strawberry), wine and wine grapes, beer, and hops. He has published many research papers, including 12 book chapters and 4 books in the field of flavor chemistry, and is a frequent speaker at national and international meetings. In 2014, Michael was named a Fellow of the Agricultural and Food Chemistry Division of the American Chemical Society.