Witrick, K.1,2, O'Keefe, S.2, Duncan, S.2, Hurley, E. K.2, Tanko, J.2 and Lindemans, G.3, (1)Southern Illinois University, Carbondale, IL, USA, (2)Virginia Tech, Blacksburg, VA, USA, (3)Lindemans Brewery, Viezenbeek, BELGIUM
Technical Session 3: Analytical Flavors
Monday, June 05, 2017
8:30–10:15 a.m.
Caloosa Ballroom
Lambic beer is one of the oldest styles of beer still being produced today using spontaneous fermentation. Gueuze is a style of lambic beer that blends “young” (1 year old) and aged (2+ years old) beers. Little is known about the development of the volatile and semi-volatile compounds in lambic beer during aging. SPME with GCMS was used for extraction and identification of volatile and semi-volatile compounds from 3-, 6-, 9-, 12-, and 28-month-old commercial samples of lambic beer. Compounds were identified using standardized retention time and mass spectra of standards. GC-O was used to characterize the aroma profiles of the samples. A total of 42 compounds were identified using GC-MS. Seventeen of the 42 compounds identified in the various aged samples have been previously reported in lambic beer. Ethyl lactate, ethyl acetate, 4-ethylphenol and 4-ethylguaiacol were identified in the 9-, 12-, and 28-month-old samples. These four compounds have been linked to the microorganism Brettanomyces. Twenty-one aroma active compounds were identified using GC-O. As the age of the gueuze samples increased, a larger number of aroma compounds were identified by the panelists; compounds identified increased from seven for the 3-month-old samples to nine for the 6-month-old samples, and eleven for both the 9- and 12-month-old samples, and seventeen for the 28-month-old samples.
Katherine Witrick has appointments in chemistry and biochemistry and the Fermentation Science Institute, with animal science, food and nutrition being her primary appointment and tenure home. Katherine earned her Ph.D. degree in food science and technology, with an emphasis in analytical chemistry, at Virginia Polytechnic Institute and State University (Virginia Tech) in Blacksburg, VA. Her degree focused on flavor development in lambic degrees. She received her post-doctoral training from Virginia Tech. Prior to coming to SIU she worked at SweetWater Brewing Company (Atlanta, GA) in the Quality Control Department. Her research currently focuses on the use of analytical and sensory techniques to look at how flavor and aroma compounds develop in fermented beverage systems.
View Presentation
