Kerpes, R.1, Göller, F.1, Kollmannsberger, H.1, Fischer, S.1 and Becker, T.1, (1)TU Munchen-Institute of Brewing and Beverage Technology, Freising, GERMANY
Technical Session 6: Sensory
Tuesday, June 06, 2017
1:45–3:30 p.m.
Everglades Ballroom
A gluten-free beer (<10 ppm) intended for patients suffering from celiac disease was produced from gluten-containing barley malt wort using an enzyme-enriched malt extract. Yet, the aroma profile of such beer is unknown. The results showed the treatment had a massive impact on the aroma profile concerning absence of esters such as 3-methyl-butylacetate (–93%), 2-methybutylacetate (n.d.), ethyl-hexanoate (–66%) and ethyl-acetate (–50%) compared to the reference. A reduced content of esters can be related to long-chain free fatty acids (LCFFA). The analysis of LCFFA in wort showed a significant increase in hexadecanoic acid (56 µg/g = gluten-free-wort, 2 µg/g = reference) and linoleic acid (36.5 µg/g, n.d.). The beers were analyzed further for their aging components, and analysis indicated increased amounts of heating, e.g., furfural (15.92 µg/L, 7.87 µg/L), and aging indicators, e.g., phenyl acetaldehyde (68 µg/L, 29 µg/L), although the values were below the odor threshold. GC-O/MS following a descriptive profile test showed the attribute honey was significantly increased. To clarify the findings conventional barley malt worts were spiked with hexadecanoic acid, linoleic acid and a mixture thereof, in which a significant decrease of all esters concomitant with a honey-like aroma was determined. Here, the aging aroma component analysis showed no significant difference. Through adjustment of ester content equal to the reference, the spiked beers were rated as having less honey aroma. The results show aging components are sensed more strongly in the absence of esters and, therefore, by reducing LCFFA concentrations of gluten-free wort the aroma of the resulting beer could be improved.
Roland Kerpes studied brewing science and beverage technology at the Technische Universität München (TUM). He finished his diploma thesis on the impact of unmalted oats on the quality and processability of mashes, worts, and beers at University College Cork (UCC), Ireland, in 2011 (Prof. Elke Arendt). Since 2011 he has been working on the development of a gluten-free beer using peptidase-enriched malts at the Institute of Brewing and Beverage Technology (BGT/TUM, Prof. Thomas Becker) in the Beverage and Cereal Biotechnology research group, where he’s also assistant group leader. This project (AIF 16971 N) is founded by the FEI (Research Association of the German Food Industry).
