56. Influence of Fusarium avenaceum on barley malt—Monitoring the changes in the protein profile of barley during the malting process

Cajetan Geißinger (1), Thomas Becker (1), Martina Gastl (1); (1) Chair of Brewing and Beverage Technology, Technische Universität München, Freising, Germany

Technical Session 16: Barley & Malt II
Tuesday, August 16  •  2:00–3:15 p.m.
Plaza Building, Concourse Level, Governor’s Square 14

m ssp. are ubiquitous field pathogens, which are known to affect quality characteristics of cereals. Fusarium infection in brewing cereals is problematic and a hint of poor malt quality. The negative effects of Fusarium infestation are multiple. Besides agronomic losses, kernel discoloration and the production of several mycotoxins, Fusarium ssp. are known to enhance especially proteolytic activity in infected barley malt. A previous study showed that, in the last crop years, the predominant Fusarium ssp. in Europe is Fusarium avenaceum. This study focuses on the changes in the protein spectrum during the malting process of barley samples infected with Fusarium avenaceum. The examined barley samples were grown under controlled conditions in a greenhouse trial. Two control samples were included: one sample was not infected with Fusarium spores, and the other one was inoculated during anthesis with a spore suspension of Fusarium avenaceum. Malting trials were carried out in a micro-malting facility under defined conditions. To monitor the changes in the protein profile, samples were analyzed at different stages of the malting process: after steeping, germination and kilning. To evaluate the changes in the protein composition different fractionation techniques (e.g., Osborne fractionation, isoelectric focusing and capillary gel electrophoresis) were used. Data were collected and protein maps of the different malting steps were plotted. Results elucidate changes in the protein profile during the malting process and reveal the influence of a Fusarium infection on protein composition.

After completing an apprenticeship as a brewer and maltster at the Andechs monastery brewery (Andechs, Germany), Cajetan Geißinger studied brewing and beverage technology at the Technische Universität München, Germany. He carried out his diploma thesis at the Institute of Brewing and Beverage Technology (Prof. Thomas Becker) in TUM-Weihenstephan. The topic of his work was “Critical Examination and Systematic Assessment of the Modified Carlsberg Test (MCT).” In April 2012 he began as a Ph.D. fellow under the supervision of Prof. Becker. A significant portion of his research activities are directed toward investigation of the influence of fungal contamination on quality characteristics in cereal processing. Since September 2015 he is head of the laboratory for malt and beer analysis at the Institute of Brewing and Beverage Technology (TUM).