O-6
Fate of ergot alkaloids in brewing
Presenter: Paul Schwarz, North Dakota State University, Fargo, ND
Co-Authors: G.E. Rottinghaus, University of Missouri, Columbia, MO; and N.S. Hill, University of Georgia, Athens, GA

Ergot, caused by Claviceps purpurea, is a common disease of cereals, and occurs in Midwestern barley during most years, albeit infrequently and typically at very low levels. It is easily recognized by purple-black sclerotia that replace kernels in diseased spikes. Ergot is of concern as the sclerotia contain alkaloids that can cause gangrenous and convulsive ergotism in humans and livestock. As such, it is important that sclerotia are removed from grain by cleaning. Barley that contains in excess of 0.1% sclerotia is down-graded to ergoty under Official U.S. grades. The scientific literature contains very little to no information on the ergot alkaloids and beer. The historical record, however, indicates that ergot was epidemic during much of the Middle Ages in Europe and contains references to ergot mycotoxicoses associated with the consumption of beer. The objective of this research was to investigate the survival of ergot alkaloids during the malting and brewing processes. Beer was brewed (N=3) from malt containing 0.1% ergot sclerotia. Total alkaloids were estimated by ELISA and quantitation of the individual ergopeptine alkaloids was by HPLC with fluorescence detection. The grist contained 2.2 (±0.8) mg alkaloids/kg malt. Approximately 35% of the alkaloids were recovered with the spent grains. Less than 5% of the total alkaloids were recovered in the beer, and in all cases the beer contained below 10.0 micrograms/L. Alkaloids in malt were predominately ergotamine, ergocryptine, and ergocristine. Thermal degradation during mashing and wort boiling is strongly suggested as less than 60% of the alkaloids originally present in the malt grist were recovered in the spent grains and beer.

Dr Paul Schwarz is professor of plant sciences at North Dakota State University in Fargo, where he directs the barley and malt quality research program. He has published numerous manuscripts on malt quality and malting and brewing. His research interests are in the area of molds/mycotoxins, barley cell wall polysaccharides, and lipid metabolism. Dr Schwarz has worked at the Kurth Malting Corp., Milwaukee, Wisconsin, and has completed practical training/sabbatical at the A. Egger Bierbrauerei, Worb, Switzerland, and the Coors Brewing Co., Golden, Colorado.