VIEW ARTICLE    http://dx.doi.org/10.1094/ASBCJ-2014-0703-01

Occurrence of Deoxynivalenol-3-Glucoside on Barley from the Upper Midwestern United States. Paul B. Schwarz (1), Department of Plant Sciences, North Dakota State University, PO Box 6050, Dept. 7670, Fargo, ND 58108; Steven Y. Qian, Department of Pharmaceutical Sciences, North Dakota State University, PO Box 6050, Dept. 2665, Fargo, ND 58108; Bing Zhou, Department of Applied Engineering, Zhejiang Economic and Trade Polytechnic, Hangzhou, China; Yi Xu, Department of Pharmaceutical Sciences, North Dakota State University, PO Box 6050, Dept. 2665, Fargo, ND 58108; and John M. Barr, Richard D. Horsley, and James Gillespie, Department of Plant Sciences, North Dakota State University, PO Box 6050, Dept. 7670, Fargo, ND 58108. (1) Corresponding author. E-mail: <Paul.Schwarz@ndsu.edu>. J. Am. Soc. Brew. Chem. 72(3):208-213, 2014.

The natural occurrence of deoxynivalenol-3-glucoside (DON-3-G) on wheat was first reported in 2005. Subsequent research has shown its occurrence on wheat, maize, and barley grains that have been infected with Fusarium head blight (FHB), as well as in processed products derived from the grain, including malt and beer. The mycotoxin, deoxynivalenol (DON), is produced by several species of Fusarium during infection, and DON-3-G is subsequently formed by a detoxification mechanism of the host plant. There has been considerable interest in DON-3-G because it is not detected by most routine methodologies that are employed for DON, but may contribute to the overall DON if broken down during digestion or processing. As such, it has been designated as a “masked” mycotoxin. The objective of the current work was to assess the levels of DON-3-G on infected barley from the upper Midwest region of the United States. Three sets of commercially grown barley samples, representing multiple crop years, were selected for this study. FHB-infected samples were purposely selected, based upon previous results of DON analysis. Analysis of barley samples collected from 2001 to 2012 showed that DON-3-G was present at levels of <0.20–3.11 mg/kg. In the case of the 2001–2011 crop, DON-3-G was always at levels that represented less than 10 mol% of the DON present on the same samples. However, the overall average ratio was higher with the 2012 crop (19 mol%), and results of this study suggest that levels of DON-3-G might be impacted by environmental/cropping conditions. It was also observed that DON levels were a poor predictor of DON-3-G. Samples where the proportion of DON-3-G was high, or even in excess of DON, were very few and were found only within a single crop year. However, because similar results have been observed in previous studies conducted in both Europe and Asia, grain processors need to be well aware of DON-3-G.

La presencia natural de deoxinivalenol-3-glucósido (DON-3-G) en el trigo fue reportado por primera vez en 2005. Investigaciones posteriores han demostrado su ocurrencia en los granos de trigo, maíz y cebada que han sido infectados con fusariosis de la espiga (FHB), así como en los productos procesados derivados de los cereales, incluido la malta y cerveza. La micotoxina, deoxinivalenol (DON), es producida por varias especies de Fusarium durante la infección, y DON-3-G se forma posteriormente por un mecanismo de detoxificación de la planta huésped. Ha habido un considerable interés por DON-3-G, ya que no es detectado por la mayoría de los métodos de rutina que se emplean para el DON, pero puede contribuir al DON total si se descompone durante la digestión o procesamiento. Como tal, ha sido designada como una micotoxina “enmascarada.” El objetivo del presente trabajo fue evaluar los niveles de DON-3-G en una cebada infectada procedentes de la región superior del Medio Oeste de los Estados Unidos. Tres conjuntos de muestras de cebada cultivadas comercialmente, en representación de varios años de cultivo, fueron seleccionados para este estudio. Muestras infectadas por el FHB fueron seleccionados a propósito, en base a los resultados previos de análisis de DON. Análisis de muestras de cebada recogidos desde 2001–2012 mostró que el DON-3-G estaba presente a niveles de <0.20 a 3.11 mg/kg. En el caso de la cosecha 2001–2011, DON-3-G era siempre en niveles que representan menos del 10% en moles de la presente DON en las mismas muestras. Sin embargo, la proporción media general fue mayor con la cosecha de 2012 (19% en moles), y los resultados de este estudio sugieren que los niveles de DON-3-G pueden verse afectados por las condiciones ambientales/cultivo. También se observó que los niveles de DON fueron un pobre predictor de DON-3-G. Las muestras donde la proporción de DON-3-G era alta, o incluso mayor que DON, eran muy pocos y sólo se han encontraron dentro de un solo año de cosecha. Sin embargo, ya que los resultados similares se han observado en estudios previos llevados a cabo en Europa y Asia, los procesadores de grano tienen que ser muy conscientes de DON-3-G.