A comparison of two milling strategies to reduce the mycotoxin deoxynivalenol in barley

Authors: KHATIBI, PLYUM - Virginia Polytechnic Institution & State University; WILSON, JHANEL - Former ARS Employee; BERGER, GREG - Virginia Polytechnic Institution & State University; BROOKS, WYNSE - Virginia Polytechnic Institution & State University; MCMASTER, NIKKI - Virginia Polytechnic Institution & State University; GRIFFEY, CARL - Virginia Polytechnic Institution & State University; Hicks, Kevin; Nghiem, Nhuan; SCHMALE, DAVID - Virginia Polytechnic Institution & State University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2014
Publication Date: 1/14/2014
Citation: Khatibi, P.A., Wilson, J., Berger, G., Brooks, W.S., Mcmaster, N., Griffey, C.A., Hicks, K.B., Nghiem, N.P., Schmale, D.G. 2014. A comparison of two milling strategies to reduce the mycotoxin deoxynivalenol in barley. Journal of Agricultural and Food Chemistry. 62(18):4204-4213.

Interpretive Summary: Barley grown on the East Coast of the US frequently becomes infected with a type of fungi called Fusarium because of the high humidity in the climate of that area. When Fusarium grows on barley kernels, it produces a toxin called a “mycotoxin” which is toxic to animals and humans, thus rendering the grain unsuitable for food, feed, or fuel ethanol feedstock. We hypothesized that removal of the hull from the barley kernel would also remove most of the mycotoxins from the barley. Two different hull removal processes were used which included roller milling, a processed used to make flour from wheat kernels and a “precision” dehulling process previously developed by ARS researchers. The precision milling process was far more effective than the roller milling process at removing mycotoxins from hulled barley, removing the hull and up to 85 percent of the mycotoxins without significant loss of important kernel components such as starch and protein. This work will be very useful to barley growers and processers who can detoxify contaminated barley and use it for a multitude of food, feed, and fuel uses.

Technical Abstract: The trichothecene mycotoxin deoxynivalenol (DON), a common contaminant of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) grain, is a threat to feed and food safety in the United States. New strategies to reduce the threat of DON need to be developed and implemented. Previous work has suggested that large concentrations of DON accumulate in barley hulls. Consequently, improved strategies are needed to carefully remove the hull from the grain and preserve the endosperm. Two different milling strategies (roller milling and precision milling (FitzMill)) were evaluated for their effectiveness in reducing DON in Virginia barley. These strategies were employed to efficiently remove barley hulls and retain endosperm. DON was quantified in the hull and endosperm fractions resulting from both milling strategies. Precision milling was more effective at hull removal, with hull mass fractions ranging from 15.7 percent to 36.8 percent compared to roller milling, which resulted in hull mass fractions ranging from 10.1 percent to 15.9 percent. Grain mass recovery was highest with precision milling (98.79 percent to 100.63 percent) compared to roller milling (96.61 percent to 98.31 percent). The precision mill resulted in an 85.5 percent mean reduction of DON, while the roller mill resulted in a 36.2 percent mean reduction. This work has important implications for the reduction of mycotoxins such as DON in barley fuel ethanol co-products and barley enriched animal feeds and human foods.