Acoustic Sensing of Don in Malting Cereal Grains

Abstract

A fast acoustic screening method in combination with an ELISA method was applied for the detection of deoxynivalenol (DON) in malting cereal grains. Strong correlations between the amplitude of the acoustic signal that penetrated through the malting wheat and barley samples and near it belonging quantity of DON also quantitative verified by an ELISA method, were found (R2 = 0.787 and R2 = 0.771, respectively). These correlations suggest that quantitative and qualitative screening of DON in malt with a non-invasive acoustic spectrometer is world’s fastest and cheapest method to determine this marker mycotoxin in by Fusarium infected grain intended for malting. The dependency determined between the acoustic signal and structural physical characteristics (1,000-kernel-weight) of the grain matrix could therefore be the basis for the developed rapid acoustic method for cereal quality and safety control. Additional examination of the microstructure of wholesome and by Fusarium affected kernels under the scanning electron microscope revealed that obvious damage to the starch granules and lack of protein matrix was caused by the increase of several enzyme activities in the infected grains. Significant positive relationships between xylanase (R2 = 0.682), α-amylase (R2 = 0.623) and protease (R2 = 0.823) activities, and the degree of Fusarium infection were found in malting wheat, and xylanase (R2 = 0.601), α-amylase (R2 = 0.571) and protease (R2 = 0.649) activities, in malting barley. An intriguing characterization may contribute to explanations as how and to what extent malting cereal starch granules of different sizes stay more or less intact by lightly infected grains while by seriously infected grains the malting cereal starch granules are damaged and/or completely destroyed. The changes of the protease activity had a slightly detectable influence on the crude protein content in seriously infected grain samples which might certainly have its effect on propert