Acoustic sensing of deoxynivalenol in co-occurrence with zearalenone and T-2/HT-2 toxin in winter wheat cultivar Sirvinta from Lithuania

A fast acoustic screening method in combination with an ELISA method was applied for the detection of deoxynivalenol (DON) in co-occurrence with some trichothecenes such as zearalenone (ZEA) and T-2/HT-2 toxins in winter wheat grains (Triticum aestivum L.) of the most popular Lithuanian cultivar Sirvinta. Strong correlations between the amplitude of the acoustic signal that penetrated the wheat samples and DON as well as total amount of mentioned trichothecenes quantified by ELISA method were found (R²=0.787 and R²=0.794, respectively). It turned out that weak correlations between the acoustic signal and the concentrations of ZEA and T-2/HT-2 were found. These correlations suggest that DON is the marker of the Fusarium infected wheat grain. This statement is also strengthened by the fact that DON is the most significant trichothecene contaminant of cereal grains in the world and levels are generally higher in the wetter climates. The dependency determined between the acoustic signal and structural physical characteristics (1000-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 microstructure of wholesome and 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 in several enzyme activities in the infected grains. Moderate positive relationships between α-amylase, protease and xylanase activities, and the degree of Fusarium infection were found (for α-amylase R²=0.623, for protease R²=0.823, and for xylanase R²=0.682). An intriguing characterisation may contribute to explanations as to how and to what extent wheat starch granules of different sizes stay more or less intact by slightly infected grains while the wheat starch granules are damaged and/ or completely destroyed by seriously infected grains. The changes of the protease activity had a slightly detectable influence on the crude protein content in seriously infected grain samples which might have an effect on dough properties and the quality of bread.