Session 1: Food Safety, Toxicology and Utilization of Mycotoxin-contaminated Grain

Barley quality and safety is affected by Fusarium both in the field and during post-harvest processes. Fusarium strains can survive, grow and produce mycotoxins during malting. We evaluated percentage of Fusarium infection (FI), and deoxynivalenol (DON) concentration in three, raw barley samples (high quality, naturallyinfected, F. graminearum inoculated barley) during various stages of malting. We also applied real-time PCR and real-time reverse transcriptase PCR (real-time RT-PCR) methods to quantify the Tri5 DNA concentration and expression respectively in the barley samples. We observed that FI significantly (P < 0.05) increased during the germination stage of malting in all the barley samples. Temperatures of 49°C and higher during kilning reduced the FI in high quality barley samples, but for inoculated samples more than 60°C during kilning was needed to reduce Fusarium infection. The average Tri5 DNA was found to be in the range of 0 to 3.9 ng/ 50 mg, 0.06 to 109.79 ng/50 mg and 3.38 to 397.55 ng/50 mg in malted high quality, inoculated and infected barley samples respectively. Strong gene expression (Tri5) in naturally infected barley samples was found during 3rd day of germination, however very low amounts of gene expression were observed in high quality and inoculated barley samples during malting. Deoxynivalenol was found to be present even at high kilning temperatures as DON is heat stable. The average DON concentration was found to be in the range of 0 to 0.13 μg/g, 0 to1.09μg/g and 1.53 to 45.86 μg/g during malting in high quality, inoculated and infected barley samples respectively. Overall, the last two days of germination and initial stages of kilning were peak processing stages for FI, Tri5 gene production, Tri5 gene expression and DON production.