Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4368070 | International Journal of Food Microbiology | 2011 | 7 Pages |
Fusarium can survive, grow, and produce mycotoxins during malting. We evaluated the percentage of barley kernels infected with Fusarium (FI) and deoxynivalenol (DON) concentration in three barley treatments (high-quality, naturally infected, and Fusarium graminearum inoculated barley) during various stages of malting. We also applied real-time polymerase chain reaction (real-time PCR) and real-time reverse transcriptase PCR (real-time RT-PCR) methods to quantify trichothecene-producing (Tri5) DNA concentration and expression, respectively. We observed that FI significantly (P < 0.05) increased during the germination stage of malting in all barley treatments. Temperatures of 49 °C and higher during kilning reduced the FI in high-quality barley treatments, but for inoculated treatments temperatures in excess of 60 °C were needed to reduce FI. The Tri5 DNA concentration ranged from non-detectable to 3.9 ng/50 mg, 0.1 to 109.8 ng/50 mg and 3.4 to 397.5 ng/50 mg in malted high-quality, inoculated and naturally infected barley treatments respectively. Strong gene expression (Tri5) in naturally infected barley treatments was found during the third day of germination, when compared to high-quality and inoculated barley treatments during malting. Deoxynivalenol was present even at high kilning temperatures, as DON is heat stable. The average DON concentration ranged from non-detectable to 0.1 μg/g, non-detectable to 1.1 μg/g, and 1.5 to 45.9 μg/g during various stages of malting in high-quality, inoculated and infected barley and malt samples respectively. Overall, the last 2 days of germination and initial stages of kilning were peak stages for FI, Tri5 gene production, Tri5 gene expression and DON production.
► Fusarium survival and growth during malting of barley.► Fusarium infection and deoxynivalenol reduced during steeping. ► Highest Tri5 gene expression during third day of germination. ► Deoxynivalenol production peaked during germination and initial hours of kilning.