Quality variation and deoxynivalenol accumulation in corn inoculated with Fusarium graminearum under aerobic conditions

Abstract:

[Objective] The objective of this trial is to investigate the quality variation and the accumulation of deoxynivalenol and 15-acetyldeoxynivalenol in corn with different Fusarium graminearum inoculation under aerobic conditions.[Methods] Single factor experiment design was used, the inoculation amount of Fusarium graminearum was 1×10⁵, 1×10⁶, 1×10⁷ conidia/g, the corn moisture was 22%, cultured in a Erlenmeyer flask, and the oxygen flux was 1020 m²/m³. The temperature was 25±2℃, the humidity was 75%±5%, and the culture time was 60 d. The quality index and two toxins content in corn culture on different culture time were measured.[Results] The amino acid content had a quadratic curve variation (P<0.01), the content of crude fat, starch and crude fiber decreased linearly (P<0.01), the acid value increased linearly (P<0.01), the protein solubility and energy decreased linearly (P<0.01), the mold counting and content of deoxynivalenol, 15-acetyldeoxynivalenol showed a quadratic curve variation (P<0.01). The accumulation dynamic of deoxynivalenol was that the toxin production ranged from 0.17 to 0.23 mg/kg between 0-15 d, from 0.14 to 0.41 mg/kg between 16-20 d, from 0.06 to 0.15 mg/kg between 21-60 d. The accumulation dynamic of 15-acetyldeoxynivalenol was that the toxin production ranged from 1.11 to 5.28 mg/kg between 0 to 5 d, from 5.55 to 10.05 mg/kg between 6-15 d, from 4.68 to 12.06 mg/kg between 16-60 d.[Conclusion] The corn quality decreased gradually with the increase of Fusarium graminearum inoculation amount and culture time. There was a dose-dependent relationship between content of deoxynivalenol, 15-acetyldeoxynivalenol and Fusarium graminearum inoculation amount. The accumulation dynamic of two toxins was found within 60 days.