New Zealand Journal of Crop and Horticultural Science abstracts

---

Effects of temperature on fusaria and Fusarium mycotoxins during short-term storage of maize kernels (Zea mays)

D. R. Lauren¹
M. E. Di Menna²
W. A. Smith¹

¹The Horticulture and Food Research
   Institute of New Zealand Ltd
 Ruakura Research Centre
 Hamilton, New Zealand
 email: dlauren@hortresearch.co.nz

²New Zealand Pastoral Agriculture
   Research Institute Ltd
 Ruakura Research Centre
 Hamilton, New Zealand

Abstract  In three trials freshly harvested maize kernels (Zea mays) of different moisture contents (MC) (19%, 24%, 27%) were stored at 20¼C, 25¼C, 30¼C, and 37¼C for 3, 6, and 10 days and changes in the percentages of Fusarium-infected kernels and in the concentrations of the mycotoxins nivalenol (NIV) and deoxynivalenol (DON) measured. The effects of storage varied with the initial Fusarium infections and moisture content as well as with time and temperature. In the grain of 19% MC, F. subglutinans was the dominant Fusarium species and initially infected 16% of kernels, while the NIV + DON concentration was below 0.2 mg/kg. Neither the percentage of Fusarium infection nor the toxin concentration changed greatly at any temperature during the storage period, although the proportion of F. subglutinans increased at 30¼C and 37¼C. In the harvest sample of 24% MC, F. graminearum was the dominant Fusarium species on day 0 and infected 26% of kernels. The total content of NIV plus DON was less than 0.5 mg/kg. By day 10 during storage at 20-30¼C the infection rate of F. graminearum rose to 42-60% and NIV + DON concentration to over 2 mg/kg. At 37¼C F. graminearum was no longer recovered by day 6 and NIV + DON concentration was unchanged from the initial level. In the harvest sample of 27% MC, F. graminearum was dominant and initially infected 80% of the kernels. The initial NIV + DON concentration was 2 mg/kg. At 20-30¼C the infection rates did not materially change but toxin content rose to c. 6 mg/kg by day 10. At 37¼C F. graminearum was no longer recoverable at day 10 while the NIV + DON concentration remained at the original level. Visual inspection of the incubated samples showed visible mould growth about the grains in samples incubated for 10 days at 37¼C for the 24% MC sample or for 6-10 days at all temperatures in for the 27% MC sample. The incidence of Penicillium was favoured by storage, and at 37¼C the predominant fungus found at day 10 was Penicillium (19% MC and 27% MC samples) or Aspergillus (24% MC sample).

Keywords  maize; mycotoxins; Fusarium; storage; temperature; moisture content

H03065; Online publication date 17 March 2004; Received 30 June 2003; accepted 24 October 2003
New Zealand Journal of Crop and Horticultural Science, 2004, Vol. 32: 77-84
0014-0671/04/3201-0077 © The Royal Society of New Zealand 2004

PDF file of entire paper: Print-quality (172K) | screen-quality (121K)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page