Fusarium graminearum and deoxynivalenol in wheat sPikes, grains and flour in argentina: effect on food safety and quality of wheat grains and by-Products

JUAN M. PALAZZINI; VERÓNICA FUMERO; GERMÁN BARROS; MARTHA CUNIBERTI; SOFÍA N. CHULZE

Workshop; Food Mycology in a Globalized World ? Challenges and Solutions to the Safety of Food; 2013

International Commission on Food Mycology

Fusarium graminearum sensu stricto is the predominant causal agent of Fusarium Head Blight (FHB) in Argentina, res ulting in economic losses through reduction in grain yield, quality and accumulation of mycotoxins mainly trichothecenes such as deoxynivalenol (DON). During the harvest season 2012/2013 an epidemic of FHB occurred in Argentina. The aims of the present study were: - to correlate FHB severity with F. graminearum DNA levels in spikes, - to determine the levels of DON in wheat grain and flour samples collected from the wheat growing region from Argentina, -to quantify F. graminearum both by a microbiological method and using TaqMan real-time PCR, and - to evaluate the quality of the grains. On wheat spikes obtained from the field, a good correlation was observed between disease severity and F. graminearum DNA levels. From 69 wheat grain samples evaluated, 56 (81%) showed DON contamination in levels ranging from 0.4 to 8.5 ppm, mean 2.4 ppm. From the contaminated wheat grain samples, 4 groups were selected based on the DON content. From each group, 3 flour samples were evaluated for DON contamination. Nine flour samples showed DON levels approximately 50% lower than the levels detected in grains. The microbiological examination of the wheat grain and flour samples showed F. graminearum contamination. Also most of the samples including grains and flour showed detection of F. graminearum genomic DNA using the TaqMan real-time PCR assay. The grain quality indicators such as weight per 1,000 kernels (g), test weight (Kg/hl) and protein content (%) were altered in comparison with a non-epidemic year.