Impact of food-grade antioxidants on sclerotia production and toxigenic profile of Aspergillus section Flavi population at stored peanut level

PASSONE, M.A.; NESCI, A.; RESNIK, S.; ETCHEVERRY, M.G.

Estambul, Turquía

Congreso; XII International IUPAC Symposium on Mycotoxin and Phycotoxins; 2007

Tubitak ATAL

The purposes of this study were to determine the effect of food-grade antioxidants (butylated hydroxyanisole-BHA 10 mM-S2, BHA + propyl paraben-PP 10 + 10 mM-S3, BHA + PP + butylated hydroxytoluene-BHT 10 + 5 + 10 mM-S4, BHA + PP + BHT 10 + 10 + 10 mM-S5) on Aspergillus section Flavi populations, to evaluate the impact on natural occurrence of aflatoxins (AF) and to elucidate the influence of these chemicals on sclerotia production and toxigenic profile. Treatments showed a significant control on Aspergillus section Flavi population. Reduction percentages were about of 35.3, 72.4, 80.3, and 80.6% from seed treated with mixtures S2, S3, S4 and S5, respectively. Natural occurrence of aflatoxins from five silos was negative. Aspergillus flavus was the dominant specie from peanut pod and seed tissues, showing 75.5% of incidence. From 291 strains identified as A. flavus, only 36 were isolated from peanut treated with mixtures S4 and S5. In these treated silos and during the three first sampling it was observed the highest incidence (100 %) of L strains, which were unable to produce aflatoxins, whereas non-sclerotial (NS) phenotype increased to 38% at the end of the storage period. The highest AF-producers, S strains, only were recovered (4%) from silos control and 2. Antioxidants mixtures inhibited A. parasiticus population. Twenty-two isolates were A. parasiticus, L and S morphotypes were 100% AF-producing, while 89% of NS strains were toxigenic. Food-grade antioxidants showed a significant effect on species from section Flavi from stored peanut during a 5-months period.