Impact of 2(3)-tert-butyl-4 hydroxyanisole microcapsules at sub-lethal doses on behavior of Aspergillus flavus in culture medium and peanut kernels.

GIRARDI, N.S.; GARCÍA, D.; PASSONE, M.A.; NESCI, A.; ETCHEVERRY, MIRIAM

Congreso; XII Congreso argentino de microbiología General - SAMIGE.; 2017

Peanuts are considered to be a high-risk product for contamination with aflatoxins (AFs) since it is frequently contaminated with fungi, particularly Aspergillus flavus and Aspergillus parasiticus, and for the long peanut drying times and occurrence of rainy periods after uprooting. In addition, mycotoxins can be produced in grains in the field, and also during transport and storage where conditions are suitable for their production. Formulation of the food grade antioxidant of 2(3)-tert-butyl-4 hydroxyanisole (BHA) have shown antifungal effects on stored peanuts. In this work, our interest focuses on the physiological behavior of Aspergillus flavus affected by the exposure to sub-lethal doses of microencapsulated BHA. For this, peanut meal extract agar (PMEA), peanut kernels with modified water activity (aw) (0.96 and 0.99) and a sub-lethal dose (0.6 mM) of an BHA formulation were used. Fungal physiological aspects as growth rate, time to growth and AFB1 evolution were modified by the formulation, especially on PMEA at both aw. In general, conidial and vesicle sizes of the mold only were affected by growth substrate, being higher on sterile kernels than on PMEA, regardless of aw condition. However, positive correlation (p