In vitro control of growth and ochratoxin A production by butylated hydroxyanisole in Aspergillus section Nigri species

Abstract

This study was carried out to determine the efficacy of phenolic antioxidant butylated hydroxyanisole (BHA) under different interacting water activity ( a W) and temperature regimes on the lag phase and growth rate by Aspergillus section Nigri strains . In this experiment four A. section Nigri strains were used. Peanut meal extract agar (PMEA) was prepared at 2%. The a W of the medium was adjusted to 0.995, 0.980 and 0.930, BHA at 1, 5, 10 and 20 mmol l −1 was added to the basic medium. The plates were inoculated and incubated for 30 days at 18 and 25 °C. Radial growth rates (mm d −1) and lag phase ( h) were calculated. In control treatments, the growth rate decreased as water activity reduced in all strains assayed. At all a W levels tested, BHA at 20 mmol l −1 completely inhibited growth. In general, at 10 mmol l −1 and 0.995 and 0.980 a W level, a significant reduction respect to control was observed. This antioxidant completely inhibited OTA production, at concentrations of 20 mmol l −1, regardless of a W used by all the strains evaluated.