Influence of water activity, temperature and time on mycotoxins production on barley rootlets

Abstract

Aims: The objective of this study was to determine the ochratoxin (OT) and aflatoxin (AF) production by three strains of Aspergillus spp. under different water activities, temperature and incubation time on barley rootlets (BR). Methods and Results: Aspergillus ochraceus and Aspergillus flavus were able to produce mycotoxins on BR. Aspergillus ochraceus produced ochratoxin A (OTA) at 0·80 water activity (a_w), at 25 and 30°C as optimal environmental conditions. The OTA production varies at different incubation days depending on a_w. Aflatoxin B₁ (AFB1) accumulation was obtained at 25°C, at 0·80 and 0·95 a_w, after 14 and 21 incubation days respectively. Temperature was a critical factor influencing OTA and AFB₁ production. Conclusions: This study demonstrates that BR support OTA and AFB₁ production at relatively low water activity (0·80 a_w) and high temperatures (25–30°C). Significance and Impact of the Study: The study of ecophysiological parameters and their interactions would determine the prevailing environmental factors, which enhance the mycotoxin production on BR used as animal feed.