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

RIBEIRO JESSIKA M.M., CAVAGLIERI, LILIA R.; FRAGA, MARCELO E., DIREITO, GLORIA M.; DALCERO, ANA M. AND ROSA CARLOS A.R

LETTERS IN APPLIED MICROBIOLOGY

Blackwell Publishing

Lugar: Londres (Inglaterra); Año: 2006 p. 1 - 8

0266-8254

Aims: The objective of this study was to determine the ochratoxin and aflatoxin production by three strains of Aspergillus spp. under different water activities, temperature and incubation time on barley rootlets. Methods and Results: A. ochraceus and A. flavus were able to produce mycotoxins on barley rootlets (BR). A.ochraceus produced ochratoxin A at 0.80 aW, at 25º and 30ºC as optimal environmental conditions. The OTA production varies at different incubation days depending on aW. Aflatoxin B1 accumulation was obtained at 25ºC, at 0.80 and 0.95 aW, after 14 and 21 incubation days, respectively. Temperature was a critical factor influencing ochratoxin A and aflatoxin B1 production. Conclusions: This study demonstrates that barley rootlets support OTA and AFB1 production at relatively low water activity (0.80 aW) and high temperatures (25-30ºC). 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 barley rootlets used as animal feed.