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


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 degrees C as optimal environmental conditions. The OTA production varies at different incubation days depending on a(w). Aflatoxin B(1) (AFB1) accumulation was obtained at 25 degrees C, at 0.80 and 0.95 a(w), after 14 and 21 incubation days respectively. Temperature was a critical factor influencing OTA and AFB(1) production.


CONCLUSIONS
This study demonstrates that BR support OTA and AFB(1) production at relatively low water activity (0.80 a(w)) and high temperatures (25-30 degrees C).


CONCLUSIONS
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.
Ribeiro
J M M
JM
Departamento de Microbiologia e Imunología Veterinária, Universidade Federal Rural do Rio de Janeiro, Instituto de Veterinária, Rio de Janeiro, Brazil.
Cavaglieri
L R
LR
Fraga
M E
ME
Direito
G M
GM
Dalcero
A M
AM
Rosa
C A R
CA
D000348:Aflatoxins / Q000096:biosynthesis*; D001230:Aspergillus / Q000254:growth & development / Q000378:metabolism*; D005516:Food Microbiology; D001467:Hordeum / Q000382:microbiology*; D009183:Mycotoxins / Q000096:biosynthesis*; D009793:Ochratoxins / Q000096:biosynthesis*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000378:metabolism*
D000348:Aflatoxins; D009183:Mycotoxins; D009793:Ochratoxins; D014867:Water