Predicting noncompliant levels of ochratoxin A in cereal grain from Penicillium verrucosum counts.
OBJECTIVE
To model the probability of exceeding the European legislative limit of 5 microg ochratoxin A (OTA) per kilogram grain in relation to Penicillium verrucosum levels and storage conditions, and to evaluate the possibilities of using P. verrucosum colony counts for predicting noncompliant OTA levels.


RESULTS
Cereal samples were inoculated with P. verrucosum spores and stored for up to 9 months at temperatures and water activities ranging from 10-25 degrees C and aw 0.77-0.95. A logistic regression analysis showed that the probability of exceeding 5 microg OTA kg(-1) grain was related to colony counts of P. verrucosum and water activity. The sensitivity and specificity of various P. verrucosum count thresholds for predicting noncompliant OTA levels were estimated, using data from the storage trial and natural cereal samples.


CONCLUSIONS
The risk of exceeding 5 microg OTA kg(-1) grain increased with increasing levels of P. verrucosum, and with increasing water activities. A threshold of 1000 CFU P. verrucosum per gram grain is suggested to predict whether or not the legislative limit is exceeded.


CONCLUSIONS
This study has provided a tool to evaluate the levels of P. verrucosum in grain in relation to OTA levels. Hence, mycological analyses can be used to identify cereal samples with high risk of containing OTA levels above the legislative limit.
National Food Administration, Microbiology Division, Uppsala, Sweden.
M
M
Lindblad
P
P
Johnsson
N
N
Jonsson
R
R
Lindqvist
M
M
Olsen
D018554:Avena / Q000737:chemistry / Q000382:microbiology; D002273:Carcinogens / Q000032:analysis; D015169:Colony Count, Microbial; D002523:Edible Grain / Q000737:chemistry* / Q000382:microbiology; D005060:Europe; D005511:Food Handling / Q000331:legislation & jurisprudence*; D009183:Mycotoxins / Q000032:analysis; D009793:Ochratoxins / Q000032:analysis*; D010407:Penicillium / Q000302:isolation & purification*; D011336:Probability; D014908:Triticum / Q000737:chemistry / Q000382:microbiology
D002273:Carcinogens; D009183:Mycotoxins; D009793:Ochratoxins; C025589:ochratoxin A