Incidence of penicillium verrucosum in grain samples from oat varieties commonly grown in South Dakota

Abstract

Ochratoxin A (OTA) can cause toxicogenic effects in humans and animals when contaminated food products are consumed. Oat (Avena sativa), like any other cereal grain, can be contaminated with OTA when storage conditions are favorable for fungal growth and toxin production. South Dakota is among the leading oat-producing states in the United States. It is therefore important to determine the frequency of occurrence of the primary OTA-producing fungal species on oat grains produced in the state. In this study, we evaluated oat grain samples from South Dakota for the incidence of Penicillium verrucosum, the major ochratoxigenic fungus in temperate regions. Kernels from 12 oat cultivars grown at multiple locations in South Dakota from 2014 to 2016 (15 location-year combinations) were plated on dichloran yeast extract sucrose glycerol agar medium. P. verrucosum was detected on 0.30, 0.19, and 0.05% of the kernels tested in 2014, 2015, and 2016, respectively. Overall, 22 of the 360 evaluated samples had kernels contaminated with P. verrucosum. The fungal incidence of the contaminated samples ranged from 1 to 16%, and the majority of those samples originated from one location. All samples from 2014 and 2015 (n = 240), except two, had no detectable levels of OTA. The concentration of OTA was well under the maximum limit recommended by the European Union for the two samples with detectable levels of OTA.