Use of ozone to control conidial germination in Ochratoxin a producing black Aspergilli isolated in raisins from Algeria

Ochratoxin A (OTA) contamination in raisins is related to the presence of black Aspergilli. In this work, raisin samples belonging to the cultivars 'Sublime seedless', 'Sultanine' and 'Centennial' were collected from different regions in Algeria and analyzed for the presence of OTA-producing black Aspergilli and of OTA. Black Aspergilli were found in all the samples with differences between cultivars and sampling regions. Generally, Aspergillus carbonarius was the most frequently isolated species among black Aspergilli. About 86.7% of A. carbonarius isolates and 72.2% of A. niger isolates were OTA producers. We also investigated the effect of ozone (0.3 ppm) treatment on the ability of conidia to germinate. Ozone significantly controlled the ability of conidia to germinate of both OTA producing and non-producing isolates. These results underline the need to establish a limit for OTA contamination in raisins in Algeria and highlight the potential of 03 to control fungal contaminants, especially those responsible for OTA production.