Aflatoxins and ochratoxin A in pistachios sampled in Spain: occurrence and presence of mycotoxigenic fungi

Abstract

A survey of the fungal contamination and occurrence of aflatoxins and ochratoxin A (OTA) in 50 pistachio nutsamples collected from commercial stores around Catalonia (Spain) was carried out.Aspergillus flavuswas foundin 30% of samples, whereasAspergillussectionNigri,Aspergillus ochraceus, andPenicillium verrucosumwere found in 40%, 2% and 26% of samples, respectively. A total of 204 fungal isolates were obtained; 70.8% ofA. flavusisolates were able to produce aflatoxin B1and B2, whereas OTA production capacity was detectedin 54.4% of theA. sectionNigribiseriate isolates. Aflatoxins were detected in five samples (10% of total),all exceeding the maximum legal limit set for aflatoxin B1(2mgkg1) or for total aflatoxins (4mgkg1), with onesample having a very high level of contamination (1134.5mgkg1). Only one sample of pistachio showed OTAcontamination at 0.67mgkg1. Simultaneous contamination by aflatoxins and OTA was not observed in thesesamples. It was concluded that the frequency of aflatoxins and OTA contamination in pistachio samples availablein the Spanish market is relatively low. Thus, no significant contribution to health risk should be expected fromaflatoxin consumption through pistachios among healthy consumers. However, the existence of single sampleswith an extremely high aflatoxin concentration reinforces the need for effective prevention strategies in pistachioprocessing and commercialization.

The authors are grateful to the EC (Project KBBE 2007-222738) Spanish (Project Number AGL2007-66416-C05-03)and Catalonian (XaRTA – Reference Network on FoodTechnology) Governments and the University of Lleida forfinancial support. F. Fernane is grateful to the Agencia Española de Cooperación Internacional para el Desarrollo (MAEC-AECID) for its financial support