Forty cashew nut samples randomly collected from Riyadh, kingdom of Saudi Arabia was surveyed using the direct plating technique. The mycological investigation revealed that seventeen fungal species belonging to 11 genera were isolated. Aspergillus niger was generally the most distributed and the most frequent fungus. Mycotoxin production ability of Aspergillus flavus and A. niger was evaluated using HPLC analysis. Most of A. flavus isolates were toxigenic and capable of producing maltoryzine (3-10ppb) and sterigmatocystin (325-525 ppb) in the culture media. Meanwhile, 40% were aflatrem (2ppb) producers. On the other hand, 80% of the tested A. niger isolates were capable of producing oxalic acids in the culture media. Oxalic acid production ability was ranged from 200 to 625 mg/ml. Mycotoxigenic A. flavus and A. niger are the most potent contaminants of the food and should be eradicated to minimize the risk of toxin contamination of commoditized nuts.
Sterigmatocystin, Oxalic acid, Aspergillii, HPLC, Aflatrem
© The Author(s) 2014. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.