The Effects of Segregating Stained Nuts on Reducing the Aflatoxin Content of Ahmad-Aghaei, Fandoghi and Kale-Ghoochi Pistachio Cultivars

Introduction: The physical specifications of pistachios after processing are associated with the presence of aflatoxin. The classification of pistachio nuts based on the appearance of raw dried pistachios could have a very important effect on the amount of aflatoxin. Materials and Methods: Samples of three commercial pistachio cultivars (Ahmad-Aghaei, Fandoghi, and Kale-Ghoochi) were categorized to different groups, which were large, medium, tiny, damaged, non-split yellow-brown stain and dark-greyish stain. The thin layer chromatography method was applied for the measurement of aflatoxins at the wavelength of 366 nm. Results: The yellow-brown stained nuts in Ahmad-Aghaei, Fandoghi and Kale-Ghoochi cultivars were 2.3, 4.6 and 1.1%, and the grey-black stained nuts were 4.6, 4.7 and 1.2%, respectively. By completely separating stained nuts, the amount of aflatoxin in Ahmad-Aghaei, Fandoghi and Kale-Ghoochi lots decreased more than 89.0%. There were significant differences (p<0.05) in the aflatoxin amounts of stained pistachio cultivars. Conclusion: This study pointed out that physical separation of the stained nuts from the pistachio lots could reduce the amount of aflatoxin in the final lots.