Determination of Aflatoxin Bi in Pistachio Kernels and Shells
Abstract A method was developed for accurate measurement of aflatoxin B1 in the edible portion of pistachio nuts. Twenty-nine samples of kernels with and without their shells were slurried with a Mega Ultra Turrax. A subsample of the homogenate was extracted with water–methanol, defatted with petroleum ether, purified with a silica solid-phase extraction column, and redissolved in methanol. After separation on an octadecy! column and postcolumn reaction with on-line electrochemically generated bromine, the aflatoxin Bi derivative was detected fluorometrically. The shells contained less than 1 % of the aflatoxin Bi found in the edible kernel, and they accounted for 41.7–46.8% of the weight of the whole pistachio. These observations indicate it is possible to analyze an entire sample, up to 25 kg, as a whole and still be able to judge whether it meets the legal tolerance limit of 5 μg aflatoxin B1/kg edible part, as set by the Dutch Food Act.
