Distribution of aflatoxin in almonds. 2. Distribution in almonds with heavy insect damage

The aflatoxin distribution function in individual insect-damaged NePlus Ultra almonds was determined and found to be the sum of two distributions. Substantially all almonds exhibited a positive aflatoxin level between 0.02 ng/g (the detection level) and 0.3 ng/g, the precise form of this distribution depending on the lot studied. In addition, 1/1000 of the nuts showed contamination between 60 and 600 000 ng/g, independent of the lot. The latter distribution showed a smooth decrease with log concentration in this range, with no evidence of a minimum, as had been found previously for pistachios. No distribution data between 0.3 and 60 ng/g could be obtained. The distribution below 0.3 ng/g was assigned to contamination during post-harvest storage. The distribution above 60 ng/g was tentatively assigned to navel orange worm damage occurring when insects enter the kernel during split hulls late in the growing season. Considerable additional work will be required to verify these assignments.