Dependence of aflatoxin in almonds on the type and amount of insect damage

The aflatoxin distribution of single insect damaged Nonpareil almonds (1999 crop) has been measured. Separate distributions were obtained for pinhole, insect (feeding), and gross damage. Only a low level of aflatoxin contamination ([c] = 0.0003 ng/g) was found for pinhole-only damaged nuts. The distributions for insect and gross damage did not differ, but did differ significantly from the distribution previously obtained for gross damaged Ne Plus almonds from a different producer (Schatzki, T. F.; Ong, M. S. J. Agric. Food Chem. 2000, 48, 489-492; also 1999 crop). The Nonpareil almond distribution could be explained on the basis of a preharvest hull splitting, similar to previous results in pistachios (0-4 weeks versus 2-6 weeks preharvest). The Ne Plus distribution differs in detail from pistachio results and from the Nonpareil results found here. This may indicate additional cultural damage of Ne Plus almonds around harvest time and/or use of different sorting parameters. Aflatoxin lot averages of 31.7 and 3.47 ng/g were obtained for 100% insect damaged Ne Plus and Nonpareil almonds, respectively. (The previous Ne Plus work contained a calculation error, which is corrected here.) The distribution functions were used to compute the seller's risk of nonacceptance of lots in the European Union. To obtain a 95% acceptance rate, aflatoxin B-1 levels of 0.12 and 0.22 ng/g would be required, which would correspond to 3.8 and 1.2% (feeding and gross) insect damage in Nonpareil and Ne Plus almond lots, respectively.