Whitaker Thomas B, Slate Andrew B, Hurley J Michael, Giesbrecht Francis G
U.S. Department of Agriculture, Agricultural Research Service, North Carolina State University, Box 7625, Raleigh, NC 27695-7625, USA.
J AOAC Int. 2007 May-Jun;90(3):778-85.
About 100 nations have established regulatory limits for aflatoxin in food and feeds. Because these limits vary widely from one country to another, the Codex Alimentarius Commission, working through the Codex Committee on Food Additives and Contaminants, has initiated work to harmonize aflatoxin limits and sampling plans for almonds, pistachios, hazelnuts, and Brazil nuts. Studies were developed to measure the uncertainty and distribution among test results for replicate samples taken from aflatoxin-contaminated almond shipments. The uncertainty and distribution information was used to develop a model to evaluate the performance of aflatoxin sampling plans so that harmonized sampling plans can be developed for almonds that reduce the misclassifying of lots in the export trade. Twenty lots of shelled almonds were sampled according to an experimental protocol in which sixteen 10 kg samples were taken from each lot. The observed aflatoxin distribution among the 16 sample test results was compared with 3 theoretical distributions. The negative binomial distribution was selected to model aflatoxin distribution among sample test results because it gave acceptable fits across all 20 observed sample distributions. By using the variance and distribution information, operating characteristics curves were developed to predict the effect of sample size and accept/reject limits on the probability of rejecting good lots and accepting bad lots.
约100个国家已制定了食品和饲料中黄曲霉毒素的监管限值。由于这些限值在不同国家之间差异很大，食品法典委员会通过食品添加剂和污染物法典委员会开展工作，已启动了协调杏仁、开心果、榛子和巴西坚果中黄曲霉毒素限值及抽样计划的工作。开展了相关研究，以测量从受黄曲霉毒素污染的杏仁货物中抽取的重复样品的检测结果之间的不确定性和分布情况。不确定性和分布信息被用于建立一个模型，以评估黄曲霉毒素抽样计划的性能，从而能够为杏仁制定协调一致的抽样计划，减少出口贸易中批次的误判。根据一项实验方案对20批带壳杏仁进行了抽样，该方案是从每批杏仁中抽取16个10千克的样品。将16个样品检测结果中观察到的黄曲霉毒素分布与3种理论分布进行了比较。选择负二项分布来模拟样品检测结果中的黄曲霉毒素分布，因为它在所有20个观察到的样品分布中都给出了可接受的拟合度。通过使用方差和分布信息，绘制了操作特性曲线，以预测样本大小和接受/拒绝限值对拒收合格批次和接受不合格批次概率的影响。
