Sampling almonds for aflatoxin, part II: estimating risks associated with various sampling plan designs.

Area of Science:

• Food Science
• Analytical Chemistry
• Regulatory Science

Background:

• Regulatory limits for aflatoxin, a toxic mold byproduct, vary significantly across approximately 100 nations.
• The Codex Alimentarius Commission is working to harmonize aflatoxin limits and sampling plans for various nuts.
• Accurate aflatoxin testing and sampling are vital for food safety and international trade.

Purpose of the Study:

• To develop a model for evaluating aflatoxin sampling plan performance in almonds.
• To reduce misclassification of almond lots in the export trade through harmonized sampling plans.
• To measure uncertainty and distribution of test results for aflatoxin in almond samples.

Main Methods:

• Twenty lots of shelled almonds were sampled, with sixteen 10 kg samples taken per lot.
• Aflatoxin distribution among replicate samples was analyzed and compared to theoretical distributions.
• The negative binomial distribution was selected to model observed aflatoxin distribution patterns.

Main Results:

• The negative binomial distribution provided an acceptable fit for observed aflatoxin distributions across all tested almond samples.
• Operating characteristics curves were developed using variance and distribution data.
• The model predicts the impact of sample size and decision limits on lot rejection/acceptance probabilities.

Conclusions:

• The negative binomial distribution is a suitable model for aflatoxin distribution in almond samples.
• The developed model aids in creating more effective and harmonized aflatoxin sampling plans for almonds.
• Improved sampling plans will enhance accuracy in classifying export lots, supporting international trade standards.