Sampling hazelnuts for aflatoxin: uncertainty associated with sampling, sample preparation, and analysis

Area of Science:

• Food Science
• Analytical Chemistry
• Agricultural Science

Background:

• Aflatoxins are toxic fungal metabolites posing significant risks to food safety, particularly in commodities like hazelnuts.
• Accurate estimation of aflatoxin levels in bulk shipments is crucial for regulatory compliance and consumer protection.

Purpose of the Study:

• To investigate and quantify the sources of variability in the aflatoxin testing procedure for shelled hazelnuts.
• To develop mathematical models for predicting testing variability based on aflatoxin concentration and testing parameters.

Main Methods:

• Investigated variability by analyzing 160 samples (16 per lot) from 20 suspected aflatoxin-contaminated hazelnut lots.
• Partitioned total variance into sampling, sample preparation, and analytical components.
• Utilized regression analysis to model the relationship between aflatoxin concentration and variance components.

Main Results:

• Each variance component (sampling, sample preparation, analytical) increased with rising aflatoxin concentration (B1 or total).
• Developed mathematical expressions to model these relationships, enabling variance estimation for various testing parameters.
• At 10 ng/g total aflatoxin, sampling variance (174.40) dominated, followed by sample preparation (0.74) and analytical (0.27) variances.

Conclusions:

• Sampling is the predominant source of variability (99.4%) in aflatoxin testing of hazelnuts, significantly outweighing sample preparation (0.4%) and analytical (0.2%) steps.
• The developed models provide a tool to optimize testing strategies and manage risks associated with aflatoxin contamination in hazelnut lots.