Distribution of aflatoxin in pistachios. 7. Sequential sampling

Area of Science:

• Agricultural Science
• Food Science
• Analytical Chemistry

Background:

• Aflatoxins are toxic fungal metabolites that contaminate food crops like pistachios.
• Accurate and efficient testing methods are crucial for ensuring food safety and compliance with regulatory standards.
• Current testing protocols may be resource-intensive; sequential sampling offers a potential optimization.

Purpose of the Study:

• To evaluate a sequential sampling protocol for aflatoxin testing in pistachios.
• To assess the efficiency and accuracy of a three-step sequential sampling plan based on EU protocols.
• To determine the potential impact of this protocol on lot acceptance, rejection, and retesting rates.

Main Methods:

• Utilized existing aflatoxin distribution and Monte Carlo simulation data.
• Modeled a three-step sequential sampling protocol (10, 20, 30 kg sample averages).
• Applied an acceptance level of 15 ng/g total aflatoxin and optimized indifference regions (2-30 ng/g).

Main Results:

• The sequential protocol's Operating Characteristic (OC) curve approximated that of a single 50 kg sample.
• Application to 1293 pistachio lots (1998 crop year) showed 95% acceptance and 1.5% rejection based on single 10 kg tests.
• A significant 3.5% of lots would have required retesting under the sequential protocol.

Conclusions:

• Sequential sampling offers a viable alternative for aflatoxin testing in pistachios.
• The evaluated protocol demonstrates potential for efficient lot management, balancing acceptance, rejection, and retesting.
• Further validation could support adoption for U.S. standards, potentially improving testing efficiency.