Dilution errors in aflatoxin determinations caused by compounds extracted from peanuts

Area of Science:

• Food Science
• Analytical Chemistry
• Mycotoxicology

Background:

• Thin layer chromatography (TLC) is a common technique for analyzing peanuts for aflatoxin.
• Current TLC methods rely on solvent extraction, which co-extracts interfering compounds like oils and fats.
• These co-extracted substances introduce errors in both the solvent proportion analysis and the aflatoxin measurement on TLC plates.

Purpose of the Study:

• To evaluate the underestimation errors in common aflatoxin analysis methods for peanuts.
• To quantify the impact of co-extracted compounds on aflatoxin concentration measurements.
• To assess the effectiveness of correction procedures in improving analytical accuracy.

Main Methods:

• Analysis of aflatoxin in peanuts using thin layer chromatography (TLC).
• Evaluation of solvent extraction procedures, including the CB method, a modified BF method, and a water slurry method.
• Assessment of the impact of co-extracted oils, fats, sugars, and proteins on measurement accuracy.
• Investigation of the CB method's fat correction procedure.

Main Results:

• Underestimation of aflatoxin concentrations by approximately 11%, 14%, and 5% for the CB, modified BF, and water slurry methods, respectively.
• Co-extracted compounds significantly interfere with accurate aflatoxin quantification.
• The CB method's correction for fats in the extraction solvent reduced its approximate error from 11% to 1%.

Conclusions:

• Standard TLC methods for peanut aflatoxin analysis are prone to underestimation due to co-extracted matrix components.
• Methodological adjustments, particularly fat correction in the CB method, are crucial for accurate aflatoxin determination.
• Improved cleanup and extraction protocols are necessary to enhance the reliability of aflatoxin testing in food products.