Determination of Aflatoxin Levels in Macadamia Nuts

Introduction: Aflatoxin contamination in tree nuts, including macadamia nuts, pose a serious health risk to humans, so an accurate and reliable analytical method to determine the concentration of aflatoxin in the samples is required. High-performance liquid chromatography (HPLC) is an attractive method for identification and quantification of aflatoxins because it can provide accurate and precise analytical results. Effectiveness and reduced labor required for analysis.

Purpose: The purpose of this study was to evaluate an HPLC method developed specially for the determination of the aflatoxins in nuts that naturally contaminated with aflatoxin.

Methods: Ground macadamia nuts were extracted using a 60:40 methanol: water solution and then diluted 1:2 in phosphate buffered saline solution (PBS). Clean up was performed using immune-affinity columns and samples were analyzed by HPLC using KOBRA cell derivatization.

Results: Immuno-affinity column effectiveness was gauged by spiking a non-detect samples with an aflatoxin standard and comparing the resulting value with the spiked value. Recovery values for our spiked samples ranged from 85% - 108%.

Significance: The developed HPLC method is an effective means of determining aflatoxin concentration in macadamia nuts reducing matrix interference and providing high accuracy and precision.