Methods for Characterization of Kernel Density and Aflatoxin Levels of Individual Peanuts¹

A helium pycnometer, specific gravity bottle and a displacement method were evaluated for the determination of individual peanut (Arachis hypogaea L.) kernel densities. Three coating materials were tested to minimize water absorption with the latter two methods. The displacement technique with a coefficient of variation (CV) of less than 0.1% was found to be most reproducible and had a total variability of 0.002 g/cm³. Polyurethane was adopted as the coating material of choice. A reverse phase High Performance Liquid Chromatography (HPLC) assay was adapted for quantification of the aflatoxins in individual peanuts. Picogram levels of aflatoxin were quantified with an average recovery of 82%. Characterization of peanut kernel density distributions and relationships between kernel density and aflatoxin level are envisioned with data generated using this method.