Variability among peanut subsamples prepared for aflatoxin analysis with four mills

Area of Science:

• Food Science and Technology
• Analytical Chemistry
• Agricultural Science

Background:

• Aflatoxins are toxic secondary metabolites produced by Aspergillus fungi, commonly found in peanuts.
• Accurate aflatoxin testing relies on minimizing variability during sample preparation, particularly grinding.
• Different grinding mills may introduce varying levels of heterogeneity in peanut samples.

Purpose of the Study:

• To evaluate the impact of four different mills on aflatoxin concentration variability in peanut subsamples.
• To identify grinding equipment that minimizes subsample variability for more reliable aflatoxin analysis.

Main Methods:

• Naturally contaminated peanut samples (2 kg and 4 kg) were ground using three mills: Dickens (DM), Stephan (SM), and two Robot Coupe models (RC1, RC2).
• Ten subsamples (100 g or 200 g) were taken from each ground sample.
• Aflatoxin concentration in subsamples was determined using liquid chromatography; coefficient of variation (CV) was calculated and analyzed.

Main Results:

• For 2 kg samples, RC1 exhibited significantly lower CVs (average 17.2%) compared to SM (32.8%) and DM (40.6%).
• For 4 kg samples, RC2 (21.2%) and SM (26.0%) showed significantly lower CVs than DM (47.0%).
• The Dickens mill consistently resulted in the highest aflatoxin variability across both sample sizes.

Conclusions:

• The choice of grinding mill significantly influences the variability of aflatoxin concentration in peanut subsamples.
• Robot Coupe (RC1, RC2) and Stephan (SM) mills are more effective than the Dickens mill (DM) in reducing subsample heterogeneity for aflatoxin analysis.
• Selecting appropriate grinding equipment is crucial for accurate and reliable aflatoxin testing in peanuts.