Detection of aflatoxin M1 in milk using spectroscopy and multivariate analyses

Area of Science:

• Analytical Chemistry
• Food Safety
• Spectroscopy

Background:

• Aflatoxin M1 (AFM1) is a carcinogenic mycotoxin found in milk from cows consuming contaminated feed.
• Accurate and rapid detection of AFM1 is crucial for ensuring milk product safety and preventing public health risks.

Purpose of the Study:

• To investigate the feasibility of using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy combined with chemometrics for AFM1 detection in milk.
• To develop a rapid and reliable method for quantifying AFM1 levels in bovine milk.

Main Methods:

• Bovine milk samples were spiked with varying concentrations of AFM1 (0-0.1 μg/l).
• Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra were acquired for all samples.
• Chemometric techniques, including Principal Component Analysis (PCA), SIMCA classification, and Partial Least Square (PLS) regression, were applied for data analysis.

Main Results:

• ATR-FTIR spectra showed significant differences between pure and AFM1-spiked milk samples, particularly in the 1800-650 cm⁻¹ and 3689-3499 cm⁻¹ regions.
• PCA demonstrated clear sample clustering (p≤0.05), indicating distinct spectral profiles based on AFM1 presence.
• SIMCA models achieved >86% classification accuracy and successfully detected AFM1 at concentrations as low as 0.02 μg/l (p≤0.05).
• PLS regression provided high prediction accuracy for AFM1 quantification (R²=0.99 for calibration, R²=0.98 for validation) in the 1800-650 cm⁻¹ range.

Conclusions:

• ATR-FTIR spectroscopy coupled with chemometrics offers a feasible and effective approach for the rapid detection and quantification of AFM1 in milk.
• The developed method demonstrates high sensitivity and accuracy, suitable for routine milk quality control and safety monitoring.