Interaction study of aflatoxin M1 with milk proteins using ATR-FTIR

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Biochemistry

Background:

• Aflatoxin M1 (AFM1), a milk-borne carcinogen, is a metabolite of aflatoxin B1 (AFB1).
• AFM1 is known to interact with milk proteins, but the precise mechanism remains unclear.
• Understanding this interaction is crucial for food safety and dairy product quality.

Purpose of the Study:

• To investigate the interaction mechanism between AFM1 and milk proteins.
• To identify spectral signatures indicative of AFM1-protein binding.
• To elucidate conformational changes in milk protein secondary structure induced by AFM1.

Main Methods:

• Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) spectroscopy was employed.
• Chemometric analysis, including second-order derivative spectra and Principal Component Analysis (PCA), was utilized.
• Spectral data in the 1700-1600 cm⁻¹ region were analyzed.

Main Results:

• Second-order derivative spectra confirmed the affinity of AFM1 for milk proteins.
• PCA indicated the spectral window of 1700-1600 cm⁻¹ is highly informative for detecting AFM1.
• The study identified spectral changes corresponding to conformational alterations in milk protein secondary structures due to AFM1.

Conclusions:

• ATR-FTIR coupled with chemometrics effectively characterizes AFM1-milk protein interactions.
• AFM1 binding induces measurable changes in the secondary structure of milk proteins.
• This approach offers a sensitive method for detecting AFM1 contamination in milk products.