Study of polycyclic aromatic hydrocarbons generated from fatty acids by a model system.

Area of Science:

• Food Chemistry
• Environmental Health
• Organic Chemistry

Background:

• Carcinogenic polycyclic aromatic hydrocarbons (PAHs) are significant food contaminants.
• PAH formation from fatty acids under thermal processing is not well understood.
• Existing data often comes from complex food matrices, limiting specific insights.

Purpose of the Study:

• To investigate the generation of 12 PAHs from nine different fatty acids (SFAs, MUFAs, PUFAs).
• To analyze PAH production characteristics across three controlled heating temperatures (98°C, 165°C, 240°C).
• To establish the relationship between fatty acid type, temperature, and PAH yield.

Main Methods:

• Utilized a model system to study PAH formation from saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs).
• Heated fatty acids at 98°C, 165°C, and 240°C to quantify PAH yields.
• Analyzed the types and quantities of 12 specific PAHs produced.

Main Results:

• PAH generation from SFAs was minimal at 98°C, while MUFAs and PUFAs produced detectable amounts.
• At 165°C, total PAHs increased significantly across all fatty acid types, with PUFAs yielding the highest concentrations (449.68 µg kg⁻¹).
• Higher temperatures (240°C) resulted in significantly greater PAH formation (P < 0.05) compared to 165°C, with a notable increase in four- to five-ring PAHs. PAH concentration increased with the number of double bonds in the fatty acids.

Conclusions:

• Elevated temperatures promote the formation of PAHs, including carcinogenic four- to five-ring compounds, from fatty acids.
• The degree of fatty acid unsaturation (number of double bonds) is a critical factor influencing PAH yield.
• This research provides a clearer understanding of PAH production mechanisms from diverse fatty acids during thermal processing.