Stability of the insecticide cypermethrin during tomato processing and implications for endocrine activity

Area of Science:

• Food Chemistry
• Environmental Chemistry
• Analytical Chemistry

Background:

• Cypermethrin is a widely used insecticide.
• Understanding pesticide stability during food processing is crucial for food safety.
• Potential risks associated with pesticide degradation products require investigation.

Purpose of the Study:

• To investigate the thermal and pH stability of cypermethrin during food processing.
• To quantify cypermethrin degradation in a model food system (tomatoes).
• To identify potential breakdown products and assess their implications.

Main Methods:

• High-performance liquid chromatography (HPLC) was used for quantitative analysis.
• Thermal degradation studies were conducted in aqueous solutions and canned tomatoes.
• pH stability was assessed in phosphate buffers and acidic tomato paste.

Main Results:

• Cypermethrin demonstrated thermal instability, with significant degradation in water and canned tomatoes.
• Degradation was accelerated by heat, with levels decreasing substantially over time.
• Cypermethrin was unstable at extreme pHs, with faster hydrolysis under acidic conditions.
• 3-Phenoxybenzaldehyde, a breakdown product, was detected.
• Tomato paste's acidity (pH 4.3) led to a 30% decrease in cypermethrin within 12 days at 5°C.

Conclusions:

• Cypermethrin residues likely degrade via hydrolysis during food processing.
• This degradation can reduce consumer exposure to the parent pesticide.
• The endocrine activity of cypermethrin breakdown products remains a concern due to limited data.