Objective:

To assess how vegetable oils degrade during repeated deep-frying using a chemometrics-guided lipidomics approach.

Key Findings:

• Triglyceride concentrations decreased significantly after 40 frying cycles: ~55% in soybean and sunflower oils, ~50% in rapeseed oil, ~45% in palm oil.
• Formation of oxidized triglycerides, diglycerides, and free fatty acids was observed.
• Oils with higher unsaturation (soybean, sunflower) were more prone to degradation compared to palm oil, which showed greater stability.
• Chemometric analysis identified lipid species as potential markers of frying-induced degradation with predictive performance (AUC values ≥ 0.778).
• Conventional measurements (acid value, p-anisidine value, thiobarbituric acid value) confirmed oxidative and hydrolytic degradation.

Interpretation:

The lipidomics approach provides a more sensitive and detailed understanding of oil degradation during frying, identifying specific molecular markers for quality control.

Limitations:

• Study focused on only four types of vegetable oils.
• Results may not be generalizable to all cooking oils or frying conditions.

Conclusion:

Combining lipidomics with chemometric modeling enhances the monitoring of oil degradation and supports quality control in food production.