Unveiling the oxidative degradation profiles of vegetable oils under thermal stress via Raman spectroscopy and machine learning methods

This study investigates the thermal stability of seven commonly consumed vegetable oils (canola, corn, frying, sesame, soybean, olive, and sunflower) using Raman spectroscopy and chemometrics. Thermal treatment during cooking can induce degradation reactions impacting oil quality, with oxidation being a major concern. Raman spectra were acquired during controlled heating from 25 °C to 205 °C. Principal component analysis revealed distinct degradation patterns among oils based on spectral variations. Multivariate curve resolution resolved compositional changes, indicating degradation of heat-sensitive species and formation of oxidation products. Calculating feasible solution bands accounted for rotational ambiguity effects. Contrasting behaviors were attributed to differences in fatty acid compositions and natural antioxidant levels. Oils richer in polyunsaturated fatty acids like soybean exhibited delayed degradation onset compared to olive oil. Sesame and commercial frying oil demonstrated superior heat resistance. This integrated approach enables robust comparative analysis of oil thermal stabilities for optimizing high-temperature food processing while preserving quality.