DSSM-integrated Raman spectroscopy for dynamic tracking of functional group evolution in frying oils: A...

This study employed Raman spectroscopy combined with characteristic-peak-intensity-ratio analysis and a novel difference-spectral-statistical-mapping (DSSM) method to elucidate dynamic functional group transformations in flaxseed oil during various frying temperatures (100-185 °C) and repeated frying frequencies (1-5 times). The multiple linear regression models of I₉₆₉/I₁₂₆₆ with I₉₆₉/I₁₃₀₀ and I₉₆₉/I₁₄₄₁ exhibit high correlation coefficients (R²) between 0.93 and 0.94, suggesting that the changes in trans-CC are closely related to the variations in cis-CC and methylene (CH₂), which provides key insights for optimizing industrial detection models and fundamental oxidation kinetics research. DSSM identified hidden oxidation features, including epoxy groups and conjugated trienes, visualizing their evolution trends, offering critical spectroscopic evidence for assessing the quality degradation of frying oils. These methods provide theoretical support for real-time and rapid monitoring of the dynamic changes of functional groups in frying oil, taking a key step towards industrial level real-time monitoring of Raman spectroscopy technology.