Rapid Assessment of Total Polar Material in Used Frying Oils Using Manganese Tetraphenylporphyrin Fluorescent Sensor with Enhanced Sensitivity

Probe-based three-dimensional fluorescence spectroscopy was developed for the rapid assessment of frying oil quality. Tetraphenylporphyrin manganese (MnTPP) was selected due to its sensitivity and selectivity in response to dissolved organic matter, which is typically produced during the frying process of oil analyte. Parallel factor analysis (PARAFAC) was then performed to decompose three-dimensional fluorescence data for model construction. The digital data representing the change of the MnTPP-base fluorescent probe before and after exposure to dissolved organic matter were analyzed using support vector regression (SVR). SVR was then used for the construction of the regression model between the fluorescence data and the total polar material (TPM). The coefficients of determination (R-2) in the training set (R-2= 0.9719) and the test set (R-2= 0.9699) were achieved to evaluate the robustness of the best models for TPM. This study demonstrated that the probe-based three-dimensional fluorescence spectroscopy is useful for assessing the quality of frying oil and perhaps could be used for other food products with high oil contents.