Non-Destructive and Rapid Evaluation of the Potentiality of Faba Bean Lipoxygenase to Promote Lipid Oxidation of Rapeseed Oil by Using Mid-Infrared and Near-Infrared Spectroscopies

Rapeseed oil is regarded as one of the healthiest vegetable oils in terms of its biological functions and its ability to aid in reducing disease-related risk factors and improving health. However, rapeseed oil is susceptible to oxidation during processing and storage which can lead to reduce its nutritional value. In this work, the potential of near-infrared (NIR) and mid-infrared (MIR) spectroscopy along with chemometrics was investigated for monitoring enzymatic oxidation of rapeseed oil. Changes in the chemical parameters (free fatty acids (FFA), peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and total oxidation (TOTOX)) and in infrared spectra occurring during the storage of rapeseed oil treated with faba bean lipoxygenase were studied. Principal component analysis (PCA) applied to chemical and infrared (MIR and NIR) data allowed clear discrimination between rapeseed oils during storage time. Partial least squares regression (PLSR) established using raw and pre-processed MIR and NIR infrared data allowed excellent prediction of FFA (R2 = 0.99), PV (R2 = 0.99), TOTOX (R2 = 0.99) and approximate prediction of TBARS (R2 = 0.87). Therefore, infrared spectroscopic techniques could be used for analyzing the chemical changes of vegetable oils during storage and can be considered as fast and non-destructive techniques offering good alternatives to the classical analytical methods.