Real-time monitoring of vegetable oils photo-oxidation kinetics using differential photocalorimetry

• Published in: Food chemistry Vol. 456; p. 140011
• Main Authors: Suhag, Rajat, Razem, Mutasem, Ferrentino, Giovanna, Morozova, Ksenia, Zatelli, Daniele, Scampicchio, Matteo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 30-10-2024
• Subjects: Antioxidant activity; Calorimetry; Induction time; Lipid oxidation; Oxidation kinetics; Induction time; Oxidation kinetics; Calorimetry; Antioxidant activity; Lipid oxidation
• ISSN: 0308-8146; 1873-7072; 1873-7072
• DOI: 10.1016/j.foodchem.2024.140011

This study introduced differential photocalorimetry (DPC) as a method for real-time monitoring of the photo-oxidation kinetics of vegetable oils. DPC measures the heat flow generated during the oxidation of oils upon light exposure. Experiments conducted with stripped linseed oil (SLSO), an oil depleted from its natural antioxidants, showed no induction time (τ). Conversely, spiking SLSO with increasing concentrations of trans-ferulic acid resulted in an induction time (τ) proportional to the antioxidant concentration (R2 = 0.99). A comparative study among different vegetable oils revealed that rice bran oil exhibited the highest resistant to photo-oxidation, followed by corn, soybean, and sunflower oils. The results are discussed in terms of sample oxidizability and antioxidant efficiency (A.E.), and validated through high-performance liquid chromatography with diode array detection (HPLC-DAD). Furthermore, the measured heat flow enabled the determination of the rates of inhibited (Rinh) and uninhibited (Runi) periods, as well as the rate constant of propagation (kp) and inhibition (kinh) reactions.
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•DPC allowed real-time monitoring of oil photo-oxidation kinetics.•An increase of the light intensity showed a consistent decrease in induction time.•DPC enabled determination of antioxidant efficiency, capacity and oil oxidizability.