A multiple‐variable approach to study corn oil oxidation

The induction time for oxidation (Γ i ) and the rate constant for bimolecular peroxide decomposition (k 2 ) were determined in refined corn oil with (CW) and without (CWO) antioxidant (ter‐butil hydroxy‐quinolein 0.0014%, citric acid 0.0012%), and their magnitude and variability were described through multiple regression. Γ i in both CW and CWO was mainly described (R 2 > 0.93) through linear and quadratic interactions between the temperature (T°) and the initial peroxide concentration. Although the antioxidant increased Γ i , carbonyls were produced in earlier stages ( i.e., <Γ i ) and lower T° than in CWO. These carbonyls were produced through a bimolecular peroxide decomposition. The equations for k 2 (R 2 > 0.96) indicated a faster decomposition of peroxide in CWO than in CW; nevertheless, as a function of T°, k 2 increased at a slower rate in CWO than in CW.