Oxidation kinetics of linoleic acid in the presence of saturated acyl l ‐ascorbate

The oxidation processes of linoleic acid (LA) in the presence of l‐ascorbic acid or saturated acyl l‐ascorbate additives were measured at various temperatures and molar ratios of the additive to LA. Higher oxidative stability of LA was observed at higher additive levels for all additives. The addition of the ascorbates lengthened the induction period for the oxidation of LA. An autocatalytic kinetic rate equation was used to model the oxidation processes of LA mixed with the ascorbates, and the dependence of the rate constant, k, on acyl‐chain carbon number was determined. At any temperature, the use of ascorbate additives decreased the k value for LA, and there was a slight tendency for k values to decrease with increasing acyl‐chain length. The apparent activation energy, Ea, and the frequency factor, k0, for the rate constant were determined from Arrhenius plots. The calculated Ea and k0 values also decreased with increasing ascorbate acyl‐chain length.