Premium
A kinetic study of the competitive oxidation of oleic acid‐linoleic acid mixtures
Author(s) -
Romero Alfredo J. Rosas,
Morton Ian D.
Publication year - 1975
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740260914
Subject(s) - oleic acid , chemistry , autoxidation , linoleic acid , reaction rate constant , antioxidant , fraction (chemistry) , induction period , decomposition , diluent , kinetics , organic chemistry , catalysis , fatty acid , biochemistry , physics , quantum mechanics
The kinetics of the autoxidation of oleic acid‐linoleic acid mixtures have been investigated by the rate of oxygen uptake. Mixtures with different molar fractions were prepared, keeping the total number of moles constant. Oxidations were carried out at 30 °C and graphs were made of the percentage of oxidation against time, overall first order rate constant against molar fraction and overall second order rate constant against molar fraction. It was found that during the mono‐molecular decomposition of hydroperoxides, the reaction rates decrease with decreasing linoleic acid molar fraction. No prooxidant or antioxidant effects were observed during this period, the predominant effect being that of oleic acid acting as a diluent for the oxidation of linoleic acid. When the reaction enters the period of bimolecular decomposition of hydroperoxides, a slight antioxidant effect was found, for mixtures containing less than 25% oleic acid. With increasing oleic acid concentration this effect levels off and gives way to a more marked prooxidant effect when the oleic acid is above 75%.