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Oxidation kinetics in olive oil triacylglycerols under accelerated shelf‐life testing (25–75 °C)
Author(s) -
GómezAlonso Sergio,
ManceboCampos Vanessa,
Desamparados Salvador Ma,
Fregapane Giuseppe
Publication year - 2004
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.200300921
Subject(s) - autoxidation , chemistry , arrhenius equation , oxidizing agent , kinetics , shelf life , reaction rate constant , induction period , order of reaction , substrate (aquarium) , chemical kinetics , analytical chemistry (journal) , activation energy , chromatography , food science , organic chemistry , catalysis , physics , quantum mechanics , oceanography , geology
A kinetic study of the autoxidation reaction in olive oil triacylglycerols stored in darkness at different temperatures (25, 40, 50, 60 and 75 °C), in absence of pro‐ and antioxidant compounds to avoid confounding effects, is described. After the induction period (IP) the decrease in the oxidizing substrate and the formation of primary oxidation products followed a pseudo‐zero‐order kinetic, and the calculated E a from the Arrhenius equation for the formation of hydroperoxides was 32.1 kJ·mol −1 . The formation of secondary oxidation products followed a pseudo‐first‐order kinetic whose rate reaction constant also increased exponentially with temperature. The first oxidation index to exceed the upper limit in the EU regulations was PV, followed by K 232 and K 270 . The time required reaching these limits and the rancidity threshold showed a potential dependence on temperature, and therefore with accelerated storage at 75 °C, POO shelf‐life in ambient conditions (25 °C) can be predicted. Finally, there was a good linear relationship between the time required to reach the rancidity threshold and the IP of the formation of the 2,4‐decadienal, and hence this instrumental determination could be useful to measure sensory recognition of the rancid defect in POO.