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Oxidative Evolution of Virgin and Flavored Olive Oils Under Thermo‐oxidation Processes
Author(s) -
Issaoui Manel,
Flamini Guido,
Hajaij Myriem Ellouze,
Cioni Pier Luigi,
Hammami Mohamed
Publication year - 2011
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-011-1800-5
Subject(s) - chemistry , food science , peroxide value , lipid oxidation , oleic acid , hexanal , limonene , organic chemistry , oxidative phosphorylation , fatty acid , peroxide , linoleic acid , antioxidant , essential oil , biochemistry
Changes in the oxidative status of Chétoui olive oil were monitored to attest the efficiency of some bioactive compounds from aromatic plants to improve the stability of olive oils after a maceration process at different concentrations. Aromatized olive oils were prepared by addition of lemon and thyme extracts at four different concentrations (20–80 g kg −1 of oils) to virgin olive oils. The following parameters were monitored: free fatty acids, peroxide value, ultra violet absorption characteristics at 232 and 270 nm, fatty acid composition and aromatic profiles. After thermo‐oxidation processes, the oleic/linoleic acid ratio remained stable (4.5). Oxidative stability slightly decreased during thermo‐oxidation processes. The heating of the oils changed their volatile profile and led to the formation of new volatile compounds, such as the two isomers of 2,4‐heptadienal after heating at 100 °C or ( E,Z )‐2,4‐decadienal and ( E,E )‐2,4‐decadienal after thermo‐oxidation at 200 °C. The use of lemon and thyme extracts modified the aromatic and the nutritional value of the olive oil by the transfer of some bioactive compounds, such as limonene and carvacrol. In contrast, the oxidative stability of the product did not change. Furthermore, the aromatized oils may be employed in seasoning and cooking of some foods.