Volatile compounds and oxidative stability of Pinus halepensis Mill. seed oil under heating conditions

Authors

  • Madiha Dhibi,

    Corresponding author
    1.  Laboratory of Biochemistry, UR: “Human Nutrition and Metabolic Disorder” (UR03ES08), Faculty of Medicine, University of Monastir, 5019 Monastir, Tunisia
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  • Guido Flamini,

    1.  Dipartimento di Scienze Farmaceutiche, Sede di Chimica Bioorganica e Biofarmacia, via Bonanno 33, 56126 Pisa, Italy
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  • Manel Issaoui,

    1.  Laboratory of Biochemistry, UR: “Human Nutrition and Metabolic Disorder” (UR03ES08), Faculty of Medicine, University of Monastir, 5019 Monastir, Tunisia
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  • Mohamed Hammami

    Corresponding author
    1.  Laboratory of Biochemistry, UR: “Human Nutrition and Metabolic Disorder” (UR03ES08), Faculty of Medicine, University of Monastir, 5019 Monastir, Tunisia
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Fax: +216 73 460 737;
e-mails: mohamed.hammami@fmm.rnu.tn; madiha.dhibi@hotmail.fr

Summary

Heating conditions of Pinus halepensis seed oil were monitored to evaluate the effect of thermo-oxidation processes on the bioactive compounds contained in the samples. The following parameters were monitored: ultra violet absorption at 232 and 270 nm, fatty acid composition, oxidative stability, antiradical activity and aromatic profiles. Under thermo-oxidation process, trans fatty acids (TFA) increased and conjugated linoleic acid isomers appeared. The antiradical activity significantly decreased from 73.3% to 52.5% after 120 min of heating. Oxidative stability decreased (r = −0.70). The volatile profile was heavily influenced by heating with the formation of new volatile compounds, such as the two isomers (E,Z)-2,4-decadienal and (E,E)-2,4-decadienal. α-pinene, and the main terpene compound was very vulnerable to heating conditions. Despite its peculiar pleasant aroma and nutritional value, the P. halepensis seed oil should not be used for cooking. Indeed, under frying conditions, its antioxidant properties and oxidative stability are lost and potential toxic compounds, such as TFA and unsaturated aldehydes, are formed.

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