Characterization of vegetable oils-alumina membranes interactions by diffuse reflectance Fourier transform infrared spectroscopy

Hafidi Abdellatif, Anglaret Eric, Pioch Daniel, Ajana Hamid. 2004. Characterization of vegetable oils-alumina membranes interactions by diffuse reflectance Fourier transform infrared spectroscopy. European Journal of Lipid Science and Technology, 106 : 11-25.

Résumé : Adsorption of vegetable oil components, either as pure molecules or as mixtures, on alumina membranes was investigated by diffuse reflectance Fourier transform infrared spectroscopy. All tested compounds displayed very similar spectra. Triolein and diolein physically adsorb onto alumina by hydrogen bonding with the carbonyl groups of the carboxylic ester and surface hydroxyls. Monolein most likely interacts with glycerol hydroxyls, while phospholipids appear to adsorb either by the ester carbonyl or charged phosphate group. Due to the catalytic properties of alumina some hydrolysis takes place during treatments. The resulting oleic acid, most likely chemisorbs by ionic interactions with the carboxylic C=O bond of the alumina. The fact that no change in the symmetric and asymmetric CH2 stretches is noticed in comparison with the free (unbound) form indicates that the molecules are not parallel, but at an angle to the surface. When alumina comes into contact with increasing amounts of crude vegetable oils a broadening of the band at 3280 cm-1 indicates an increasing adsorption of molecules with free hydroxyls, such as mono- and di-acylglycerols or phospholipids. Among all oil components, sodium oleate seems to adsorb preferentially to alumina. However, a subsequent adsorption of a lipidic monolayer at the membrane surface or even inside the pores, is not consistent with the drastic flux reduction observed in previous studies during microfiltration, and could only initiate formation or/and deposition of macromolecular structures inside membrane pores.

Mots-clés Agrovoc : huile végétale, adsorption, spectrométrie, filtre, membrane, acide oléique, phosphatide, oléine, Réflectance, colmatage

Mots-clés complémentaires : Phospholipide

Classification Agris : Q04 - Composition des produits alimentaires
Q02 - Traitement et conservation des produits alimentaires

Auteurs et affiliations

• Hafidi Abdellatif, Université Cadi Ayyad (MAR)
• Anglaret Eric, UM2 (FRA)
• Pioch Daniel, CIRAD-AMIS-AGROALIMENTAIRE (FRA)
• Ajana Hamid, Université Cadi Ayyad (MAR)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/534853/)

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