Institutional Repository [SANDBOX]
Technical University of Crete
EN  |  EL

Search

Browse

My Space

Decolorization of vegetable oils: A study of the mechanism of adsorption of b-carotene by an acid-activated bentonite from Cyprus

Christidis Georgios, Sotiria Kosiari

Simple record


URIhttp://purl.tuc.gr/dl/dias/FC3CAC90-F034-4C23-BCED-6467F2152BC2-
Identifierhttps://doi.org/10.1346/CCMN.2003.0510309-
Languageen-
Extent327-333en
TitleDecolorization of vegetable oils: A study of the mechanism of adsorption of b-carotene by an acid-activated bentonite from Cyprusen
CreatorChristidis Georgiosen
CreatorΧρηστιδης Γεωργιοςel
CreatorSotiria Kosiarien
PublisherClay Minerals Societyen
Content SummaryThe mechanism of decolorization of crude maize and sunflower oils was studied by means of adsorption of b-carotene by a low-grade bentonite , containin g mixed-layered illite-smectite. Decolorization depends on temperature and the time required for equilibrium decreases with increasing temperature. The study of the kinetics of adsorption showed that decolorization of maize oil is a first-order process which occurs in two steps: a first fast step with higher activation energy (25.6 kJ mol –1), indicating the influence of a chemical interaction between the pigment and the clay surface, followed by a second slow step with low activation energy (12.3 kJ mol –1), characteristic of physical adsorption on the previously adsorbed molecules. Decolorization of sunflower oil is also a first-order process, described by a single mechanism with intermediate activation energy (19.0 kJ mol –1). Adsorption isotherms of decolorization of maize oil follow the Freundlich equation, indicating the existence of heterogeneous adsorption sites on the solid’s surface. Heterogeneity is attributed both to different active centers on the smectite surface (Bro¨ nsted and Lewis centers) and to the different phases present in bentonite, such as illitic layers and clinoptilolite, which also have active centers on their surfaces.en
Type of ItemPeer-Reviewed Journal Publicationen
Type of ItemΔημοσίευση σε Περιοδικό με Κριτέςel
Licensehttp://creativecommons.org/licenses/by/4.0/en
Date of Item2015-10-01-
Date of Publication2003-
Bibliographic CitationG. E. Christidis, S. Kosiari , "Decolorization of vegetable oils: A study of the mechanism of adsorption of B-Carotene by an acid-activated bentonite from Cyprus ",Cl. and Clay Min, vol. 51, no. 3, pp.327–333, 2003.doi :10.1346/CCMN.2003.0510309en

Available Files

Services

Statistics