Elucidating how two different types of bleaching earths widely used in vegetable oils industry remove carotenes from palm oil: Equilibrium, kinetics and thermodynamic parameters.

Autor: Almeida ES; Institute of Chemistry, University of Brasília, Brasília, DF, Brazil., Carvalho ACB; Institute of Chemistry, University of Brasília, Brasília, DF, Brazil., Soares IOS; Institute of Chemistry, University of Brasília, Brasília, DF, Brazil., Valadares LF; Embrapa Agroenergia, Brasília, DF, Brazil., Mendonça ARV; Institute of Chemistry, University of Brasília, Brasília, DF, Brazil., Silva IJ Jr; Chemical Engineering Department, Federal University of Ceará, Ceará, CE, Brazil., Monteiro S; Institute of Chemistry, University of Brasília, Brasília, DF, Brazil. Electronic address: simonems@unb.br.
Jazyk: angličtina
Zdroj: Food research international (Ottawa, Ont.) [Food Res Int] 2019 Jul; Vol. 121, pp. 785-797. Date of Electronic Publication: 2019 Jan 02.
DOI: 10.1016/j.foodres.2018.12.061
Abstrakt: This work compared the mechanisms of adsorption of carotenes from hybrid palm oil onto two kinds of bleaching earths widely used by industrial refiners (acid-activated and neutral). First, it was performed a deep characterization of adsorbent surfaces: acid activated adsorbent showed micropore volumes twice larger than the neutral. FTIR analysis of adsorbent after adsorption demonstrated that active site was Si-O-Si for both adsorbents. However, comparison of peak shapes suggested distinctive interactions between adsorbent/adsorbate for each adsorbent. Latterly, an extensive kinetic and equilibrium study was performed. Kinetic data were in accordance with pseudo-first and pseudo-second-order models. Adjusting to the intra-particle diffusion model evidenced more than one mechanism controlling the adsorption process. Equilibrium data demonstrated adsorption is only favorable at low carotene concentration at liquid phase for acid adsorbent (lower than 1 mg/mL). For neutral adsorbent, it was not clearly observed a favorable region with the studied conditions. The acid adsorbent could adsorb more carotenes per adsorbent weight than neutral. Finally, neutral adsorbent showed higher heterogeneity of interaction between adsorbate and adsorbent than the acid, especially at low adsorbent coverages.
(Copyright © 2019 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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