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BioMed Research International
Volume 2013, Article ID 978256, 8 pages
Research Article

Evaluation of an Adsorbent Based on Agricultural Waste (Corn Cobs) for Removal of Tyrosine and Phenylalanine from Aqueous Solutions

1PPGCA/Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil
2DEMEC/Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil

Received 22 April 2013; Accepted 29 May 2013

Academic Editor: Ismail Kiran

Copyright © 2013 Cibele C. O. Alves et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Adsorption of phenolic amino acids, such as phenylalanine and tyrosine, is quite relevant for the production of protein hydrolysates used as dietary formulations for patients suffering from congenital disorders of amino acid metabolism, such as phenylketonuria. In this study, an adsorbent prepared from corn cobs was evaluated for the removal of tyrosine (Tyr) from both a single component solution and a binary aqueous solution with phenylalanine (Phe). The adsorption behavior of tyrosine was similar to that of phenylalanine in single component solutions, however, with a much lower adsorption capacity (14 mg g−1 for Tyr compared to 109 mg g−1 for Phe). Tyr adsorption kinetics was satisfactorily described by a pseudosecond-order model as it was for Phe. In adsorption equilibrium studies for binary mixtures, the presence of Tyr in Phe solutions favored Phe faster adsorption whereas the opposite behavior was observed for the presence of Phe in Tyr solutions. Such results indicate that, in binary systems, Phe will be adsorbed preferably to Tyr, and this is a welcome feature when employing the prepared adsorbent for the removal of Phe from protein hydrolysates to be used in dietary formulations for phenylketonuria treatment.