Study of partition of ovomucoid protein in aqueous twophase systems and anionic or hydrophobic resins / Estudo da partição da proteína ovomucoide em sistemas aquosos bifásicos e em resinas aniônica ou hidrofóbica

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

In this work, the application of the liquid-liquid extraction technique with aqueous two-phase systems (ATPS) was evaluated for the separation of ovomucoid, an egg white protein. This technique is an advisable purification process applied to large scale since it provides a selective partition with high yields. The ATPS were composed by PEG 1500 and an inorganic salt (lithium sulfate, sodium sulfate, magnesium sulfate, sodium carbonate and sodium citrate), at 25 C. The results showed that the partition coefficient ranges from 0.02 to 6.0, showing that, depending on the system used, the protein concentrates either in the bottom phase (salt-rich) or in the upper phase (PEG-rich). The highest values of the partition coefficient were obtained in systems composed of sodium carbonate and the smallest ones in systems composed of magnesium sulfate, and in this last one it was obtained a recovery percentage higher than 90%. The different trends for the partition coefficient according to the properties of the systems show that it is possible to separate the properly protein of the mixture, which states that system as an alternative to be considered in the planning processes of recovery and purification of biomolecules. It was also evaluated the ovomucoid adsorption behavior in anionic exchange resin (Streamline Q XL) and hydrophobic interaction resin (Streamline Phenyl) in stirred tanks at 25 C, in different experimental conditions. For anionic exchange resin different NaCl concentrations (0.00, 0.03, 0.07 and 0.10) mol L-1 and three pH values (6.2, 7.0 and 8.0) were studied. The Langmuir model fitted to the experimental data, with R2 higher than 0.99. A reduction in the ovomucoid adsorption capacity was observed with the increasing concentration of salt and pH. The influence of the type of salt (NaCl, Na2SO4 and (NH4)2SO4) and its concentration (0.3, 0.5, 0.8 and 1.0) mol L-1, in pH 7.0, was evaluated in the hydrophobic interaction resin. The experimental data were fitted by Langmuir model, and an increase in the adsorption capacity was observed with increasing concentration of salt. A higher adsorption of protein in the resin was obtained using the salt Na2SO4.

ASSUNTO(S)

purificação purification ovomucoide egg white clara do ovo tecnologia de alimentos ovomucoid

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