Separação da lisozima, conalbumina e ovalbumina presentes na clara do ovo: aspectos tecnológicos e termodinâmicos

• Autor(a) principal: Sousa, Rita de Cássia Superbi de
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2832
• topic: Clara de ovo; Adsorção em leito expandido; Sistema aquoso bifásico; Egg white; Expanded bed adsorption; Aqueous two-phase system; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::ENGENHARIA DE ALIMENTOS

In this work, the separation of egg white proteins (lysozyme, conalbumina and ovalbumin) was studied integrating liquid- liquid extraction with aqueous two-phase systems (ATPS) and expanded bed adsorption (EBA). EBA was used to separate two egg white protein fractions, one rich in ovalbumin and other rich in conalbumina and lysozyme. The partition behavior of conalbumin and lysozyme between top and bottom phases of ATPS was investigated with the objective to separate these proteins from EBA fraction. This technique is an advisable purification process applied to large scale since it provides a selective partition with high yields. The influence of the type of salt (potassium phosphate, sodium citrate, lithium sulfate or sodium sulfate) and polymer (PEG 1500) phase concentrations (tie line length) in the system was studied in order to fit ratio of system to the separation. In addition, thermodynamic parameters (ΔtrH, ΔtrS, ΔtrG) were calculated and the results imply thermodynamic differences between partitioning of proteins. It was observed that the lysozyme partitioned preferentially to PEG phase and conalbumina to salt phase. Among the systems analyzed the ATPS PEG1500 (18 %)-sodium sulfate provided the best results for lysozyme extraction in the top phase (approximately 95,0 %) what demonstrates a good separation. The higher recovery of conalbumina in salt phase was obtained in the ATPS PEG1500 (18 %)-sodium citrate (approximately 86,0 %). This study showed that EBA and ATPS can be successfully used for recovery and initial purification of ovalbumin, lysozyme and conalbumin from egg white.