Process for Avidin Recovery from Egg White by Pseudo-Affinity Chromatography

Background: Avidin (AV) represents the third most important protein of major commercial interest derived from egg white, alongside ovotransferrin and lysozyme. It constitutes only 0.05% of the total protein content. Despite the widespread natural availability of AV, its purification remains a significant challenge due to its low abundance within a highly concentrated and complex protein matrix. Methods: Developing efficient downstream processing for AV has the potential to significantly enhance profitability within the egg protein industry. This work presents a novel integrated process for AV recovery. It comprises ovomucin removal, AV preconcentration, and final purification using pseudo-affinity chromatography. The latter utilizes a novel resin with 4′-hydroxyazobenzene-2-carboxylic acid (HABA) as the ligand. The HABA–agarose matrix was characterized by an adsorption isotherm and breakthrough curves, indicating an AV adsorption performance higher than that of other pseudo-affinity matrices. Results and Conclusions: The HABA pseudo-affinity chromatographic process was a crucial step to purify AV more than 300-fold with high yield (86%). Despite the low AV recovery, the proposed integrated process aligns with the biorefinery concept, which maximizes the economic value of raw materials by utilizing all components.