Comparison: Adsorption of papain using immobilized dye ligands on affinity membranes

Novel membranes that involve the immobilization of Reactive Red 120 or Reactive Brown 10 as dye ligands were prepared. These were used in the purification of papain from papaya powder extracts. Papain adsorption capacities for the Red 120 and Brown 10 membranes were 143.6 mg/g and 107.3 mg/g, respectively. The effectiveness of adsorption was demonstrated by Freundlich isotherm proficiency. The enzyme was eluted from the respective dye membranes using 1.0 M NaCl at pH 6.0 and yields of over 80% were found for the Red 120–CS (chitosan)–nylon membrane whereas only a 50% recovery was possible using the Brown 10–CS–nylon membranes. It is concluded that Red 120–CS–nylon membranes could play an active role in the separation and purification of papain from crude extracts. This system has the potential to be developed for the commercial isolation of the protein.