Effects of kinetics of adsorption and coalescence on continuous foam concentration of proteins: Comparison of experimental results with model predictions

Abstract

Protein enrichment and recovery were measured in a continuous foam concentration column for bovine serum albumin (BSA) for different pool heights, foam heights, superficial gas velocities, bubble sizes, feed flow rates, pH, and ionic strengths. Protein enrichment was found to decrease with an increase in pool height for low pool heights, reach a minimum at an intermediate pool height, and subsequently increase with pool height for sufficiently large pool heights eventually approaching an asymptotic value. Such a behavior was due to the combined effects of kinetics of adsorption of protein and coalescence. The increase in protein enrichment with pool height was due to the predominant effect of kinetics of adsorption of protein, whereas the opposite behavior at low pool heights was due to the predominant effect of coalescence in the foam. Protein enrichment was found to be higher for smaller feed concentrations, smaller gas velocities, larger bubble sizes, and larger foam heights. Enrichment at pH values different from the isoelectric point was found to be higher because of more coalescence. A model for foam concentration of proteins was employed to predict enrichment and recovery. The model predictions agreed well with the experimental data. © 1996 John Wiley & Sons, Inc.

Enrichment behavior of immunoglobulin by foam fractionation using response surface methodology

“…As mentioned for the model system, Robertson and Vermeulen (1969) demonstrated in their foam fractionation study of rare earth elements that low concentrations of the materials in the bulk are a desired property for extraction [ROBERTSON and VERMEULEN 1969]. Ahmad (1975), and Uraizee and Narsimhan (1996) proved in their work with proteins that a low concentration of materials present in the bulk is key for an effective separation. They pointed out that there is an optimal concentration range, which is more suitable for achieving effective separation [AHMAD 1975, URAIZEE andNARSIMHAN 1996].…”

“…Therefore, a proper foam height is essential to obtain a good enrichment. Ahmad and Uraizee and Narsimhan investigated the influence of foam height on enrichment in their work with proteins [AHMAD 1975, URAIZEE andNARSIMHAN 1996].…”

“…The liquid height in the foam-generating vessel is known to influence the protein foam fractionation performance [GRIEVES 1975, URAIZEE andNARSIMHAN 1996], thus the liquid height in the glass two-port container was evaluated before …”

“…Ahmad (1975), and Uraizee and Narsimhan (1996) proved in their work with proteins that a low concentration of materials present in the bulk is key for an effective separation. They pointed out that there is an optimal concentration range, which is more suitable for achieving effective separation [AHMAD 1975, URAIZEE andNARSIMHAN 1996]. Maas (1974) …”

“…The liquid height in the foam-generating vessel is known to influence the protein foam fractionation performance [GRIEVES 1975, URAIZEE andNARSIMHAN 1996], thus the liquid height in the glass two-port container was evaluated before the column height. The initial volume of the tested solution added to the glass two-port container was varied from 12.5 to 100 mL in order to see if changes in the internal liquid height within the glass two-port container would affect the enrichment result.…”