Kafirin Adsorption on Ion-Exchange Resins: Isotherm and Kinetic Studies

Abstract

Kafirin is a natural, hydrophobic, celiac-safe prolamin protein from sorghum seeds with promising applications in delayed delivery systems and pharmaceutical and nutraceutical coatings. This study provides the first scientific investigation into kafirin adsorption isotherm and kinetic behaviour on ion-exchange resins for preparative chromatography applications, providing essential data for designing scalable purification processes.

Adsorption isotherms were determined for five anion-exchange and two cation-exchange resins using batch equilibrium experiments. The Langmuir and Freundlich isotherm models were applied, with the Langmuir model providing a good fit to the equilibrium data. UNOsphere Q (78.26 mg/mL) and Toyopearl SP-650M (57.4 mg/mL) demonstrated the highest kafirin binding capacities among the resins tested. Kinetic studies identified film diffusion resistance as the major governing factor for adsorption. Film mass transfer coefficients, effective diffusion coefficients, and Biot numbers were calculated using a film-pore diffusion model. Based on an objective function analysis of capacity and kinetic parameters, UNOsphere Q was determined to be the best adsorbent for kafirin purification. The data provide a foundation for designing large-scale preparative adsorptive chromatographic processes for kafirin purification from sorghum.

@article{kumar2014kafirin,
  title         = {Kafirin Adsorption on Ion-Exchange Resins: Isotherm and Kinetic Studies},
  author        = {Kumar, Prashant and Lau, Pei Wen and Kale, Sandeep and Johnson, Stuart
                  and Pareek, Vishnu and Utikar, Ranjeet and Lali, Arvind},
  year          = 2014,
  journal       = {Journal of Chromatography A},
  publisher     = {Elsevier},
  volume        = 1356,
  pages         = {105--116},
  doi           = {10.1016/j.chroma.2014.06.035}
}