title: Kafirin adsorption on ion-exchange resins: isotherm and kinetic studies.
abstract: Kafirin is a natural, hydrophobic and celiac safe prolamin protein obtained from sorghum seeds. Today kafirin is found to be useful in designing delayed delivery systems and coatings of pharmaceuticals and nutraceuticals where its purity is important and this can be obtained by adsorptive chromatography. This study is the first scientific insight into the isotherm and kinetic studies of kafirin adsorption on anion- and cation-exchange resins for practical applications in preparative scale chromatography. Adsorption isotherms of kafirin were determined for five anion- and two cation-exchange resins in batch systems. Isotherm parameters such as maximum binding capacity and dissociation constant were determined from Langmuir isotherm, and adsorptive capacity and affinity constant from Freundlich isotherm. Langmuir isotherm was found to fit the adsorption equilibrium data well. Batch uptake kinetics for kafirin adsorption on these resins was also carried out and critical parameters including the diffusion coefficient, film mass transfer coefficient, and Biot number for film-pore diffusion model were calculated. Both the isotherm and the kinetic parameters were considered for selection of appropriate resin for kafirin purification. UNOsphere Q (78.26 mg/ml) and Toyopearl SP-650M (57.4 mg/ml) were found to offer better kafirin binding capacities and interaction strength with excellent uptake kinetics under moderate operating conditions. With these adsorbents, film diffusion resistance was found to be major governing factor for adsorption (Bi<10 and δ<1). Based on designer objective function, UNOsphere Q was found be best adsorbent for binding of kafirin. The data presented is valuable for designing large scale preparative adsorptive chromatographic kafirin purification systems.
authors.affiliation: DBT-ICT-Centre for Energy Biosciences, Institute of Chemical Technology (ICT), Mumbai, India.
authors.forename: Prashant
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Chemical Engineering, Curtin University, Perth, WA, Australia.
authors.forename: Pei Wen
authors.initials: PW
authors.lastname: Lau
authors.affiliation: DBT-ICT-Centre for Energy Biosciences, Institute of Chemical Technology (ICT), Mumbai, India. Electronic address: sb.kale@ictmumbai.edu.in.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kale
authors.affiliation: School of Public Health, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia.
authors.forename: Stuart
authors.initials: S
authors.lastname: Johnson
authors.affiliation: Department of Chemical Engineering, Curtin University, Perth, WA, Australia.
authors.forename: Vishnu
authors.initials: V
authors.lastname: Pareek
authors.affiliation: Department of Chemical Engineering, Curtin University, Perth, WA, Australia.
authors.forename: Ranjeet
authors.initials: R
authors.lastname: Utikar
authors.affiliation: DBT-ICT-Centre for Energy Biosciences, Institute of Chemical Technology (ICT), Mumbai, India.
authors.forename: Arvind
authors.initials: A
authors.lastname: Lali
mesh_terms: D000327:Adsorption; D000837:Anion Exchange Resins / Q000737:chemistry*; D002411:Cation Exchange Resins / Q000737:chemistry*; D002852:Chromatography, Ion Exchange; D004058:Diffusion; D007700:Kinetics; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry; D045868:Sorghum / Q000737:chemistry
chemical_list: D000837:Anion Exchange Resins; D002411:Cation Exchange Resins; D010936:Plant Extracts; D010940:Plant Proteins; C080615:kafirin protein, Sorghum bicolor
keywords: Adsorption isotherm; Chromatography; Kafirin; Kinetics; Prolamin