title: Effect of heat on the adsorption capacity of an activated carbon for decolorizing/deodorizing yellow zein.
abstract: The Freundlich model was evaluated for use to assess the effect of heat on the adsorption capacity of an activated carbon for decolorizing/deodorizing corn zein. Because zein protein and its color/odor components are all adsorbed by activated carbon, a method to monitor their removal was needed. Yellow color is due to xanthophylls; a contributor to off-odor is diferuloylputrescine. The off-odor component absorbs ultraviolet (UV) light at about 325 nm and its removal coincides with removal of yellow color. A spectrophotometric method based on UV absorbances 280 nm for protein and 325 nm for the off-odor component was used to monitor their adsorptions onto activated carbon. Equilibrium studies were performed over temperature range from 25 to 60 degrees C for zein dissolved in 70% aqueous ethanol. Runs made at 55 degrees C adsorbed significantly more of the color/odor components than the protein.
authors.affiliation: Plant Polymer Research, National Center for Agricultural Utilization Research, US Department of Agriculture, Agricultural Research Service, 1815 N. University Street, Peoria, IL 61604-3902, USA. David.Sessa@ARS.USDA.GOV
authors.forename: D J
authors.initials: DJ
authors.lastname: Sessa
authors.forename: D E
authors.initials: DE
authors.lastname: Palmquist
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D003116:Color; D006358:Hot Temperature; D009812:Odorants; D013816:Thermodynamics; D015028:Zein / Q000592:standards
chemical_list: D002244:Carbon; D015028:Zein