Decolorization/deodorization of zein via activated carbons and molecular sieves

Commercially available corn zeins from co-products of the corn ethanol industry possess yellow color and off-odors that deter their usage in food, medical, pharmaceutical and cosmetic industries. A pilot-scale process (patent pending) was developed to purify those products. Our objective is to investigate a series of activated carbons and zeolites, clay-based particles acting as molecular sieves, as potential column media for that process. A batch process was used to evaluate each of five different activated carbons and zeolites to determine the adsorption characteristics of protein and the color and off-odor components. Adsorptive properties of those media were performed by spectral analyses at wavelengths 280 nm for the protein component and 325 nm for the contaminants. Statistical evaluation of the batch adsorption data from each series demonstrated that activated carbon generated from coconut hulls and zeolite 5 A (5 angstrom pore size) adsorbed the least amount of protein relative to contaminant adsorptions. Our selection of column media for the pilot-scale process was based on these findings. Published by Elsevier B.V.