Corn Gluten Meal as an Emulsifier
October 6/Mexico City/Journal of Technology & Science -- "Corn gluten meal is a by-product of starch production that is readily available. Corn protein isolates have limited applications due to their hydrophobic nature, low solubility and limited functionality as emulsifiers," scientists in Mexico report.
"In this study, a mild acidic treatment of corn gluten meal was performed in order to achieve deamidation of asparagine and glutamine residues and modify the interfacial behavior of this byproduct. A 0.1N HCl treatment for six hours at 70 degrees C rendered a deamidation degree of 20.4%, which increased the emulsification activity index of corn gluten meal from 6.8 to 16.8m(2)/g protein, with a remarkable increase in emulsion stability from 0 to 90.6% oil retention. Proteins participating in the emulsion were separated by SDS-PAGE and the main polypeptides were identified as alpha and beta-zeins," wrote I. Flores and colleagues, National Autonomous University.
The researchers concluded, "After deamidation, protein dissociation and unfolding due to the obtained negative charges resulted in enhanced functionality."
Flores and colleagues published their study in Food Science and Technology International ("Emulsifying Properties of Chemically Deamidated Corn (Zea Mays) Gluten Meal." Food Science and Technology International, 2010;16(3):241-250).
For additional information, contact A. Galvez, National Autonomous University of Mexico, Dept. of Alimentos & Biotecnol, Faculty Quim, Circuito Invest Cient S-N, Mexico City 04510, DF, Mexico.
From the October 18, 2010, Prepared Foods E-dition