Emulsifying properties of chemically deamidated corn (Zea mays) gluten meal.

摘要

Corn gluten meal is a readily available by-product of starch production. Corn protein isolates have limited applications due to their hydrophobic nature, low solubility and limited functionality as emulsifiers. 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 by-product. A 0.1N HCl treatment for 6 h at 70 degrees C led to 20.4% deamidation, which increased the emulsification activity index of corn gluten meal from 6.8 to 16.8 m2/g protein and considerably increased 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. After deamidation, protein dissociation and unfolding due to the obtained negative charges resulted in enhanced functional properties.