Deamidation of food proteins to improve functionality.

Many proteins, particularly those in plants, require structural modifications to improve their functional properties for expanded use. Several chemical and enzymatic methods are described for food protein deamidation to improve solubility, emulsification, foaming, and other functional properties of the proteins. The use of enzymes in protein modification is more desirable than chemical treatments because of their speed, mild reaction conditions, and their high specificity. Transglutaminase, protease, and peptidoglutaminase (PGase) are the only enzymes reported in the literature for protein deamidation. Of these, PGase appears to be the most feasible for practical application. PGase production, purification, and use in deamidation are discussed.