Nonenzymatic deamidation of food proteins

Abstract

Many cereal proteins, such as wheat, corn, and oat proteins, have high levels of the amide-containing amino acids, glutamine and asparagine. These side chains are susceptible to hydrolysis of the amide bond, which leads to release of ammonia and transformation to acidic groups. The released ammonia has been implicated in the formation of aroma compounds and pigments because of its participation in the Maillard browning reaction. The conversion of the amide groups to acid groups may partially unfold the protein, resulting in an amphiphilic molecule that can be used as a surface active agent or emulsifier by food processors. This review provides general information on the factors that affect deamidation of proteins as well as the implications of deamidation for food processing.

Effect of Different Cations on Pidan Composition and Flavor in Comparison to the Fresh Duck Egg

“…Ammonia was formed in the pidan white, and yolk possibly by deamination process (Hou, 1981). Deamidation of proteins occurs at pH above 8.0, dependent upon the H + or OH − concentration and adjacent amino acid residue (Riha et al, 1996). Higher ammonia content was found in pidan white treated with 0.2% ZnCl 2 treated pidan confirm that higher deamination of pidan white and yolk during production of pidan.…”

Heat-induced Irreversible Denaturation of the Camelid Single Domain VHH Antibody Is Governed by Chemical Modifications

“…In addition, deamidation is responsible for much of the heterogeneity of pharmaceutically important proteins such as antibodies (1). Conversely, deamidation of food proteins, such as in whey and wheat, improves their functional properties and makes them more useful for the industry (60). Deamidation of Asn changes the net charge of food proteins and thus gives a preferable effect on the solubility at neutral pH.…”

Effect of acetic acid deamidation‐induced modification on functional and nutritional properties and conformation of wheat gluten

“…1 Deamidation by transforming amides of glutamine (Gln) and asparagine (Asn) into carboxyl groups can beneficially modify proteins via effects such as changing charge density, increasing electrostatic repulsion and breaking hydrogen bonds, consequently unfolding protein conformation and enhancing protein-water interactions. 2 Wright and Urry 3 stated that deamidation was a hydrolytic reaction catalysed by acids or bases. Different reaction mechanisms occur under acidic and basic conditions.…”