Deamidation of Wheat-Flour Gluten with Ion-Exchange Resin and Its Functional Properties.

Improvement of Digestibility, Reduction in Allergenicity, and Induction of Oral Tolerance of Wheat Gliadin by Deamidation

“…This effect of deamidation has already been verified with some proteins. 5,6,[19][20][21] In agreement with those findings, each deamidated gliadin was more soluble in water, a salt solution, and buffered solution at neutral and alkaline pH than the undeamidated type (Fig. 2).…”

“…3,4) We have also shown that deamidating ethanol-soluble wheat gliadin and gluten was effective for increasing their solubility in water and an NaCl solution, 5,6) as well as their foaming capacity. 6) Such changes in the solubility and surface properties of these proteins improve their food processing qualities. Moreover, the increase in water solubility may contribute to improving their in vivo digestibility, because they would become more susceptible to the action of digestive enzymes.…”

“…We have developed a method that uses a cation-exchange resin of the carboxylate type for effectively deamidating proteins, without causing any detectable peptide-bond hydrolysis. [2][3][4][5][6] Since a cation-exchange resin is resistant to an ethanol solution, this method is applicable to alcohol-soluble proteins such as prolamines. We have found that the use of an ion exchanger resulted in 28% deamidation of gliadin 5) and 30% deamidation of gluten.…”

“…[16][17][18] There are several methods that can be used to deamidate proteins, including the use of acids, [19][20][21][22][23][24] enzymes, 1,[25][26][27] and cation exchangers. [2][3][4][5][6]28) Among them, an acid treatment is the most commonly used, y To whom correspondence should be addressed. Fax: +81-466-84-3946; E-mail: kumagai@brs.nihon-u.ac.jp although this causes unfavorable peptide-bond hydrolysis resulting in the production of bitter-tasting peptides and a reduction in the processing properties of the protein.…”

Evaluation of Reduced Allergenicity of Deamidated Gliadin in a Mouse Model of Wheat-Gliadin Allergy Using an Antibody Prepared by a Peptide Containing Three Epitopes

“…25−30 Since cation-exchange resins are resistant to ethanol, this method is applicable to the deamidation of ethanol-soluble proteins such as gliadins. 25,29 The deamidated gliadin obtained by this technique showed higher foaming property than egg-white albumin and globulin; this property may improve the texture of bakery products such as bread and cakes. Deamidation increased the solubility of gliadin in water and salt solutions, which led to improved digestibility.…”