title: Effect of citric acid deamidation on in vitro digestibility and antioxidant properties of wheat gluten.
abstract: The effects of citric acid deamidation on the physiochemical properties of wheat gluten were investigated. In vitro digestion was carried out to determine changes of molecular weight distribution, amino acids composition and antioxidant efficacy of wheat gluten hydrolysates. Results indicated that citric acid deamidation significantly increased gluten solubility and surface hydrophobicity, at a neutral pH. Deamidation induced molecular weight distribution change of gluten with little proteolysis. Results from FTIR indicated that the α-helix and β-turn of deamidated gluten increased accompanied by a decrease of the β-sheet structure. After deamidation, in vitro pepsin digestibility of wheat gluten decreased, while in vitro pancreatin digestibility increased. The oxygen radical absorbance capacity (ORAC) activity of the in vitro digests decreased with increase of deamidation time. The high Lys and total essential AAs amounts in the final digests suggested that the nutritional values of wheat gluten after deamidation might be enhanced.
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China.
authors.forename: Chaoying
authors.initials: C
authors.lastname: Qiu
authors.forename: Weizheng
authors.initials: W
authors.lastname: Sun
authors.forename: Chun
authors.initials: C
authors.lastname: Cui
authors.forename: Mouming
authors.initials: M
authors.lastname: Zhao
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000378:metabolism; D000975:Antioxidants / Q000737:chemistry* / Q000378:metabolism; D019343:Citric Acid / Q000737:chemistry*; D004063:Digestion; D005983:Glutens / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D009753:Nutritive Value; D017433:Protein Structure, Secondary; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D014908:Triticum / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000975:Antioxidants; D019343:Citric Acid; D005983:Glutens
keywords: Amino acid composition; Citric acid deamidation; In vitro digestion; ORAC; Wheat gluten