title: Comparative characterization of the deamidation of carboxylic acid deamidated wheat gluten by altering the processing conditions.
abstract: The physicochemical, structural and functional properties of citric-acid-deamidated wheat gluten at controlled degrees of deamidation (25%, 40% and 55%), which were obtained by using different acid concentrations (3.93×10(-5), 3.14×10(-3) and 2.36×10(-2)mol/L) and temperatures (70°C 2h, 90°C 1h and 110°C 40min), were compared. Various deamidation processing conditions leading to the same degree of deamidation resulted in proteins with different physicochemical and structural characteristics, as indicted by the degree of hydrolysis, Z-potential, surface hydrophobicity, particle size, SDS-PAGE results, SEC-HPLC results, intrinsic fluorescence and FTIR spectra. Agglomerative hierarchical clustering analysis and principal component analysis qualitatively indicated a significant effect of pH on protein deamidation. Three samples at 40% deamidation, which were produced by a moderate acid concentration, showed the best emulsifying and foaming properties. Processes conducted at greater than 90°C causing protein aggregation and at a high acid concentration rupturing peptide bonds, impaired protein quality. These findings demonstrated that a limited amount of H(+) could function well in the catalysis of the deamidation of amide groups without an excess of H(+), which hydrolyses peptide bonds in a stronger hydrothermal treatment.
authors.affiliation: Institute of Food Science and Technology, College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China; Fujian Center of Excellence for Food Biotechnology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China. Electronic address: felliao@fzu.edu.cn.
authors.forename: Lan
authors.initials: L
authors.lastname: Liao
authors.affiliation: Institute of Food Science and Technology, College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China; Fujian Center of Excellence for Food Biotechnology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China.
authors.forename: Xueyue
authors.initials: X
authors.lastname: Han
authors.affiliation: Institute of Food Science and Technology, College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China; Fujian Center of Excellence for Food Biotechnology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China.
authors.forename: Lin-Ping
authors.initials: LP
authors.lastname: Chen
authors.affiliation: Institute of Food Science and Technology, College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China; Fujian Center of Excellence for Food Biotechnology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Ni
authors.affiliation: Institute of Food Science and Technology, College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China; Fujian Center of Excellence for Food Biotechnology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China.
authors.forename: Zhi-Bin
authors.initials: ZB
authors.lastname: Liu
authors.affiliation: Institute of Food Science and Technology, College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China; Fujian Center of Excellence for Food Biotechnology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Institute of Food Science and Technology, College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China; Fujian Center of Excellence for Food Biotechnology, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Chen
mesh_terms: D000577:Amides / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D055598:Chemical Phenomena; D019343:Citric Acid / Q000737:chemistry; D005511:Food Handling / Q000379:methods*; D005983:Glutens / Q000737:chemistry*; D006358:Hot Temperature; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D014908:Triticum / Q000737:chemistry*
chemical_list: D000577:Amides; D002264:Carboxylic Acids; D019343:Citric Acid; D005983:Glutens
keywords: Aggregation; Deamidation; Functional properties; Processing conditions; Structure; Wheat gluten