title: Exploring the Relationship between Structural and Air-Water Interfacial Properties of Wheat (Triticum aestivum L.) Gluten Hydrolysates in a Food System Relevant pH Range.
abstract: The relationship between structural and foaming properties of two tryptic and two peptic wheat gluten hydrolysates was studied at different pH conditions. The impact of pH on foam stability (FS) of the samples heavily depended on the peptidase used and the degree of hydrolysis reached. Surface dilatational moduli were in most, but not all, instances related to FS, implying that, although the formation of a viscoelastic protein hydrolysate film is certainly important, this is not the only phenomenon that determines FS. In contrast to what might be expected, surface charge was not a major factor contributing to FS, except when close to the point-of-zero-charge. Surface hydrophobicity and intrinsic fluorescence measurements suggested that changes in protein conformation take place when the pH is varied, which can in turn influence foaming. Finally, hydrolyzed gluten proteins formed relatively large particles, suggesting that protein hydrolysate aggregation probably influences its foaming properties.
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Center (LFoRCe), KU Leuven , Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
authors.forename: Arno G B
authors.identifier: http://orcid.org/0000-0002-6868-4432
authors.initials: AG
authors.lastname: Wouters
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Center (LFoRCe), KU Leuven , Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
authors.forename: Ellen
authors.initials: E
authors.lastname: Fierens
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Center (LFoRCe), KU Leuven , Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
authors.forename: Ine
authors.initials: I
authors.lastname: Rombouts
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Center (LFoRCe), KU Leuven , Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
authors.forename: Kristof
authors.initials: K
authors.lastname: Brijs
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Center (LFoRCe), KU Leuven , Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.|Food Science Department, University of Guelph , 50 Stone Road East Guelph, Ontario N1G 2W1, Canada.
authors.forename: Iris J
authors.initials: IJ
authors.lastname: Joye
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Center (LFoRCe), KU Leuven , Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Delcour
mesh_terms: D000388:Air; D000067493:Dynamic Light Scattering; D005453:Fluorescence; D005983:Glutens / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D010316:Particle Size; D011487:Protein Conformation; D011492:Protein Hydrolysates / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D014908:Triticum / Q000737:chemistry*; D014364:Tryptophan; D014867:Water / Q000737:chemistry
chemical_list: D011492:Protein Hydrolysates; D014867:Water; D005983:Glutens; D014364:Tryptophan
keywords: air−water interface; foam; gluten hydrolysates; interfacial properties; pH; protein conformation