title: Hydrophobicity of whey protein concentrates measured by fluorescence quenching and its relation with surface functional properties.
abstract: Surface hydrophobicity of whey protein concentrate (WPC) under heated (85 degrees C for 5, 10, 20, 30, 40, and 60 min) and unheated conditions was measured using cis-parinaric acid (CPA), 1-anilino-8-naphthalenesulfonate (ANS), and a fluorescence quenching method using acrylamide as a quencher. This last method evaluates the degree of exposure of tryptophanyl residues in proteins to the solvent. The initial slope of Stern-Volmer plots, K(app), was used as an index of protein hydrophobicity. Surface hydrophobicity of WPC exhibited good relation with surface functional properties such as emulsifying and foaming. Analysis of the data obtained in this work showed that the fluorescence quenching method gave results similar to those obtained using CPA and ANS. Therefore, this simple technique is satisfactory in effectively obtaining information about the hydrophobicity of whey proteins.
authors.affiliation: Area Fisicoquímica, Departamento de Química-Física, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, (2000) Rosario, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Moro
authors.forename: C
authors.initials: C
authors.lastname: Gatti
authors.forename: N
authors.initials: N
authors.lastname: Delorenzi
mesh_terms: D020106:Acrylamide; D000817:Anilino Naphthalenesulfonates; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004655:Emulsions; D005231:Fatty Acids, Unsaturated; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D007202:Indicators and Reagents; D007782:Lactoglobulins / Q000737:chemistry; D008894:Milk Proteins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013499:Surface Properties; D000067816:Whey Proteins
chemical_list: D000817:Anilino Naphthalenesulfonates; D004655:Emulsions; D005231:Fatty Acids, Unsaturated; D007202:Indicators and Reagents; D007782:Lactoglobulins; D008894:Milk Proteins; D000067816:Whey Proteins; D020106:Acrylamide; C027149:cis-parinaric acid methyl ester; C027132:1-anilino-8-naphthalenesulfonate