title: Structural and thermo-rheological analysis of solutions and gels of a β-lactoglobulin fraction isolated from bovine whey.
abstract: A β-Lactoglobulin fraction (r-βLg) was isolated from milk whey hydrolysates produced with cardosins from Cynara cardunculus. The impact of the technological process on the r-βLg structure and how in turn this determined its heat-induced gelation was investigated. Results were analysed taking pure β-Lg (p-βLg) as control sample. The process induced changes in the r-βLg native conformation causing exposure of hydrophobic groups, lower thermal stability and also, shorter thermal treatments needed to give rise to non-native and aggregated species. At pH 3.2, r-βLg and p-βLg solutions exhibited two gelation steps, with the advantage that r-βLg protein may form stable gels at lower temperature than p-βLg. At pH 7.2, a specific thermo-viscoelastic stability to 73 °C was found, which corresponded to the gel point in both protein solutions. The difference was that while for p-βLg solution in sol state δ<45° (solid-like), however for r-βLg solution δ>45° (fluid-like).
authors.affiliation: Analytical and Food Chemistry Department, Faculty of Sciences, University of Vigo, As Lagoas, 32004 Ourense, Spain. Electronic address: nataliatelle@uvigo.es.
authors.forename: Natalia
authors.initials: N
authors.lastname: Estévez
authors.affiliation: Analytical and Food Chemistry Department, Faculty of Sciences, University of Vigo, As Lagoas, 32004 Ourense, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Fuciños
authors.affiliation: Applied Physics Department, Faculty of Sciences, University of Vigo, As Lagoas, 32004 Ourense, Spain.
authors.forename: Verónica
authors.initials: V
authors.lastname: Bargiela
authors.affiliation: Analytical and Food Chemistry Department, Faculty of Sciences, University of Vigo, As Lagoas, 32004 Ourense, Spain.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pastrana
authors.affiliation: Applied Physics Department, Faculty of Sciences, University of Vigo, As Lagoas, 32004 Ourense, Spain.
authors.forename: Clara Asunción
authors.initials: CA
authors.lastname: Tovar
authors.affiliation: Analytical and Food Chemistry Department, Faculty of Sciences, University of Vigo, As Lagoas, 32004 Ourense, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Luisa Rúa
mesh_terms: D000818:Animals; D002417:Cattle; D005782:Gels; D007782:Lactoglobulins / Q000737:chemistry*; D000067796:Whey / Q000737:chemistry*; D000067816:Whey Proteins / Q000737:chemistry*
chemical_list: D005782:Gels; D007782:Lactoglobulins; D000067816:Whey Proteins
keywords: Aggregation; Conformational changes; Enzymatic hydrolysis; Thermal gelation profiles; Whey protein; β-Lactoglobulin