title: Effect of pH on the thermal gelation of carob protein isolate.
abstract: The specific aim of this work was to study the capability of a carob protein isolate (CPI) to produce self-supporting gels when subjected to a thermal treatment. CPI aqueous dispersions (10, 20 and 30 wt% protein basis) at three different pH values (2, 6 and 10) were subjected to a heating/cooling process (95 °C-30 min/4 °C-24 h) leading to the formation of self-supporting gels. Those gels were characterized for dynamic rheological properties; water holding capacity (WHC); textural properties; extractability in different media; scanning electron microscopy; and SDS-PAGE profiles of the soluble proteins. The results demonstrated that self-supporting CPI gels can only be obtained at concentrations higher than 20 wt%, being favoured at extreme pH values, especially at alkaline pH. At pH 10, gels with higher dynamic elastic and hardness properties and appropriate WHC were formed due to the promotion of disulphide bonds formation. Thus, if higher rheological properties and hardness are required for thermally treated CPI gels, alkaline pH conditions that favour hydrophobic interactions and disulphide bonding should be selected.
authors.affiliation: Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, C/Profesor García González, 1, 41012 Seville, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Bengoechea
authors.affiliation: Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA, CONICET, La Plata, UNLP), 47 and 116, 1900 La Plata, Argentina.
authors.forename: Sara E Molina
authors.initials: SEM
authors.lastname: Ortiz
authors.affiliation: Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA, CONICET, La Plata, UNLP), 47 and 116, 1900 La Plata, Argentina.
authors.forename: Antonio
authors.initials: A
authors.lastname: Guerrero
authors.affiliation: Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA, CONICET, La Plata, UNLP), 47 and 116, 1900 La Plata, Argentina.
authors.forename: María C
authors.initials: MC
authors.lastname: Puppo
keywords: Carob protein; Gel; Solubility; Structure; Texture