title: Interfacial and oil/water emulsions characterization of potato protein isolates.
abstract: Interfacial and emulsifying properties of potato protein isolate (PPI) have been studied to evaluate its potential application to stabilize oil/water emulsions at two pH values (2 and 8). The amount, type, and solubility of proteins and the size of aggregates have been determined in aqueous dispersion. Air-water and oil-water interfacial properties (adsorption, spreading, and viscoelastic properties) have been determined as a function of concentration and pH using soluble phases of PPI. The behavior of PPI stabilized oil/water emulsions has been then analyzed by droplet size distribution measurements and interfacial concentration. PPI exhibits low solubility over a wide range of pH values, with the presence of submicrometer aggregates. The pH value exerts a negligible effect on interfacial tension (oil-water) or surface pressure (air-water) but displays very important differences in viscoelastic properties of the interfacial films formed between oil and water. In this sense, pH 8 provides a major elastic response at oil-water interfaces as compared to pH 2. In relation with this result, a much higher ability to produce fine and stable emulsions is noticed at pH 8 as compared to pH 2. Consequently, there is an evident relationship between the rheological properties of the oil-water interfacial films and the macroscopic emulsion behavior.
authors.affiliation: Departamento de Ingeniería Química, Universidad de Sevilla, Facultad de Química, 41012 Sevilla, Spain. alromero@us.es
authors.forename: Alberto
authors.initials: A
authors.lastname: Romero
authors.forename: Valérie
authors.initials: V
authors.lastname: Beaumal
authors.forename: Elisabeth
authors.initials: E
authors.lastname: David-Briand
authors.forename: Felipe
authors.initials: F
authors.lastname: Cordobés
authors.forename: Antonio
authors.initials: A
authors.lastname: Guerrero
authors.forename: Marc
authors.initials: M
authors.lastname: Anton
mesh_terms: D055598:Chemical Phenomena; D004355:Drug Stability; D004655:Emulsions / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009821:Oils / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D012212:Rheology; D011198:Solanum tuberosum / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D004655:Emulsions; D009821:Oils; D010940:Plant Proteins; D014867:Water