title: Complex coacervates obtained from peptide leucine and gum arabic: formation and characterization.
abstract: In this study, interactions between polypeptide-leucine (0.2% w/w) and gum arabic (0.03, 0.06, 0.09, 0.12, and 0.15% w/w) were examined at concentrations of NaCl (0, 0.01, 0.25, 0.3, 0.5mol/l) and at different pH values (from 1.0 to 12.0). Formation of insoluble complex coacervates was highest at pH 4.0. At pH 2.0, which is the pKa of the gum Arabic, the dissociation of precipitate occurred. The pHØ2 positively shifted with the addition of higher concentrations of salt. Samples containing 0.2% PL and 0.03% GA and no salt had higher turbidity and increased formation of precipitates showing greater turbidity and particle sizes. The Fourier transform infrared spectroscopy confirms the complex coacervate formation of leucine and gum arabic, and rheological measurements suggest the elastic behavior of 0.2% PL and 0.03% GA complex. Overall, the study suggests that complex coacervates of PLs could be one feasible ways of incorporating amino acids in food products.
authors.affiliation: Programa de Pós-graduação em Ciência e Tecnologia de Alimentos (PPGCTA), Universidade Federal Rural de Rio de Janeiro (UFRRJ), Rodovia BR 465, Km 7, Seropédica/RJ 23890-000, Brazil.
authors.forename: Eliana da S
authors.initials: Eda S
authors.lastname: Gulão
authors.affiliation: Programa de Pós-graduação em Ciência e Tecnologia de Alimentos (PPGCTA), Universidade Federal Rural de Rio de Janeiro (UFRRJ), Rodovia BR 465, Km 7, Seropédica/RJ 23890-000, Brazil.
authors.forename: Clitor J F
authors.initials: CJ
authors.lastname: de Souza
authors.affiliation: Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Bloco J, Rio de Janeiro/RJ 21941-598, Brazil.
authors.forename: Cristina T
authors.initials: CT
authors.lastname: Andrade
authors.affiliation: Programa de Pós-graduação em Ciência e Tecnologia de Alimentos (PPGCTA), Universidade Federal Rural de Rio de Janeiro (UFRRJ), Rodovia BR 465, Km 7, Seropédica/RJ 23890-000, Brazil; Laboratório de Engenharia e Tecnologia Agroindustrial (LETA), Universidade Federal Fluminense (UFF), Av. dos Trabalhadores 420, Volta Redonda/RJ 27255-125, Brazil. Electronic address: edwin@vm.uff.br.
authors.forename: Edwin E
authors.initials: EE
authors.lastname: Garcia-Rojas
mesh_terms: D006170:Gum Arabic / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007930:Leucine; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D012212:Rheology; D012965:Sodium Chloride / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010455:Peptides; D012965:Sodium Chloride; D006170:Gum Arabic; D007930:Leucine
keywords: Bioactives; Biopolymers; Complex coacervation; Polypeptide; Whey proteins