Characterization of β-lactoglobulin nano-hydrogels formed by heat treatment under selective ph range conditions

Autor: Ramos, Óscar Leandro Silva, Pereira, Ricardo Nuno Correia, Malcata, X., Vicente, A. A.
Přispěvatelé: Universidade do Minho
Jazyk: angličtina
Rok vydání: 2013
Popis: Bovine beta-lactoglobulin (beta-Lg) is a globular protein from milk that has considerable potential as a functional ingredient in food, cosmetic, and pharmaceutical applications. It is, indeed, the major component (i.e. 50 wt%) and the primary gelling agent of whey proteins. Beta-Lg is stable at low pH and highly resistant to proteolytic degradation in the stomach. Another interesting feature is its ability to act as an encapsulating agent. The objective of this work was to understand the kinetics of aggregation during heat treatment, under narrow pH ranges, that leads to the formation of food-grade beta-Lg nano-hydrogels, and to postulate a model for its mechanism of aggregation. In this study, aqueous dispersions of beta-lg were accordingly generated, and formation of stable beta-Lg nano-aggregates were evaluated after heating under different temperatures (75, 80, and 85 ºC), holding periods (5, 10, 15, and 20 min), and pH values (4, 5, 6, and 7); particular emphasis was put at pH ca. 6.0. The protein aggregates formed were characterized for stability (turbidity), morphology, size, surface charge, and content in accessible thiol groups. Stable dispersions of beta-Lg nano-hydrogels were obtained at pH 6, corresponding to an aggregation yield of ca. 65, 77, and 92% at 75, 80, and 85 ºC, respectively, for a holding period of 20 min. Nano-hydrogels at pH 6 were characterized by a particle size between 160 and 250 nm and a low degree of polydispersity (
info:eu-repo/semantics/publishedVersion
Databáze: OpenAIRE