title: Core-shell biopolymer nanoparticles produced by electrostatic deposition of beet pectin onto heat-denatured beta-lactoglobulin aggregates.
abstract: The purpose of this study was to produce and characterize core-shell biopolymer particles based on electrostatic deposition of an anionic polysaccharide (beet pectin) onto amphoteric protein aggregates (heat-denatured beta-lactoglobulin [beta-lg]). Initially, the optimum conditions for forming stable protein particles were established by thermal treatment (80 degrees C for 15 min) of 0.5 wt% beta-lg solutions at different pH values (3 to 7). After heating, stable submicron-sized (d=100 to 300 nm) protein aggregates could be formed in the pH range from 5.6 to 6. Core-shell biopolymer particles were formed by mixing a suspension of protein aggregates (formed by heating at pH 5.8) with a beet pectin solution at pH 7 and then adjusting the pH to values where the beet pectin is adsorbed (< pH 6). The impact of pH (3 to 7) and salt concentration (0 to 250 mM NaCl) on the properties of the core-shell biopolymer particles formed was then established. The biopolymer particles were stable to aggregation from pH 4 to 6, but aggregated at lower pH values because they had a relatively small -potential. The biopolymer particles remained intact and stable to aggregation up to 250 mM NaCl at pH 4, indicating that they had good salt stability. The core-shell biopolymer particles prepared in this study may be useful for encapsulation and delivery of bioactive food components or as substitutes for lipid droplets.
authors.affiliation: Dept. of Biotechnology, Faculty of Science, Mahidol Univ., Rama 6 Road, Bangkok 10400, Thailand.
authors.forename: R
authors.initials: R
authors.lastname: Santipanichwong
authors.forename: M
authors.initials: M
authors.lastname: Suphantharika
authors.forename: J
authors.initials: J
authors.lastname: Weiss
authors.forename: D J
authors.initials: DJ
authors.lastname: McClements
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry*; D053758:Nanoparticles; D011489:Protein Denaturation; D055672:Static Electricity; D013997:Time Factors
chemical_list: D001704:Biopolymers; D007782:Lactoglobulins