title: Sonolysis of high macroviscosity systems: hen albumen hydrogel.
abstract: To understand molecular effects of ultrasound on protein gels (cross-linked, hydrated macromolecular systems of immeasurably high macroviscosity, but low microviscosity), the thick fraction of hen albumen was sonicated. The immeasurably high viscosity of the intact thick fraction decreased to 2.5-4.0 mPa·s (depending on the sample) after a 12 min sonication (0.14 mM of radicals were produced and 19 J g(-1) of thermal energy absorbed) indicating that the 3D protein network was degraded. SDS-PAGE analysis indicated the breaking of intermolecular S-S bridges holding together the protein network rather than the primary structure of constituent proteins. Despite the relatively large concentration of OH radical produced in the sonication time range applied, no protein cross-linking was observed which can be attributed to the high degree of protein glycosylation and protein immobility. Differential scanning calorimetry (DSC) showed that both the amount of bound water and the enthalpy of denaturation of the constituent proteins are not affected by sonication, which is consistent with the SDS-PAGE results. A small increase in sample turbidity can be attributed to the small extent of thermal denaturation occurring in the vicinity of cavitation sites.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, 104 Chemistry Research Building, University Park, Pennsylvania 16802, USA.
authors.forename: Keith M
authors.initials: KM
authors.lastname: Krise
authors.forename: Ellen R
authors.initials: ER
authors.lastname: Forsyth
authors.forename: Kay M
authors.initials: KM
authors.lastname: DiMarco
authors.forename: Bratoljub H
authors.initials: BH
authors.lastname: Milosavljevic
mesh_terms: D000418:Albumins / Q000737:chemistry*; D000818:Animals; D002645:Chickens; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D011489:Protein Denaturation; D013010:Sonication; D013696:Temperature; D014783:Viscosity
chemical_list: D000418:Albumins; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D017665:Hydroxyl Radical