Heteroprotein complex coacervation: bovine β-lactoglobulin and lactoferrin.

Lactoferrin (LF) and β-lactoglobulin (BLG), strongly basic and weakly acidic bovine milk proteins, form optically clear coacervates under highly limited conditions of pH, ionic strength I, total protein concentration C(P), and BLG:LF stoichiometry. At 1:1 weight ratio, the coacervate composition has the same stoichiometry as its supernatant, which along with DLS measurements is consistent with an average structure LF(BLG2)2. In contrast to coacervation involving polyelectrolytes here, coacervates only form at I < 20 mM.

Tuning the structure of protein particles and gels with calcium or sodium ions.

The effect of the addition of NaCl or CaCl2 on the structure of protein particles and gels was investigated in detail for aqueous solutions of the globular milk protein β-lactoglobulin at 40g/L and pH 7.0. When heated in the presence of NaCl or at very low CaCl2 concentrations, the proteins form small strand-like particles, but if more than about two Ca(2+) ions per protein are present, larger spherical particles (microgels) are formed, which increase in size with increasing CaCl2 concentration.

On the crucial importance of the pH for the formation and self-stabilization of protein microgels and strands.

Stable suspensions of protein microgels are formed by heating salt-free β-lactoglobulin solutions at concentrations up to about C = 50 g·L(-1) if the pH is set within a narrow range between 5.75 and 6.1.

Prevalence of hepatitis C infection and risk factors in hospitalized diabetic patients: results of a cross-sectional study.

Objectives: Although there may exist a nosocomial risk of hepatitis C virus (HCV) infection in patients with type 1 or type 2 diabetes, this risk has not been fully investigated thus far and its magnitude is unknown. The aim of this multicenter cross-sectional study was to evaluate the prevalence of, and risk factors for, hepatitis C infection in consecutive hospitalized patients with diabetes and to assess the nosocomial risk and magnitude of HCV infection in these patients.

Patients And Methods: Consecutive hospitalized patients with diabetes seen in 11 French hepatogastroenterology and diabetology departments were studied.

Acid gelation in heated and unheated milks: interactions between serum protein complexes and the surfaces of casein micelles.

The acid-induced interactions between different protein particles in milk (casein micelles and serum protein/kappa-casein complexes) were studied in a series of different mixtures of heated and unheated proteins using diffusing wave spectroscopy (DWS) and small deformation rheology. The measurements were made as functions of pH during acidification by addition of glucono-delta-lactone (GDL). Heat treatment (85 degrees C, 10 min) affected the composition of the serum and the reactivity of casein micellar surface based on the pH at which the casein micelles aggregated during acidification.

Effect of the pH of heating on the qualitative and quantitative compositions of the sera of reconstituted skim milks and on the mechanisms of formation of soluble aggregates.

The effect of the pH of heating (6.3-7.3) on the composition of sera in reconstituted skimmed milks was investigated.

Effects of added sodium caseinate on the formation of particles in heated milk.

The effects of heat at temperatures in the range of 80-90 degrees C on mixtures of reconstituted skim milk powder (RSMP) and sodium caseinate have been determined. In the absence of caseinate, the action of heat on RSMP produces soluble complexes of whey proteins and kappa-casein, as well as complexes of whey protein with the casein micelles. When sodium caseinate was added to RSMP at levels of 0.

Influence of the NaCl or CaCl2 concentration on the structure of heat-set bovine serum albumin gels at pH 7.

The structure of heat-set systems of the globular protein bovine serum albumin (BSA) was investigated at pH 7 in different salt conditions (NaCl or CaCl(2)) using light scattering. Cross-correlation dynamic light scattering was used to correct for multiple scattering from turbid samples. After heat treatment, aggregates are formed whose size increases as the protein concentration increases.

Heat-induced gelation of bovine serum albumin/low-methoxyl pectin systems and the effect of calcium ions.

Influence of low-methoxyl pectin (LM pectin) and calcium ions (3 mM) on mechanical behavior and microstructure of bovine serum albumin (BSA) gels (pH 6.8, in 0.1 M NaCl) was evaluated.