Antioxidant, Antidiabetic, and Antiobesity Properties, TC7-Cell Cytotoxicity and Uptake of (Marcela) Conventional and High Pressure-Assisted Extracts.

The growing incidence of non-communicable diseases makes the search for natural sources of bioactive compounds a priority for such disease prevention/control. ('marcela'), a plant rich in polyphenols and native to Brazil, Uruguay, Paraguay, and Argentina, could be used for this purpose. Data on its antidiabetic/antiobesity properties and cellular uptake of bioactive compounds are lacking.

Inhibitor and substrate binding induced stability of HIV-1 protease against sequential dissociation and unfolding revealed by high pressure spectroscopy and kinetics.

High-pressure methods have become an interesting tool of investigation of structural stability of proteins. They are used to study protein unfolding, but dissociation of oligomeric proteins can be addressed this way, too. HIV-1 protease, although an interesting object of biophysical experiments, has not been studied at high pressure yet.

UHPH-processed O/W submicron emulsions stabilised with a lipid-based surfactant: physicochemical characteristics and behaviour on in vitro TC7-cell monolayers and ex vivo pig's ear skin.

Submicron O/W emulsions formulated with sesame oil plus a lipid-base surfactant, and with or without retinyl acetate (RAC) as a model hydrophobic biomolecule, were prepared by single-pass homogenisation at ≥ 200 MPa (UHPH) and an initial fluid temperature (Tin) of 24°C. These emulsions were characterised by a monomodal distribution (peak maximum at 260 nm) and a 2-year potential physical stability at ambient temperature. Submicron droplets were investigated in term of (i) physicochemical characteristics (size distribution curves; ζ-potential value), and (ii) impact on TC7-cell monolayers (MTT-assay and cell LDH-leakage).

Interaction of curcumin with phosphocasein micelles processed or not by dynamic high-pressure.

The binding of curcumin to native-like phosphocaseins (PC) dispersed in simulated milk ultrafiltrate at pH 6.6 was assessed by fluorescence spectrophotometry. Curcumin binds to native-like PC micelles with ∼1 binding site per casein molecule, and a binding constant of 0.

Staphylococcal enterotoxin A: Partial unfolding caused by high pressure or denaturing agents enhances superantigenicity.

The effect of transient exposure of Staphylococcus aureus enterotoxin A (SEA) to high pressure and/or denaturing agents was examined by assessing the toxin superantigenicity and immunoreactivity, and by monitoring pressure-induced changes in fluorescence emission spectra. Pressurization of SEA at 600 MPa and 45 degrees C in Tris-HCl buffer (20 mM, pH 7.4) resulted in a marked increase in both T-cell proliferation (superantigenicity) and immunoreactivity.

Selective transport of staphylococcal enterotoxin A through in vitro generated human M cells.

Staphylococcal enterotoxins are responsible for food poisoning and toxic shock syndrome due to their superantigen activity on T cells. Although their activity necessarily involves passage through the intestinal epithelium, little is known about this critical step. In the present study, we compared the in vitro transport of staphylococcal enterotoxin A through human intestinal absorptive and M cells.

Effects of high pressure homogenisation of raw bovine milk on alkaline phosphatase and microbial inactivation. A comparison with continuous short-time thermal treatments.

Raw whole milk of high microbial quality ( View Article and Find Full Text PDF

High pressure-low temperature processing of food proteins.

High pressure-low temperature (HP-LT) processing is of interest in the food field in view of: (i) obtaining a "cold" pasteurisation effect, the level of microbial inactivation being higher after pressurisation at low or sub-zero than at ambient temperature; (ii) limiting the negative impact of atmospheric pressure freezing on food structures. The specific effects of freezing by fast pressure release on the formation of ice I crystals have been investigated on oil in water emulsions stabilized by proteins, and protein gels, showing the formation of a high number of small ice nuclei compared to the long needle-shaped crystals obtained by conventional freezing at 0.1 MPa.

Pressurisation of raw skim milk and of a dispersion of phosphocaseinate at 9 degrees C or 20 degrees C: effects on the distribution of minerals and proteins between colloidal and soluble phases.

The effects of high pressure treatments (100-300 MPa; 15 min; 9 degrees C or 20 degrees C) on the distribution of minerals and proteins of raw skim milk (RSM) and of a dispersion of industrial phosphocaseinate (PC) were studied after separation of the micellar and soluble phases by ultracentrifugation (UCF). Whatever the temperature of high pressure treatments, the pressure-induced dissociation of the casein micelles was accompanied by calcium (Ca), phosphorus (P) and casein release from the micelles. The released Ca and P were or became bound to soluble proteins since progressive increases in Ca and P concentrations were observed in the UCF supernatants of RSM and of the PC dispersion but not in the ultrafiltrates from these UCF supernatants (free of soluble proteins).