High pressure-induced changes in bovine milk proteins: a review.

High pressure (HP)-induced changes in the proteins of bovine milk have become an area of considerable research interest in recent years; as a result, there is now a detailed understanding of the effects of HP on casein micelles and whey proteins. HP treatment at pressures >400 or >100 MPa denatures the two most abundant whey proteins, alpha-lactalbumin (alpha-la) and beta-lactoglobulin (beta-lg), respectively. The majority of denatured beta-lg in HP-treated milk associates with the casein micelles, although some denatured beta-lg remains in the serum phase or is attached to the milk fat globule membrane; HP-denatured alpha-la is also associated with the milk fat globules.

A novel pH-dependent dimerization motif in beta-lactoglobulin from pig (Sus scrofa).

beta-Lactoglobulin (BLG) is a lipocalin and is the major protein in the whey of the milk of cows and other ruminants, but not in all mammalian species. The biological function of BLG is not clear, but a potential role in carrying fatty acids through the digestive tract has been proposed. The capability of BLG to aggregate and form gels is often used to thicken foodstuffs.

Thermodynamics of conformational ordering of iota-carrageenan in KCl solutions using high-sensitivity differential scanning calorimetry.

Thermodynamic properties of aqueous solutions of iota-carrageenan as affected by KCl (0.15-1.2 M) or iota-carrageenan (0.

Mechanism for the ethanol-dependent heat-induced dissociation of casein micelles.

An explanation as to how casein micelles dissociate when heated in the presence of ethanol is presented. Dissociation of casein micelles in milk-ethanol mixtures was studied using (1)H NMR, and the effects of addition of CaCl(2), NaCl, or EDTA or alteration of milk pH on this dissociation were studied. It is proposed that at low temperatures, ethanol reduces the solvent quality of milk serum, but above a critical temperature (approximately 30 degrees C in a 35% ethanol solution), ethanol enhances solvent quality and dissociates the casein micelles.

Ethanol-dependent heat-induced dissociation of casein micelles.

The dissociation of casein micelles when heated to approximately 65 degrees C in the presence of ethanol [1:1 mixture (v/v) of milk and 65% (w/w) aqueous ethanol] was investigated using L* values and transmission measurements. Mixtures of milk and ethanol became transparent on heating, which suggests dissociation of casein micelles. Results of experiments using confocal laser scanning microscopy, light scattering (static and dynamic), and dialysis to examine the changes of milk during heating in the presence of ethanol supported the assertion that such treatments result in dissociation of casein micelles, as did studies of model beta-casein micellar systems.