Heat induced β-lactoglobulin polymerization: role of the change in medium permittivity

• Published in: Food chemistry Vol. 85; no. 3; pp. 399 - 406
• Main Authors: Labouré, H., Cases, E., Cayot, Ph
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-05-2004; Elsevier
• Subjects: Biological and medical sciences; Food engineering; Food industries; Fundamental and applied biological sciences. Psychology; Life Sciences; Permittivity; Polymerization; Thermal treatment; Water structure; β-Lactoglobulin; Polymerization; Water structure; Permittivity; β-Lactoglobulin; Thermal treatment; Water; Milk protein; Heat; Whey protein; Structure; b-Lactoglobulin
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2003.07.017

The decrease in medium permittivity due to temperature rise could play an important role in the denaturation/polymerization of heat-treated β-lactoglobulin. The permittivity of a β-lactoglobulin suspension was decreased, either by heat treatment or by adding organic solvent, and the rate of loss of the native β-lactoglobulin was estimated by SDS-PAGE analysis. Setting the permittivity to 63.8 by addition of organic solvent, induced β-lactoglobulin polymerization, but it differed from that induced by change in permittivity upon thermal treatment itself (heating to 70 °C). To explain the protein polymerization process induced by heating, other physical parameters should be taken into account, such as change in water organization around the protein.