High-Pressure Induced Physicochemical and Functional Modifications of Low-Density Lipoproteins from Hen Egg Yolk

• Published in: Journal of agricultural and food chemistry Vol. 53; no. 14; pp. 5719 - 5725
• Main Authors: Speroni, F, Puppo, M. C, Chapleau, N, de Lamballerie, M, Castellani, O, Añón, M. C, Anton, M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13.07.2005
• Subjects: Animals; Biological and medical sciences; Chemical Phenomena; Chemistry, Physical; Chickens; denaturation; Egg and egg product industries; egg yolk; Egg Yolk - chemistry; Emulsifying Agents - chemistry; emulsifying properties; Female; flocculation; Food engineering; Food industries; Fundamental and applied biological sciences. Psychology; high pressure treatment; Hot Temperature; Hydrogen-Ion Concentration; Life Sciences; Lipoproteins, LDL - chemistry; low density lipoprotein; Pressure; protein aggregates; Protein Denaturation; solubility; viscosity; Egg yolk; Modification; Physical dressing; Denaturation; protein denaturation; Properties; Protein; High pressure; Aggregation; Lipoprotein LDL; Hen; Vertebrata; LDL; protein aggregation; Egg product; high-pressure treatment; Aves; emulsifying properties; LOW DENSITY LIPOPROTEINS;LDL;HIGH PRESSURE TREATMENT; PROTEIN DENATURATION;PROTEIN AGGREGATION; EMULSIFYING PROPERTIES; LIPOPROTEINE;JAUNE D'OEUF; HAUTE PRESSION; DENATURATION DES PROTEINES; AGREGATION; TRAITEMENT TECHNOLOGIQUE; PROPRIETE PHYSICOCHIMIQUE; PROPRIETE FONCTIONNELLE; POUVOIR EMULSIFIANT; FLOCULATION
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0502808

High-pressure treatment represents a potential method to stabilize microbiologically agricultural raw materials that are sensitive to heat treatments. Low-density lipoproteins (LDL), the main contributors to the exceptional emulsifying properties of yolk, are particularly sensitive to heat treatment. In this study, high-pressure treatments have been performed on LDL, and their impact on LDL physicochemical and emulsifying properties has been assessed. LDL dispersions at two pH levels (pH 3 and 8) were treated at different pressure levels:  200, 400, and 600 MPa at 20 °C. LDL dispersion characteristics (solubility, aggregation, and protein denaturation) and LDL emulsifying properties (o/w 30:70 emulsions:  droplet size, flocculation, and protein adsorption) of nontreated and high-pressure treated dispersions were compared. Solubility is not altered by high-pressure treatment whatever the pH, whereas aggregation and protein denaturation are drastically enhanced, in particular at pH 8. The effects of these modifications on LDL emulsifying properties are mainly a diminution of the flocculation (depletion and bridging) at this same pH. Finally, it seems that high-pressure treatment combined with an alkaline pH decreases droplet flocculation of LDL dispersions. Keywords: LDL; high-pressure treatment; protein denaturation; protein aggregation; emulsifying properties