Acid-induced cold gelation of globular proteins: effects of protein aggregate characteristics ans disulfide bonding on Rheological properties
| Autor: | Rob J. Hamer, Ronald W. Visschers, Arno C. Alting, Martien A. Cohen Stuart, Anne M van de Pijpekamp, Els H. A. de Hoog, Cornelis G de Kruif, Mireille Weijers |
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| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Whey protein
Globular protein Laboratorium voor Fysische chemie en Kolloïdkunde interchange reactions Protein aggregation isolate Whey protein isolate Protein purification alpha-lactalbumin Levensmiddelenchemie Organic chemistry Disulfides Sulfhydryl Compounds Beta-lactoglobulin Physical Chemistry and Colloid Science ca2+-induced gelation VLAG chemistry.chemical_classification biology Food Chemistry beta-lactoglobulin ovalbumin General Chemistry Hydrogen-Ion Concentration denatured whey-protein Milk Proteins phase-separation Cold Temperature Microscopy Electron Cross-Linking Reagents Whey Proteins chemistry Covalent bond heat-induced gelation Thiol biology.protein Biophysics Rheology General Agricultural and Biological Sciences Gels set gels |
| Zdroj: | Journal of Agricultural and Food Chemistry 52 (2004) 3 Journal of Agricultural and Food Chemistry, 52(3), 623-631 |
| ISSN: | 0021-8561 |
| DOI: | 10.1021/jf034753r |
| Popis: | The process of cold gelation of ovalbumin and the properties of the resulting cold-set gels were compared to those of whey protein isolate. Under the chosen heating conditions, most protein was organized in aggregates. For both protein preparations, the aggregates consisted of covalently linked monomers. Both types of protein aggregates had comparable numbers of thiol groups exposed at their surfaces but had clearly different shapes. During acid-induced gelation, the characteristic ordering caused by the repulsive character disappeared and was replaced by a random distribution. This process did not depend on aggregate characteristics and probably applies to any type of protein aggregate. Covalent bonds are the main determinants of the gel hardness. The formation of additional disulfide bonds during gelation depended on the number and accessibility of thiol groups and disulfide bonds in the molecule and was found to clearly differ between the proteins studied. However, upon blocking of the thiol groups, long fibrillar structures of ovalbumin contribute significantly to gel hardness, demonstrating the importance of aggregate shape. |
| Databáze: | OpenAIRE |
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