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Polyphenol-beta-casein complexes at the air/water interface and in solution: effects of polyphenol structure
V Aguié-Béghin1, P Sausse, E Meudec
1INRA UMR 614 Fractionnement des Agro-Ressources et Environnement (FARE) INRA/Universite de Reims Champagne Ardennes, Centre de Recherche en Environnement et Agronomie, 2 Esplanade R. Garros, BP 224, F-51686 Reims, France. Veronique.Aguie@reims.inra.fr
Journal of Agricultural and Food Chemistry
|October 2, 2008
Summary
Certain plant polyphenols, like galloylated flavanols, significantly alter protein surface properties, impacting beverage quality. These interactions slow protein adsorption, affecting foam stability and texture.
Area of Science:
- Food Science
- Biochemistry
- Colloid Science
Background:
- Protein-polyphenol interactions influence beverage characteristics like astringency, haze, and foam.
- Understanding these interactions is crucial for controlling beverage quality and stability.
Purpose of the Study:
- To investigate the impact of various phenolic compounds on the surface properties of beta-casein.
- To elucidate the mechanisms behind polyphenol-protein interactions at the air/liquid interface.
Main Methods:
- Surface properties were monitored using tensiometry and ellipsometry.
- Complex formation in the bulk phase was analyzed via electrospray ionization mass spectrometry (ESI-MS) and light scattering.
Main Results:
- Galloylated flavanol monomers (epicatechin gallate and epigallocatechin gallate) significantly modified beta-casein's surface pressure, concentration, and dilational modulus.
- Lower molecular weight polyphenols (<306 g/mol) showed minimal impact on protein surface properties.
- ESI-MS and light scattering confirmed polyphenol-protein aggregate formation in the bulk, correlating with slowed protein adsorption.
Conclusions:
- Galloylated flavanols, but not simpler polyphenols, substantially affect protein adsorption and surface behavior.
- Polyphenol-induced aggregation in the bulk phase influences the kinetics of protein adsorption at the air/liquid interface.
- Findings provide insights into managing beverage texture and stability through controlled polyphenol-protein interactions.
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