Aguié-Béghin V, Sausse P, Meudec E, Cheynier V, Douillard R
INRA 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.
J Agric Food Chem. 2008 Oct 22;56(20):9600-11. doi: 10.1021/jf801672x. Epub 2008 Oct 1.
The interactions between proteins and plant polyphenols are responsible for astringency and haze formation in beverages and may participate in foam stabilization. The effect of phenolic compounds with different structures, namely, catechin (C), epicatechin (Ec), epigallocatechin (Egc), epicatechin gallate (EcG), and epigallocatechin gallate (EgcG), on the surface properties at the air/liquid interface of beta-casein, chosen as model protein, were monitored by tensiometry and ellipsometry. The formation of complexes in the bulk phase was measured by electrospray ionization mass spectrometry (ESI-MS). Adsorption of polyphenols from pure solution was not observed. Surface pressure, surface concentration, and dilational modulus of the protein adsorption layer were greatly modified in the presence of galloylated flavanol monomers (EcG and EgcG) but not of lower molecular weight polyphenols (<306 g/mol). The formation of polyphenol-protein aggregates in the bulk, as evidenced by ESI-MS and light scattering experiments, was related to the slowdown of protein adsorption.
蛋白质与植物多酚之间的相互作用导致了饮料中的涩味和浑浊形成，并且可能参与泡沫的稳定。以β-酪蛋白作为模型蛋白，通过表面张力测定法和椭偏仪监测了具有不同结构的酚类化合物，即儿茶素（C）、表儿茶素（Ec）、表没食子儿茶素（Egc）、表儿茶素没食子酸酯（EcG）和表没食子儿茶素没食子酸酯（EgcG）对气/液界面表面性质的影响。通过电喷雾电离质谱（ESI-MS）测定本体相中复合物的形成。未观察到多酚从纯溶液中的吸附现象。在存在没食子酰化黄烷醇单体（EcG和EgcG）而非较低分子量多酚（<306 g/mol）的情况下，蛋白质吸附层的表面压力、表面浓度和扩张模量发生了很大变化。ESI-MS和光散射实验证明，本体中多酚-蛋白质聚集体的形成与蛋白质吸附的减缓有关。
