INRA-UMR 614 Fractionnement des Agro-Ressources et Environnement 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. 2009 Nov 11;57(21):10399-407. doi: 10.1021/jf9016948.
The structure and the chemical composition of the layer adsorbed at interfaces involving champagne have been investigated using native champagne, as well as ultrafiltrate (UFch) and ultraconcentrate (UCch) obtained by ultrafiltration with a 10(4) nominal molar mass cutoff. The layer adsorbed at the air/liquid interface was examined by surface tension and ellipsometry kinetic measurements. Brewster angle microscopy demonstrated that the layer formed on polystyrene by adsorption or drop evaporation was heterogeneous, with a domain structure presenting similarities with the layer adsorbed at the air/liquid interface. The surface chemical composition of polystyrene with the adlayer was determined by X-ray photoelectron spectroscopy (XPS). The contribution of champagne constituents varied according to the liquid (native, UFch, and UCch) and to the procedure of adlayer formation (evaporation, adsorption, and adsorption + rinsing). However, their chemical composition was not significantly influenced either by ultrafiltration or by the procedure of deposition on polystyrene. Modeling this composition in terms of classes of model compounds gave approximately 35% (w/w) of proteins and 65% (w/w) of polysaccharides. In the adlayer, the carboxyl groups or esters represent about 18% of carbon due to nonpolypeptidic compounds, indicating the presence of either uronic acids in the complex structure of pectic polysaccharides or of polyphenolic esters. This structural and chemical information and its relationship with the experimental procedures indicate that proteins alone cannot be used as a realistic model for the macromolecules forming the adsorption layer of champagne. Polysaccharides, the other major macromolecular components of champagne wine, are assembled with proteins at the interfaces, in agreement with the heterogeneous character of the adsorbed layer at interfaces.
采用香槟原生液、超滤（UFch）和超滤浓缩液（UCch）研究了涉及香槟的界面吸附层的结构和化学组成，超滤的标称摩尔质量截止值为 10(4)。通过表面张力和椭圆偏振动力学测量研究了气/液界面上的吸附层。掠入射反射式光学显微镜（ Brewster angle microscopy ）证明，通过吸附或液滴蒸发在聚苯乙烯上形成的层是不均匀的，具有与气/液界面上吸附的层相似的域结构。通过 X 射线光电子能谱（ XPS ）确定了带有吸附层的聚苯乙烯的表面化学组成。香槟成分的贡献取决于液体（原生、UFch 和 UCch）和吸附层形成过程（蒸发、吸附和吸附+冲洗）。然而，超滤或在聚苯乙烯上沉积的过程对其化学组成没有显著影响。根据模型化合物的类别对该组成进行建模，得到约 35%（w/w）的蛋白质和 65%（w/w）的多糖。在吸附层中，由于非多肽化合物，羧基或酯基约占 18%的碳，表明果胶多糖的复杂结构中存在要么是糖醛酸，要么是多酚酯。这种结构和化学信息及其与实验过程的关系表明，蛋白质本身不能用作形成香槟吸附层的大分子的现实模型。多糖是香槟酒的另一种主要大分子成分，与蛋白质一起在界面组装，这与界面上吸附层的异质性质一致。
