Champagne Bubbles : Isolation and Characterization of amphiphilic macromolecules responsible for the stability of the collar at the Champagne / air interface

The effervescence and the stability of the ring of fine bubbles crowning the surface of a champagne glass, the "collar", constitute one of the hallmarks of Champagne. Defects in the stability of this collar are not well understood and account for a significant proportion of bottle return. This study aims to better understand the surface properties of champagne wine such that the foaming properties can be controlled more effectively. Early studies on Champagne foaming properties using the "Mosalux" measurement of the foam level formed by air flow in champagne through fritted glass pointed to a link between protein concentration and foam level [5] but no satisfactory correlation between protein content and foam stability was established. Later measurements were conducted with either ultra-filtrates or ultra-concentrates [4]. The authors demonstrated that macromolecule concentration was an essential parameter in the foam stability. The stability of bubbles is usually ascribed to the presence of an adsorption layer formed at the gas/liquid interface and its properties [3]. Thus surface properties of Champagne were analysed by ellipsometry and tensiometry. Measurements conducted on base wine, on ultra-filtered base wines and degassed champagne samples showed the presence of an adsorption layer formed at the air/champagne wine interface [6] and that adsorption layer being composed of macromolecules in a 104 to 105 molecular range [7]. Previous studies on champagne wine macromolecules had shown wine macromolecules to be mostly proteins and polysaccharides [8] with very little insight as to the chemical constitution. The present study describes the isolation and characterization of these macromolecules and their link with the adsorption layer.
https://www.lavoisier.fr/livre/agro-alimentaire/macromolecules-and-secondary-metabolites-of-grapevine-and-wine-fruit-development-biotic-and-abiotic-stresses/jeandet/descriptif-9782743009656