The transition towards sustainable, plant-based protein sources for food systems requires knowledge on how plant-based proteins interact with food-relevant microstructures. In particular, in the formulation of aerated food systems (e.g. foams), the mechanism by which plant-based proteins stabilise the interfaces is considerably different than that of traditional animal-based protein. In our recent experiment SC-5498, we measured combined grazing-incidence small-angle x-ray scattering (GISAXS) and x-ray reflectivity (XRR) of in situ structures and formation dynamics of plant-based proteins at the air-water interface. While XRR provided clear results, the combined setup proved to be too much of a compromise and no successful GISAXS signal was obtained. In this follow-up proposal we aim to redo the GISAXS measurements. The structural information provided by GISAXS forms the missing link between (in house) state of the art interfacial rheology and high resolution but ex situ and static ato