Plant-based proteins are considered more sustainable than animal-based proteins. But are they? Currently, the plant proteins are taken out of the plant crops and processed into plant protein ingredients. This process requires copious amounts of water and energy. The current process reduces the sustainability of plant proteins and simultaneously damages the proteins. In this thesis, we used a novel and more sustainable method to extract proteins from rapeseed. Next to a sustainability increase, we also observe better functionality of the proteins to make foams compared to the protein ingredients obtained through the conventional method. A slight drawback of the sustainable method is the presence of phenols and lipids. We extensively studied the impact of these components, and defined conditions on how to control the impact of phenols and lipids on the plant proteins. With the findings in this thesis, we provided crucial design rules to extract plant proteins sustainably.