Proteins are an important category of stabilizers for multiphase food systems such as foams and emulsions. In recent years, a growing interest can be observed in replacing animal-based by plant-based proteins to stabilize such products. Often, these plant-based proteins have inferior functionality compared to animal-based proteins. In this review, we will discuss recent insights into possible reasons for the differences in behavior between animal-based and plant-based proteins, and present an overview of strategies to improve the performance of plant-based extracts. Improving plant-protein functionality may ultimately allow us to engineer interfaces with properties tailored to specific applications.