Pulses are of high interest from an agronomy perspective, and their high protein content makes them suitable to produce protein ingredients with interesting emulsifying properties. Indeed, many food products consist in emulsions (dairy products, beverages, toppings, ice creams, etc.), and plant proteins are increasingly prevailing over dairy proteins to stabilize them. However, knowledge regarding the full composition and functionalities of these ingredients is still limited; this is partly due to the fact that these parameters are greatly affected by the involved preparation processes. For instance, lab-made ingredients do not display equal properties as industrially produced ones. Therefore, we selected commercial protein isolates from pea and lupin, high in proteins but involving harsh processing, along with protein concentrates, more complex yet more sustainably processed. Our objective is to understand and master the ingredients’ properties all the way from their composition, behaviour upon model food formulation and eventually to their digestive fate. We highlighted that 1/ these protein ingredients also contain a large proportion of non-proteinaceous compounds, notably lipids, displaying surface-active properties; and 2/ the processing route affects the colloidal state of the proteins, which plays a critical role for ingredient functionality (e.g., solubility). The interactions between proteins and endogenous lipids were deepened in terms of emulsifying and interfacial properties. We demonstrated how the resulting emulsion structure can be modulated by the protein colloidal state, and protein-lipid competitive affinity to adsorb at the oil-water interface. In vitro lipid digestibility and bioavailability in the emulsions were analyzed and related to the complexity of the generated interfacial architectures. Taking advantage of the possibilities given by complex protein ingredients can lead to a large variety of tailor-designed emulsions. Understanding how to master these ingredients stands as a strategic advantage for food manufacturers, to reach functional, sensorial, and nutritional objectives in a rational and sustainable manner