The modern food industry faces a growing demand for natural, sustainable, and functional ingredients that can replace synthetic additives and animal-derived ingredients [1]. Emulsifiers play a key role in stabilizing oil-water emulsions by adsorbing at the interface, lowering surface tension, and forming a protective layer around fat droplets, preventing them from merging. In products such as sauces, instant beverages, creamers, and fermented dairy products, emulsifiers are responsible for uniform consistency, creaminess, and extended shelf life [2,3]. Commonly used emulsifiers, such as lecithin, milk proteins (e.g., casein, whey), and monoglycerides and diglycerides of fatty acids, effectively stabilize emulsions, but they are increasingly controversial among consumers and are unacceptable in a vegan diet or in the context of food allergies [4,5]. In response to the needs of vegans, allergy sufferers, and consumers seeking a "clean label," the food industry is increasingly using plant proteins, polysaccharides, microalgae emulsifiers, and innovative Pickering systems as effective and safe substitutes for traditional animal and synthetic emulsifiers [6–9]. The aim of this study is to evaluate the physicochemical properties of selected plant proteins as natural emulsifiers in food emulsions. The obtained results will be used to develop emulsions that will be spray-dried and used as an alternative to traditional casein-based creamers in instant products. Spray-drying is a demanding process, in which emulsion stability, high-temperature resistance, and the ability to form a homogeneous, stable powder are crucial. Therefore, it is crucial that the protein-emulsifier used exhibits appropriate physicochemical properties to enable effective processing and ensure the quality of the finished product [10]. Eleven commercial protein preparations derived from pea, rice, chickpea, hemp, sunflower, and oat, used in their unmodified form, were analyzed. A number of physicochemical and functional parameters were assessed, including emulsification activity and stability (EA, ES), foam formation and maintenance (FC, FS), water and oil absorption capacity (WAC, OAC), and emulsion color (CIE Lab* model). Based on the conducted research, it was found that plant proteins exhibit significant variation in their physicochemical properties, such as emulsification capacity, foaming ability, foam stabilization, water and oil absorption, and their effect on emulsion color. Pea isolates (PP1, PP2, PP3, PP4), rice proteins (RP1 and RP2), and chickpea protein (CP1) demonstrated particularly favorable technological properties, including high emulsification activity and stability, and good foam formation and retention. These preparations were considered the most promising for further analysis and applications in spray-drying food emulsion formulations, especially as an effective alternative to dairy proteins, particularly in instant products such as beverage whiteners. The use of selected plant proteins in the design of this type of emulsion opens real prospects for their implementation as functional ingredients in modern food products, considering current market trends aimed at reducing the share of animal-derived proteins.

Funding: This research was funded by National Centre for Research and Development project entitled "Development of innovative vegan instant products using alternative emulsifiers, including plant proteins, enriched with a starch fiber preparation with prebiotic properties" (NUTRITECH1/0038/2022), headed by Professor Janusz Kapusniak, DSc, PhD.