Introduction. Animal origin food generates different types of diseases, specifically egg protein is classified as the second most serious food allergen, which predominantly affects children, is for it is necessary to find alternatives. Legumes possess excellent nutritional characteristics and specifically, the wastewater from their cooking stands out as a new type of vegan ingredient called "aquafaba", which possesses emulsifying properties similar to egg white. Objective. The main objective is to find that legume generates aquafaba with the optimal physico-chemical and functional properties to use it as a substitute for egg white. Methodology. In this experimental study, a factorial design with 3 factors was used: legume type, cooking time and, legume-to-water ratio (3 levels) to determine the optimal conditions to maximize functional and physicochemical characteristics (yield, turbidity, proteins, emulsion capacity, emulsion stability, foaming capacity, oil retention capacity, foam stability and, water retention capacity). Results. Functional properties such as emulsion capacity, emulsion stability, foaming ability, and oil retention were maximum in the 2:3 soybean-to-water ratio and a cooking time of 60 min. The longest stability time of the foam was 58 minutes in the 1:2 soybean-to-water ratio with 60 minutes of cooking. The water retention capacity reached the maximum level in the soybean-to-water ratio 1:2 when in cooking time it was 60 minutes. The protein percentage peaked in the 1:2 soybean-to-water ratio with 60 minutes of cooking. The highest yield was reported in the legume-to-water ratio 1:4 and 30 minutes of cooking. The sample with the highest turbidity was obtained in the soybean-to-water ratio when the cooking time was 60 minutes. Conclusion. This research concluded that soybean is the legume that produces aquafaba with the best properties.