Techno-functional properties and antioxidant capacity of the concentrate and protein fractions of Leucaena spp. seeds. Introduction: The use of vegetable proteins as ingredients in food systems is based on their functional properties. The water and oil holding capacity, foaming, and emulsifying capacity/stability, and antioxidant assay of the protein fractions -albumins, globulins 7S/11S, glutelins and prolamins -isolated from leucaena seed were evaluated. Objective: The objective of this study was to evaluate the functional properties and antioxidant capacity of the concentrate and protein fractions of ripe Leucaena spp. seeds. Materials and methods: Ripe leucaena seeds were collected and evaluated in Oaxaca, Mexico (16 degrees 59'21"N 96 degrees 43'26"O) during the months of February-April 2021.The protein concentrate was isolated by isoelectric precipitation (pH=9, pH=4). The albumins, globulins, glutelins and prolamins were isolated based on their solubility properties in different extracting solutions. Results: Glutelins constituted the main protein fraction (75.88%). Prolamins were not found. The glutelins fractions showed the highest oil holding capacity (0.93 +/- 0.08 mL g-1). The albumins fraction had the highest water holding capacity (2.53 +/- 0.15 mL g-1), foaming capacity and foam stability (71.83 +/- 1.26 % and 70.00 +/- 0.00%, respectively) and antioxidant capacity (18.09 +/- 0.88%). The globulins exhibited the highest emulsifying capacity and emulsion stability (56.83 +/- 1.76% and 55.67 +/- 1.20%, respectively). Conclusions: The concentrate and protein fraction of leucaena seeds showed different techno-functional and antioxidant properties of interest for the food industry, like those showed by other commercial vegetable proteins. Arch Latinoam Nutr 2022; 72(3): 196-204.