Production, Characterization, and Functional Properties of Protein Concentrate from Momordica cochinchinensis Seeds

Momordica cochinchinensis protein concentrate (MCPC) was obtained from partially defatted M. cochinchinensis seeds through isoelectric precipitation and subsequent physical separation. The effects of various parameters in ultrasound-assisted extraction were investigated to optimize protein yield. The optimal extraction conditions were identified as pH 11, ultrasound amplitude of 25%, sonication time of 20 minutes, and a material-to-solvent ratio of 1:25. MCPC and partially defatted Gac flour (PDS) were analyzed for proximate composition, amino acid profile, antioxidant capacity, and functional properties, including protein solubility, water- and oil-binding capacities, emulsifying ability, foaming capacity and stability, and gelation behavior. The results showed that MCPC contained more than 81% protein, comprising both essential and non-essential amino acids, with glutamic acid (4.47 g/100 g) and aspartic acid (2.28 g/100 g) as the predominant residues. MCPC also exhibited moderate yet significant antioxidant activity compared with commonly studied plant proteins. Comprehensive characterization of the defatted seed and its protein concentrate revealed distinct modifications in physicochemical and functional attributes following protein isolation, underscoring the potential of MCPC as a high-quality plant-based protein source for food applications.