Impact of ultrasound and microwave-assisted extraction on protein structure and functional properties of underutilized legumes: Inga jinicuil (jinicuil), Pithecellobium dulce (guamúchil), Leucaena leucocephala (green guaje), and Leucaena esculenta (pigmented guaje)
Academic Article in Scopus
This study evaluates, for the first time, the underutilized legumes Inga jinicuil (JN), Pithecellobium dulce (GM), Leucaena leucocephala (GG), and Leucaena esculenta (PG) as potential alternative sources of food protein. Ultrasound-assisted alkaline extraction (UAAE) and microwave-assisted alkaline extraction (MAE) were compared with conventional extraction to assess their effects on protein yield and physicochemical characteristics, with UAAE selected as the method for future characterizations. The amino acid profile and the techno-functional properties of the protein extracts obtained by UAAE were determined. UAAE significantly increased (p ' 0.05) protein yield in PG and GG and modified their molecular profile by promoting new protein-protein interactions. FTIR analysis showed reduced ¿-helix content in JN after UAAE and increased ß-sheet content in GM, changes associated with higher surface hydrophobicity in JN and improved emulsifying capacity in GM. Amino acid analysis revealed that GM and PG protein extracts met FAO/WHO essential-to-total amino acid recommendations, and JN with a high content of hydrophobic, charged, and aromatic amino acids, suggesting bioactivity and nutraceutical potential. Techno-functional properties demonstrated that proteins from PG and GG had higher water-and oil-holding capacities, GM had the highest emulsifying activity, and JN and GM exhibited foaming properties. The knowledge gained in this study is expected to provide reliable scientific data for the potential applications of these underutilized legumes in plant-based food products.
