Unraveling distinct potential of pea (Pisum sativum L.) fractions (legumin, vicilin and albumin) by structural and functional characterization.

Limited and unclear research exists on the individual capacity of major fractions of pea protein legumin (PL), vicilin (PV) and albumin (PA), which collectively contribute to the structural and functional properties of pea protein. Findings revealed that PV (72.26 ± 2.6 %) and PA (57.42 ± 4.1 %) displayed better solubility compared to PL. PL fraction possessed a complex three-dimensional structure, higher surface hydrophobicity (S), and superior oil-holding-capacity (OHC) contributing to its 4-fold strength (8.58 ± 0.5 N) and structured gel formation. The smaller particle size of PA was also accountable for the comparatively weaker gels and unstable emulsions compared to PL, while PV had the least emulsifying capacity, by non-uniform droplet distribution in CLSM served as proof. PL was found to be responsible for gelation, emulsification, and foaming in pea protein due to structural factors (relative abundance of α-helix and β-sheet). While, the flexible structure of PV, absence of cysteine residues, and disulfide bridges played a role in characteristics like foaming stability. Some protein in PV gel was found loose and did not appear to participate in gelation, hence forming a significantly weaker gel than PL. Despite relatively less S and complex structure, albumin (PA) had a smoother but weaker gel, more consistent and a smaller droplet size distribution in emulsions (compared to PV). Nonetheless, this study aims to fill a forgotten gap by providing baseline knowledge on the individual fractions of pea protein, defining their roles and paving the path for future research focusing on structural and functional properties of pea protein.