Peroxyl radical-mediated oxidative crosslinking of faba and pea proteins: Differential aggregation behavior and implications for protein structuring.

Faba and pea proteins are increasingly used as alternative proteins in plant-based food systems; however, their comparative susceptibility to oxidation by peroxyl radicals (ROO•) remains poorly understood. This study aimed to compare the oxidative behavior of faba and pea proteins, individually and in mixtures, using ROO• generated by thermolysis of AAPH (2,2'-azobis(2-methylpropionamidine) dihydrochloride), to elucidate how protein profile influences the oxidative pattern. Oxidation induced similar levels of hydroperoxides and carbonyls, without major changes in secondary structure. However, faba proteins exhibited greater formation of high-molecular-mass aggregates than pea proteins. In faba proteins, crosslinked species were associated with formation of di-tyrosine and di-tryptophan mainly involving legumin-α, whereas oxidation in pea proteins was primarily linked to modification of the ∼47 kDa vicilin fraction. These findings demonstrate that faba and pea proteins differ markedly in their oxidation-induced crosslinking behavior, highlighting the role of protein profile in modulating oxidative structural changes in plant-based protein systems.