Screening and mechanistic evaluation of antioxidants for mitigating beany flavor formation during pea protein isolation

This study investigated the role of lipid oxidation in off-flavor development during pea protein (PP) extraction via alkaline solubilization and isoelectric precipitation and its mitigation through antioxidant treatment. Four antioxidants (coffee extract, caffeic acid, catechins, and Duralox®) were screened by tracking oxidation markers: malondialdehyde, hydroxyoctadecadienoic acids (HODE), and volatile compounds. Catechins and Duralox® effectively reduced the formation of HODE and beany volatiles in PP. Further optimization explored the dosage effect of catechins (250–2000ppm), Duralox® (0.25–2%), and their combinations (25:75, 50:50, 75:25). Higher catechin concentrations nearly eliminated hexanal formation by suppressing lipoxygenase activity and free radicals generation, indicating dual enzymatic and non-enzymatic inhibition. Duralox® limited primary oxidation but increased radicals and volatiles at higher doses. Sensory analysis confirmed that catechins reduced beany off-flavors in PP but introduced bitterness and astringency. Overall, these findings highlight the potential of targeted antioxidant treatments to mitigate lipid oxidation-driven off-flavor formation during PP extraction. • Lipid oxidation (LO) drives off-flavor formation during wet fractionation (WF). • Hydroxyoctadecadienoic acids are effective biomarkers of LO during WF. • Addition of catechins effectively inhibits beany flavor development during WF. • Catechin suppressed both enzymatic and radical-driven lipid oxidation pathways. • Duralox® and caffeic acid are not effective antioxidants during pea protein WF.