Antioxidative Properties of Plant-Based Protein Isolates: NUTRALYS® Pea Protein

OBJECTIVES: Antioxidants display protective benefits both in food and pharmaceutical products against oxidative deterioration and in the body against pathologies brought by oxidative stress. Proteins can contain peptides sequences with potential antioxidant bioactivities. As plant-based proteins sources are more and more consumed, the screening of their antioxidant properties is of great interest to provide new alternative solutions in place of synthetic antioxidants and to meet enhanced public awareness about health issues. Various in vitro methods are validated for screening and some have been used here to qualify the antioxidative potential of NUTRALYS(®) pea protein range (Roquette). METHODS: Two grades of pea protein isolates, NUTRALYS® S85F and NUTRALYS® S85 Plus, were screened before or after in vitro gastro-intestinal digestion (IVD) for their antioxidant activity with different methods: 1/reactive oxygen species (ROS) adapted scavenging assays (acellular) (Haliwell et al., 1987; Aruoma et al., 1989) to determine their ability to inhibit the productions of O2.-, H2O2 and HO. radicals; 2/AOP1 (LUCS) technology (Gironde et al., 2020), evaluating on human keratinocytes (HaCat cells) the ROS scavenging potential by the kinetic evolution of a fluorescence emission; 3/Nrf2 technology (Furger, 2021) measuring on HaCat cells the ability to activate the ARE/Nrf2 gene pathway, responsible for natural antioxidant cell defense (cytoprotective effect), by oxyluciferin luminescent detection. RESULTS: NUTRALYS(®) S85F and S85 Plus demonstrated significant scavenging activities towards HO. and H2O2 (before and after IVD) and NUTRALYS(®) S85F towards O2.- (before IVD), with all IC(50) far below 5 mg.mL(−1) (Dugardin et al., 2020). No significant direct antioxidant effect (LUCS) was observed with NUTRALYS(®) S85 Plus digests, but significant activation of the ARE/Nrf2 gene pathway (EC50 = 1.39 mg.mL-1 dry matter), indicating a potential induction of cell anticipation towards putative radical aggression, and a long-term effect. CONCLUSIONS: NUTRALYS(®) S85F and NUTRALYS(®) S85 Plus exhibit intrinsic antioxidative properties, often conserved after IVD, as observed through various methods. Based on these results, NUTRALYS(®) S85F and NUTRALYS(®) S85 Plus may therefore provide oxidative stability to food products and health benefits to the consumer. FUNDING SOURCES: Roquette.