Influence of iron, calcium, and zinc on the oxidative stability of omega‐3 fatty acids in pea protein‐stabilized oil‐in‐water emulsions

Background Plant‐based emulsified foods fortified with omega‐3 fatty acids and minerals are nutritionally attractive, but their formulation is challenging because alpha‐linolenic acid (ALA) is highly susceptible to oxidation and some mineral salts may act as pro‐oxidants. This study evaluated how iron, zinc, and calcium salts affect pea protein isolate (PPI) properties and ALA oxidative stability in PPI/kappa‐carrageenan (KC) gelled emulsions. Treatments included PPI–mineral systems containing ferrous glycinate (FeGly), zinc gluconate (ZnG), calcium gluconate (CaG), calcium lactate (CaL), calcium chloride (CaCl 2 ), or tricalcium phosphate (CaP), and ALA‐enriched emulsions evaluated under different pH conditions. Results FeGly, ZnG, CaG, CaL, and CaCl 2 shifted PPI ζ‐potential toward less negative values, whereas CaP showed limited interaction, probably due to its low solubility. Fluorescence spectroscopy confirmed mineral‐induced conformational changes. PPI–FeGly and PPI–ZnG increased ABTS + radical scavenging activity from 42.48% to 50.38% and 47.30%, respectively, while calcium salts reduced or did not improve antioxidant activity. In Rancimat assays, FeGly‐containing emulsions showed the highest induction times (20.39 h without tocopherols and 19.62 h with tocopherols), followed by ZnG‐containing emulsions (15.06 h). Calcium‐containing formulations showed lower stability (7.33–8.43 h), and CaP did not improve oxidation resistance. At pH 7, FeGly and ZnG improved oxidative stability, whereas at pH 3–5 they reduced stability and increased peroxide formation. Conclusion PPI–mineral interactions can protect or destabilize ALA depending on mineral type, and pH. These findings provide formulation criteria for omega‐3 fatty acid and mineral‐fortified plant‐based gelled emulsions.