Dual control of 3-MCPD esters in vegetable oils: Formation pathways modulated by storage, heat, chlorides, and mitigation via antioxidant and mesoporous silica nanoparticle

Abstract

This study investigated the formation and mitigation of 3-monochloro-1,2-propanediol (3-MCPD) ester in vegetable oils under storage, thermal processing, and chloride supplementation. Prolonged storage (>6 months) markedly accelerated formation (80.8–190 μg/kg·month⁻¹), a rate substantially higher than in the initial 6 months (15.2–71.9 μg/kg·month⁻¹), underscoring a previously underestimated risk in long-term stored oils even if levels remain below EU limits. Thermal treatment revealed a matrix-dependent dynamic equilibrium, with soybean oil peaking at 220 °C (1250 μg/kg) and rapeseed oil at 180 °C (997 μg/kg). Among chloride salts, CaCl₂ induced the highest 3-MCPD ester level (2189 μg/kg), revealing the critical, previously detailed role of metal cation properties (coordination capacity, charge density) beyond the mere presence of Cl⁻. Antioxidants provided dose-dependent mitigation (up to 49 % suppression), though their efficacy was limited by thermal stability. Most significantly, mesoporous silica nanoparticles (MSNs) demonstrated exceptional efficacy, achieving a 98 % adsorption removal rate of 3-MCPD esters from oil, with a high fitted maximum capacity (Q_max = 412.5 μg/g). The combined strategy of antioxidant application followed by MSN treatment offers a novel, practical, and industrially viable solution for significantly reducing 3-MCPD ester exposure in oils and lipid-rich foods.