Unveiling the fate, function, and bioimpact of oxidized antioxidant derivatives in food systems

Abstract

Antioxidants are traditionally recognized for their ability to neutralize reactive oxygen species and prevent oxidative deterioration in food systems. However, their biological and technological significance extends beyond radical scavenging, as they undergo oxidation to form reactive derivatives that may exert both beneficial and adverse effects. This review comprehensively examines the oxidative transformation pathways of major dietary antioxidants, including ascorbic acid, tocopherols, and polyphenols, together with selected synthetic food antioxidants, emphasizing the influence of food matrices, processing conditions, and environmental factors on their chemical fate. Representative model system studies are discussed to illustrate the formation of key oxidation products, including dehydroascorbic acid, tocopheryl quinones, quinone intermediates, theaflavins, and polymeric polyphenols, and their implications for food quality and stability. Advances in analytical techniques, including liquid chromatography–high-resolution mass spectrometry (LC-HRMS), electron spin resonance (ESR), nuclear magnetic resonance (NMR) spectroscopy, and density functional theory (DFT), are highlighted for their roles in elucidating the structures and mechanisms of these oxidized derivatives. The review further summarizes the current understanding of their biological activities, demonstrating that oxidized antioxidant derivatives may function either as adaptive redox-signaling molecules by modulating pathways such as Nrf2 and NF-κB or as pro-oxidants capable of promoting oxidative stress, protein modification, and cytotoxicity under specific conditions. By integrating evidence from food chemistry, analytical science, and toxicology, this review provides a comprehensive perspective on the complete life cycle of antioxidants and highlights future research priorities for improving food quality, safety, and nutritional functionality.