A mechanistic perspective: How does tert-butylhydroquinone retain antioxidative efficacy in edible oils during storage?

A comprehensively antioxidative mechanism was systematically investigated for tert-butylhydroquinone (TBHQ) in edible oils during storage. Three key aspects were elucidated to demonstrate how TBHQ retains its antioxidative activity: (1) the molecular advantages of TBHQ compared to other synthetic phenolic antioxidants; (2) the antioxidative performance of tert-butylbenzoquinone (TBBQ), TBHQ's main transformation product, which demonstrated the ability to be reduced back to TBHQ in both free radical and pure triglyceride systems; and (3) the identification and verification of two additional phenolic transformation products 2-methylallyl-hydroquinone (MAHQ) and 2,2-dimethyl-2,3-dihydrobenzofuran-5-ol from various edible oils using GC–MS and NMR techniques. MAHQ showed antioxidative activity similar to TBHQ, while the monophenolic product was hypothesized to possess antioxidative properties. These findings reveal that TBHQ's retained antioxidative activity during oil storage is through both its molecular advantages and the antioxidative properties of its transformation products, providing theoretical support for TBHQ applications in the food industry.