Ultrasonic-Assisted Ginkgo biloba Leaves Extract as Natural Antioxidant on Oxidative Stability of Oils During...

Ginkgo biloba leaf flavonoids, while demonstrating antioxidant potential, remain underexplored as natural stabilizers for frying oils under thermo-oxidative stress. This study assessed Ginkgo biloba leaf flavonoids efficacy against synthetic tertiary-butylhydroquinone (0.02%). Ginkgo biloba leaf flavonoids were extracted via optimized ultrasonic-assisted methods (15 mL/g solvent, 80% ethanol, 45 °C, 120 s). Frying stability in flaxseed and soybean oils over 6 days (24 cycles/day) was evaluated using multi-indicator kinetic analysis. Ginkgo biloba leaf flavonoids significantly outperformed tertiary-butylhydroquinone in reducing oxidation markers after 6 days. In flaxseed oil, Ginkgo biloba leaf flavonoids reduced acid value (18.4%), peroxide value (33.79%), and polar compounds (52.03%); reductions in soybean oil reached 61.34% for polar compounds. Ginkgo biloba leaf flavonoids better preserved γ-tocopherol in flaxseed oil (increased 2.09% retention) and key tocopherols in soybean oil. Critically, it mitigated unsaturated fatty acid losses (flaxseed C18:3: 2.72% higher; soybean C18:2: 4.4% higher) and limited saturated fatty acid increases. Optimized Ginkgo biloba leaf flavonoid extraction facilitates its application as a promising natural candidate for high-temperature frying, where its matrix-specific stabilization effect shows potential in commercial functional oil formulations.