Comparative Characterization of Phenolic Compounds, Fatty Acid Profile, and Antioxidant Activity of Pecan (Carya illinoinensis) Oil Obtained Using Conventional and Green Extraction Methods

Pecan oil is a valuable source of unsaturated fatty acids and bioactive compounds whose recovery and stability may be influenced by the extraction process. This study compared Soxhlet extraction (SE), ultrasound-assisted extraction (UAE), and supercritical CO2 extraction (sCO2) in terms of extraction yield, fatty acid profile, physicochemical properties, total phenolic content (TPC), antioxidant activity, and oxidative stability. SE achieved the highest extraction yield (69.21%), followed by sCO2 (52.89%) and UAE (48.68%). The fatty acid profile was relatively stable among extraction methods, although differences were observed in the relative proportions of oleic and linolenic acids. UAE produced oil with the highest TPC (32.55 µg GAE/g oil), whereas sCO2 showed the highest initial antioxidant activity (2681 µmol TE/100 g oil). After 12 days, UAE oil exhibited the lowest peroxide value (10.49 meq O2/kg) and the highest TPC retention, whereas sCO2 oil showed the greatest peroxide accumulation (28.16 meq O2/kg) and the largest decrease in TPC. These results demonstrate that extraction conditions differently affect oil recovery, antioxidant-related properties, and oxidative stability. Under the conditions evaluated, UAE showed particular advantages in preserving TPC and limiting primary oxidation during accelerated storage, despite its lower extraction yield.