Effect of High Temperature and High Pressure on Antioxidant Activity of Cultivated Wild Ginseng

This study investigated the impact of high-temperature and high-pressure (HTHP) steaming on the antioxidant properties of cultivated wild ginseng. Steaming was performed at 95℃ (0 kgf/cm²), 117℃ (1.0 kgf/cm²), 126℃ (1.5 kgf/cm²), and 132℃ (2.0 kgf/cm²). The total phenolic and flavonoid contents and antioxidant capacities of the resulting extracts were analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and hydroxyl radical scavenging assays. Higher temperatures and pressures resulted in higher total phenolic (6.04 mg GAE/g) and flavonoid (2.11 mg QE/g) contents. The antioxidant activities also showed significant enhancement (p<0.05) under elevated processing conditions, reaching maximum values for DPPH (14.42 mM TE/g), ABTS (68.94 mM TE/g), FRAP (675.75 μM TE/g), ORAC (265.43 mg TE/g), and hydroxyl radical scavenging activity (34.40%) at 132℃ (2.0 kgf/cm²). These improvements were attributed to the thermal degradation and transformation of phenolic compounds, the formation of low-molecular-weight antioxidants, and the generation of Maillard reaction products, such as melanoidins, with strong reducing and radical scavenging abilities. Overall, HTHP steaming enhanced the antioxidant potential of cultivated wild ginseng significantly, suggesting that treatment at 132℃ (2.0 kgf/cm²) is optimal for maximizing the bioactivity and may contribute to the development of functional ginseng products with improved health-promoting properties.