Abstract
Yuzu (Citrus junos) seeds, a by-product of juice processing, are a valuable source of oil and bioactive compounds. This study investigates the effects of air drying (40 °C and 60 °C), and freeze-drying methods for yuzu seeds on the physicochemical and functional properties of mechanically extracted yuzu seed oil. 40 °C air drying was most effective, yielding the highest oil (11.43%) and vitamin E (19.38 mg/100 g) content, and lowest acid value (0.84-1.26 mg KOH/g) indicating reduced rancidity. It showed greater oxidative stability, with a 1.7-fold lower peroxide value, and retention of linoleic and linolenic acids (~ 76% unsaturated fatty acids). 40 °C air drying preserved the highest levels of anti-inflammatory compounds limonin (61 mg/100 g) and nomilin (32 mg/100 g), while 60 °C air drying reduced them by 25% from control. In lipopolysaccharide (LPS) stimulated RAW 264.7 macrophages, 40 °C air-dried oil showed strongest anti-inflammatory activity, reducing nitric oxide, IL-6, and TNF-α by 1.6-, 1.43-, and 1.79-fold, respectively.