The present study investigated the phenolic profile, antioxidant activity, and neuroprotective properties of ‘Tadanishiki’ yuzu (Citrus junos, a seedless variety of yuzu) according to harvesting period and extraction condition. High-performance liquid chromatography (HPLC) was used to identify the functional components. To evaluate the neuroprotective properties, scopolamine was used to induce cholinergic dysfunction in human neuroblastoma SH-SY5Y cells pretreated with yuzu extracts. Among the harvesting periods, September provided the optimum fruit weight of yuzu and relatively high amounts of total phenolics (3.67 mg/g DW), flavonoids (10.13 mg/g DW), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (29.10 μg Vit. C eq.). Of the functional compounds, hesperidin (13.57 mg/100 g DW) and naringin (5.84 mg/100 g DW) were the highest in 5% (w/v) yuzu extracted with 80% ethanol and this extract showed the highest DPPH (289.2 μg Vit. C eq.) scavenging activity. This same extract showed the highest cell viability and lowest cortisol or acetylcholinesterase content in scopolamine-treated SH-SY5Y cells. These results indicate that ‘Tadanishiki’ yuzu harvested in September should be extracted at 5% (w/v) yuzu with 80% EtOH, and this extract might be useful for application as a natural functional additive
