Changes in quality characteristics of shiitake mushrooms treated with UV-C and the inhibitory effect of their ethanol extract on lung cancer cell proliferation

This study evaluated the quality characteristics of fresh shiitake mushrooms after UV-C treatment and storage at 20°C, along with the antioxidant activity and antiproliferative effects of their 85% ethanol extracts on A549 lung cancer cells. UV-C treatment delayed tissue softening, reduced decay rates, and maintained phenolic compound content and antioxidant activity. The highest guanylic acid and ergosterol contents were observed in the UV-C 180 s treatment. Ethanol extracts from UV-C-treated mushrooms inhibited A549 cell proliferation by 20.5-42.4%, but antiproliferative activity decreased over time. Cytotoxicity toward normal lung epithelial cells (MRC-5) increased across all groups by day 5, with the untreated group exhibiting the sharpest rise. Pearson correlation analysis revealed a positive correlation between A549 cell viability and total phenolics, flavonoids, antioxidant activity, guanylic acid, and ergosterol, whereas MRC-5 cell viability negatively correlated with weight loss. UV-C treatment effectively maintained mushroom quality and enhanced antioxidant activity but increased moisture loss, potentially reducing bioactive compounds and elevating cytotoxicity during prolonged storage. UV-C 90 s treatment is optimal for quality retention, while UV-C 180 s may be preferable for functional food applications. Further research is needed to evaluate long-term storage effects and safety under varying UV-C conditions.