Effects of drying methods on active components, antioxidant properties and volatile Flavor Profiles of Chrysanthemum morifolium

As a traditional medicinal and edible dual-use resource, the drying process of Chrysanthemum morifolium directly affects the retention of active ingredients and product quality. This study compared the effects of six drying methods, including steam de-enzyming and hot air drying（50℃）, steam de-enzyming and drying in the shade, steam de-enzyming and freeze-drying, hot air drying, drying in the shade, and freeze-drying, on the color, active ingredients（total phenols, total flavonoids）, antioxidant capacity（DPPH, FRAP, ABTS）, and volatile flavor of Chrysanthemum morifolium. Key results are as follows: The combination of E-nose and principal component analysis（PCA）showed that the shade drying group exhibited significantly higher comprehensive response values for volatile compounds compared to the other groups（P＜0.05）, while the volatile components were significantly lost in the steam de-enzyming and hot air drying as well as freeze-drying groups due to high temperature or vacuum environment. The shade drying and freeze-drying treatments yielded the highest total flavonoid contents（86.46 and 84.37 mg·g⁻¹）significantly better than that in the steam de-enzyming and hot air drying group（46.19 mg·g⁻¹）（P＜0.05）. The steam de-enzyming pretreatment significantly reduced the flavonoid retention rate, with an average loss rate of 26.3%. Antioxidant activity results were showed methods dependence, with the shade dried and hot air dried samples showing the best DPPH（213.81 and 212.10 μmol·g⁻¹）and ABTS（84.44 and 82.83 μmol·g⁻¹）radical scavenging ability, while the FRAP reducing ability was highest in the hot air dried group（356.02 μmol·g⁻¹）. It is suggested that drying in the shade or freeze-drying should be prioritized for functional products, while industrial production can consider multi-stage hot air drying to balance quality and efficiency.