| 内容提要: |
The effect of drying methods were evaluated in the study, which include hot air drying (HD), blanching-hot air drying (BHD), shade drying (SD), microwave-hot air drying (MHD), freeze drying (FD), and vacuum-hot air drying (VHD) on the quality and bioactivities of chrysanthemum. HD had lower total flavonoid (TF) values due to the reaction between flavonoids and oxidase during the process of drying. Reduced activities of polyphenol oxidase (PPO) and peroxidase (POD) in samples from MHD and BHD indicated that they are effective at inhibiting enzymatic browning, while the BHD can cause the loss of some water-soluble components. Microwave treatment for 30 sec combined with 75oC hot air drying (MHD1) was the most effective treatment in preserving biologically active compounds, resulting in higher antioxidant capacity and greater inhibition for the enzyme acetylcholinesterase (AChE). FT-IR showed that the powerful structures of BHD, MHD3, and VHD were more destructive compared with that of FD. This work also found that 3,5-di-caffeoylquinic acid (3,5-DCQA), luteolin-7-O-glucoside (LuG), luteolin (Lut), and kaempferol (Kae) were the key bioactive substances inhibiting AChE. Furthermore, molecular docking studies showed that a high inhibition of AChE by 3,5-DCQA and LuG could be attributed to the formation of strong hydrogen bonds. The study is beneficial for understanding chrysanthemum’s nutritional value and the effects of drying methods on the quality of the final product. |