Comparison of phenolic substances and antioxidant activities in different varieties of chrysanthemum flower under simulated tea making conditions

摘要

Chrysanthemum flowers are rich in phenolic substances. The chrysanthemum flower tea (CT) obtained by simulating the process of hot water brewing as the research object and 80% methanol aqueous extract (ME) as the controls to explore the composition of phenolic compounds and antioxidant capacities of five varieties of chrysanthemum flowers including Xueju, Taiju, Hangbaiju, Gongju and Jinzhanju. Nine phenolic compounds including p-hydroxybenzoic acid, catechin, vanillic acid, caffeic acid, syringic acid, epicatechin, p-coumaric acid, ferulic acid and sinapic acid were initially identified and quantified by using high-performance liquid chromatography with diode-array detection (HPLC-DAD). The content of catechin in Xueju, Taiju, Hangbaiju, Gongju and Jinzhanju was 45.6, 50.9, 51.8, 55.0 and 53.2 mu g/g, respectively, which is the highest among the nine monomeric phenolic compounds. The Xueju variant had the largest total phenolic content of 123.7 mg gallic acid equivalent (GAE)/g and total flavonoid content of 92.5 catechin equivalent (CE)/g when compared to other cultivars, which was also consistent with the results from the HPLC-DAD measurements. After 15 min of simulated brewing, the DPPH radical eliminating ability of different varieties of CT was higher than that of the ME which corresponded with the FRAP results. The process of tea making improves the bioactive component and antioxidant activity of the chrysanthemum flower.