Effects of drying methods on the phytochemicals contents and antioxidant properties of chrysanthemum flower heads harvested at two developmental stages

The dried flower head of chrysanthemum is a Chinese medicine, and also used as functional food material. The effects of different drying processes on the bioactive chemical contents and antioxidant activities of 'Xiaobaiju' and 'Taiju' were examined. Two kinds of harvest materials were handled with sun-dried, shade-dried or oven-dried at low, middle and high levels. An HPLC (high performance liquid chromatography) method was used to simultaneously quantify eight bioactive compounds. The antioxidant activities were assayed in vitro. The results showed that oven-drying had faster drying rate. The drying processes had significant effects on the contents of bioactive constituents and antioxidant properties. The appropriate drying process was suggested to be oven-dried at 60 degrees C for 'Xiaobaiju' and 70 degrees C for 'Taiju'. The sufficient dried samples were capable of scavenging DPPH (1,1-dipheny1-2-picrylhydrazyl) and O-2(center dot-), inhibiting linoleic acid oxidation. The results also implied that 'Taiju' possesses better functional effectiveness than 'Xiaobaiju'. (C) 2015 Elsevier Ltd. All rights reserved.