Effect of drying conditions on antioxidant activities and volatile compounds of chrysanthemum

Chrysanthemum (Chrysanthemum indicum L.) flowers have been traditionally used in oriental medicine to treat vertigo, hypertensive symptoms and several infectious diseases. In this study, we evaluated the effects of the drying conditions on antioxidant activities and volatile compounds of chrysanthemum flowers. The flowers were dried with hot-air (HAD) or far-infrared (FID) at 40, 50, or 60°C to reach 78% of dryness factor, calculated as the weight of (fresh flowers – weight of dried flowers), the whole multiplied by 100. 10 gr. of each dried flower sample were extracted with 100 mL of ethanol. Antioxidant activities of the extracts were determined by their radical scavenging activity (RSA) [1] and superoxide dismutase (SOD)-like activity [2]. Increasing temperature in HAD increased antioxidant activities of extracts from chrysanthemum flowers. For example, RSA and SOD activities of the extract at 60°°C HAD were of 92% and 85%, respectively, while those at 40°C were of 36% and 82%, respectively. However, increasing temperature in FID decreased antioxidant activities of the extract. RSA and SOD activities of the extract from flowers at 60°C FID were of 22% and 74%, respectively, while those at 40°C were of 92% and 84%, respectively. Volatile compounds of the dried flowers were extracted by solid phase micro extraction (SPME) method, and were analyzed by gas chromatography. Thirteen compounds including camphor and α-farnesene were identified in chromatograms. Higher amount of volatiles were found at 50°C HAD and 40°C FID. The results indicated that the antioxidant activities and volatile compounds of chrysanthemum flowers were significantly affected by drying conditions.

Acknowledgements: This study was supported by Brain Korea 21 Program.

References: 1. Muller, H.E. (1985) Zentralbl. Bakteriol. Mikrobio. Hyg. 259: 151–158.

2. Marklund, S., Marklund, G. (1974) Eur. J. Biochem. 47: 469–474.