Impacts of Extraction Methods on Volatile Constituents of Longan Flower
CHING-HUI CHANG1,3*, TUNG-HSI YU2, CHI-YUE CHANG2 AND YUNG-CHUAN LIU1
1. Department of Chemical Engineering, National Chung-Hsing University, Taichung, Taiwan (R.O.C.)
2. Department of Bioindustry Technology, Da-Yeh University, Changhua, Taiwan (R.O.C.)
3. Eco-material Technology, Industrial Technology Research Institute, Tainan, Taiwan (R.O.C.)
(Received: September 1, 2006; Accepted: October 13, 2007)
ABSTRACT
This study investigated the impacts of three extraction methods on the composition of the flavor isolates of fresh longan (Euphoria longana Lam.) flower. These extraction methods included Lickens-Nickerson (L-N) steam distillation solvent extraction, direct solvent extraction (DSE), and headspace purge and trap (HS) methods. Volatile compounds were then analyzed qualitatively and quantitatively by GC and GC-MS. A total of 51 volatile compounds were identified from fresh longan flower in this study. The major volatile compounds were trans-caryophyllene, linalool oxide and α-humulene by L-N, linalool oxide, 2-phenylethanol and epoxylinalool by DSE, and trans-ocimene, linalool oxide, and linalool by HS, respectively.
Key words: aroma, Likens-Nickerson, direct solvent extraction, headspace purge and trap, longan flower