| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 98 === A high performance liquid chromatographic method for guantitative determination of ellagic acid (EA) from longan seed was developed. EA was eluted by using a polyethylene glycol (Supelco Discovery HS PEG, 25 cm × 4.6 mm) column. The mobile phase was composed of water and acetonitrile (70:30, v/v)(pH 2.5) and the Uv detector was set at 254 nm. Good separation of EA from other compounds in longan seed methaolic extract was obtained within 15 minuites.
The methanolic extracts of seed of four longan cultivars (Fu Yen, Fenke, Ta Fen Ko and October) contained 2.6, 4.9, 3.2 and 3.8 mg/g DW of free ellagic acid, respectively. The content of EA was generally increased after hydrolysis due to the presence of ellagitannins in longan seed. The best condition for the determination of the total ellagic acid content in longan seed was optimized. Recoveries of 97.10-99.83% were found when hydrolyzed by 2N HCl at 120℃ for 6 hours. The process raised ellagic acid content to 3.10-9.73 fold. Moreover, the ellagic acid content of manufactured dried Fenke longan seed was found to increase from 4.7 to 22.5 mg/g DW after acid hydrolysis.
|
|---|
