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Extraction and Analysis of Ellagic Acid from Longan Seed
|Contributors: ||NTOU:Department of Food Science|
|Issue Date: ||2011-06-30T08:20:23Z
|Abstract: ||利用高效能液相層析法分析龍眼核中之鞣花酸，最適條件是以聚乙二醇 (Supelco Discovery HS PEG, 25 cm × 4.6 mm) 管柱搭配水及乙腈之比例為 7:3 (v/v)(pH 2.5) 之移動相沖提，並於波長 254 nm 下偵測。此層析條件能使鞣花酸與龍眼核甲醇萃取物中其他物質間做有效分離，且總分析時間小於 15 分鐘。 將4品種之新鮮龍眼核（福眼、粉殼、大粉殼及十月龍眼）以甲醇萃取，其游離鞣花酸含量分別為 2.6、4.9、3.2 及 3.8 mg/g DW，然而由於龍眼核中含有鞣花單寧，故可經由酸水解過程使鞣花酸含量增加，以添加 2N HCl 在 120℃ 下降解 6 小時為最佳降解條件，回收率達 97.10-99.83%，而經過此程序後，鞣花酸釋出量能提升 3.10-9.73 倍。此外，分析加工烘乾之粉殼龍眼核中所含之鞣花酸，其含量亦可經酸水解後由 4.7 mg/g DW 增加至 22.5 mg/g DW。|
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.
|Appears in Collections:||[食品科學系] 博碩士論文|
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