Antioxidant Activity Of Eugenia Caryophyllata

Clove, the sun-dried unopened flower bud from the plant Eugenia caryophyllata is used for both food and medicine. This study examined the antioxidant activities of various fractions (prepared by using solvents of varying polarity) of the non-volatiles from Clove to develop natural antioxidants used for the functional food. The main conclusions are as follows.(1)The antioxidant activity of three different fractions was evaluated using eight different antioxidant tests. In the above eight assays, ethyl acetate fraction exhibited more antioxidant potency than other fractions and is effective fraction.(2)Correlation analysis indicated that there was a linear relationship between antioxidant activity and the content of phenolic compounds, and it is necessary to use various antioxidant assays to evaluate the antioxidant activity.(3)Through the use of thin-layer chromatography (TLC), there are8major constituents in the effective fraction.(4)The antioxidants of Clove were extracted by water bath shaking, ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE) and ultrasonic and microwave-assisted extraction (UMAE). The results showed that the total polyphenols and flavonoids recoveries were highest, and the antioxidant capacities were strongest for the extracted liquids by MAE and UMAE. However, the extraction time of UMAE was only half of MAE. The extraction efficiency of UMAE was the highest.(5)The ethyl acetate fraction of Clove was found to be more effective by acid hydrolysis.(6)The ethyl acetate fraction of Clove were immersed in the artificial gastrointestinal juice. The antioxidant capacities of the effective fraction of Clove were significantly improved after immersed by the artificial gastric juice. However, its antioxidant capacities were significantly reduced after immersed by the artificial intestinal juice.