| 摘要 |
PROBLEM TO BE SOLVED: To obtain an antioxidant which is useful for preventing food products, feeding, cosmetics, medicines and the like from being deteriorated by oxidation by using a hydrolyzate of the extract from olive plant with a solvent as an active ingredient because of its excellent antioxidant activity originating from the natural product. SOLUTION: Methanol is added to olive leaves and they are heated at 60 deg.C for 15 minutes to effect extraction. This operation is repeated three times to collect the extract and the solvent is evaporated at 40 deg.C, freeze-dried to obtain an extract of olive leaves. This extract is mixed with 0.5N hydrochloric acid in 0.2% concentration, stirred at room temperature one overnight to give the hydrolyzate of the extract from olive leaf with a solvent. The hydrolyzate is adjusted in its pH to 3.0 with sodium hydroxide, subjected to column chromatography to collect the fractions eluted with 20% methanol aqueous solution. Then, the collected fraction is evaporated, freeze-dried to prepare the purified hydrolyzate of the extract from olive leaf. Finally, this purified hydrolyzate is used in food product, feedings, cosmetics, medicines and the like, as an active ingredient of a naturally occurring antioxidant. |
