| Author: | Wong, Tsz-hang Jan |
| Title: | Evaluation of antioxidative power of six Chinese medicinal herbs extracted by different extraction methods |
| Degree: | M.Sc. |
| Year: | 2004 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Herbs -- Therapeutic use -- Evaluation Medicinal plants -- China -- Identification Medicine, Chinese |
| Department: | Department of Applied Biology and Chemical Technology |
| Pages: | iii, 60 leaves : ill. ; 30 cm |
| Language: | English |
| Abstract: | The six selected herb samples were first extracted by three different methods: soaked in distilled water for 3 hours followed by boiling at 100C for 40 minutes; soaked in ethanol at 37C for overnight; and soaked in distilled water for 3 hours followed by heating at 85C for 10 minutes. The extracts were then analyzed individually for their total phenolic content by Folin-Ciocalteau Assay. The result showed that total phenolic content of the extracts varies according to extraction methods. The extracts was later examined by 2,2-diphenyl-/-picrylhydrazyl (DPPH) assay to reveal free radicals scavenging ability of different extraction methods. Sample extracts were also taken to test on 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) assay and ferric reducing/antioxidant power (FRAP) assay. In this research, all sample extracts demonstrated certain antioxidative activities. The antioxidative activities varies upon different extraction methods. This study also demonstrated that antioxidants in the sample extracts could protect biological membranes from free radical induced oxidative damages. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b17490960.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.32 MB | Adobe PDF | View/Open |
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